WorldWideScience

Sample records for high caffeine consumers

  1. Differential responsiveness to caffeine and perceived effects of caffeine in moderate and high regular caffeine consumers.

    Science.gov (United States)

    Attwood, A S; Higgs, S; Terry, P

    2007-03-01

    Individual differences in responsiveness to caffeine occur even within a caffeine-consuming population, but the factors that mediate differential responsiveness remain unclear. To compare caffeine's effects on performance and mood in a group of high vs moderate consumers of caffeine and to examine the potential role of subjective awareness of the effects of caffeine in mediating any differential responsiveness. Two groups of regular caffeine consumers (200 mg/day) attended two sessions at which mood and cognitive functions were measured before and 30 min after consumption of 400-mg caffeine or placebo in a capsule. Cognitive tests included visual information processing, match-to-sample visual search (MTS) and simple and choice reaction times. Post-session questionnaires asked participants to describe any perceived effect of capsule consumption. High consumers, but not moderate consumers, demonstrated significantly faster simple and choice reaction times after caffeine relative to placebo. These effects were not attributable to obvious group differences in withdrawal or tolerance because there were no group differences in baseline mood or in reports of negative affect after caffeine. Instead, the high consumers were more likely to report experiencing positive effects of caffeine, whereas the moderate consumers were more likely to report no effect. The sensitivity of caffeine consumers to the mood- and performance-enhancing effects of caffeine is related to their levels of habitual intake. High caffeine consumers are more likely than moderate consumers to perceive broadly positive effects of caffeine, and this may contribute to their levels of use.

  2. Attentional bias for caffeine-related stimuli in high but not moderate or non-caffeine consumers.

    Science.gov (United States)

    Yeomans, Martin R; Javaherian, Shabnam; Tovey, Heather M; Stafford, Lorenzo D

    2005-09-01

    Attentional bias for drug-related cues has been reported with a wide range of drugs, but to date the extent to which caffeine consumers show similar biases for caffeine-related stimuli has not been tested. The present study therefore examined this issue in terms of differences in attentional bias for caffeine-related words in High, Moderate and Non-caffeine consumers using a dot-probe word task following overnight caffeine abstinence. This study was conducted to test whether caffeine consumers show an attentional bias for caffeine-related words, and whether such biases relate to habitual levels of caffeine use. Sixteen High, Moderate and Non-consumers of caffeine were asked to complete a modified dot-probe task in order to measure attentional bias for caffeine-related relative to neutral control word groups. The task was completed following overnight caffeine abstinence, and participants also completed mood and caffeine-craving measures. The High consumer group showed a significant attentional bias for the caffeine-related words, but no such bias was seen in Moderate or Non-consumer groups. As expected, craving for caffeine was strongest in the High consumers and weakest in the Non-consumers. Attentional bias in the High group correlated with self-reported caffeine consumption and with craving for caffeine, but neither effect was significant in the Moderate group. These data confirm that High caffeine consumers show attentional bias for caffeine-related stimuli, consistent with current theories of drug addiction.

  3. Effects of low doses of caffeine on cognitive performance, mood and thirst in low and higher caffeine consumers.

    Science.gov (United States)

    Smit, H J; Rogers, P J

    2000-10-01

    Caffeine is present in many widely consumed drinks and some foods. In the fairly extensive literature on the psychostimulant effects of caffeine, there are few dose-response studies and even fewer studies of the effects of doses of caffeine lower than 50 mg (the range of the amounts of caffeine contained in, for example, a typical serving of tea or cola). This study measured the effects of 0, 12.5, 25, 50 and 100 mg caffeine on cognitive performance, mood and thirst in adults with low and moderate to high habitual caffeine intakes. This was a double-blind, within-subjects study. Following overnight caffeine abstinence, participants (n=23) completed a test battery once before and three times after placebo or caffeine administration. The test battery consisted of two performance tests, a long duration simple reaction time task and a rapid visual information processing task, and a mood questionnaire (including also an item on thirst). Effects on performance and mood confirmed a psychostimulant action of caffeine. All doses of caffeine significantly affected cognitive performance, and the dose-response relationships for these effects were rather flat. The effects on performance were more marked in individuals with a higher level of habitual caffeine intake, whereas caffeine increased thirst only in low caffeine consumers. After overnight caffeine abstinence, caffeine can significantly affect cognitive performance, mood and thirst at doses within and even lower than the range of amounts of caffeine contained in a single serving of popular caffeine-containing drinks. Regular caffeine consumers appear to show substantial tolerance to the thirst-increasing but not to the performance and mood effects of caffeine.

  4. Expectation of having consumed caffeine can improve performance and mood

    OpenAIRE

    Dawkins, Lynne; Shahzad, Fatima-Zahra; Ahmed, Suada S.; Edmonds, Caroline J.

    2011-01-01

    We explored whether caffeine, and expectation of having consumed caffeine, affects attention, reward responsivity and mood using double-blinded methodology. 88 participants were randomly allocated to ‘drink-type’ (caffeinated/decaffeinated coffee) and ‘expectancy’ (told caffeinated/told decaffeinated coffee) manipulations. Both caffeine and expectation of having consumed caffeine improved attention and psychomotor speed. Expectation enhanced self-reported vigour and reward responsivity. Self-...

  5. Caffeine alters emotion and emotional responses in low habitual caffeine consumers.

    Science.gov (United States)

    Giles, Grace E; Spring, Alexander M; Urry, Heather L; Moran, Joseph M; Mahoney, Caroline R; Kanarek, Robin B

    2018-02-01

    Caffeine reliably increases emotional arousal, but it is unclear whether and how it influences other dimensions of emotion such as emotional valence. These experiments documented whether caffeine influences emotion and emotion regulation choice and success. Low to abstinent caffeine consumers (maximum 100 mg/day) completed measures of state anxiety, positive and negative emotion, and salivary cortisol before, 45 min after, and 75 min after consuming 400 mg caffeine or placebo. Participants also completed an emotion regulation choice task, in which they chose to employ cognitive reappraisal or distraction in response to high and low intensity negative pictures (Experiment 1), or a cognitive reappraisal task, in which they employed cognitive reappraisal or no emotion regulation strategy in response to negative and neutral pictures (Experiment 2). State anxiety, negative emotion, and salivary cortisol were heightened both 45 and 75 min after caffeine intake relative to placebo. In Experiment 1, caffeine did not influence the frequency with which participants chose reappraisal or distraction, but reduced negativity of the picture ratings. In Experiment 2, caffeine did not influence cognitive reappraisal success. Thus, caffeine mitigated emotional responses to negative situations, but not how participants chose to regulate such responses or the success with which they did so.

  6. Expectation of having consumed caffeine can improve performance and mood.

    Science.gov (United States)

    Dawkins, Lynne; Shahzad, Fatima-Zahra; Ahmed, Suada S; Edmonds, Caroline J

    2011-12-01

    We explored whether caffeine, and expectation of having consumed caffeine, affects attention, reward responsivity and mood using double-blinded methodology. 88 participants were randomly allocated to 'drink-type' (caffeinated/decaffeinated coffee) and 'expectancy' (told caffeinated/told decaffeinated coffee) manipulations. Both caffeine and expectation of having consumed caffeine improved attention and psychomotor speed. Expectation enhanced self-reported vigour and reward responsivity. Self-reported depression increased at post-drink for all participants, but less in those receiving or expecting caffeine. These results suggest caffeine expectation can affect mood and performance but do not support a synergistic effect. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Caffeine promotes global spatial processing in habitual and non-habitual caffeine consumers

    Directory of Open Access Journals (Sweden)

    Grace E. Giles

    2013-10-01

    Full Text Available Information processing is generally biased toward global cues, often at the expense of local information. Equivocal extant data suggests that arousal states may accentuate either a local or global processing bias, at least partially dependent on the nature of the manipulation, task and stimuli. To further differentiate the conditions responsible for such equivocal results we varied caffeine doses to alter physiological arousal states and measured their effect on tasks requiring the retrieval of local versus global spatial knowledge. In a double-blind, repeated-measures design, non-habitual (Exp. 1; N=36, M=42.5±29 mg/day caffeine and habitual (Exp. 2; N=34, M=579.5±311.5 mg/day caffeine caffeine consumers completed four test sessions corresponding to each of four caffeine doses (0 mg, 100 mg, 200 mg, 400 mg. During each test session, participants consumed a capsule containing one of the three doses of caffeine or placebo, waited sixty minutes, and then completed two spatial tasks, one involving memorizing maps and one spatial descriptions. A spatial statement verification task tested local versus global spatial knowledge by differentially probing memory for proximal versus distal landmark relationships. On the map learning task, results indicated that caffeine enhanced memory for distal (i.e. global compared to proximal (i.e. local comparisons at 100 (marginal, 200, and 400 mg caffeine in non-habitual consumers, and marginally beginning at 200 mg caffeine in habitual consumers. On the spatial descriptions task, caffeine enhanced memory for distal compared to proximal comparisons beginning at 100 mg in non-habitual but not habitual consumers. We thus provide evidence that caffeine-induced physiological arousal amplifies global spatial processing biases, and these effects are at least partially driven by habitual caffeine consumption.

  8. Caffeine and Creatine Content of Dietary Supplements Consumed by Brazilian Soccer Players.

    Science.gov (United States)

    Inácio, Suelen Galante; de Oliveira, Gustavo Vieira; Alvares, Thiago Silveira

    2016-08-01

    Caffeine and creatine are ingredients in the most popular dietary supplements consumed by soccer players. However, some products may not contain the disclosed amounts of the ingredients listed on the label, compromising the safe usage and the effectiveness of these supplements. Therefore, the aim of this study was to evaluate the content of caffeine and creatine in dietary supplements consumed by Brazilian soccer players. The results obtained were compared with the caffeine content listed on the product label. Two batches of the supplement brands consumed by ≥ 50% of the players were considered for analysis. The quantification of caffeine and creatine in the supplements was determined by a high-performance liquid chromatography system with UV detector. Nine supplements of caffeine and 7 supplements of creatine met the inclusion criteria for analysis. Eight brands of caffeine and five brands of creatine showed significantly different values (p soccer players present inaccurate values listed on the label, although most presented no difference among batches. To ensure consumer safety and product efficacy, accurate information on caffeine and creatine content should be provided on all dietary supplement labels.

  9. Carcinogenic and neurotoxic risks of acrylamide consumed through caffeinated beverages among the lebanese population.

    Science.gov (United States)

    El-Zakhem Naous, Ghada; Merhi, Areej; Abboud, Martine I; Mroueh, Mohamad; Taleb, Robin I

    2018-06-06

    The present study aims to quantify acrylamide in caffeinated beverages including American coffee, Lebanese coffee, espresso, instant coffee and hot chocolate, and to determine their carcinogenic and neurotoxic risks. A survey was carried for this purpose whereby 78% of the Lebanese population was found to consume at least one type of caffeinated beverages. Gas Chromatography Mass Spectrometry analysis revealed that the average acrylamide level in caffeinated beverages is 29,176 μg/kg sample. The daily consumption of acrylamide from Lebanese coffee (10.9 μg/kg-bw/day), hot chocolate (1.2 μg/kg-bw/day) and Espresso (7.4 μg/kg-bw/day) was found to be higher than the risk intake for carcinogenicity and neurotoxicity as set by World Health Organization (WHO; 0.3-2 μg/kg-bw/day) at both the mean (average consumers) and high (high consumers) dietary exposures. On the other hand, American coffee (0.37 μg/kg-bw/day) was shown to pose no carcinogenic or neurotoxic risks among the Lebanese community for consumers with a mean dietary exposure. The study shows alarming results that call for regulating the caffeinated product industry by setting legislations and standard protocols for product preparation in order to limit the acrylamide content and protect consumers. In order to avoid carcinogenic and neurotoxic risks, we propose that WHO/FAO set acrylamide levels in caffeinated beverages to 7000 μg acrylamide/kg sample, a value which is 4-folds lower than the average acrylamide levels of 29,176 μg/kg sample found in caffeinated beverages sold in the Lebanese market. Alternatively, consumers of caffeinated products, especially Lebanese coffee and espresso, would have to lower their daily consumption to 0.3-0.4 cups/day. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Effects of caffeine on alcohol-related changes in behavioural control and perceived intoxication in light caffeine consumers.

    Science.gov (United States)

    Attwood, Angela S; Rogers, Peter J; Ataya, Alia F; Adams, Sally; Munafò, Marcus R

    2012-06-01

    Caffeinated alcoholic beverages have been associated with increased risk of alcohol-related harms. However, few studies have examined these combined effects on behavioural control, which is believed to underlie many of the negative effects of alcohol consumption. In addition, studies have often omitted subjective measures, and none have directly assessed the role of caffeine consumer history. To examine the combined effects of alcohol and caffeine on measures of behavioural control and perceived intoxication in abstinent, light caffeine consumers. Participants (n = 28; 50% male) attended four sessions at which they consumed one of the following beverages in a randomised order: placebo, alcohol alone (0.6 g/kg), caffeine alone (2.0 mg/kg), and alcohol/caffeine. They completed measures of mood, intoxication, anxiety and alcohol craving before and after a task battery comprising measures of behavioural control and reaction time performance. Caffeine attenuated alcohol-related performance deficits on stop-signal accuracy, had no effect on go-no-go performance deficits, and worsened accuracy on the Stroop task. Caffeine did not influence absolute changes in perceived intoxication but there was suggestion that caffeine may have changed the nature of intoxication with increases in stimulation. Caffeine appears to have mixed effects on alcohol intoxication that are task-dependent. We found increased stimulation in the alcohol/caffeine condition, supporting the contention that caffeinated alcoholic beverages enable an individual to drink for longer. Future research should model real world drinking behaviour by examining how these effects change across multiple drink administrations.

  11. Acute effects of caffeine on attention: a comparison of non-consumers and withdrawn consumers.

    Science.gov (United States)

    Smith, Andrew P; Christopher, Gary; Sutherland, David

    2013-01-01

    Despite the large number of studies on caffeine and attention, interpretation is often difficult because of methodological weaknesses. In the present study, use of a small battery of tests with four key outcome measures, combined with an appropriate sample size, addresses many of these problems. This methodology was used to examine whether effects of caffeine (a dose of 2 mg/kg) could be explained in terms of reversal of the effects of caffeine withdrawal. This was achieved by examining effects in non-consumers (N = 35), who could not be withdrawn, and also in a group of consumers (N = 35) who had undergone withdrawal for a week and no longer reported symptoms of withdrawal. The results showed no effect of short-term withdrawal on the performance measures, even though subjective reports showed an increase in symptoms after withdrawal. In contrast, the caffeine challenge carried out on Day 8 showed that ingestion of caffeine was associated with faster simple reaction time, fewer long responses, greater detection of targets in the cognitive vigilance task, and faster encoding of new information. These results suggest that it is important to continue to investigate mechanisms underlying these effects of caffeine and to further evaluate the practical implications of such effects.

  12. Fewer but heavier caffeine consumers in schizophrenia: a case-control study.

    Science.gov (United States)

    Gurpegui, Manuel; Aguilar, M Carmen; Martínez-Ortega, José M; Jurado, Dolores; Diaz, Francisco J; Quintana, Hernando M; de Leon, Jose

    2006-09-01

    According to the literature, there is an association between schizophrenia and caffeine consumption, but it is not clear whether schizophrenia is associated with either higher prevalence of daily caffeine intake or the amount consumed. In this study we compared our previously published schizophrenia patients (n=250) with a control sample (n=290) after controlling for demographic variables and tobacco and alcohol consumption. Current caffeine intake was less frequent in schizophrenia patients (59%, 147/250) than in controls (70%, 204/290). In the multivariate analyses, caffeine intake was less frequent at an older age and in schizophrenia patients, and more frequent in smokers and alcohol users. Among caffeine consumers, heavy caffeine intake (> or =200 mg/day) was significantly associated with schizophrenia (64%, 94/147 in schizophrenia versus 36%, 73/204 in controls), as well as older age and smoking. Daily amount of caffeine intake and smoked cigarettes correlated significantly in the schizophrenia group but not in the control group; the correlation of caffeine intake with nicotine dependence was low and non-significant in both groups. The association between current smoking and heavy caffeine intake may be partly explained by a pharmacokinetic effect: tobacco smoke compounds induce caffeine metabolism by the cytochrome P450 1A2. Although schizophrenia by itself may be associated with heavy caffeine intake in caffeine users, part of this association was explained by the association between schizophrenia and smoking. The relationship between caffeine and alcohol intake appeared to be more complex; alcohol and caffeine use were significantly associated, but within caffeine users alcohol was associated with less frequent heavy caffeine consumption among smokers. In future studies, the measurement of plasma caffeine levels will help both to better define heavy caffeine intake and to control for smoking pharmacokinetic effects.

  13. Caffeine withdrawal and high-intensity endurance cycling performance.

    Science.gov (United States)

    Irwin, Christopher; Desbrow, Ben; Ellis, Aleisha; O'Keeffe, Brooke; Grant, Gary; Leveritt, Michael

    2011-03-01

    In this study, we investigated the impact of a controlled 4-day caffeine withdrawal period on the effect of an acute caffeine dose on endurance exercise performance. Twelve well-trained and familiarized male cyclists, who were caffeine consumers (from coffee and a range of other sources), were recruited for the study. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials. Participants abstained from dietary caffeine sources for 4 days before the trials and ingested capsules (one in the morning and one in the afternoon) containing either placebo or caffeine (1.5 mg · kg(-1) body weight · day(-1)). On day 5, capsules containing placebo or caffeine (3 mg · kg(-1) body weight) were ingested 90 min before completing a time trial, equivalent to one hour of cycling at 75% peak sustainable power output. Hence the study was designed to incorporate placebo-placebo, placebo-caffeine, caffeine-placebo, and caffeine-caffeine conditions. Performance time was significantly improved after acute caffeine ingestion by 1:49 ± 1:41 min (3.0%, P = 0.021) following a withdrawal period (placebo-placebo vs. placebo-caffeine), and by 2:07 ± 1:28 min (3.6%, P = 0.002) following the non-withdrawal period (caffeine-placebo vs. caffeine-caffeine). No significant difference was detected between the two acute caffeine trials (placebo-caffeine vs. caffeine-caffeine). Average heart rate throughout exercise was significantly higher following acute caffeine administration compared with placebo. No differences were observed in ratings of perceived exertion between trials. A 3 mg · kg(-1) dose of caffeine significantly improves exercise performance irrespective of whether a 4-day withdrawal period is imposed on habitual caffeine users.

  14. Acute Caffeine Consumption Enhances the Executive Control of Visual Attention in Habitual Consumers

    Science.gov (United States)

    Brunye, Tad T.; Mahoney, Caroline R.; Lieberman, Harris R.; Giles, Grace E.; Taylor, Holly A.

    2010-01-01

    Recent work suggests that a dose of 200-400mg caffeine can enhance both vigilance and the executive control of visual attention in individuals with low caffeine consumption profiles. The present study seeks to determine whether individuals with relatively high caffeine consumption profiles would show similar advantages. To this end, we examined…

  15. Caffeine

    Science.gov (United States)

    What is caffeine? Caffeine is a bitter substance that occurs naturally in more than 60 plants including Coffee beans Tea leaves Kola nuts, ... chocolate products There is also synthetic (man-made) caffeine, which is added to some medicines, foods, and ...

  16. Caffein

    DEFF Research Database (Denmark)

    Nørager, Charlotte Buchard; Jensen, Martin Bach; Madsen, Mogens Rørbæk

    2005-01-01

    /kg) can increase the endurance of athletes engaged in running, bicycling, swimming and other endurance sports. Caffeine is used both in training and in competitions, and the International Olympic Commitée (IOC) has included caffeine as a drug used for doping. There are several theories about caffeine...

  17. Faster but not smarter:effects of caffeine and caffeine withdrawal on alertness and performance

    OpenAIRE

    Rogers, Peter J; Heatherley, Susan V; Mullings, Emma L; Smith, Jessica E

    2013-01-01

    Despite 100 years of psychopharmacological research, the extent to which caffeine consumption benefits human functioning remains unclear.To measure the effects of overnight caffeine abstinence and caffeine administration as a function of level of habitual caffeine consumption.Medium-high (n = 212) and non-low (n = 157) caffeine consumers completed self-report measures and computer-based tasks before (starting at 10:30 AM) and after double-blind treatment with either caffeine (100 mg, then 150...

  18. Caffeine promotes global spatial processing in habitual and non-habitual caffeine consumers

    OpenAIRE

    Grace E. Giles; Caroline R. Mahoney; Tad T. Brunye; Holly A. Taylor; Robin B. Kanarek

    2013-01-01

    Information processing is generally biased toward global cues, often at the expense of local information. Equivocal extant data suggests that arousal states may accentuate either a local or global processing bias, at least partially dependent on the nature of the manipulation, task, and stimuli. To further differentiate the conditions responsible for such equivocal results we varied caffeine doses to alter physiological arousal states and measured their effect on tasks requiring the retrieval...

  19. Caffeine can decrease subjective energy depending on the vehicle with which it is consumed and when it is measured.

    Science.gov (United States)

    Young, H A; Benton, D

    2013-07-01

    Energy drinks contain glucose and caffeine, although in the longer term both adversely influence blood glucose homeostasis, with the unconsidered potential to have adverse consequences for cognition and mood. The objective of this study was to consider the influence on interstitial glucose levels, mood and cognition of drinks differing in their caffeine content and glycaemic load. Ninety minutes after a standard breakfast, a yoghurt-, glucose- or water-based drink, with or without 80 mg of caffeine, was consumed. The consumption of caffeine negatively influenced glucose homeostasis: that is, irrespective of the vehicle, caffeine consumption resulted in elevated levels of blood glucose throughout the study. Thirty minutes after consuming caffeine and water, rather than water alone, greater subjective energy was reported. However, after 90 and 150 min, caffeine administered in water increased tiredness, hostility and confusion. In contrast, combining caffeine with a yoghurt-based drink increased energy, agreeableness and clearheadedness later in the morning. There were no effects of caffeine on ratings of mood when it was taken with glucose. Caffeine, irrespective of vehicle, resulted in better memory, quicker reaction times in the choice reaction time test and the working memory task, and better and quicker responses with the vigilance task. Further research should consider how caffeine interacts with macronutrients and the timescale over which such effects occur.

  20. Caffeine in the diet

    Science.gov (United States)

    Diet - caffeine ... Caffeine is absorbed and passes quickly into the brain. It does not collect in the bloodstream or ... been consumed. There is no nutritional need for caffeine. It can be avoided in the diet. Caffeine ...

  1. Caffeine and exercise.

    Science.gov (United States)

    Paluska, Scott A

    2003-08-01

    Caffeine is the most commonly consumed drug in the world, and athletes frequently use it as an ergogenic aid. It improves performance and endurance during prolonged, exhaustive exercise. To a lesser degree it also enhances short-term, high-intensity athletic performance. Caffeine improves concentration, reduces fatigue, and enhances alertness. Habitual intake does not diminish caffeine's ergogenic properties. Several mechanisms have been proposed to explain the physiologic effects of caffeine, but adenosine receptor antagonism most likely accounts for the primary mode of action. It is relatively safe and has no known negative performance effects, nor does it cause significant dehydration or electrolyte imbalance during exercise. Routine caffeine consumption may cause tolerance or dependence, and abrupt discontinuation produces irritability, mood shifts, headache, drowsiness, or fatigue. Major sport governing bodies ban excessive use of caffeine, but current monitoring techniques are inadequate, and ethical dilemmas persist regarding caffeine intake by athletes.

  2. High versus standard dose caffeine for apnoea: a systematic review

    NARCIS (Netherlands)

    Vliegenthart, Roos; Miedema, Martijn; Hutten, Gerard J.; van Kaam, Anton H.; Onland, Wes

    2018-01-01

    Placebo-controlled trials have shown that caffeine is highly effective in treating apnoea of prematurity and reduces the risk of bronchopulmonary dysplasia (BPD) and neurodevelopmental impairment (NDI). To identify, appraise and summarise studies investigating the modulating effect of different

  3. A survey of college-bound high school graduates regarding circadian preference, caffeine use, and academic performance.

    Science.gov (United States)

    Cole, James S

    2015-03-01

    This study examines the relationships between circadian preference and caffeine use with academic performance and hours spent studying for recent high school graduates entering their first year of college. Entering first-year college students enrolled at 90 baccalaureate-level institutions across the USA were invited to complete the Beginning College Survey of Student Engagement (BCSSE) and the Composite Scale of Morningness (CSM) as well as answer questions regarding caffeine consumption. Surveys were administered on each campus during the summer months of 2013. Only those that graduated from a US high school in the spring of 2013 were included in this study. The final sample for this study included 25,200 students that completed the BCSSE, CSM, and questions regarding caffeine consumption. Evening types (E-types) were significantly less likely to report earning A/A-'s in high school and less likely to study 16 or more hours per week compared to intermediate or morning types (M-types) (p students reported an average of 1.1 servings of caffeine per day, with 39 % reporting no caffeine consumption. M-types were more likely to consume no caffeine (54 %) compared to E-types that also indicated no daily caffeine (31 %) (p amount (7 %) (p high school. However, the apparent advantage that morning types had over evening types regarding high school grades was completely ameliorated once three or more servings of caffeine were consumed per day. This study provides additional information to educators and health professionals to create programs and provide resource to help adolescents better understand the impact of their sleep behaviors and use of caffeine on their academic performance.

  4. Effects of Smoking Cues on Caffeine Urges in Heavy Smokers and Caffeine Consumers with and without Schizophrenia

    OpenAIRE

    Adolfo, Amy B.; AhnAllen, Christopher G.; Tidey, Jennifer W.

    2008-01-01

    Cigarette smoking and caffeine use are established and problematic drug-use behaviors in people with schizophrenia. Associative links between drugs of abuse may occur but the relationship between caffeine use and cigarette smoking has received little attention in schizophrenia. In this cross-cue reactivity laboratory study, we examined the effects of neutral and smoking cues on craving for caffeinated beverages in participants with schizophrenia or schizoaffective disorder (SS; n = 15) and no...

  5. Effects of smoking cues on caffeine urges in heavy smokers and caffeine consumers with and without schizophrenia.

    Science.gov (United States)

    Adolfo, Amy B; AhnAllen, Christopher G; Tidey, Jennifer W

    2009-02-01

    Cigarette smoking and caffeine use are established and problematic drug-use behaviors in people with schizophrenia. Associative links between drugs of abuse may occur but the relationship between caffeine use and cigarette smoking has received little attention in schizophrenia. In this cross-cue reactivity laboratory study, we examined the effects of neutral and smoking cues on craving for caffeinated beverages in participants with schizophrenia or schizoaffective disorder (SS; n=15) and non-psychiatric controls (CS; n=18) all of whom were heavy smokers and daily caffeine users. Participants were tested under non-abstinent and 5-hour abstinent conditions. SS tended to report greater daily levels of caffeine use than CS. Although this difference was not significant, that may be due to the small sample sizes as the size of this effect was large. Daily caffeine intake was significantly correlated with daily smoking rate in SS but not CS. A significant interaction between group and cue type after controlling for caffeine intake indicated that exposure to smoking cues increased urge for caffeinated beverages in SS but not CS. These results indicate support for associative connections between cigarette smoking cues and craving for caffeine in smokers with schizophrenia.

  6. Guarana: revisiting a highly caffeinated plant from the Amazon.

    Science.gov (United States)

    Schimpl, Flávia Camila; da Silva, José Ferreira; Gonçalves, José Francisco de Carvalho; Mazzafera, Paulo

    2013-10-28

    Guarana (Paullinia cupana Kunth var. sorbilis (Mart.) Ducke) has been traditionally consumed by indigenous communities of the Amazon region. It is valued mainly for its stimulant property because of its high content of caffeine, which can be up to 6% in the seeds. The purpose of this review is to revisit this typically Brazilian plant, addressing economic considerations, the chemical makeup of the seeds and pharmacological properties so far investigated. Guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries. In addition to its stimulant property, guarana has other therapeutic properties, which have aroused the interest of the scientific community. This review shows that other guarana properties may be explored and how scarce are the studies regarding agronomic, plant pathology, physiology and breeding. So far, caffeine has been the main reason to study guarana and still will lead the researches because the demand for this alkaloid by food and pharmaceutical industry, and a strongly growing market related with beauty products. However, guarana has other components and there is great interest in studies designed to elucidate the effects of guarana's bioactive components and their potential pharmacological applications. Significant part of the guarana production in Brazil still comes from Indians tribes in the Amazon State, and any improvement in this plant, in any aspect, may propitiate a positive economic impact in their lives. © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Caffeine intake among adolescents in Delhi

    Directory of Open Access Journals (Sweden)

    Mridul Gera

    2016-01-01

    Full Text Available Background: Availability and advertising of caffeinated drinks is on the rise in Indian market. Excess caffeine intake may have deleterious effects on health. Objective: To estimate the daily consumption of caffeine among urban school-going adolescents from Delhi. Materials and Methods: A school-based survey was conducted to determine the amount and pattern of caffeine consumption among students of classes 9-12, using a self-administered questionnaire. Results: Of 300 participants (median age 15 year, 174 boys, 291 (97% were consuming caffeine [mean (SD: 121.0 (98.2 mg/day]. Nineteen (6% students were consuming more than 300 mg of caffeine per day. Tea/coffee contributed to more than 50% of the caffeine intake. The rest was derived from cola beverages, chocolates, and energy drinks. Conclusion: Average caffeine consumption among school-going adolescents from Delhi is high. The findings of this preliminary survey need to be confirmed in larger data sets.

  8. Habitual coffee and tea drinkers experienced increases in blood pressure after consuming low to moderate doses of caffeine; these increases were larger upright than in the supine posture.

    Science.gov (United States)

    McMullen, Michael K; Whitehouse, Julie M; Shine, Gillian; Towell, Anthony

    2011-04-01

    Caffeine users have been encouraged to consume caffeine regularly to maintain their caffeine tolerance and so avoid caffeine's acute pressor effects. In controlled conditions complete caffeine tolerance to intervention doses of 250 mg develops rapidly following several days of caffeine ingestion, nevertheless, complete tolerance is not evident for lower intervention doses. Similarly complete caffeine tolerance to 250 mg intervention doses has been demonstrated in habitual coffee and tea drinkers' but for lower intervention doses complete tolerance is not evident. This study investigated a group of habitual caffeine users following their self-determined consumption pattern involving two to six servings daily. Cardiovascular responses following the ingestion of low to moderate amounts caffeine (67, 133 and 200 mg) were compared with placebo in a double-blind, randomised design without caffeine abstinence. Pre-intervention and post-intervention (30 and 60 min) 90 s continuous cardiovascular recordings were obtained with the Finometer in both the supine and upright postures. Participants were 12 healthy habitual coffee and tea drinkers (10 female, mean age 36). Doses of 67 and 133 mg increased systolic pressure in both postures while in the upright posture diastolic pressure and aortic impedance increased while arterial compliance decreased. These vascular changes were larger upright than supine for 133 mg caffeine. Additionally 67 mg caffeine increased dp/dt and indexed peripheral resistance in the upright posture. For 200 mg caffeine there was complete caffeine tolerance. Cardiovascular responses to caffeine appear to be associated with the size of the intervention dose. Habitual tea and coffee drinking does not generate complete tolerance to caffeine as has been previously suggested. Both the type and the extent of caffeine induced cardiovascular changes were influenced by posture.

  9. Determination of Caffeine in Beverages by High Performance Liquid Chromatography.

    Science.gov (United States)

    DiNunzio, James E.

    1985-01-01

    Describes the equipment, procedures, and results for the determination of caffeine in beverages by high performance liquid chromatography. The method is simple, fast, accurate, and, because sample preparation is minimal, it is well suited for use in a teaching laboratory. (JN)

  10. The Physiological and Performance Effects of Caffeine Gum Consumed During A Simulated Half-Time By Professional Academy Rugby Union Players.

    Science.gov (United States)

    M, Russell; N A, Reynolds; B T, Crewther; C J, Cook; L, Kilduff

    2017-11-27

    Despite the prevalence of caffeine as an ergogenic aid, few studies have examined the use of caffeinated gums, especially during half-time in team sports. The physiological (blood lactate, salivary hormone concentrations) and performance (repeated sprints, cognitive function) effects of consuming caffeine gum during a simulated half-time were examined. Professional academy rugby union players (n=14) completed this double-blind, randomized, counterbalanced study. Following pre-exercise measurements , players chewed a placebo (PL) gum for five min before a standardized warm-up and completing repeated sprint testing (RSSA1). Thereafter, during a 15 min simulated half-time period, players chewed either caffeine (CAF: 400 mg; 4.1 ± 0.5 mg·kg) or PL gum for five min before completing a second repeated sprint test (RSSA2). Blood lactate, salivary testosterone and cortisol concentrations, and indices of cognitive function (i.e., reaction time and Stroop test) were measured at baseline, pre-RSSA1, post-RSSA1, pre-RSSA2 and post-RSSA2. Sprint performance was not affected by CAF (P=0.995) despite slower sprint times following the first sprint of both RSSA tests (all P0.05). Although performance effects were absent, chewing caffeine gum increased the salivary testosterone concentrations of professional rugby union players over a simulated half-time. Practitioners may therefore choose to recommend caffeine gum between successive exercise bouts due to the increases in salivary testosterone observed; a variable associated with increased motivation and high-intensity exercise performance.

  11. Cognitive and psychomotor performance, mood, and pressor effects of caffeine after 4, 6 and 8 h caffeine abstinence.

    Science.gov (United States)

    Heatherley, Susan V; Hayward, Robert C; Seers, Helen E; Rogers, Peter J

    2005-04-01

    Many studies have found that caffeine consumed after overnight caffeine abstinence improves cognitive performance and mood. Much less is known, however, about the effects of caffeine after shorter periods of caffeine abstinence. The aim of this study was to measure the effects on psychomotor and cognitive performance, mood, hand steadiness, blood pressure and heart rate of caffeine administration after periods of 4, 6, and 8 h of caffeine abstinence. Participants (n = 49, 27 female) were moderate to moderate-high caffeine consumers (mean daily intake 370 mg/day). Following overnight caffeine abstinence, a 'pre-dose' of caffeine (1.2 mg/kg) was administered at 9 A.M, 11 A.M or 1 P.M. The participants started a baseline battery of measurements at 4 P.M.: before receiving caffeine (1.2 mg/kg) or placebo at 5 P.M.: They then performed the battery of tests again, starting at 5:30 P.M. This was a double-blind, placebo-controlled, randomised study. Performance and mood measurements confirmed a psychostimulant action of caffeine (versus placebo), but only after 8 h of caffeine abstinence. Caffeine also increased blood pressure after 8-h abstinence, whereas hand steadiness was decreased and perception of task demand was increased by caffeine after 4 h, but not after 6- and 8-h abstinence. A second cup-of-coffee equivalent dose of caffeine only reliably affected cognitive performance and mood after an 8-h interval between doses, but not after shorter intervals (when caffeine had some adverse effects). These results show that, apart from caffeine consumption soon after waking, the daily pattern of caffeine intake of many typical caffeine consumers is not well explained by the short-term psychostimulant effects of caffeine.

  12. [Caffeine dependence].

    Science.gov (United States)

    Ogawa, Naoshi; Ueki, Hirofumi

    2010-08-01

    Caffeine is the most widely consumed psychoactive substance in the world and is a legal stimulant that is readily available to children. The potential for dependence on caffeine has been debated. Presently, due to a paucity of clinical evidence on caffeine dependence, no such diagnosis is included in the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision (DSM-IV-TR). Although in recent studies, a subset of the general population was found to demonstrate caffeine dependence. It is valuable for psychiatrists and primary care physicians to recognize caffeine dependence as a clinical syndrome, since some people are distressed by their caffeine use and feel they can not control or stop their problematic use.

  13. Associations of Caffeinated Beverage Consumption and Screen Time with Excessive Daytime Sleepiness in Korean High School Students.

    Science.gov (United States)

    Jun, Nuri; Lee, Aeri; Baik, Inkyung

    2017-01-01

    The present study investigated caffeinated beverage consumption and screen time in the association with excessive daytime sleepiness (EDS) and sleep duration. We conducted a cross-sectional study including 249 Korean male high school students. These participants responded to a questionnaire inquiring the information on lifestyle factors, consumption of caffeinated beverages, time spent for screen media, and sleep duration as well as to the Epworth Sleepiness Scale (ESS) questionnaire. EDS was defined as ESS scores of 9 or greater. Students with EDS consumed greater amount of chocolate/cocoa drinks and spent longer time for a TV and a mobile phone than those without EDS (p students with short sleep (≤ 6 hours) consumed greater amount of coffee than others whereas students with long sleep (> 8 hours) consumed greater amount of chocolate/cocoa drinks than others (p sleep duration. Although these findings do not support causal relationships, they suggest that screen time is associated with EDS, but not with sleep duration, and that consumption of certain types of caffeinated beverages is associated with EDS and sleep duration. Adolescents may need to reduce screen time and caffeine consumption to improve sleep quality and avoid daytime sleepiness.

  14. Reconsidering Caffeine: An Awake and Alert New Look at America's Most Commonly Consumed Drug

    OpenAIRE

    Mrazik, David M.

    2004-01-01

    Caffeine is one of the most pervasively ingested addictive substances in the United States, yet astoundingly little attention is paid to its ubiquitous presence. This Paper examines caffeine, the substance, from many perspectives. First, it discusses caffeine with particular regard to its chemical properties; its presence in foods, beverages, and medications both naturally and as an additive; and its known impacts on human biological and psychological functioning. Relevant medical investigati...

  15. Caffeine's implications for women's health and survey of obstetrician-gynecologists' caffeine knowledge and assessment practices.

    Science.gov (United States)

    Anderson, Britta L; Juliano, Laura M; Schulkin, Jay

    2009-09-01

    Caffeine has relevance for women's health and pregnancy, including significant associations with spontaneous abortion and low birth weight. According to scientific data, pregnant women and women of reproductive age should be advised to limit their caffeine consumption. This article reviews the implications of caffeine for women's psychological and physical health, and presents data on obstetrician-gynecologists' (ob-gyns) knowledge and practices pertaining to caffeine. Ob-gyns (N = 386) who are members of the American College of Obstetricians and Gynecologists' Collaborative Ambulatory Research Network responded to a 21-item survey about caffeine. Although most knew that caffeine is passed through breast milk, only 24.8% were aware that caffeine metabolism significantly slows as pregnancy progresses. Many respondents were not aware of the caffeine content of commonly used products, such as espresso and Diet Coke, with 14.3% and 57.8% indicating amounts within an accurate range, respectively. Furthermore, ob-gyns did not take into account large differences in caffeine content across different caffeinated beverages with most recommending one to two servings of coffee or tea or soft drinks per day. There was substantial inconsistency in what was considered to be "high levels" of maternal caffeine consumption, with only 31.6% providing a response. When asked to indicate the risk that high levels of caffeine have on various pregnancy outcomes, responses were not consistent with scientific data. For example, respondents overestimated the relative risk of stillbirths and underestimated the relative risk of spontaneous abortion. There was great variability in assessment and advice practices pertaining to caffeine. More than half advise their pregnant patients to consume caffeine under certain circumstances, most commonly to alleviate headache and caffeine withdrawal. The data suggest that ob-gyns could benefit from information about caffeine and its relevance to their

  16. Caffeine dependence in teenagers.

    Science.gov (United States)

    Bernstein, Gail A; Carroll, Marilyn E; Thuras, Paul D; Cosgrove, Kelly P; Roth, Megan E

    2002-03-01

    This study identifies and characterizes symptoms of caffeine dependence in adolescents. Thirty-six adolescents who consumed caffeine daily and had some features of caffeine dependence on telephone screen were scheduled for outpatient evaluation. Evaluation included the Diagnostic Interview Schedule for Children-IV-Youth Version (DISC-IV) and modified DISC-IV questions that assessed caffeine dependence based on DSM-IV substance dependence criteria. Of 36 subjects, 41.7% (n=15) reported tolerance to caffeine, 77.8% (n=28) described withdrawal symptoms after cessation or reduction of caffeine intake, 38.9% (n=14) reported desire or unsuccessful attempts to control use, and 16.7% (n=6) endorsed use despite knowledge of physical or psychological problems associated with caffeine. There was no significant difference in the amount of caffeine consumed daily by caffeine dependent versus non-dependent teenagers. These findings are important due to the vast number of adolescents who drink caffeinated beverages.

  17. Interindividual Differences in Caffeine Metabolism and Factors Driving Caffeine Consumption.

    Science.gov (United States)

    Nehlig, Astrid

    2018-04-01

    Most individuals adjust their caffeine intake according to the objective and subjective effects induced by the methylxanthine. However, to reach the desired effects, the quantity of caffeine consumed varies largely among individuals. It has been known for decades that the metabolism, clearance, and pharmacokinetics of caffeine is affected by many factors such as age, sex and hormones, liver disease, obesity, smoking, and diet. Caffeine also interacts with many medications. All these factors will be reviewed in the present document and discussed in light of the most recent data concerning the genetic variability affecting caffeine levels and effects at the pharmacokinetic and pharmacodynamic levels that both critically drive the level of caffeine consumption. The pharmacokinetics of caffeine are highly variable among individuals due to a polymorphism at the level of the CYP1A2 isoform of cytochrome P450, which metabolizes 95% of the caffeine ingested. Moreover there is a polymorphism at the level of another critical enzyme, N -acetyltransferase 2. At the pharmacodynamic level, there are several polymorphisms at the main brain target of caffeine, the adenosine A2A receptor or ADORA2. Genetic studies, including genome-wide association studies, identified several loci critically involved in caffeine consumption and its consequences on sleep, anxiety, and potentially in neurodegenerative and psychiatric diseases. We start reaching a better picture on how a multiplicity of biologic mechanisms seems to drive the levels of caffeine consumption, although much more knowledge is still required to understand caffeine consumption and effects on body functions. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

  18. Faster but not smarter: effects of caffeine and caffeine withdrawal on alertness and performance.

    Science.gov (United States)

    Rogers, Peter J; Heatherley, Susan V; Mullings, Emma L; Smith, Jessica E

    2013-03-01

    Despite 100 years of psychopharmacological research, the extent to which caffeine consumption benefits human functioning remains unclear. To measure the effects of overnight caffeine abstinence and caffeine administration as a function of level of habitual caffeine consumption. Medium-high (n = 212) and non-low (n = 157) caffeine consumers completed self-report measures and computer-based tasks before (starting at 10:30 AM) and after double-blind treatment with either caffeine (100 mg, then 150 mg) or placebo. The first treatment was given at 11:15 AM and the second at 12:45 PM, with post-treatment measures repeated twice between 1:45 PM and 3:30 PM. Caffeine withdrawal was associated with some detrimental effects at 10:30 AM, and more severe effects, including greater sleepiness, lower mental alertness, and poorer performance on simple reaction time, choice reaction time and recognition memory tasks, later in the afternoon. Caffeine improved these measures in medium-high consumers but, apart from decreasing sleepiness, had little effect on them in non-low consumers. The failure of caffeine to increase mental alertness and improve mental performance in non-low consumers was related to a substantial caffeine-induced increase in anxiety/jitteriness that offset the benefit of decreased sleepiness. Caffeine enhanced physical performance (faster tapping speed and faster simple and choice reaction times) in both medium-high and non-low consumers. While caffeine benefits motor performance and tolerance develops to its tendency to increase anxiety/jitteriness, tolerance to its effects on sleepiness means that frequent consumption fails to enhance mental alertness and mental performance.

  19. Caffeine withdrawal symptoms and self-administration following caffeine deprivation.

    Science.gov (United States)

    Mitchell, S H; de Wit, H; Zacny, J P

    1995-08-01

    This study examined the effects of complete or partial caffeine deprivation on withdrawal symptomatology and self-administration of coffee in caffeine-dependent coffee drinkers. Nine habitual coffee drinkers abstained from dietary sources of caffeine for 33.5 h. Caffeine deprivation was manipulated by administering capsules containing 0%, 50%, or 100% of each subject's daily caffeine intake (complete, partial, and no deprivation conditions). Caffeine withdrawal symptomatology was measured using self-report questionnaires. Caffeine self-administration was measured using: i) the amount of coffee subjects earned on a series of concurrent random-ratio schedules that yielded coffee and money reinforcers; ii) the amount of earned coffee they consumed. Saliva samples revealed that subjects complied with the caffeine abstinence instructions. Caffeine withdrawal symptoms occurred reliably following complete caffeine deprivation, though not in the partial deprivation condition. Caffeine self-administration was not related to deprivation condition. We conclude that caffeine withdrawal symptomatology is not necessarily associated with increased caffeine consumption.

  20. Caffeine Reinforces Flavor Preference and Behavior in Moderate Users but Not in Low Caffeine Users

    Science.gov (United States)

    Dack, Charlotte; Reed, Phil

    2009-01-01

    The study examined the role of caffeine consumption in caffeine reinforcement. Previous findings have shown that caffeine reinforced flavor preference in moderate caffeine consumers who are caffeine deprived. However, most of these studies have employed rating procedures only, and have not shown the effectiveness of caffeine to reinforce behaviors…

  1. High Blood Caffeine Levels in MCI Linked to Lack of Progression to Dementia

    Science.gov (United States)

    Cao, Chuanhai; Loewenstein, David A.; Lin, Xiaoyang; Zhang, Chi; Wang, Li; Duara, Ranjan; Wu, Yougui; Giannini, Alessandra; Bai, Ge; Cai, Jianfeng; Greig, Maria; Schofield, Elizabeth; Ashok, Raj; Small, Brent; Potter, Huntington; Arendash, Gary W.

    2017-01-01

    Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer’s disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65–88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2–4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (−51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCI→DEM) compared to levels in stable MCI subjects (MCI→MCI). Moreover, none of the MCI→DEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCI→MCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 µM) in MCI subjects were associated with no conversion to dementia during the ensuing 2–4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects, but not in stable MCI→MCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI. PMID:22430531

  2. Caffeine Consumption Among Naval Aviation Candidates.

    Science.gov (United States)

    Sather, Thomas E; Williams, Ronald D; Delorey, Donald R; Woolsey, Conrad L

    2017-04-01

    Education frequently dictates students need to study for prolonged periods of time to adequately prepare for examinations. This is especially true with aviation preflight indoctrination (API) candidates who have to assimilate large volumes of information in a limited amount of time during API training. The purpose of this study was to assess caffeine consumption patterns (frequency, type, and volume) among naval aviation candidates attending API to determine the most frequently consumed caffeinated beverage and to examine if the consumption of a nonenergy drink caffeinated beverage was related to energy drink consumption. Data were collected by means of an anonymous 44-item survey administered and completed by 302 students enrolled in API at Naval Air Station Pensacola, FL. Results indicated the most frequently consumed caffeinated beverage consumed by API students was coffee (86.4%), with daily coffee consumption being approximately 28% and the most frequent pattern of consumption being 2 cups per day (85%). The least frequently consumed caffeinated beverages reported were energy drinks (52%) and energy shots (29.1%). The present study also found that the consumption patterns (weekly and daily) of caffeinated beverages (coffee and cola) were positively correlated to energy drink consumption patterns. Naval aviation candidates' consumption of caffeinated beverages is comparable to other college and high school cohorts. This study found that coffee and colas were the beverages of choice, with energy drinks and energy shots being the least frequently reported caffeinated beverages used. Additionally, a relationship between the consumption of caffeinated beverages and energy drinks was identified.Sather TE, Williams RD, Delorey DR, Woolsey CL. Caffeine consumption among naval aviation candidates. Aerosp Med Hum Perform. 2017; 88(4):399-405.

  3. Dispelling the myth that habitual caffeine consumption influences the performance response to acute caffeine supplementation.

    Science.gov (United States)

    Gonçalves, Lívia de Souza; Painelli, Vitor de Salles; Yamaguchi, Guilherme; Oliveira, Luana Farias de; Saunders, Bryan; da Silva, Rafael Pires; Maciel, Erika; Artioli, Guilherme Giannini; Roschel, Hamilton; Gualano, Bruno

    2017-07-01

    This study investigates the influence of habitual caffeine intake on aerobic exercise-performance responses to acute caffeine supplementation. A double-blind, crossover, counterbalanced study was performed. Forty male endurance-trained cyclists were allocated into tertiles, according to their daily caffeine intake: low (58 ± 29 mg/d), moderate (143 ± 25 mg/d), and high (351 ± 139 mg/d) consumers. Participants completed three trials in which they performed simulated cycling time trials (TTs) in the fastest time possible following ingestion of the following: caffeine (CAF: 6 mg/kg body mass), placebo (PLA), and no supplement (CON). A mixed-model analysis revealed that TT performance was significantly improved in CAF compared with PLA and CON (29.92 ± 2.18 vs. 30.81 ± 2.67 and 31.14 ± 2.71 min, respectively; P = 0.0002). Analysis of covariance revealed no influence of habitual caffeine intake as a covariate on exercise performance ( P = 0.47). TT performance was not significantly different among tertiles ( P = 0.75). No correlation was observed between habitual caffeine intake and absolute changes (CAF - CON) in TT performance with caffeine ( P = 0.524). Individual analysis showed that eight, seven, and five individuals improved above the variation of the test in CAF in the low, moderate, and high tertiles, respectively. A Fisher's exact test did not show any significant differences in the number of individuals who improved in CAF among the tertiles ( P > 0.05). Blood lactate and ratings of perceived exertion were not different between trials and tertiles ( P > 0.05). Performance effects of acute caffeine supplementation during an ~30-min cycling TT performance were not influenced by the level of habitual caffeine consumption. NEW & NOTEWORTHY There has been a long-standing paradigm that habitual caffeine intake may influence the ergogenicity of caffeine supplementation. Low, moderate, and high caffeine consumers showed similar absolute and

  4. Effects of caffeine and caffeine withdrawal on mood and cognitive performance degraded by sleep restriction.

    Science.gov (United States)

    Rogers, Peter J; Heatherley, Susan V; Hayward, Robert C; Seers, Helen E; Hill, Joanne; Kane, Marian

    2005-06-01

    It has been suggested that caffeine is most likely to benefit mood and performance when alertness is low. To measure the effects of caffeine on psychomotor and cognitive performance, mood, blood pressure and heart rate in sleep-restricted participants. To do this in a group of participants who had also been previously deprived of caffeine for 3 weeks, thereby potentially removing the confounding effects of acute caffeine withdrawal. Participants were moderate to moderate-high caffeine consumers who were provided with either decaffeinated tea and/or coffee for 3 weeks (LTW) or regular tea and/or coffee for 3 weeks (overnight caffeine-withdrawn participants, ONW). Then, following overnight caffeine abstinence, they were tested on a battery of tasks assessing mood, cognitive performance, etc. before and after receiving caffeine (1.2 mg/kg) or on another day after receiving placebo. Final analyses were based on 17 long-term caffeine-withdrawn participants (LTW) and 17 ONW participants whose salivary caffeine levels on each test day confirmed probable compliance with the instructions concerning restrictions on consumption of caffeine-containing drinks. Acute caffeine withdrawal (ONW) had a number of negative effects, including impairment of cognitive performance, increased headache, and reduced alertness and clear-headedness. Caffeine (versus placebo) did not significantly improve cognitive performance in LTW participants, although it prevented further deterioration of performance in ONW participants. Caffeine increased tapping speed (but tended to impair hand steadiness), increased blood pressure, and had some effects on mood in both groups. The findings provide strong support for the withdrawal reversal hypothesis. In particular, cognitive performance was found to be affected adversely by acute caffeine withdrawal and, even in the context of alertness lowered by sleep restriction, cognitive performance was not improved by caffeine in the absence of these withdrawal

  5. Energy drink consumption and impact on caffeine risk.

    Science.gov (United States)

    Thomson, Barbara M; Campbell, Donald M; Cressey, Peter; Egan, Ursula; Horn, Beverley

    2014-01-01

    The impact of caffeine from energy drinks occurs against a background exposure from naturally occurring caffeine (coffee, tea, cocoa and foods containing these ingredients) and caffeinated beverages (kola-type soft drinks). Background caffeine exposure, excluding energy drinks, was assessed for six New Zealand population groups aged 15 years and over (n = 4503) by combining concentration data for 53 caffeine-containing foods with consumption information from the 2008/09 New Zealand Adult Nutrition Survey (ANS). Caffeine exposure for those who consumed energy drinks (n = 138) was similarly assessed, with inclusion of energy drinks. Forty-seven energy drink products were identified on the New Zealand market in 2010. Product volumes ranged from 30 to 600 ml per unit, resulting in exposures of 10-300 mg caffeine per retail unit consumed. A small percentage, 3.1%, of New Zealanders reported consuming energy drinks, with most energy drink consumers (110/138) drinking one serving per 24 h. The maximum number of energy drinks consumed per 24 h was 14 (total caffeine of 390 mg). A high degree of brand loyalty was evident. Since only a minor proportion of New Zealanders reported consuming energy drinks, a greater number of New Zealanders exceeded a potentially adverse effect level (AEL) of 3 mg kg(-1) bw day(-1) for caffeine from caffeine-containing foods than from energy drinks. Energy drink consumption is not a risk at a population level because of the low prevalence of consumption. At an individual level, however, teenagers, adults (20-64 years) and females (16-44 years) were more likely to exceed the AEL by consuming energy drinks in combination with caffeine-containing foods.

  6. Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports

    Science.gov (United States)

    2011-01-01

    Introduction Energy drinks and highly caffeinated drinks comprise some of the fastest growing products of the beverage industry, often targeting teenagers and young adults. Cardiac arrhythmias in children related to high caffeine consumption have not been well described in the literature. This case series describes the possible association between the consumption of highly caffeinated drinks and the subsequent development of atrial fibrillation in the adolescent population. Case presentations We report the cases of two Caucasian adolescent boys of 14 and 16 years of age at the time of presentation, each without a significant cardiac history, who presented with palpitations or vague chest discomfort or both after a recent history of excessive caffeine consumption. Both were found to have atrial fibrillation on electrocardiogram; one patient required digoxin to restore a normal sinus rhythm, and the other self-converted after intravenous fluid administration. Conclusion With the increasing popularity of energy drinks in the pediatric and adolescent population, physicians should be aware of the arrhythmogenic potential associated with highly caffeinated beverage consumption. It is important for pediatricians to understand the lack of regulation in the caffeine content and other ingredients of these high-energy beverages and their complications so that parents and children can be educated about the risk of cardiac arrhythmias with excessive energy drink consumption. PMID:21247417

  7. Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports

    Directory of Open Access Journals (Sweden)

    Heyden Marybeth

    2011-01-01

    Full Text Available Abstract Introduction Energy drinks and highly caffeinated drinks comprise some of the fastest growing products of the beverage industry, often targeting teenagers and young adults. Cardiac arrhythmias in children related to high caffeine consumption have not been well described in the literature. This case series describes the possible association between the consumption of highly caffeinated drinks and the subsequent development of atrial fibrillation in the adolescent population. Case presentations We report the cases of two Caucasian adolescent boys of 14 and 16 years of age at the time of presentation, each without a significant cardiac history, who presented with palpitations or vague chest discomfort or both after a recent history of excessive caffeine consumption. Both were found to have atrial fibrillation on electrocardiogram; one patient required digoxin to restore a normal sinus rhythm, and the other self-converted after intravenous fluid administration. Conclusion With the increasing popularity of energy drinks in the pediatric and adolescent population, physicians should be aware of the arrhythmogenic potential associated with highly caffeinated beverage consumption. It is important for pediatricians to understand the lack of regulation in the caffeine content and other ingredients of these high-energy beverages and their complications so that parents and children can be educated about the risk of cardiac arrhythmias with excessive energy drink consumption.

  8. Caffeine prevents cognitive impairment induced by chronic psychosocial stress and/or high fat-high carbohydrate diet.

    Science.gov (United States)

    Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

    2013-01-15

    Caffeine alleviates cognitive impairment associated with a variety of health conditions. In this study, we examined the effect of caffeine treatment on chronic stress- and/or high fat-high carbohydrate Western diet (WD)-induced impairment of learning and memory in rats. Chronic psychosocial stress, WD and caffeine (0.3 g/L in drinking water) were simultaneously administered for 3 months to adult male Wistar rats. At the conclusion of the 3 months, and while the previous treatments continued, rats were tested in the radial arm water maze (RAWM) for learning, short-term and long-term memory. This procedure was applied on a daily basis to all animals for 5 consecutive days or until the animal reaches days to criterion (DTC) in the 12th learning trial and memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Chronic stress and/or WD groups caused impaired learning, which was prevented by chronic caffeine administration. In the memory tests, chronic caffeine administration also prevented memory impairment during chronic stress conditions and/or WD. Furthermore, DTC value for caffeine treated stress, WD, and stress/WD groups indicated that caffeine normalizes memory impairment in these groups. These results showed that chronic caffeine administration prevented stress and/or WD-induced impairment of spatial learning and memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Association of the Anxiogenic and Alerting Effects of Caffeine with ADORA2A and ADORA1 Polymorphisms and Habitual Level of Caffeine Consumption

    Science.gov (United States)

    Rogers, Peter J; Hohoff, Christa; Heatherley, Susan V; Mullings, Emma L; Maxfield, Peter J; Evershed, Richard P; Deckert, Jürgen; Nutt, David J

    2010-01-01

    Caffeine, a widely consumed adenosine A1 and A2A receptor antagonist, is valued as a psychostimulant, but it is also anxiogenic. An association between a variant within the ADORA2A gene (rs5751876) and caffeine-induced anxiety has been reported for individuals who habitually consume little caffeine. This study investigated whether this single nucleotide polymorphism (SNP) might also affect habitual caffeine intake, and whether habitual intake might moderate the anxiogenic effect of caffeine. Participants were 162 non-/low (NL) and 217 medium/high (MH) caffeine consumers. In a randomized, double-blind, parallel groups design they rated anxiety, alertness, and headache before and after 100 mg caffeine and again after another 150 mg caffeine given 90 min later, or after placebo on both occasions. Caffeine intake was prohibited for 16 h before the first dose of caffeine/placebo. Results showed greater susceptibility to caffeine-induced anxiety, but not lower habitual caffeine intake (indeed coffee intake was higher), in the rs5751876 TT genotype group, and a reduced anxiety response in MH vs NL participants irrespective of genotype. Apart from the almost completely linked ADORA2A SNP rs3761422, no other of eight ADORA2A and seven ADORA1 SNPs studied were found to be clearly associated with effects of caffeine on anxiety, alertness, or headache. Placebo administration in MH participants decreased alertness and increased headache. Caffeine did not increase alertness in NL participants. With frequent consumption, substantial tolerance develops to the anxiogenic effect of caffeine, even in genetically susceptible individuals, but no net benefit for alertness is gained, as caffeine abstinence reduces alertness and consumption merely returns it to baseline. PMID:20520601

  10. Low, but not high, dose caffeine is a readily available probe for adenosine actions.

    Science.gov (United States)

    Fredholm, Bertil B; Yang, Jiangning; Wang, Yingqing

    2017-06-01

    Caffeine is very widely used and knowledge of its mode of action can be used to gain an understanding of basal physiological regulation. This review makes the point that caffeine is - in low doses - an antagonist of adenosine acting at A 1 , A 2A and A 2B receptors. We use published and unpublished data to make the point that high dose effects of caffeine are not only qualitatively different but have a different underlying mechanism. Therefore one must be careful in only using epidemiological or experimental data where rather low doses of caffeine are used to draw conclusions about the physiology and pathophysiology of adenosine. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Understanding adolescent caffeine use: connecting use patterns with expectancies, reasons, and sleep.

    Science.gov (United States)

    Bryant Ludden, Alison; Wolfson, Amy R

    2010-06-01

    Little is known about adolescents' caffeine use, yet caffeinated soda, and more recently coffee and energy drinks, are part of youth culture. This study examines adolescents' caffeine use and, using cluster analysis, identifies three groups of caffeine users who differed in their reasons for use, expectancies, and sleep behaviors. In this high school student sample (N = 197), 95% of participants reported recent caffeine use-most often soda-where typical first use of the day was in the evening. Results reveal that adolescents in the mixed use and high soda use groups consumed similar amounts of soda, reporting significantly more use than the low caffeine use group. In contrast with high soda users, mixed users drank more coffee, expected more dependence symptoms and energy enhancement from caffeine, and were more likely to report getting up early, daytime sleepiness, and using caffeine to get through the day.

  12. Cross-sectional surveys of the amount of sugar, energy and caffeine in sugar-sweetened drinks marketed and consumed as energy drinks in the UK between 2015 and 2017: monitoring reformulation progress.

    Science.gov (United States)

    Hashem, Kawther M; He, Feng J; MacGregor, Graham A

    2017-12-14

    To investigate the sugar, energy and caffeine content of sugar-sweetened drinks marketed and consumed as energy drinks available in the UK. We carried out a cross-sectional survey in 2015 and 2017 of energy drinks available in the main UK retailers. The sugar (sugars g/100 mL), energy (kcal/100 mL), caffeine (mg/100 mL) and serving size were collected from product packaging and nutrition information panels of energy drinks available in the nine main UK grocery retailers, three health and beauty retailers and one convenience store. The number of formulations (per 100 mL) and number of products (per serving) have fallen (from 75 to 49 and from 90 to 59) between 2015 and 2017, respectively. Energy drinks surveyed showed a 10% reduction in sugar, from 10.6 to 9.5 g/100 mL (P=0.011) and a 6% reduction in energy content (P=0.005) per 100 mL between 2015 and 2017. The average caffeine content of energy drinks, with a warning label, has remained high at 31.5±0.9 in 2015 and 31.3±1.0 mg/100 mL in 2017. Despite there being reductions, sugar, energy and caffeine content remain at concerning levels in 2017. To reduce the harmful impact of energy drinks, further reduction in sugar and a reduction in caffeine by reformulation are urgently needed. Other measures such as ban on the sale of energy drinks to children and smaller product sizes should also be explored, while warning labels should be kept. A reduction in sugar, energy and caffeine content and overall energy drinks consumption could be beneficial in reducing sugar, energy and caffeine intake of consumers of energy drinks. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Acute high-caffeine exposure increases autophagic flux and reduces protein synthesis in C2C12 skeletal myotubes.

    Science.gov (United States)

    Hughes, M A; Downs, R M; Webb, G W; Crocker, C L; Kinsey, S T; Baumgarner, Bradley L

    2017-04-01

    Caffeine is a highly catabolic dietary stimulant. High caffeine concentrations (1-10 mM) have previously been shown to inhibit protein synthesis and increase protein degradation in various mammalian cell lines. The purpose of this study was to examine the effect of short-term caffeine exposure on cell signaling pathways that regulate protein metabolism in mammalian skeletal muscle cells. Fully differentiated C2C12 skeletal myotubes either received vehicle (DMSO) or 5 mM caffeine for 6 h. Our analysis revealed that caffeine promoted a 40% increase in autolysosome formation and a 25% increase in autophagic flux. In contrast, caffeine treatment did not significantly increase the expression of the skeletal muscle specific ubiquitin ligases MAFbx and MuRF1 or 20S proteasome activity. Caffeine treatment significantly reduced mTORC1 signaling, total protein synthesis and myotube diameter in a CaMKKβ/AMPK-dependent manner. Further, caffeine promoted a CaMKII-dependent increase in myostatin mRNA expression that did not significantly contribute to the caffeine-dependent reduction in protein synthesis. Our results indicate that short-term caffeine exposure significantly reduced skeletal myotube diameter by increasing autophagic flux and promoting a CaMKKβ/AMPK-dependent reduction in protein synthesis.

  14. Teratogenic effects of caffeine and clomipramine on rat fetus

    Directory of Open Access Journals (Sweden)

    Takzare N

    2012-09-01

    Full Text Available Background: Obsessive-compulsive disorders and depression have a high prevalence during pregnancy therefore, pregnant women may take clomipramine and also take other drugs or consume foods that contain caffeine. As investigations about the teratogenic effects of clomipramine and its concurrent administration with caffeine during organogenesis period are scarce, we aimed to study the teratogenicity of simultaneous administration of clomipramine and caffeine in rat fetus.Methods: After dividing 42 pregnant rats to several case and control groups, we injected different doses of caffeine and clomipramine to the animals. All the injections were performed on the eighth until the 15th day of pregnancy. We removed the fetuses on the 17th day of pregnancy and studied the morphological features and apparent anomalies of the fetuses macroscopically. Results: We found a significant rate of mortality, apparent anomalies, abnormal torsion, shrinkage of skin and subcutaneous bleeding in fetuses of rats receiving high doses of caffeine or a combination of caffeine and clomipramine. Statistical analysis of the data revealed a significant increase (P?0.001 in teratogenicity of high doses of caffeine and its combination with clomipramine. Conclusion: This study implies simultaneous intake of high amounts of caffeine and clomipramine lead to teratogenicity. We recommend pregnant women to avoid uncontrolled consumption of foods that contain caffeine or drugs that contain high amounts of this substance. They should not also take clomipramine with caffeine in the first trimester of pregnancy.

  15. Performance effects and metabolic consequences of caffeine and caffeinated energy drink consumption on glucose disposal.

    Science.gov (United States)

    Shearer, Jane; Graham, Terry E

    2014-10-01

    This review documents two opposing effects of caffeine and caffeine-containing energy drinks, i.e., their positive effects on athletic performance and their negative impacts on glucose tolerance in the sedentary state. Analysis of studies examining caffeine administration prior to performance-based exercise showed caffeine improved completion time by 3.6%. Similar analyses following consumption of caffeine-containing energy drinks yielded positive, but more varied, benefits, which were likely due to the diverse nature of the studies performed, the highly variable composition of the beverages consumed, and the range of caffeine doses administered. Conversely, analyses of studies administering caffeine prior to either an oral glucose tolerance test or insulin clamp showed a decline in whole-body glucose disposal of ~30%. The consequences of this resistance are unknown, but there may be implications for the development of a number of chronic diseases. Both caffeine-induced performance enhancement and insulin resistance converge with the primary actions of caffeine on skeletal muscle. © 2014 International Life Sciences Institute.

  16. Radiomodifying effect of caffeine on mammalian cellular system using gamma radiation and proton beam radiation

    International Nuclear Information System (INIS)

    Samanth, Sneha P.; Yadav, Usha; Shirsath, K.B.; Desai, Utkarsha N.; Chaurasia, Rajesh K.; Bhat, Nagesh N.; Anjaria, K.B.; Sapra, B.K.

    2016-01-01

    Caffeine is a commonly consumed neurostimulant in the world. Reports suggest the radiomodifying effects of caffeine against low Linear Energy Transfer (LET) radiation when administered pre and post irradiation by releasing checkpoint arrest. In the present report, the radioprotective and radiosensitizing ability of caffeine (10μM - 2mM) were studied on Chinese Hamster Ovary (CRO) cell line against low as well as high LET radiation when administered pre, post and continuously during radiation. Effect of caffeine treatment on the genotoxicity induced by gamma and proton beam radiation was assessed by micronucleus assay. Effect of caffeine treatment on clonogenic survival of irradiated cells was also assessed

  17. International society of sports nutrition position stand: caffeine and performance

    Directory of Open Access Journals (Sweden)

    Wildman Robert

    2010-01-01

    Full Text Available Abstract Position Statement: The position of The Society regarding caffeine supplementation and sport performance is summarized by the following seven points: 1. Caffeine is effective for enhancing sport performance in trained athletes when consumed in low-to-moderate dosages (~3-6 mg/kg and overall does not result in further enhancement in performance when consumed in higher dosages (≥ 9 mg/kg. 2. Caffeine exerts a greater ergogenic effect when consumed in an anhydrous state as compared to coffee. 3. It has been shown that caffeine can enhance vigilance during bouts of extended exhaustive exercise, as well as periods of sustained sleep deprivation. 4. Caffeine is ergogenic for sustained maximal endurance exercise, and has been shown to be highly effective for time-trial performance. 5. Caffeine supplementation is beneficial for high-intensity exercise, including team sports such as soccer and rugby, both of which are categorized by intermittent activity within a period of prolonged duration. 6. The literature is equivocal when considering the effects of caffeine supplementation on strength-power performance, and additional research in this area is warranted. 7. The scientific literature does not support caffeine-induced diuresis during exercise, or any harmful change in fluid balance that would negatively affect performance.

  18. High Doses of Caffeine during the Peripubertal Period in the Rat Impair the Growth and Function of the Testis

    Directory of Open Access Journals (Sweden)

    Minji Park

    2015-01-01

    Full Text Available Prenatal caffeine exposure adversely affects the development of the reproductive organs of male rat offspring. Thus, it is conceivable that peripubertal caffeine exposure would also influence physiologic gonadal changes and function during this critical period for sexual maturation. This study investigated the impact of high doses of caffeine on the testes of prepubertal male rats. A total of 45 immature male rats were divided randomly into three groups: a control group and 2 groups fed 120 and 180 mg/kg/day of caffeine, respectively, via the stomach for 4 weeks. Caffeine caused a significant decrease in body weight gain, accompanied by proportional decreases in lean body mass and body fat. The caffeine-fed animals had smaller and lighter testes than those of the control that were accompanied by negative influences on the histologic parameters of the testes. In addition, stimulated-testosterone ex vivo production was reduced in Leydig cells retrieved from the caffeine-fed animals. Our results demonstrate that peripubertal caffeine consumption can interfere with the maturation and function of the testis, possibly by interrupting endogenous testosterone secretion and reducing the sensitivity of Leydig cells to gonadotrophic stimulation. In addition, we confirmed that pubertal administration of caffeine reduced testis growth and altered testis histomorphology.

  19. Effects of caffeine on performance and mood depend on the level of caffeine abstinence.

    Science.gov (United States)

    Yeomans, Martin R; Ripley, Tamzin; Davies, Laura H; Rusted, Jennifer M; Rogers, Peter J

    2002-11-01

    Most studies of the effects of caffeine on performance have used regular caffeine consumers who are deprived at test. Thus the reported effects of caffeine could be explained through reversal of caffeine withdrawal. To test how preloading deprived caffeine consumers with 0, 1 or 2 mg/kg caffeine altered the subsequent ability of caffeine to modify mood and performance. Thirty moderate caffeine consumers were given a drink containing 0, 1 or 2 mg/kg caffeine at breakfast followed 60 min later by a second drink containing either 0 or 1 mg/kg caffeine. Performance on a measure of sustained attention and mood were measured before and after each drink. Administration of both 1 and 2 mg/kg caffeine at breakfast decreased reaction time and 1 mg/kg caffeine also increased performance accuracy on the sustained attention (RVIP) task relative to placebo. Both breakfast doses of caffeine also improved rated mental alertness. Similarly, 1 mg/kg caffeine administered 60 min after breakfast decreased reaction time and increased rated mental alertness in the group who had not been given caffeine at breakfast. However, this second dose of caffeine had no effect on subsequent performance or mood in the two groups who had received caffeine at breakfast. Caffeine reliably improved performance on a sustained attention task, and increased rated mental alertness, in moderate caffeine consumers who were tested when caffeine-deprived. However, caffeine had no such effects when consumers were no longer caffeine deprived. These data are consistent with the view that reversal of caffeine withdrawal is a major component of the effects of caffeine on mood and performance.

  20. Withdrawal syndrome after the double-blind cessation of caffeine consumption.

    Science.gov (United States)

    Silverman, K; Evans, S M; Strain, E C; Griffiths, R R

    1992-10-15

    People who stop consuming caffeine may have symptoms, but the incidence and severity of caffeine withdrawal are not known. This study was performed to determine the effects in the general population of ending one's dietary intake of caffeine. We studied 62 normal adults whose intake of caffeine was low to moderate (mean amount, 235 mg--the equivalent of 2.5 cups of coffee--per day). They completed questionnaires about symptoms and tests of their mood and performance when consuming their normal diets (base-line period) and at the end of each of two two-day periods during which they consumed caffeine-free diets and under double-blind conditions received capsules containing placebo (placebo period) or caffeine (caffeine period) in amounts equal to their daily caffeine consumption. More subjects had abnormally high Beck Depression Inventory scores (11 percent), high scores on the trait scale of the State-Trait Anxiety Inventory (8 percent), low vigor scores (11 percent) and high fatigue scores (8 percent) on the Profile of Mood States, and moderate or severe headache (52 percent) during the placebo period than during either the base-line period (2, 0, 0, 0, and 2 percent, respectively; P less than 0.05) or the caffeine period (3, 2, 2, 0, and 6 percent; P less than 0.05). More subjects reported unauthorized use of medications during the placebo period (13 percent) than during the caffeine period (2 percent, P = 0.017). Performance of a tapping task was slower during the placebo period than during the base-line and caffeine periods (P less than 0.01). Persons who consume low or moderate amounts of caffeine may have a withdrawal syndrome after their daily consumption of caffeine ceases.

  1. The Effect of Caffeine on Repeat-High-Intensity-Effort Performance in Rugby League Players.

    Science.gov (United States)

    Wellington, Brandon M; Leveritt, Michael D; Kelly, Vincent G

    2017-02-01

    Repeat-high-intensity efforts (RHIEs) have recently been shown to occur at critical periods of rugby league matches. To examine the effect that caffeine has on RHIE performance in rugby league players. Using a double-blind, placebo-controlled, crossover design, 11 semiprofessional rugby league players (age 19.0 ± 0.5 y, body mass 87.4 ± 12.9 kg, height 178.9 ± 2.6 cm) completed 2 experimental trials that involved completing an RHIE test after either caffeine (300 mg caffeine) or placebo (vitamin H) ingestion. Each trial consisted of 3 sets of 20-m sprints interspersed with bouts of tackling. During the RHIE test, 20-m-sprint time, heart rate (HR), rating of perceived exertion (RPE), and blood lactate were measured. Total time to complete the nine 20-m sprints during the caffeine condition was 1.0% faster (28.46 ± 1.4 s) than during the placebo condition (28.77 ± 1.7 s) (ES = 0.18, 90%CI -0.7 to 0.1 s). This resulted in a very likely chance of caffeine being of benefit to RHIE performance (99% likely to be beneficial). These improvements were more pronounced in the early stages of the test, with a 1.3%, 1.0%, and 0.9% improvement in sprint performance during sets 1, 2, and 3 respectively. There was no significant difference in RPE across the 3 sets (P = .47, 0.48, 1.00) or mean HR (P = .36), maximal HR (P = .74), or blood lactate (P = .50) between treatment conditions. Preexercise ingestion of 300 mg caffeine produced practically meaningful improvements in RHIE performance in rugby league players.

  2. Exercise and sport performance with low doses of caffeine.

    Science.gov (United States)

    Spriet, Lawrence L

    2014-11-01

    Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5-13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (caffeine doses (1) do not alter the peripheral whole-body responses to exercise; (2) improve vigilance, alertness, and mood and cognitive processes during and after exercise; and (3) are associated with few, if any, side effects. Therefore, the ergogenic effect of low caffeine doses appears to result from alterations in the central nervous system. However, several aspects of consuming low doses of caffeine remain unresolved and suffer from a paucity of research, including the potential effects on high-intensity sprint and burst activities. The responses to low doses of caffeine are also variable and athletes need to determine whether the ingestion of ~200 mg of caffeine before and/or during training and competitions is ergogenic on an individual basis.

  3. High performance liquid chromatography determination of theobromine and caffeine in cocoa beans gamma irradiated

    International Nuclear Information System (INIS)

    Soares, Anderson D.B.; Mansur Neto, Elias

    1997-01-01

    Irradiation is a processing technology that has been shown to be a wholesome process by many scientific studies conducted worldwide during the past 40 years, which has been approved by 37 countries. Irradiated foods have been studied so extensively, that the effects on foods are better understood than any other preservation process, including food freezing and dehydration. Cocoa beans has been commercially irradiated in countries such as Ivory Coast and Argentina. The alkaloids theobromine and caffeine are responsible for the mildly stimulating properties and bitter taste of cocoa and chocolate products. Previously fermented dried and nonfumigated cocoa beans were irradiated at doses of 0, 5.0, 10.0 and 20.0 kGy using Co-60 gamma rays. The samples were analysed for determining theobromine and caffeine contents in the cocoa beans by TIMBIE et al. (1978) high performance liquid chromatography (HPLC) method. Boiling water extracts were cooled, centrifuged and injected into the chromatograph. Theobromine and caffeine were quantitated at 273 nm and showed the tendency of decreasing as the dose of radiation increases. Theobromine and caffeine ranged from 42.3 to 37.1 mg/g and from 7.60 to 6.13 mg/g. respectively from 0 to 20.0 kGy. These results were discussed in relation to the possible acceptance of radiosterization of cocoa beans commercially up to the dose of 20.0 kGy. (author). 10 refs., 1 tab

  4. High performance liquid chromatography determination of theobromine and caffeine in cocoa beans gamma irradiated

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Anderson D.B. [Faculdade de Engenharia de Varginha, MG (Brazil); Mansur Neto, Elias [Minas Gerais Univ., Belo Horizonte, MG (Brazil)

    1997-12-01

    Irradiation is a processing technology that has been shown to be a wholesome process by many scientific studies conducted worldwide during the past 40 years, which has been approved by 37 countries. Irradiated foods have been studied so extensively, that the effects on foods are better understood than any other preservation process, including food freezing and dehydration. Cocoa beans has been commercially irradiated in countries such as Ivory Coast and Argentina. The alkaloids theobromine and caffeine are responsible for the mildly stimulating properties and bitter taste of cocoa and chocolate products. Previously fermented dried and nonfumigated cocoa beans were irradiated at doses of 0, 5.0, 10.0 and 20.0 kGy using Co-60 gamma rays. The samples were analysed for determining theobromine and caffeine contents in the cocoa beans by TIMBIE et al. (1978) high performance liquid chromatography (HPLC) method. Boiling water extracts were cooled, centrifuged and injected into the chromatograph. Theobromine and caffeine were quantitated at 273 nm and showed the tendency of decreasing as the dose of radiation increases. Theobromine and caffeine ranged from 42.3 to 37.1 mg/g and from 7.60 to 6.13 mg/g. respectively from 0 to 20.0 kGy. These results were discussed in relation to the possible acceptance of radiosterization of cocoa beans commercially up to the dose of 20.0 kGy. (author). 10 refs., 1 tab.

  5. Caffeine induces high expression of cyp-35A family genes and inhibits the early larval development in Caenorhabditis elegans.

    Science.gov (United States)

    Min, Hyemin; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2015-03-01

    Intake of caffeine during pregnancy can cause retardation of fetal development. Although the significant influence of caffeine on animal development is widely recognized, much remains unknown about its mode of action because of its pleiotropic effects on living organisms. In the present study, by using Caenorhabditis elegans as a model organism, the effects of caffeine on development were examined. Brood size, embryonic lethality, and percent larval development were investigated, and caffeine was found to inhibit the development of C. elegans at most of the stages in a dosage-dependent fashion. Upon treatment with 30 mM caffeine, the majority (86.1 ± 3.4%) of the L1 larvae were irreversibly arrested without further development. In contrast, many of the late-stage larvae survived and grew to adults when exposed to the same 30 mM caffeine. These results suggest that early-stage larvae are more susceptible to caffeine than later-stage larvae. To understand the metabolic responses to caffeine treatment, the levels of expression of cytochrome P450 (cyp) genes were examined with or without caffeine treatment using comparative micro-array, and it was found that the expression of 24 cyp genes was increased by more than 2-fold (p family was the most prominent. Interestingly, depletion of the cyp-35A family genes one-by-one or in combination through RNA interference resulted in partial rescue from early larval developmental arrest caused by caffeine treatment, suggesting that the high-level induction of cyp-35A family genes can be fatal to the development of early-stage larvae.

  6. Effects of caffeine on neuromuscular fatigue and performance during high-intensity cycling exercise in moderate hypoxia.

    Science.gov (United States)

    Smirmaul, Bruno P C; de Moraes, Antonio Carlos; Angius, Luca; Marcora, Samuele M

    2017-01-01

    To investigate the effects of caffeine on performance, neuromuscular fatigue and perception of effort during high-intensity cycling exercise in moderate hypoxia. Seven adult male participants firstly underwent an incremental exercise test on a cycle ergometer in conditions of acute normobaric hypoxia (fraction inspired oxygen = 0.15) to establish peak power output (PPO). In the following two visits, they performed a time to exhaustion test (78 ± 3% PPO) in the same hypoxic conditions after caffeine ingestion (4 mg kg -1 ) and one after placebo ingestion in a double-blind, randomized, counterbalanced cross-over design. Caffeine significantly improved time to exhaustion by 12%. A significant decrease in subjective fatigue was found after caffeine consumption. Perception of effort and surface electromyographic signal amplitude of the vastus lateralis were lower and heart rate was higher in the caffeine condition when compared to placebo. However, caffeine did not reduce the peripheral and central fatigue induced by high-intensity cycling exercise in moderate hypoxia. The caffeine-induced improvement in time to exhaustion during high-intensity cycling exercise in moderate hypoxia seems to be mediated by a reduction in perception of effort, which occurs despite no reduction in neuromuscular fatigue.

  7. Caffeine prevents weight gain and cognitive impairment caused by a high-fat diet while elevating hippocampal BDNF

    OpenAIRE

    Moy, Gregory A.; McNay, Ewan C.

    2012-01-01

    Obesity, high-fat diets, and subsequent type 2 diabetes (T2DM) are associated with cognitive impairment. Moreover, T2DM increases the risk of Alzheimer’s disease (AD) and leads to abnormal elevation of brain beta-amyloid levels, one of the hallmarks of AD. The psychoactive alkaloid caffeine has been shown to have therapeutic potential in AD but the central impact of caffeine has not been well-studied in the context of a high-fat diet. Here we investigated the impact of caffeine administration...

  8. Tobacco, Caffeine, Alcohol and Illicit Substance Use among Consumers of a National Psychiatric Disability Support Service

    Science.gov (United States)

    Zimmermann, Adam; Lubman, Dan I.; Cox, Merrilee

    2012-01-01

    Previous research has consistently documented high rates of tobacco smoking and substance use disorders among young people with serious mental illness. However, limited studies have been conducted outside traditional clinical settings. In an attempt to address this shortfall and to better understand the needs of young people accessing its…

  9. Blood pressure response to caffeine shows incomplete tolerance after short-term regular consumption.

    Science.gov (United States)

    Lovallo, William R; Wilson, Michael F; Vincent, Andrea S; Sung, Bong Hee; McKey, Barbara S; Whitsett, Thomas L

    2004-04-01

    Caffeine acutely raises blood pressure (BP). The clinical significance of this effect depends on whether BP responses persist in persons who consume caffeine on a daily basis. Accordingly, the ability of caffeine to raise BP after 5 days of regular daily intake was tested in a randomized controlled trial. Individual differences in tolerance formation were then examined. Men (n=49) and women (n=48) completed a double-blind, crossover trial conducted over 4 weeks. During each week, subjects abstained for 5 days from dietary caffeine and instead used capsules totaling 0 mg, 300 mg, and 600 mg of caffeine per day in 3 divided doses. On day 6, in the laboratory, they used capsules with either 0 mg or 250 mg of caffeine at 9:00 am and 1:00 pm. Systolic/diastolic BP increases as a result of 250 mg of caffeine remained significant (P7.90, P <0.001). The sexes did not differ in degree of tolerance formation. Daily caffeine consumption failed to eliminate the BP response to repeated challenge doses of caffeine in half of the healthy adults who were tested. Caffeine may therefore cause persistent BP effects in persons who are regular consumers, even when daily intake is at moderately high levels.

  10. Caffeine content of decaffeinated coffee.

    Science.gov (United States)

    McCusker, Rachel R; Fuehrlein, Brian; Goldberger, Bruce A; Gold, Mark S; Cone, Edward J

    2006-10-01

    Caffeine is the most widely consumed drug in the world with coffee representing a major source of intake. Despite widespread availability, various medical conditions necessitate caffeine-restricted diets. Patients on certain prescription medications are advised to discontinue caffeine intake. Such admonition has implications for certain psychiatric patients because of pharmacokinetic interactions between caffeine and certain anti-anxiety drugs. In an effort to abstain from caffeine, patients may substitute decaffeinated for caffeinated coffee. However, decaffeinated beverages are known to contain caffeine in varying amounts. The present study determined the caffeine content in a variety of decaffeinated coffee drinks. In phase 1 of the study, 10 decaffeinated samples were collected from different coffee establishments. In phase 2 of the study, Starbucks espresso decaffeinated (N=6) and Starbucks brewed decaffeinated coffee (N=6) samples were collected from the same outlet to evaluate variability of caffeine content of the same drink. The 10 decaffeinated coffee samples from different outlets contained caffeine in the range of 0-13.9 mg/16-oz serving. The caffeine content for the Starbucks espresso and the Starbucks brewed samples collected from the same outlet were 3.0-15.8 mg/shot and 12.0-13.4 mg/16-oz serving, respectively. Patients vulnerable to caffeine effects should be advised that caffeine may be present in coffees purported to be decaffeinated. Further research is warranted on the potential deleterious effects of consumption of "decaffeinated" coffee that contains caffeine on caffeine-restricted patients. Additionally, further exploration is merited for the possible physical dependence potential of low doses of caffeine such as those concentrations found in decaffeinated coffee.

  11. Associations of Caffeinated Beverage Consumption and Screen Time with Excessive Daytime Sleepiness in Korean High School Students

    OpenAIRE

    Jun, Nuri; Lee, Aeri; Baik, Inkyung

    2017-01-01

    The present study investigated caffeinated beverage consumption and screen time in the association with excessive daytime sleepiness (EDS) and sleep duration. We conducted a cross-sectional study including 249 Korean male high school students. These participants responded to a questionnaire inquiring the information on lifestyle factors, consumption of caffeinated beverages, time spent for screen media, and sleep duration as well as to the Epworth Sleepiness Scale (ESS) questionnaire. EDS was...

  12. The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis

    International Nuclear Information System (INIS)

    Pujol, M.; Puig, R.; Caballin, M. R.; Barrios, L.; Barquinero, J. F.

    2012-01-01

    Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemide and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR. (authors)

  13. Acute Ingestion of Caffeinated Chewing Gum Improves Repeated Sprint Performance of Team Sport Athletes With Low Habitual Caffeine Consumption.

    Science.gov (United States)

    Evans, Mark; Tierney, Peter; Gray, Nicola; Hawe, Greg; Macken, Maria; Egan, Brendan

    2018-04-23

    The effects of acute ingestion of caffeine on short-duration high-intensity performance are equivocal, while studies of novel modes of delivery and the efficacy of low doses of caffeine are warranted. The aims of the present study were to investigate the effect of acute ingestion of caffeinated chewing gum on repeated sprint performance (RSP) in team sport athletes, and whether habitual caffeine consumption alters the ergogenic effect, if any, on RSP. A total of 18 male team sport athletes undertook four RSP trials using a 40-m maximum shuttle run test, which incorporates 10 × 40-m sprints with 30 s between the start of each sprint. Each participant completed two familiarization sessions, followed by caffeine (CAF; caffeinated chewing gum; 200 mg caffeine) and placebo (PLA; noncaffeinated chewing gum) trials in a randomized, double-blind manner. RSP, assessed by sprint performance decrement (%), did not differ (p = .209; effect size = 0.16; N = 18) between CAF (5.00 ± 2.84%) and PLA (5.43 ± 2.68%). Secondary analysis revealed that low habitual caffeine consumers (130 mg/day, n = 6; 3.98 ± 2.57% vs. 3.80 ± 1.79%, respectively; p = .684; effect size = 0.08). The data suggest that a low dose of caffeine in the form of caffeinated chewing gum attenuates the sprint performance decrement during RSP by team sport athletes with low, but not moderate-to-high, habitual consumption of caffeine.

  14. Caffeine triggers behavioral and neurochemical alterations in adolescent rats.

    Science.gov (United States)

    Ardais, A P; Borges, M F; Rocha, A S; Sallaberry, C; Cunha, R A; Porciúncula, L O

    2014-06-13

    Caffeine is the psychostimulant most consumed worldwide but concerns arise about the growing intake of caffeine-containing drinks by adolescents since the effects of caffeine on cognitive functions and neurochemical aspects of late brain maturation during adolescence are poorly known. We now studied the behavioral impact in adolescent male rats of regular caffeine intake at low (0.1mg/mL), moderate (0.3mg/mL) and moderate/high (1.0mg/mL) doses only during their active period (from 7:00 P.M. to 7:00 A.M.). All tested doses of caffeine were devoid of effects on locomotor activity, but triggered anxiogenic effects. Caffeine (0.3 and 1mg/mL) improved the performance in the object recognition task, but the higher dose of caffeine (1.0mg/mL) decreased the habituation to an open-field arena, suggesting impaired non-associative memory. All tested doses of caffeine decreased the density of glial fibrillary acidic protein and synaptosomal-associated protein-25, but failed to modify neuron-specific nuclear protein immunoreactivity in the hippocampus and cerebral cortex. Caffeine (0.3-1mg/mL) increased the density of brain-derived neurotrophic factor (BDNF) and proBDNF density as well as adenosine A1 receptor density in the hippocampus, whereas the higher dose of caffeine (1mg/mL) increased the density of proBDNF and BDNF and decreased A1 receptor density in the cerebral cortex. These findings document an impact of caffeine consumption in adolescent rats with a dual impact on anxiety and recognition memory, associated with changes in BDNF levels and decreases of astrocytic and nerve terminal markers without overt neuronal damage in hippocampal and cortical regions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Caffeine and cognitive performance: persistent methodological challenges in caffeine research.

    Science.gov (United States)

    James, Jack E

    2014-09-01

    Human cognitive performance is widely perceived to be enhanced by caffeine at usual dietary doses. However, the evidence for and against this belief continues to be vigorously contested. Controversy has centred on caffeine withdrawal and withdrawal reversal as potential sources of experimental confounding. In response, some researchers have enlisted "caffeine-naïve" experimental participants (persons alleged to consume little or no caffeine) assuming that they are not subject to withdrawal. This mini-review examines relevant research to illustrate general methodological challenges that have been the cause of enduring confusion in caffeine research. At issue are the processes of caffeine withdrawal and withdrawal reversal, the definition of caffeine-naïve, the population representativeness of participants deemed to be caffeine-naïve, and confounding due to caffeine tolerance. Attention to these processes is necessary if premature conclusions are to be avoided, and if caffeine's complex effects and the mechanisms responsible for those effects are to be illuminated. Strategies are described for future caffeine research aimed at minimising confounding from withdrawal and withdrawal reversal. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Adolescent habitual caffeine consumption and hemodynamic reactivity during rest, psychosocial stress, and recovery.

    Science.gov (United States)

    James, Jack E; Baldursdottir, Birna; Johannsdottir, Kamilla R; Valdimarsdottir, Heiddis B; Sigfusdottir, Inga Dora

    2018-07-01

    Most adolescents regularly consume caffeine. Whereas observational studies have suggested that coffee may be cardio-protective, pharmacological experimentation with adults shows that caffeine at dietary doses increases blood pressure, thereby implicating regular caffeine consumption as a potential source of harm for cardiovascular health. The present study was in response to the dearth of caffeine research among younger consumers. It was hypothesised that compared to the consumption of little or no caffeine, adolescents who habitually consume caffeine have overall higher blood pressure and increased vascular resistance. Using a quasi-experimental design, continuous measurements of blood pressure, cardiac output, and total peripheral resistance were taken non-invasively from adolescents (n = 333) aged 14-15 years and 18-19 years who reported "low", "moderate", or "high" levels of caffeine intake. Measurements were conducted when participants generally had negligible or low systematic caffeine levels while at rest, during stress, and during recovery from stress. Whereas habitual caffeine consumption did not predict blood pressure level, higher caffeine intake was associated with modestly increased vascular resistance during all phases of the experiment (i.e., at rest, during stress, and during recovery from stress). Present findings are important because they suggest that early exposure to caffeine may lead to persistent increases in vascular resistance, which in turn is an acknowledged risk factor for the development of hypertension. These results highlight the need for further studies of adolescents to determine the robustness of any persistent caffeine-related hemodynamic effects, and the implications such effects could have for long-term cardiovascular health. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men.

    Directory of Open Access Journals (Sweden)

    Ricardo Mora-Rodríguez

    Full Text Available PURPOSE: To investigate whether caffeine ingestion counteracts the morning reduction in neuromuscular performance associated with the circadian rhythm pattern. METHODS: Twelve highly resistance-trained men underwent a battery of neuromuscular tests under three different conditions; i morning (10:00 a.m. with caffeine ingestion (i.e., 3 mg kg(-1; AM(CAFF trial; ii morning (10:00 a.m. with placebo ingestion (AM(PLAC trial; and iii afternoon (18:00 p.m. with placebo ingestion (PM(PLAC trial. A randomized, double-blind, crossover, placebo controlled experimental design was used, with all subjects serving as their own controls. The neuromuscular test battery consisted in the measurement of bar displacement velocity during free-weight full-squat (SQ and bench press (BP exercises against loads that elicit maximum strength (75% 1RM load and muscle power adaptations (1 m s(-1 load. Isometric maximum voluntary contraction (MVC(LEG and isometric electrically evoked strength of the right knee (EVOK(LEG were measured to identify caffeine's action mechanisms. Steroid hormone levels (serum testosterone, cortisol and growth hormone were evaluated at the beginning of each trial (PRE. In addition, plasma norepinephrine (NE and epinephrine were measured PRE and at the end of each trial following a standardized intense (85% 1RM 6 repetitions bout of SQ (POST. RESULTS: In the PM(PLAC trial, dynamic muscle strength and power output were significantly enhanced compared with AM(PLAC treatment (3.0%-7.5%; p≤0.05. During AM(CAFF trial, muscle strength and power output increased above AM(PLAC levels (4.6%-5.7%; p≤0.05 except for BP velocity with 1 m s(-1 load (p = 0.06. During AM(CAFF, EVOK(LEG and NE (a surrogate of maximal muscle sympathetic nerve activation were increased above AM(PLAC trial (14.6% and 96.8% respectively; p≤0.05. CONCLUSIONS: These results indicate that caffeine ingestion reverses the morning neuromuscular declines in highly resistance

  18. Does Caffeine Enhance Athletic Performance?

    Directory of Open Access Journals (Sweden)

    Marcou Juliana

    2016-04-01

    Conclusion: Caffeine consumption may enhance athletic endurance, based on strong evidence, but further research needs to be conducted. High caffeine doses than the optimal, 3-6 mg/kg, before exercise does not confer any additional improvement in athletic performance. Additional, higher caffeine doses may cause side effects in athletes.

  19. The Effects of Caffeine Use on Driving Safety Among Truck Drivers Who Are Habitual Caffeine Users.

    Science.gov (United States)

    Heaton, Karen; Griffin, Russell

    2015-08-01

    The purpose of this study was to describe caffeine use among a group of habitual caffeine users, truck drivers, and to explore the associations between caffeine use and critical safety events by age in the naturalistic work setting. A secondary analysis of existing data from the Naturalistic Truck Driving Study was conducted. Analyses focused on the association between sleep and caffeine consumption by duty status, comparisons of sleep and caffeine use by age, and the associations between caffeine use and safety-critical events (SCEs). Findings indicated differences in caffeine use by duty status. However, no difference in sleep time by duty status, or between sleep time and caffeine use was found regardless of when the caffeine was consumed during the 5 hours prior to sleep. Sleep time did not vary significantly by age, although increasing age was associated with decreased caffeine use. Overall, a 6% reduction in the rate of SCEs per eight ounces of caffeinated beverage consumed was found. This study makes a unique scientific contribution because it uses real-time observations of truckers in the naturalistic work setting. It also does not involve caffeine withdrawal but rather an investigation of the effects of the naturalistic consumption of caffeine on sleep and driving performance. Findings suggest that caffeine use among habitual users offers a protective effect for safety-critical driving events. Occupational health nurses may use this information to counsel workers in the use of caffeine to enhance driving safety. © 2015 The Author(s).

  20. Caffeine overdose

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002579.htm Caffeine overdose To use the sharing features on this page, please enable JavaScript. Caffeine is a substance that exists naturally in certain ...

  1. Clinical importance of caffeine dependence and abuse.

    Science.gov (United States)

    Ogawa, Naoshi; Ueki, Hirofumi

    2007-06-01

    Caffeine is the most widely consumed psychoactive substance and is a legal stimulant that is readily available to children. Caffeine has occasionally been considered a drug of abuse and the potential for dependence on caffeine has been debated. Presently, due to a paucity of clinical evidence on caffeine dependence or abuse, no such diagnosis is included in the Diagnostic and Statistical Manual of Mental Disorder-fourth edition. The authors present two cases of abuse or dependence on the caffeine contained in 'eutrophic' (energy/nutritional) beverages or caffeine preparations, followed by a review of clinical studies demonstrating evidence that some people can manifest a clinical syndrome of caffeine dependence or abuse. The cases suggest that caffeine can produce a clinical dependence syndrome similar to those produced by other psychoactive substances and has a potential for abuse. In a recent study using a structured interview and the Diagnostic and Statistical Manual of Mental Disorder-fourth edition criteria for substance dependence and abuse, a subset of the general population was found to demonstrate caffeine dependence or caffeine abuse. Therefore, the authors propose that companies or businesses manufacturing or marketing caffeine or products containing caffeine must meet the following guidelines: (i) clearly indicate the caffeine content of products containing comparatively higher quantities of caffeine; (ii) warn that such products should be avoided by infants and children wherever possible, and inform adult consumers about the precise quantity of caffeine that is considered safe for consumption; and (iii) clearly state that consuming large quantities of caffeine and the long-term use of caffeine carry health risks.

  2. Measurement of caffeine and its three primary metabolites in human plasma by HPLC-ESI-MS/MS and clinical application.

    Science.gov (United States)

    Chen, Feng; Hu, Zhe-Yi; Parker, Robert B; Laizure, S Casey

    2017-06-01

    Caffeine is a mild stimulant with significant potential for abuse, being consumed in larger doses with the widespread availability of energy drinks and by novel routes of administration such as inspired powder, oral sprays and electronic cigarettes. How these recent changes in caffeine consumption affecting caffeine disposition and abuse potential is of growing concern. In the study of caffeine disposition in humans, it is common to only measure the caffeine concentration; however, caffeine's three major metabolites (paraxanthine, theobromine and theophylline) retain central nervous system stimulant activity that may contribute to the overall pharmacological activity and toxicity. Therefore, it would be scientifically more rigorous to measure caffeine and its major metabolites in the evaluation of caffeine disposition in human subjects. Herein, we report a method for the simultaneous quantification of caffeine and its three major metabolites in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry (HPLC-ESI-MS/MS). Human plasma samples were treated by simple protein precipitation and the analytes were separated using a 6 min gradient program. Precision and accuracy were well within in the 15% acceptance range. The simple sample preparation, short runtime, sensitivity and the inclusion of caffeine's major metabolites make this assay methodology optimal for the study of caffeine's pharmacokinetics and pharmacodynamics in human subjects. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Is caffeine a cognitive enhancer?

    Science.gov (United States)

    Nehlig, Astrid

    2010-01-01

    The effects of caffeine on cognition were reviewed based on the large body of literature available on the topic. Caffeine does not usually affect performance in learning and memory tasks, although caffeine may occasionally have facilitatory or inhibitory effects on memory and learning. Caffeine facilitates learning in tasks in which information is presented passively; in tasks in which material is learned intentionally, caffeine has no effect. Caffeine facilitates performance in tasks involving working memory to a limited extent, but hinders performance in tasks that heavily depend on working memory, and caffeine appears to rather improve memory performance under suboptimal alertness conditions. Most studies, however, found improvements in reaction time. The ingestion of caffeine does not seem to affect long-term memory. At low doses, caffeine improves hedonic tone and reduces anxiety, while at high doses, there is an increase in tense arousal, including anxiety, nervousness, jitteriness. The larger improvement of performance in fatigued subjects confirms that caffeine is a mild stimulant. Caffeine has also been reported to prevent cognitive decline in healthy subjects but the results of the studies are heterogeneous, some finding no age-related effect while others reported effects only in one sex and mainly in the oldest population. In conclusion, it appears that caffeine cannot be considered a ;pure' cognitive enhancer. Its indirect action on arousal, mood and concentration contributes in large part to its cognitive enhancing properties.

  4. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    Science.gov (United States)

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Marketing mix for consumer high technology products

    Directory of Open Access Journals (Sweden)

    Dovleac, L.

    2012-01-01

    Full Text Available This paper includes an analysis upon the variables of marketing mix for high technology products used for individual consumption. There are exposed the essential aspects related to marketing policies and strategies used by high technology companies for providing consumers the best solutions tailored to their needs. A special attention is given to the necessity for inclusion in the marketing mix of the fifth element – the assistance and informational support for customers.

  6. Caffeine and acetaminophen association: Effects on mitochondrial bioenergetics.

    Science.gov (United States)

    Gonçalves, Débora F; de Carvalho, Nelson R; Leite, Martim B; Courtes, Aline A; Hartmann, Diane D; Stefanello, Sílvio T; da Silva, Ingrid K; Franco, Jéferson L; Soares, Félix A A; Dalla Corte, Cristiane L

    2018-01-15

    Many studies have been demonstrating the role of mitochondrial function in acetaminophen (APAP) hepatotoxicity. Since APAP is commonly consumed with caffeine, this work evaluated the effects of the combination of APAP and caffeine on hepatic mitochondrial bioenergetic function in mice. Mice were treated with caffeine (20mg/kg, intraperitoneal (i.p.)) or its vehicle and, after 30minutes, APAP (250mg/kg, i.p.) or its vehicle. Four hours later, livers were removed, and the parameters associated with mitochondrial function and oxidative stress were evaluated. Hepatic cellular oxygen consumption was evaluated by high-resolution respirometry (HRR). APAP treatment decreased cellular oxygen consumption and mitochondrial complex activities in the livers of mice. Additionally, treatment with APAP increased swelling of isolated mitochondria from mice livers. On the other hand, caffeine administered with APAP was able to improve hepatic mitochondrial bioenergetic function. Treatment with APAP increased lipid peroxidation and reactive oxygen species (ROS) production and decreased glutathione levels in the livers of mice. Caffeine administered with APAP was able to prevent lipid peroxidation and the ROS production in mice livers, which may be associated with the improvement of mitochondrial function caused by caffeine treatment. We suggest that the antioxidant effects of caffeine and/or its interactions with mitochondrial bioenergetics may be involved in its beneficial effects against APAP hepatotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Development and initial validation of a caffeine craving questionnaire.

    Science.gov (United States)

    West, Oliver; Roderique-Davies, Gareth

    2008-01-01

    Craving for caffeine has received little empirical attention, despite considerable research into the potential for caffeine dependence. The main aim of this study was to develop, and initially validate, a multi-item, multidimensional instrument to measure cravings for caffeine. Participants were 189 caffeine consumers who completed the Questionnaire of Caffeine Cravings, which was based on the Questionnaire of Smoking Urges (QSU), in one of five naturally occurring periods of abstinence; 1-15 min; 16-120 mins; 3-7 h; 12-48 h and +48 h. Exploratory factor analysis suggested a three-factor solution best described the data; Factor 1 reflected strong desires, intentions and positive reinforcement; Factor 2 reflected mild/general positive and negative reinforcement and Factor 3 reflected functional/mood-based negative reinforcement. Significantly higher Factor 1 and Factor 2 scores were recorded for high frequency users; significantly higher Factor 1 and Factor 3 scores were recorded as a function of increased levels of dependence. Duration of abstinence did not significantly effect cravings across all three factors. Regression analyses suggested level of dependence best predicted both current cravings and frequency of daily use. These findings suggest caffeine cravings may be conceptualized multidimensionally and further validates the use of multidimensional, multi-item instruments. Cravings for caffeine may manifest and be detected across varying levels of dependence and, frequency of use and independently of duration of abstinence.

  8. Caffeine prevents high-intensity exercise-induced increase in enzymatic antioxidant and Na+-K+-ATPase activities and reduction of anxiolytic like-behaviour in rats.

    Science.gov (United States)

    Vieira, Juliano M; Carvalho, Fabiano B; Gutierres, Jessié M; Soares, Mayara S P; Oliveira, Pathise S; Rubin, Maribel A; Morsch, Vera M; Schetinger, Maria Rosa; Spanevello, Roselia M

    2017-11-01

    Here we investigated the impact of chronic high-intensity interval training (HIIT) and caffeine consumption on the activities of Na + -K + -ATPase and enzymes of the antioxidant system, as well as anxiolytic-like behaviour in the rat brain. Animals were divided into groups: control, caffeine (4 mg/kg), caffeine (8 mg/kg), HIIT, HIIT plus caffeine (4 mg/kg) and HIIT plus caffeine (8 mg/kg). Rats were trained three times per week for 6 weeks, and caffeine was administered 30 minutes before training. We assessed the anxiolytic-like behaviour, Na + -K + -ATPase, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities, levels of reduced glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) in the brain. HIIT-induced anxiolytic-like behaviour increased Na + -K + -ATPase and GPx activities and TBARS levels, altered the activities of SOD and CAT in different brain regions, and decreased GSH levels. Caffeine, however, elicited anxiogenic-like behaviour and blocked HIIT effects. The combination of caffeine and HIIT prevented the increase in SOD activity in the cerebral cortex and GPx activity in three brain regions. Our results show that caffeine promoted anxiogenic behaviour and prevented HIIT-induced changes in the antioxidant system and Na + -K + -ATPase activities.

  9. Caffeine and cardiovascular health.

    Science.gov (United States)

    Turnbull, Duncan; Rodricks, Joseph V; Mariano, Gregory F; Chowdhury, Farah

    2017-10-01

    This report evaluates the scientific literature on caffeine with respect to potential cardiovascular outcomes, specifically relative risks of total cardiovascular disease (CVD), coronary heart disease (CHD) and acute myocardial infarction (AMI), effects on arrhythmia, heart failure, sudden cardiac arrest, stroke, blood pressure, hypertension, and other biomarkers of effect, including heart rate, cerebral blood flow, cardiac output, plasma homocysteine levels, serum cholesterol levels, electrocardiogram (EKG) parameters, heart rate variability, endothelial/platelet function and plasma/urine catecholamine levels. Caffeine intake has been associated with a range of reversible and transient physiological effects broadly and cardiovascular effects specifically. This report attempts to understand where the delineations exist in caffeine intake and corresponding cardiovascular effects among various subpopulations. The available literature suggests that cardiovascular effects experienced by caffeine consumers at levels up to 600 mg/day are in most cases mild, transient, and reversible, with no lasting adverse effect. The point at which caffeine intake may cause harm to the cardiovascular system is not readily identifiable in part because data on the effects of daily intakes greater than 600 mg is limited. However, the evidence considered within this review suggests that typical moderate caffeine intake is not associated with increased risks of total cardiovascular disease; arrhythmia; heart failure; blood pressure changes among regular coffee drinkers; or hypertension in baseline populations. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Determination of urine caffeine and its metabolites by use of high-performance liquid chromatography-tandem mass spectrometry: estimating dietary caffeine exposure and metabolic phenotyping in population studies.

    Science.gov (United States)

    Rybak, Michael E; Pao, Ching-I; Pfeiffer, Christine M

    2014-01-01

    We have developed and validated a high-performance liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for determining urine caffeine and 14 caffeine metabolites suitable for estimating caffeine exposure and metabolic phenotyping in population studies. Sample preparation consisted solely of a series of simple reagent treatments at room temperature. Stable isotope-labeled analogs were used as internal standards for all analytes. We developed rapid LC-MS/MS separations for both positive and negative ion mode electrospray ionizations to maximize measurement sensitivity. Limits of detection were 0.05-0.1 μmol/L depending on the analytes. Method imprecision, based on total coefficients of variation, was generally 1 μmol/L. Analyte recoveries were typically within 10 % of being quantitative (100 %), and good agreement was observed among analytes measured across different MS/MS transitions. We applied this method to the analysis of a convenience set of human urine samples (n = 115) and were able to detect a majority of the analytes in ≥99 % of samples as well as calculate caffeine metabolite phenotyping ratios for cytochrome P450 1A2 and N-acetyltransferase 2. Whereas existing LC-MS/MS methods are limited in number of caffeine metabolites for which they are validated, or are designed for studies in which purposely elevated caffeine levels are expected, our method is the first of its kind designed specifically for the rapid, sensitive, accurate, and precise measurement of urine caffeine and caffeine metabolites at concentrations relevant to population studies.

  11. Consumption of caffeinated beverages and the awareness of their caffeine content among Dutch students

    NARCIS (Netherlands)

    Mackus, Marlou; van de Loo, Aurora J A E; Benson, Sarah; Scholey, Andrew; Verster, Joris C

    2016-01-01

    The purpose of the current study was to examine the knowledge of caffeine content of a variety of caffeinated beverages among Dutch university students. A pencil-and-paper survey was conducted among N = 800 Dutch students. Most participants (87.8%) reported consuming caffeinated beverages during the

  12. Caffeine inhibits STAT1 signaling and downregulates inflammatory pathways involved in autoimmunity.

    Science.gov (United States)

    Iris, Merve; Tsou, Pei-Suen; Sawalha, Amr H

    2018-04-18

    Caffeine is a widely consumed pharmacologically active product. We focused on characterizing immunomodulatory effects of caffeine on peripheral blood mononuclear cells. Caffeine at high doses showed a robust downregulatory effect on cytokine activity and genes related to several autoimmune diseases including lupus and rheumatoid arthritis. Dose-dependent validation experiments showed downregulation at the mRNA levels of key inflammation-related genes including STAT1, TNF, IFNG, and PPARG. TNF and PPARG were suppressed even with the lowest caffeine dose tested, which corresponds to the serum concentration of caffeine after administration of one cup of coffee. Cytokine levels of IL-8, MIP-1β, IL-6, IFN-γ, GM-CSF, TNF, IL-2, IL-4, MCP-1, and IL-10 were decreased significantly with caffeine treatment. Upstream regulator analysis suggests that caffeine inhibits STAT1 signaling, which was confirmed by showing reduced phosphorylated STAT1 after caffeine treatment. Further studies exploring disease-modulating potential of caffeine in autoimmune diseases and further exploring the mechanisms involved are warranted. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Caffeine in the milk prevents respiratory disorders caused by in utero caffeine exposure in rats.

    Science.gov (United States)

    Bodineau, Laurence; Saadani-Makki, Fadoua; Jullien, Hugues; Frugière, Alain

    2006-01-25

    Consequences of postnatal caffeine exposure by the milk on ponto-medullary respiratory disturbances observed following an in utero caffeine exposure were analysed. Ponto-medullary-spinal cord preparations from newborn rats exposed to caffeine during gestation but not after the birth display an increase in respiratory frequency and an exaggeration of the hypoxic respiratory depression compared to not treated preparations. These data suggest that tachypneic and apneic episodes encountered in human newborns whose mother consumed caffeine during pregnancy are due in large part to central effect of caffeine at the ponto-medullary level. Both baseline respiratory frequency increase and emphasis of hypoxic respiratory depression are not encountered if rat dams consumed caffeine during nursing. Our hypothesis is that newborn rats exposed to caffeine during gestation but not after the birth would be in withdrawal situation whereas, when caffeine is present in drinking fluid of lactating dams, it goes down the milk and is able to prevent ponto-medullary respiratory disturbances.

  14. Caffeine as a model drug of dependence: recent developments in understanding caffeine withdrawal, the caffeine dependence syndrome, and caffeine negative reinforcement.

    Science.gov (United States)

    Griffiths, R R; Chausmer, A L

    2000-11-01

    Caffeine is an excellent model compound for understanding drugs of abuse/dependence. The results of self-administration and choice studies in humans clearly demonstrate the reinforcing effects of low and moderate doses of caffeine. Caffeine reinforcement has been demonstrated in about 45% of normal subjects with histories of moderate and heavy caffeine use. Recent studies provide compelling evidence that caffeine physical dependence potentiates the reinforcing effects of caffeine through the mechanism of withdrawal symptom avoidance. Tolerance to the subjective and sleep-disrupting effects of caffeine in humans has been demonstrated. Physical dependence as reflected in a withdrawal syndrome in humans has been repeatedly demonstrated in adults and recently demonstrated in children. Withdrawal severity is an increasing function of caffeine maintenance dose, with withdrawal occurring at doses as low as 100 mg per day. Increased cerebral blood flow may be the physiological mechanism for caffeine withdrawal headache. Case studies in adults and adolescents clearly demonstrate that some individuals meet DSM-IV diagnostic criteria for a substance dependence syndrome on caffeine, including feeling compelled to continue caffeine use despite desires and recommendations to the contrary. Survey data suggest that 9% to 30% percent of caffeine consumers may be caffeine dependent according to DSM-IV criteria.

  15. Simultaneous Determination of Caffeine and Vitamin B6 in Energy Drinks by High-Performance Liquid Chromatography (HPLC)

    Science.gov (United States)

    Leacock, Rachel E.; Stankus, John J.; Davis, Julian M.

    2011-01-01

    A high-performance liquid chromatography experiment to determine the concentration of caffeine and vitamin B6 in sports energy drinks has been developed. This laboratory activity, which is appropriate for an upper-level instrumental analysis course, illustrates the standard addition method and simultaneous determination of two species. (Contains 1…

  16. Caffeine as a Gelator

    Directory of Open Access Journals (Sweden)

    Nonappa

    2016-03-01

    Full Text Available Caffeine (a stimulant and ethanol (a depressant may have opposite effects in our body, but under in vitro conditions they can “gel” together. Caffeine, being one of the widely used stimulants, continued to surprise the scientific community with its unprecedented biological, medicinal and physicochemical properties. Here, we disclose the supramolecular self-assembly of anhydrous caffeine in a series of alcoholic and aromatic solvents, rendering a highly entangled microcrystalline network facilitating the encapsulation of the solvents as illustrated using direct imaging, microscopy analysis and NMR studies.

  17. Temporal patterns of caffeine intake in the United States.

    Science.gov (United States)

    Martyn, Danika; Lau, Annette; Richardson, Philip; Roberts, Ashley

    2018-01-01

    To investigate whether caffeine intake among adolescents and adults in the U.S. varies across the week or throughout the day, data from a 7-day online beverage consumption survey (2010-2011) were analyzed. Mean (206.8-213.0 mg/day) and 90th percentile (437.4-452.6 mg/day) daily caffeine intakes among consumers 13 years and older were relatively constant across the week with no marked difference among weekdays versus weekend days. Percent consumers of caffeinated beverages likewise remained stable across the week. Mean daily caffeine intake for coffee and energy drink consumers 13 years and older was higher than contributions for tea and carbonated soft drink consumers. Caffeinated beverage consumers (13 + yrs) consumed most of their caffeine in the morning (61% versus 21% and 18% in the afternoon and evening) which was driven by coffee. Caffeinated beverage consumption patterns among adolescents (13-17 yrs) - who typically consume less daily caffeine - were more evenly distributed throughout the day. These findings provide insight into U.S. temporal caffeine consumption patterns among specific caffeinated beverage consumers and different age brackets. These data suggest that while caffeine intakes do not vary from day-to-day, mornings generally drive the daily caffeine intake of adults and is predominantly attributed to coffee. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. A comparison of the effects of caffeine following abstinence and normal caffeine use.

    Science.gov (United States)

    Addicott, Merideth A; Laurienti, Paul J

    2009-12-01

    Caffeine typically produces positive effects on mood and performance. However, tolerance may develop following habitual use, and abrupt cessation can result in withdrawal symptoms, such as fatigue. This study investigated whether caffeine has a greater stimulant effect in a withdrawn state compared to a normal caffeinated state, among moderate daily caffeine consumers. Using a within-subjects design, 17 caffeine consumers (mean +/- sd = 375 +/- 101 mg/day) ingested placebo or caffeine (250 mg) following 30-h of caffeine abstention or normal dietary caffeine use on four separate days. Self-reported mood and performance on choice reaction time, selective attention, and memory tasks were measured. Caffeine had a greater effect on mood and choice reaction time in the abstained state than in the normal caffeinated state, but caffeine improved selective attention and memory in both states. Although improvements in mood and reaction time may best explained as relief from withdrawal symptoms, other performance measures showed no evidence of withdrawal and were equally sensitive to an acute dose of caffeine in the normal caffeinated state.

  19. Simultaneous determination of caffeine, theobromine, and theophylline by high-performance liquid chromatography.

    Science.gov (United States)

    Bispo, Marcia S; Veloso, Márcia Cristina C; Pinheiro, Heloísa Lúcia C; De Oliveira, Rodolfo F S; Reis, José Oscar N; De Andrade, Jailson B

    2002-01-01

    This work relates the development of an analytical methodology to simultaneously determine three methylxanthines (caffeine, theobromine, and theophylline) in beverages and urine samples based on reversed-phase high-performance liquid chromatography. Separation is made with a Bondesil C18 column using methanol-water-acetic acid or ethanol-water-acetic acid (20:75:5, v/v/v) as the mobile phase at 0.7 mL/min. Identification is made by absorbance detection at 273 nm. Under optimized conditions, the detection limit of the HPLC method is 0.1 pg/mL for all three methylxanthines. This method is applied to urine and to 25 different beverage samples, which included coffee, tea, chocolate, and coconut water. The concentration ranges determined in the beverages and urine are: < 0.1 pg/mL to 350 microg/mL and 3.21 microg/mL to 71.2 microg/mL for caffeine; < 0.1 pg/mL to 32 microg mL and < 0.1 pg/mL to 13.2 microg/mL for theobromine; < 0.1 pg/mL to 47 microg/mL and < 0.1 pg/mL to 66.3 microg/mL for theophylline. The method proposed in this study is rapid and suitable for the simultaneous quantitation of methylxanthines in beverages and human urine samples and requires no extraction step or derivatization.

  20. Brain serotonergic and dopaminergic modulators, perceptual responses and endurance exercise performance following caffeine co-ingested with a high fat meal in trained humans

    Directory of Open Access Journals (Sweden)

    Kilduff Liam P

    2010-05-01

    Full Text Available Abstract Background The present study examined putative modulators and indices of brain serotonergic and dopaminergic function, perceptual responses, and endurance exercise performance following caffeine co-ingested with a high fat meal. Methods Trained humans (n = 10 performed three constant-load cycling tests at 73% of maximal oxygen uptake (VO2max until exhaustion at 10°C remove space throughout. Prior to the first test, subjects consumed a 90% carbohydrate meal (Control trial and for the remaining two tests, a 90% fat meal with (FC trial and without (F trial caffeine. Results Time to exhaustion was not different between the F and FC trials (P > 0.05; [Control trial: 116(88-145 min; F trial: 122(96-144 min; FC trial: 127(107-176 min]. However, leg muscular discomfort during exercise was significantly lower on the FC relative to F trial (P P > 0.05 with the exception of plasma free-Trp:LNAA ratio which was higher at 90 min and at exhaustion during the FC trial (P Conclusions Neither brain 5-HT nor DA systems would appear to be implicated in the fatigue process when exercise is performed without significant thermoregulatory stress, thus indicating fatigue development during exercise in relatively cold temperatures to occur predominantly due to glycogen depletion.

  1. Caffeine Confusion

    Science.gov (United States)

    ... 20 mg* Milk chocolate 1 ounce 6 mg* Cocoa beverage 5 ounces 4 mg* Chocolate milk beverage 8 ounces 5 mg* Cold relief medication 1 tablet 30 mg* *This is an average amount of caffeine. That means some of these products may contain a little more caffeine; some may ...

  2. Caffeine: sleep and daytime sleepiness.

    Science.gov (United States)

    Roehrs, Timothy; Roth, Thomas

    2008-04-01

    Caffeine is one of the most widely consumed psychoactive substances and it has profound effects on sleep and wake function. Laboratory studies have documented its sleep-disruptive effects. It clearly enhances alertness and performance in studies with explicit sleep deprivation, restriction, or circadian sleep schedule reversals. But, under conditions of habitual sleep the evidence indicates that caffeine, rather then enhancing performance, is merely restoring performance degraded by sleepiness. The sleepiness and degraded function may be due to basal sleep insufficiency, circadian sleep schedule reversals, rebound sleepiness, and/or a withdrawal syndrome after the acute, over-night, caffeine discontinuation typical of most studies. Studies have shown that caffeine dependence develops at relatively low daily doses and after short periods of regular daily use. Large sample and population-based studies indicate that regular daily dietary caffeine intake is associated with disturbed sleep and associated daytime sleepiness. Further, children and adolescents, while reporting lower daily, weight-corrected caffeine intake, similarly experience sleep disturbance and daytime sleepiness associated with their caffeine use. The risks to sleep and alertness of regular caffeine use are greatly underestimated by both the general population and physicians.

  3. The Janus face of caffeine.

    Science.gov (United States)

    Porciúncula, Lisiane O; Sallaberry, Cássia; Mioranzza, Sabrina; Botton, Paulo Henrique S; Rosemberg, Denis B

    2013-11-01

    Caffeine is certainly the psychostimulant substance most consumed worldwide. Over the past years, chronic consumption of caffeine has been associated with prevention of cognitive decline associated to aging and mnemonic deficits of brain disorders. While its preventive effects have been reported extensively, the cognitive enhancer properties of caffeine are relatively under debate. Surprisingly, there are scarce detailed ontogenetic studies focusing on neurochemical parameters related to the effects of caffeine during prenatal and earlier postnatal periods. Furthermore, despite the large number of epidemiological studies, it remains unclear how safe is caffeine consumption during pregnancy and brain development. Thus, the purpose of this article is to review what is currently known about the actions of caffeine intake on neurobehavioral and adenosinergic system during brain development. We also reviewed other neurochemical systems affected by caffeine, but not only during brain development. Besides, some recent epidemiological studies were also outlined with the control of "pregnancy signal" as confounding variable. The idea is to tease out how studies on the impact of caffeine consumption during brain development deserve more attention and further investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Evaluating Dependence Criteria for Caffeine

    OpenAIRE

    Striley, Catherine L.W.; Griffiths, Roland R.; Cottler, Linda B.

    2011-01-01

    Background: Although caffeine is the most widely used mood-altering drug in the world, few studies have operationalized and characterized Diagnostic and Statistical Manual IV (DSM-IV) substance dependence criteria applied to caffeine. Methods: As a part of a nosological study of substance use disorders funded by the National Institute on Drug Abuse, we assessed caffeine use and dependence symptoms among high school and college students, drug treatment patients, and pain clinic patients who re...

  5. Smoking and caffeine consumption: a genetic analysis of their association.

    Science.gov (United States)

    Treur, Jorien L; Taylor, Amy E; Ware, Jennifer J; Nivard, Michel G; Neale, Michael C; McMahon, George; Hottenga, Jouke-Jan; Baselmans, Bart M L; Boomsma, Dorret I; Munafò, Marcus R; Vink, Jacqueline M

    2017-07-01

    Smoking and caffeine consumption show a strong positive correlation, but the mechanism underlying this association is unclear. Explanations include shared genetic/environmental factors or causal effects. This study employed three methods to investigate the association between smoking and caffeine. First, bivariate genetic models were applied to data of 10 368 twins from the Netherlands Twin Register in order to estimate genetic and environmental correlations between smoking and caffeine use. Second, from the summary statistics of meta-analyses of genome-wide association studies on smoking and caffeine, the genetic correlation was calculated by LD-score regression. Third, causal effects were tested using Mendelian randomization analysis in 6605 Netherlands Twin Register participants and 5714 women from the Avon Longitudinal Study of Parents and Children. Through twin modelling, a genetic correlation of r0.47 and an environmental correlation of r0.30 were estimated between current smoking (yes/no) and coffee use (high/low). Between current smoking and total caffeine use, this was r0.44 and r0.00, respectively. LD-score regression also indicated sizeable genetic correlations between smoking and coffee use (r0.44 between smoking heaviness and cups of coffee per day, r0.28 between smoking initiation and coffee use and r0.25 between smoking persistence and coffee use). Consistent with the relatively high genetic correlations and lower environmental correlations, Mendelian randomization provided no evidence for causal effects of smoking on caffeine or vice versa. Genetic factors thus explain most of the association between smoking and caffeine consumption. These findings suggest that quitting smoking may be more difficult for heavy caffeine consumers, given their genetic susceptibility. © 2016 The Authors.Addiction Biology published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

  6. Determination of Aspartame, Caffeine, Saccharin, and Benzoic Acid in Beverages by High Performance Liquid Chromatography.

    Science.gov (United States)

    Delaney, Michael F.; And Others

    1985-01-01

    Describes a simple and reliable new quantitative analysis experiment using liquid chromatography for the determinaiton of caffeine, saccharin, and sodium benzoate in beverages. Background information, procedures used, and typical results obtained are provided. (JN)

  7. Personality correlates of caffeine dependence: the role of sensation seeking, impulsivity, and risk taking.

    Science.gov (United States)

    Jones, Heather A; Lejuez, C W

    2005-08-01

    The consumption of caffeine has become a growing concern, partially because of the withdrawal properties of the drug. The current study examined personality correlates of caffeine consumption and dependence in 60 university students. Self-report and behavioral measures of sensation seeking, impulsivity, and risk taking were administered to 2 groups, identified as caffeine dependent-high consuming or caffeine nondependent-low consuming. Scores on self-report measures of sensation seeking and impulsivity were related to group status, and only sensation seeking evidenced a significant relationship with group status when both variables were considered in a regression analysis. Implications of these findings and future directions are discussed. ((c) 2005 APA, all rights reserved).

  8. Effects of Cola-Flavored Beverages and Caffeine on Streptococcus mutans Biofilm Formation and Metabolic Activity.

    Science.gov (United States)

    Dotsey, Roger P; Moser, Elizabeth A S; Eckert, George J; Gregory, Richard L

    To examine the effects of cola-flavored beverages and caffeine on growth and metabolism of Streptococcus mutans biofilm. This study was designed to determine if carbonated beverages or caffeine can increase S. mutans growth and biofilm formation and metabolic activity in vitro, potentially leading to increased S. mutans-associated cariogenicity in children that consume them. Six different cola-flavored products, plus pure caffeine, and pure high fructose corn syrup (HFCS), at different concentrations similar to those in the beverages were tested. A 16-hour culture of S. mutans was treated with different dilutions in bacteriological media. To test for the effect on biofilm formation, the biofilm was stained with crystal violet. The absorbance was determined to evaluate biofilm growth. Biofilm metabolic activity was measured based on biofilm having the ability to reduce XTT to a water-soluble orange compound. The inclusion of HFCS in the beverages, as well as pure HFCS, significantly enhanced bacterial biofilm formation and metabolic activity. Pure caffeine and the presence of caffeine in beverages did not significantly increase biofilm formation, but pure caffeine significantly increased metabolism, and Diet Coke had significantly greater metabolic activity than Caffeine-Free Diet Coke. HFCS increases both the biofilm formation and metabolism of S. mutans, and caffeine in some cases increases metabolism of S. mutans.

  9. Tobacco Metabolites and Caffeine in Human Milk Purchased via the Internet.

    Science.gov (United States)

    Geraghty, Sheela R; McNamara, Kelly; Kwiek, Jesse J; Rogers, Lynette; Klebanoff, Mark A; Augustine, Molly; Keim, Sarah A

    2015-11-01

    Chemicals inhaled or ingested by mothers can be present in their milk. Our objective was to determine levels of nicotine, cotinine, and caffeine in human milk purchased via the Internet. We purchased human milk (n=102) via the Internet and abstracted seller advertisements for information volunteered about tobacco and caffeine use. Nicotine, cotinine, and caffeine levels in the milk were quantified by mass spectrometry according to published protocols. No sellers indicated smoking in their advertisement. Many of the milk samples (58%) had detectable nicotine or cotinine; four (4%) of the samples had nicotine or cotinine levels high enough to indicate active smoking. Twelve (12%) sellers said in their advertisements that they specifically limit (4%) or avoid (8%) caffeine entirely. Five (5%) of the samples had caffeine levels consistent with consuming at least 1 cup of coffee 2 hours prior to milk expression. Detectable amounts of caffeine were found in almost all of the samples (97%). In 102 milk samples, we detected evidence of active smoking, secondhand smoke exposure, and almost ubiquitous caffeine consumption. Buyers of human milk on the Internet should be aware that advertisements do not always include accurate information as to what substances may be present. Sellers may misrepresent their health behaviors or be unaware of lifestyle factors that can lead to exposure to nicotine and caffeine.

  10. Caffeine and energy drink use by combat arms soldiers in Afghanistan as a countermeasure for sleep loss and high operational demands.

    Science.gov (United States)

    McLellan, Tom M; Riviere, Lyndon A; Williams, Kelly W; McGurk, Dennis; Lieberman, Harris R

    2018-03-11

    Combat deployments are characterized by high operational demands with limited opportunities for sleep leading to fatigue and degraded cognitive and operational performance. Caffeine in moderate doses is recognized as an effective intervention for physical and cognitive decrements associated with sleep loss. This report is based on data collected by two separate, independently conducted surveys administered in Afghanistan in 2011-2012. It assessed caffeine use and sleep disruption among U.S. Army combat soldiers (J-MHAT 8; n = 518) and among deployed soldiers with different military assignments (USARIEM Deployment Survey; n = 260). Daily caffeine intake assessed in the J-MHAT 8 survey averaged 404 ± 18 mg. In the USARIEM Deployment Survey, intake was 303 ± 29 mg and was significantly higher among combat arms soldiers (483 ± 100 mg) compared to combat service support personnel (235 ± 23 mg). In both surveys, over 55% of total caffeine intake was from energy drinks. Additional sources of caffeine included coffee, tea, sodas, gum, candy, and over-the-counter medications. Higher caffeine intake was not associated with ability to fall asleep at night or wake-up in the morning (J-MHAT 8 survey). Higher caffeine consumption was associated with disrupted sleep from high operational tempo and nighttime duties of combat operations. Overall caffeine consumption and energy drink use in Afghanistan was greater than among non-deployed soldiers and civilians. Caffeine was frequently used as a countermeasure during night operations to offset adverse effects of sleep loss on physical and cognitive function, consistent with current Department of the Army recommendations.

  11. Acute hematological and mood perception effects of bitter orange extract (p-synephrine) consumed alone and in combination with caffeine: A placebo-controlled, double-blind study.

    Science.gov (United States)

    Bush, Jill A; Ratamess, Nicholas A; Stohs, Sidney J; Ellis, Nicole L; Vought, Ira T; O'Grady, Elizabeth A; Kuper, Jeremy D; Kang, Jie; Faigenbaum, Avery D

    2018-04-19

    The purpose of this study was to examine acute hematological and mood perception responses to supplementation with p-synephrine alone and in combination with caffeine during quiet sitting. Sixteen subjects visited the laboratory on 6 occasions and were given (in randomized double-blind manner) 103-mg p-synephrine (S), 233-mg caffeine + 104-mg p-synephrine, 240-mg caffeine, 337-mg caffeine + 46-mg p-synephrine, 325-mg caffeine, or a placebo (PL). The subjects sat quietly for 3 hr while completing mood state questionnaires every 30 min. Venous blood samples were collected at baseline (pre) and 3 hr (post) to determine immune, lipid, and chemistry panels. Compared with PL, no significant supplement differences were observed during the S trial with the exception of differential time effects seen in hematocrit (decrease in PL, no change in S), triglycerides and very low-density lipoproteins (no changes in PL, significant decreases in S), and iron (no change in PL, significant elevation in S). Supplements containing caffeine showed increased feelings of attention, excitement, energy, and vigor. These data indicate that consumption of 103-mg p-synephrine does not negatively impact acute blood parameters, does not augment the effects of caffeine, or produce stimulant-like perceptual mood effects. Copyright © 2018 John Wiley & Sons, Ltd.

  12. Make Caffeine Visible: a Fluorescent Caffeine “Traffic Light” Detector

    Science.gov (United States)

    Xu, Wang; Kim, Tae-Hyeong; Zhai, Duanting; Er, Jun Cheng; Zhang, Liyun; Kale, Anup Atul; Agrawalla, Bikram Keshari; Cho, Yoon-Kyoung; Chang, Young-Tae

    2013-07-01

    Caffeine has attracted abundant attention due to its extensive existence in beverages and medicines. However, to detect it sensitively and conveniently remains a challenge, especially in resource-limited regions. Here we report a novel aqueous phase fluorescent caffeine sensor named Caffeine Orange which exhibits 250-fold fluorescence enhancement upon caffeine activation and high selectivity. Nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy indicate that π-stacking and hydrogen-bonding contribute to their interactions while dynamic light scattering and transmission electron microscopy experiments demonstrate the change of Caffeine Orange ambient environment induces its fluorescence emission. To utilize this probe in real life, we developed a non-toxic caffeine detection kit and tested it for caffeine quantification in various beverages. Naked-eye sensing of various caffeine concentrations was possible based on color changes upon irradiation with a laser pointer. Lastly, we performed the whole system on a microfluidic device to make caffeine detection quick, sensitive and automated.

  13. Caffeine Content Labeling: A Missed Opportunity for Promoting Personal and Public Health

    OpenAIRE

    Kole, Jon; Barnhill, Anne

    2013-01-01

    Current regulation of caffeine-containing products is incoherent, fails to protect consumers' interests, and should be modified in multiple ways. We make the case for one of the regulatory reforms that are needed: all consumable products containing added caffeine should be required by the Food and Drug Administration (FDA) to include caffeine quantity on their labels. Currently, no foods or beverages that contain caffeine are required to include caffeine content on their labels. Strengthening...

  14. Caffeine controversies.

    Science.gov (United States)

    Gentle, Samuel J; Travers, Colm P; Carlo, Waldemar A

    2018-04-01

    Caffeine use in preterm infants has endured several paradigms: from standard of care to possible neurotoxin to one of the few medications for which there is evidence of bronchopulmonary dysplasia (BPD) risk reduction. The purpose of the review is to analyze this dynamic trajectory and discuss controversies that still remain after decades of caffeine use. Following concerns for caffeine safety in preterm infants, a large randomized controlled trial demonstrated a reduction in BPD and treatment for patent ductus arteriosus. The lower rate of death or neurodevelopmental impairment noted at 18-21 months was not statistically different at later timepoints; however, infants in the caffeine group had lower rates of motor impairment at 11-year follow-up. The time of caffeine therapy initiation is now substantially earlier, and doses used are sometimes higher that previously used, but there are limited data to support these practices. Caffeine therapy for apnea of prematurity (AOP) remains one of the pillars of neonatal care, although more evidence to support dosing and timing of initiation and discontinuation are needed.

  15. Inhibitory effects of caffeine on hippocampal neurogenesis and function.

    Science.gov (United States)

    Han, Myoung-Eun; Park, Kyu-Hyun; Baek, Sun-Yong; Kim, Bong-Seon; Kim, Jae-Bong; Kim, Hak-Jin; Oh, Sae-Ock

    2007-05-18

    Caffeine is one of the most extensively consumed psychostimulants in the world. However, compared to short-term effects of caffeine, the long-term effects of caffeine consumption on learning and memory are poorly characterized. The present study found that long-term consumption of low dose caffeine (0.3 g/L) slowed hippocampus-dependent learning and impaired long-term memory. Caffeine consumption for 4 weeks also significantly reduced hippocampal neurogenesis compared to controls. From these results, we concluded that long-term consumption of caffeine could inhibit hippocampus-dependent learning and memory partially through inhibition of hippocampal neurogenesis.

  16. Caffeine Consumption Patterns and Beliefs of College Freshmen

    Science.gov (United States)

    McIlvain, Gary E.; Noland, Melody P.; Bickel, Robert

    2011-01-01

    Background: Caffeine consumption by young people has increased dramatically over the last decade through increased coffee consumption and "energy drinks." In higher amounts, caffeine causes many adverse effects that are cause for concern. Purpose: Purposes of this study were to determine: (1) the amount of caffeine consumed by a sample…

  17. Hydration of Caffeine at High Temperature by Neutron Scattering and Simulation Studies.

    Science.gov (United States)

    Tavagnacco, L; Brady, J W; Bruni, F; Callear, S; Ricci, M A; Saboungi, M L; Cesàro, A

    2015-10-22

    The solvation of caffeine in water is examined with neutron diffraction experiments at 353 K. The experimental data, obtained by taking advantage of isotopic H/D substitution in water, were analyzed by empirical potential structure refinement (EPSR) in order to extract partial structure factors and site-site radial distribution functions. In parallel, molecular dynamics (MD) simulations were carried out to interpret the data and gain insight into the intermolecular interactions in the solutions and the solvation process. The results obtained with the two approaches evidence differences in the individual radial distribution functions, although both confirm the presence of caffeine stacks at this temperature. The two approaches point to different accessibility of water to the caffeine sites due to different stacking configurations.

  18. Action of caffeine on x-irradiated HeLa cells. IV. Progression delays and enhanced cell killing at high caffeine concentrations

    International Nuclear Information System (INIS)

    Tolmach, L.J.; Busse, P.M.

    1980-01-01

    The response of x-irradiated and unirradiated HeLa S3 cells to treatment with caffeine at concentrations between 1 and 10 nM has been examined with respect to both delay in progression through the cell generation cycle and enhancement of the expression of potentially lethal x-ray damage. Progression is delayed in a concentration-dependent fashion: the generation time is doubled at about 4 mM. The duration of G 1 is lengthened, and the rate of DNA synthesis is reduced, although the kinetics are different in the two phases; the rate of DNA synthesis is usually unaffected at 1 or 2 mM, while there is no concentration threshold for the slowing of progression through G 1 . Progression through G 2 appears to be unaffected by concentrations up to at least 10 mM. Killing of irradiated cells in G 2 is somewhat greater after treatment with the higher caffeine concentrations than reported previously for 1 mM. Moreover, an additional mode of killing is observed in irradiated G 1 cells which had been found previously to be only slightly affected by 1 mM caffeine; they suffer extensive killing at concentrations above 5 mM. The time-survival curves for irradiated, caffeine-treated G 1 and G 2 cells have characteristically different shapes. The dose-survival curves for cells treated with the higher caffeine concentrations display steeper terminal slopes and narrower shoulders

  19. Excessive oral intake caffeine altered cerebral cortex ...

    African Journals Online (AJOL)

    Caffeine is commonly consumed in an effort to enhance speed in performance and wakefulness. However, little is known about the deleterious effects it can produce on the brain, this study aimed at determining the extents of effects and damage that can be caused by excessive consumption of caffeine on the cerebral cortex ...

  20. Pricing Policy and Strategies for Consumer High-Tech Products

    Directory of Open Access Journals (Sweden)

    Dovleac, L.

    2014-06-01

    Full Text Available This paper highlights the complex process of price setting for consumer high-tech products. These prices are highly influenced by some external factors from the economic and social environment. The main objective of this paper is to establish the most effective pricing policies and strategies used by high-tech companies of various sizes. Decisions about price fixing for consumer high-technology products are largely influenced by consumer behaviour, too.

  1. Evaluating Dependence Criteria for Caffeine.

    Science.gov (United States)

    Striley, Catherine L W; Griffiths, Roland R; Cottler, Linda B

    2011-12-01

    Background: Although caffeine is the most widely used mood-altering drug in the world, few studies have operationalized and characterized Diagnostic and Statistical Manual IV (DSM-IV) substance dependence criteria applied to caffeine. Methods: As a part of a nosological study of substance use disorders funded by the National Institute on Drug Abuse, we assessed caffeine use and dependence symptoms among high school and college students, drug treatment patients, and pain clinic patients who reported caffeine use in the last 7 days and also reported use of alcohol, nicotine, or illicit drugs within the past year ( n =167). Results: Thirty-five percent met the criteria for dependence when all seven of the adopted DSM dependence criteria were used. Rates of endorsement of several of the most applicable diagnostic criteria were as follows: 26% withdrawal, 23% desire to cut down or control use, and 44% continued use despite harm. In addition, 34% endorsed craving, 26% said they needed caffeine to function, and 10% indicated that they talked to a physician or counselor about problems experienced with caffeine. There was a trend towards increased caffeine dependence among those dependent on nicotine or alcohol. Within a subgroup that had used caffeine, alcohol, and nicotine in the past year, 28% fulfilled criteria for caffeine dependence compared to 50% for alcohol and 80% for nicotine. Conclusion: The present study adds to a growing literature suggesting the reliability, validity, and clinical utility of the caffeine dependence diagnosis. Recognition of caffeine dependence in the DSM-V may be clinically useful.

  2. The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training

    Directory of Open Access Journals (Sweden)

    Carneiro-Junior Miguel A

    2011-03-01

    Full Text Available Abstract Background The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Methods Male Wistar rats were randomly divided into 8 groups: Sedentary (S or Exercised (E [placebo (Pl, creatine (Cr, caffeine (Caf or creatine plus caffeine (CrCaf]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals, 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Results Exercised animals presented a lower carcass weight (10.9%; P = 0.01, as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05. There were no significant differences among the groups (P > 0.05 for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P Conclusions High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine supplementation alone reduces the percentage of fat. Vertical jumping training increases the percentages of water and protein and reduces the fat percentage in rats.

  3. The behavioral effects of chronic sugar and/or caffeine consumption in adult and adolescent rats.

    Science.gov (United States)

    Franklin, Jane L; Wearne, Travis A; Homewood, Judi; Cornish, Jennifer L

    2017-08-01

    Caffeine is a psychostimulant frequently consumed by adults and children, often in combination with high levels of sugar. Chronic pretreatment with either substance can amplify both amphetamine and cocaine-induced hyperactivity in rodents. The present study sought to elucidate whether age at the time of exposure to sugar and/or caffeine alters sensitivity to an acute illicit psychostimulant (methamphetamine, [METH]) challenge in adulthood. Adult and adolescent (Postnatal Day 35 on first day of treatment) male Sprague-Dawley rats were treated for 26 days with water, caffeine (0.6 g/L), 10% sucrose or their combination. Locomotor behavior was measured on the first and last day of treatment. Following 9-days treatment free, animals were challenged with saline (1 ml/kg, i.p.) or METH (1 mg/kg, i.p.) and locomotor activity was measured. During the treatment period, adolescent rats maintained a higher caffeine (mg/kg) dose than their adult counterparts. Adding sugar to caffeine increased adolescent consumption and the highest caffeine dose consumed was measured in these animals. Drinking sugar-sweetened caffeinated water or combination did not produce cross-sensitization to METH administration in either age group. Nevertheless, the finding that regular exposure through adolescence to caffeinated sugar-sweetened beverages could increase consumption of caffeine and sugar later in life is important, as there is a large body of evidence that has linked excess consumption of sugar-sweetened beverages to a broad range of other negative physical and mental health outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  4. Determination of CaffeineIn Beverages: A Review

    OpenAIRE

    Igelige Gerald; David Ebuka Arthur; Adebiyi Adedayo

    2014-01-01

    Caffeine is a well-known stimulant which is added as an ingredient to various carbonated soft drinks. Caffeine has drawn more attention due to its physiological effects beyond that of its stimulatory effect. Consumers are interested in knowing the exact amounts of caffeine existing in beverages. However, limited data exist, especially for store brand beverages. Therefore, it is pertinent to review the various methods that will effectively determine the caffeine contents in different carbonate...

  5. Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children

    Science.gov (United States)

    Richards, Gareth; Smith, Andrew

    2015-01-01

    Previous research suggests that effects of caffeine on behaviour are positive unless one is investigating sensitive groups or ingestion of large amounts. Children are a potentially sensitive subgroup, and especially so considering the high levels of caffeine currently found in energy drinks. The present study used data from the Cornish Academies Project to investigate associations between caffeine (both its total consumption, and that derived separately from energy drinks, cola, tea, and coffee) and single-item measures of stress, anxiety, and depression, in a large cohort of secondary school children from the South West of England. After adjusting for additional dietary, demographic, and lifestyle covariates, positive associations between total weekly caffeine intake and anxiety and depression remained significant, and the effects differed between males and females. Initially, effects were also observed in relation to caffeine consumed specifically from coffee. However, coffee was found to be the major contributor to high overall caffeine intake, providing explanation as to why effects relating to this source were also apparent. Findings from the current study increase our knowledge regarding associations between caffeine intake and stress, anxiety, and depression in secondary school children, though the cross-sectional nature of the research made it impossible to infer causality. PMID:26508718

  6. Urine and Serum Metabolite Profiling of Rats Fed a High-Fat Diet and the Anti-Obesity Effects of Caffeine Consumption

    Directory of Open Access Journals (Sweden)

    Hyang Yeon Kim

    2015-02-01

    Full Text Available In this study, we investigated the clinical changes induced by a high fat diet (HFD and caffeine consumption in a rat model. The mean body weight of the HFD with caffeine (HFDC-fed rat was decreased compared to that of the HFD-fed rat without caffeine. The levels of cholesterol, triglycerides (TGs, and free fatty acid, as well as the size of adipose tissue altered by HFD, were improved by caffeine consumption. To investigate the metabolites that affected the change of the clinical factors, the urine and serum of rats fed a normal diet (ND, HFD, and HFDC were analyzed using ultra performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-Q-TOF-MS, gas chromatography (GC-TOF-MS, and linear trap quadruple mass spectrometry (LTQ-XL-MS combined with multivariate analysis. A total of 68 and 52 metabolites were found to be different in urine and serum, respectively. After being fed caffeine, some glucuronide-conjugated compounds, lysoPCs, CEs, DGs, TGs, taurine, and hippuric acid were altered compared to the HFD group. In this study, caffeine might potentially inhibit HFD-induced obesity and we suggest possible biomarker candidates using MS-based metabolite profiling.

  7. Espresso coffees, caffeine and chlorogenic acid intake: potential health implications.

    Science.gov (United States)

    Crozier, Thomas W M; Stalmach, Angelique; Lean, Michael E J; Crozier, Alan

    2012-01-01

    HPLC analysis of 20 commercial espresso coffees revealed 6-fold differences in caffeine levels, a 17-fold range of caffeoylquinic acid contents, and 4-fold differences in the caffeoylquinic acid : caffeine ratio. These variations reflect differences in batch-to-batch bean composition, possible blending of arabica with robusta beans, as well as roasting and grinding procedures, but the predominant factor is likely to be the amount of beans used in the coffee-making/barista processes. The most caffeine in a single espresso was 322 mg and a further three contained >200 mg, exceeding the 200 mg day(-1) upper limit recommended during pregnancy by the UK Food Standards Agency. This snap-shot of high-street expresso coffees suggests the published assumption that a cup of strong coffee contains 50 mg caffeine may be misleading. Consumers at risk of toxicity, including pregnant women, children and those with liver disease, may unknowingly ingest excessive caffeine from a single cup of espresso coffee. As many coffee houses prepare larger volume coffees, such as Latte and Cappuccino, by dilution of a single or double shot of expresso, further study on these products is warranted. New data are needed to provide informative labelling, with attention to bean variety, preparation, and barista methods.

  8. Energy Drinks and the Neurophysiological Impact of Caffeine

    OpenAIRE

    Persad, Leeana Aarthi Bagwath

    2011-01-01

    Caffeine is the most widely used psychoactive stimulant with prevalent use across all age groups. It is a naturally occurring substance found in the coffee bean, tea leaf, the kola nut, cocoa bean. Recently there has been an increase in energy drink consumption leading to caffeine abuse, with aggressive marketing and poor awareness on the consequences of high caffeine use. With caffeine consumption being so common, it is vital to know the impact caffeine has on the body, as its effects can in...

  9. Energy drinks and the neurophysiological impacts of caffeine

    OpenAIRE

    Leeana eBagwath Persad

    2011-01-01

    Caffeine is the most widely used psychoactive stimulant with prevalent use across all age groups. It is a naturally occurring substance found in the coffee bean, tea leaf, the kola nut, cocoa bean. Recently there has been an increase in energy drink consumption leading to caffeine abuse, with aggressive marketing and poor awareness on the consequences of high caffeine use. With caffeine consumption being so common, it is vital to know the impact caffeine has on the body, as its effects can in...

  10. Administration of Caffeine in Alternate Forms.

    Science.gov (United States)

    Wickham, Kate A; Spriet, Lawrence L

    2018-03-01

    There has been recent interest in the ergogenic effects of caffeine delivered in low doses (~ 200 mg or ~ 3 mg/kg body mass) and administered in forms other than capsules, coffee and sports drinks, including chewing gum, bars, gels, mouth rinses, energy drinks and aerosols. Caffeinated chewing gum is absorbed quicker through the buccal mucosa compared with capsule delivery and absorption in the gut, although total caffeine absorption over time is not different. Rapid absorption may be important in many sporting situations. Caffeinated chewing gum improved endurance cycling performance, and there is limited evidence that repeated sprint cycling and power production may also be improved. Mouth rinsing with caffeine may stimulate nerves with direct links to the brain, in addition to caffeine absorption in the mouth. However, caffeine mouth rinsing has not been shown to have significant effects on cognitive performance. Delivering caffeine with mouth rinsing improved short-duration, high-intensity, repeated sprinting in normal and depleted glycogen states, while the majority of the literature indicates no ergogenic effect on aerobic exercise performance, and resistance exercise has not been adequately studied. Studies with caffeinated energy drinks have generally not examined the individual effects of caffeine on performance, making conclusions about this form of caffeine delivery impossible. Caffeinated aerosol mouth and nasal sprays may stimulate nerves with direct brain connections and enter the blood via mucosal and pulmonary absorption, although little support exists for caffeine delivered in this manner. Overall, more research is needed examining alternate forms of caffeine delivery including direct measures of brain activation and entry of caffeine into the blood, as well as more studies examining trained athletes and female subjects.

  11. Caffeine, postmenopausal estrogen, and risk of Parkinson's disease.

    Science.gov (United States)

    Ascherio, A; Chen, H; Schwarzschild, M A; Zhang, S M; Colditz, G A; Speizer, F E

    2003-03-11

    Men who regularly consume caffeinated drinks have a lower risk of PD than do nondrinkers, but this relation has not been found in women. Because this sex difference could be due to hormonal effects, the authors examined prospectively the risk of PD according to use of postmenopausal hormones and caffeine intake among participants in the Nurses' Health Study. The study population comprised 77,713 women free of PD, stroke, or cancer at baseline, who were postmenopausal at baseline or reached menopause before the end of the study. During 18 years of follow-up the authors documented 154 cases of PD. Overall, the risk of PD was similar in women using hormones and women who never used hormones (relative risk 1.02, 95% CI 0.69 to 1.52). Use of hormones, however, was associated with a reduced risk of PD among women with low caffeine consumption (RR 0.39, 95% CI 0.13 to 1.17), and with increased risk among women with high caffeine consumption (RR 2.44, 95% CI 0.75 to 7.86; p for interaction = 0.01). Among hormone users, women consuming six or more cups of coffee per day had a fourfold higher risk of PD (RR 3.92, 95% CI 1.49 to 10.34; p = 0.006) than did women who never drink coffee. These results suggest that caffeine reduces the risk of PD among women who do not use postmenopausal hormones, but increases risk among hormone users. Clinical trials of caffeine or estrogens in women should avoid the combined use of these agents.

  12. Novel, Highly Specific N-Demethylases Enable Bacteria To Live on Caffeine and Related Purine Alkaloids

    Science.gov (United States)

    Summers, Ryan M.; Louie, Tai Man; Yu, Chi-Li; Gakhar, Lokesh; Louie, Kailin C.

    2012-01-01

    The molecular basis for the ability of bacteria to live on caffeine as a sole carbon and nitrogen source is unknown. Pseudomonas putida CBB5, which grows on several purine alkaloids, metabolizes caffeine and related methylxanthines via sequential N-demethylation to xanthine. Metabolism of caffeine by CBB5 was previously attributed to one broad-specificity methylxanthine N-demethylase composed of two subunits, NdmA and NdmB. Here, we report that NdmA and NdmB are actually two independent Rieske nonheme iron monooxygenases with N1- and N3-specific N-demethylation activity, respectively. Activity for both enzymes is dependent on electron transfer from NADH via a redox-center-dense Rieske reductase, NdmD. NdmD itself is a novel protein with one Rieske [2Fe-2S] cluster, one plant-type [2Fe-2S] cluster, and one flavin mononucleotide (FMN) per enzyme. All ndm genes are located in a 13.2-kb genomic DNA fragment which also contained a formaldehyde dehydrogenase. ndmA, ndmB, and ndmD were cloned as His6 fusion genes, expressed in Escherichia coli, and purified using a Ni-NTA column. NdmA-His6 plus His6-NdmD catalyzed N1-demethylation of caffeine, theophylline, paraxanthine, and 1-methylxanthine to theobromine, 3-methylxanthine, 7-methylxanthine, and xanthine, respectively. NdmB-His6 plus His6-NdmD catalyzed N3-demethylation of theobromine, 3-methylxanthine, caffeine, and theophylline to 7-methylxanthine, xanthine, paraxanthine, and 1-methylxanthine, respectively. One formaldehyde was produced from each methyl group removed. Activity of an N7-specific N-demethylase, NdmC, has been confirmed biochemically. This is the first report of bacterial N-demethylase genes that enable bacteria to live on caffeine. These genes represent a new class of Rieske oxygenases and have the potential to produce biofuels, animal feed, and pharmaceuticals from coffee and tea waste. PMID:22328667

  13. Characterization of individuals seeking treatment for caffeine dependence.

    Science.gov (United States)

    Juliano, Laura M; Evatt, Daniel P; Richards, Brian D; Griffiths, Roland R

    2012-12-01

    Previous investigations have identified individuals who meet criteria for Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR; American Psychiatric Association, 2000) substance dependence as applied to caffeine, but there is little research on treatments for caffeine dependence. This study aimed to thoroughly characterize individuals who are seeking treatment for problematic caffeine use. Ninety-four individuals who identified as being psychologically or physically dependent on caffeine, or who had tried unsuccessfully to modify caffeine consumption participated in a face-to-face diagnostic clinical interview. They also completed measures concerning caffeine use and quitting history, reasons for seeking treatment, and standardized self-report measures of psychological functioning. Caffeine treatment seekers (mean age 41 years, 55% women) consumed an average of 548 mg caffeine per day. The primary source of caffeine was coffee for 50% of the sample and soft drinks for 37%. Eighty-eight percent reported prior serious attempts to modify caffeine use (mean 2.7 prior attempts), and 43% reported being advised by a medical professional to reduce or eliminate caffeine. Ninety-three percent met criteria for caffeine dependence when generic DSM-IV-TR substance dependence criteria were applied to caffeine use. The most commonly endorsed criteria were withdrawal (96%), persistent desire or unsuccessful efforts to control use (89%), and use despite knowledge of physical or psychological problems caused by caffeine (87%). The most common reasons for wanting to modify caffeine use were health-related (59%) and not wanting to be dependent on caffeine (35%). This investigation reveals that there are individuals with problematic caffeine use who are seeking treatment and suggests that there is a need for effective caffeine dependence treatments. 2013 APA, all rights reserved

  14. SPECT assessment of brain activation induced by caffeine: no effect on areas involved in dependence.

    Science.gov (United States)

    Nehlig, Astrid; Armspach, Jean-Paul; Namer, Izzie J

    2010-01-01

    Caffeine is not considered addictive, and in animals it does not trigger metabolic increases or dopamine release in brain areas involved in reinforcement and reward. Our objective was to measure caffeine effects on cerebral perfusion in humans using single photon emission computed tomography with a specific focus on areas of reinforcement and reward. Two groups of nonsmoking subjects were studied, one with a low (8 subjects) and one with a high (6 subjects) daily coffee consumption. The subjects ingested 3 mg/kg caffeine or placebo in a raspberry-tasting drink, and scans were performed 45 min after ingestion. A control group of 12 healthy volunteers receiving no drink was also studied. Caffeine consumption led to a generalized, statistically nonsignificant perfusion decrease of 6% to 8%, comparable in low and high consumers. Compared with controls, low consumers displayed neuronal activation bilaterally in inferior frontal gyrus-anterior insular cortex and uncus, left internal parietal cortex, right lingual gyrus, and cerebellum. In high consumers, brain activation occurred bilaterally only in hypothalamus. Thus, on a background of widespread low-amplitude perfusion decrease, caffeine activates a few regions mainly involved in the control of vigilance, anxiety, and cardiovascular regulation, but does not affect areas involved in reinforcing and reward.

  15. Anti-obesity effect of a novel caffeine-loaded dissolving microneedle patch in high-fat diet-induced obese C57BL/6J mice.

    Science.gov (United States)

    Dangol, Manita; Kim, Suyong; Li, Cheng Guo; Fakhraei Lahiji, Shayan; Jang, Mingyu; Ma, Yonghao; Huh, Inyoung; Jung, Hyungil

    2017-11-10

    Natural products such as caffeine have been found to be effective in reducing body weight through lipolysis. Here, we report the successful loading of caffeine onto dissolving microneedle following inhibition of its crystal growth by hyaluronic acid (HA), the matrix material of the dissolving microneedle (DMN). Further, the anti-obesity activity of caffeine was evaluated in high-fat diet-induced obese C57BL/6J mice. After 6weeks of caffeine loaded dissolving microneedle patch (CMP) administration, lipolysis improved significantly as shown by leptin and adiponectin activity, which resulted in considerable weight loss of about 12.8±0.75% in high-fat diet-induced obese mice. Comparison of the levels of triglyceride, total cholesterol, high-density lipoprotein (HDL)-cholesterol, and low-density lipoprotein (LDL)-cholesterol after CMP administration with the initial levels in obese mice indicated significant anti-obesity activity of CMP. These findings suggested that a novel CMP with an increased amount of caffeine loaded onto DMN has therapeutic activity against obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Low- and high-frequency Raman investigations on caffeine: polymorphism, disorder and phase transformation.

    Science.gov (United States)

    Hédoux, Alain; Decroix, Anne-Amandine; Guinet, Yannick; Paccou, Laurent; Derollez, Patrick; Descamps, Marc

    2011-05-19

    Raman investigations are carried out both in crystalline forms of caffeine and during the isothermal transformation of the orientationally disordered form I into the stable form II at 363 K. The time dependence of the Raman spectrum exhibits no significant change in the intramolecular regime (above 100 cm(-1)), resembling the spectrum of the liquid state. By contrast, significant changes are observed below 100 cm(-1), and the low-frequency spectra of forms I and II are observed to be different from that of the liquid. The temperature dependence of the 5-600 cm(-1) spectrum gives information on the static disorder through the analysis of collective motions, while information on dynamic disorder are obtained from the study of the 555 cm(-1) band corresponding to internal vibrations in the pyrimidine ring. This analysis indubitably reveals that form II is also orientationally disordered with a local molecular arrangement that mimics that in form I and the liquid state. The comparison of the low-frequency spectra recorded in theophylline and form II of caffeine allows one to describe the stable form of caffeine from the packing arrangement of anhydrous theophylline with the consideration of reorientational molecular disorder. © 2011 American Chemical Society

  17. Does caffeine affect cardiovascular responses?

    NARCIS (Netherlands)

    S. Bradamante; L. Barenghi (Livia); S. Versari (Silvia); A. Villa (Alessandro); J.W. de Jong (Jan Willem)

    2007-01-01

    textabstractCaffeine (1,3,7-trimethylxanthine), a natural alkaloid present in many beverages such as coffee, tea and cola drinks, is the most widely consumed pharmacological compound. Due to its common use and frequent intake in stressful conditions, a great deal of data have been produced by

  18. The effects of a high dosage of creatine and caffeine supplementation on the lean body mass composition of rats submitted to vertical jumping training.

    Science.gov (United States)

    Franco, Frederico Sc; Costa, Neuza Mb; Ferreira, Susana A; Carneiro-Junior, Miguel A; Natali, Antônio J

    2011-03-01

    The influences of creatine and caffeine supplementation associated with power exercise on lean body mass (LBM) composition are not clear. The purpose of this research was to determine whether supplementation with high doses of creatine and caffeine, either solely or combined, affects the LBM composition of rats submitted to vertical jumping training. Male Wistar rats were randomly divided into 8 groups: Sedentary (S) or Exercised (E) [placebo (Pl), creatine (Cr), caffeine (Caf) or creatine plus caffeine (CrCaf)]. The supplemented groups received creatine [load: 0.430 g/kg of body weight (BW) for 7 days; and maintenance: 0.143 g/kg of BW for 35 days], caffeine (15 mg/kg of BW for 42 days) or creatine plus caffeine. The exercised groups underwent a vertical jump training regime (load: 20 - 50% of BW, 4 sets of 10 jumps interspersed with 1 min resting intervals), 5 days/wk, for 6 weeks. LBM composition was evaluated by portions of water, protein and fat in the rat carcass. Data were submitted to ANOVA followed by the Tukey post hoc test and Student's t test. Exercised animals presented a lower carcass weight (10.9%; P = 0.01), as compared to sedentary animals. However, no effect of supplementation was observed on carcass weight (P > 0.05). There were no significant differences among the groups (P > 0.05) for percentage of water in the carcass. The percentage of fat in the group SCr was higher than in the groups SCaf and ECr (P < 0.05). A higher percentage of protein was observed in the groups EPl and ECaf when compared to the groups SPl and SCaf (P < 0.001). The percentage of fat in the carcass decreased (P < 0.001), while those of water and protein increased (P < 0.05) in exercised animals, compared to sedentary animals. Caffeine groups presented reduced percentage of fat when compared to creatine supplemented groups (P < 0.05). High combined doses of creatine and caffeine does not affect the LBM composition of either sedentary or exercised rats, however, caffeine

  19. Caffeine increases sugar-sweetened beverage consumption in a free-living population: a randomised controlled trial.

    Science.gov (United States)

    Keast, Russell S J; Swinburn, Boyd A; Sayompark, Dhoungsiri; Whitelock, Susie; Riddell, Lynn J

    2015-01-28

    Excessive sugar-sweetened beverage (SSB) consumption has been associated with overweight and obesity. Caffeine is a common additive to SSB, and through dependence effects, it has the potential to promote the consumption of caffeine-containing foods. The objective of the present study was to assess the influence that caffeine has on the consumption of SSB. Participants (n 99) were blindly assigned to either a caffeinated SSB (C-SSB) or a non-caffeinated SSB (NC-SSB) group. Following randomisation, all participants completed a 9 d flavour-conditioning paradigm. They then completed a 28 d ad libitum intake intervention where they consumed as much or as little of C-SSB or NC-SSB as desired. The amount consumed (ml) was recorded daily, 4 d diet diaries were collected and liking of SSB was assessed at the start and end of the intervention. Participants (n 50) consuming the C-SSB had a daily SSB intake of 419 (sd 298) ml (785 (sd 559) kJ/d) over the 28 d intervention, significantly more than participants (n 49) consuming the NC-SSB (273 (sd 278) ml/d, 512 (sd 521) kJ/d) (P=0.05). However, participants who consumed the C-SSB liked the SSB more than those who consumed the NC-SSB (6.3 v. 6.0 on a nine-point hedonic scale, P= 0.022). The addition of low concentrations of caffeine to the SSB significantly increases the consumption of the SSB. Regulating caffeine as a food additive may be an effective strategy to decrease the consumption of nutrient-poor high-energy foods and beverages.

  20. Estimation of caffeine intake from analysis of caffeine metabolites in wastewater

    DEFF Research Database (Denmark)

    Gracia-Lor, Emma; Rousis, Nikolaos I.; Zuccato, Ettore

    2017-01-01

    with the human urinary excretion profile. A good match was found for 1,7-dimethyluric acid, an exclusive caffeine metabolite, suggesting that might be a suitable biomarker in wastewater for assessing population-level caffeine consumption. A correction factor was developed considering the percentage of excretion......Caffeine metabolites in wastewater were investigated as potential biomarkers for assessing caffeine intake in a population. The main human urinary metabolites of caffeine were measured in the urban wastewater of ten European cities and the metabolic profiles in wastewater were compared...... of this metabolite in humans, according to published pharmacokinetic studies. Daily caffeine intake estimated from wastewater analysis was compared with the average daily intake calculated from the average amount of coffee consumed by country per capita. Good agreement was found in some cities but further...

  1. Impact of caffeine and coffee on our health.

    Science.gov (United States)

    Gonzalez de Mejia, Elvira; Ramirez-Mares, Marco Vinicio

    2014-10-01

    Coffee is the most frequently consumed caffeine-containing beverage. The caffeine in coffee is a bioactive compound with stimulatory effects on the central nervous system and a positive effect on long-term memory. Although coffee consumption has been historically linked to adverse health effects, new research indicates that coffee consumption may be beneficial. Here we discuss the impact of coffee and caffeine on health and bring attention to the changing caffeine landscape that includes new caffeine-containing energy drinks and supplements, often targeting children and adolescents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. "Clozapine makes me quite drowsy, so when I wake up in the morning those first cups of coffee are really handy": an exploratory qualitative study of excessive caffeine consumption among individuals with schizophrenia.

    Science.gov (United States)

    Thompson, Lisa; Pennay, Amy; Zimmermann, Adam; Cox, Merrilee; Lubman, Dan I

    2014-04-16

    Research has shown that individuals with schizophrenia use caffeine at higher rates than the general population; however, no qualitative research has been undertaken investigating problematic caffeine use and its effects on this population. This article explores the role of caffeine consumption in the lives of people with schizophrenia through a narrative analysis of the attitudes and beliefs associated with this practice, and how these, in turn, influence caffeine consumption. A qualitative study was undertaken with individuals who had previously scored in either a 'moderate' or 'high' risk category for caffeine use on the Alcohol, Smoking and Substance Involvement Screening Tool (ASSIST). In-depth interviews were undertaken with 20 individuals, and transcripts were analysed thematically to identify prominent perspectives. Consistent with previous literature, participants' caffeine consumption was driven largely by its stimulating properties; however, participants also identified 'cravings' as an important motivating factor. Participants' behaviours related to caffeine consumption seemed to be tempered by their previous experiences of consumption; if participants had experienced positive effects such as alertness or relaxation in the past, their use was maintained at a similar level or increased. Conversely, participants who anticipated negative consequences often altered their patterns of caffeine consumption; for example, by substituting caffeinated drinks that minimised or ceased their experience of negative side effects for those that directly caused such impacts. Overall, participants largely identified caffeine consumption as a highly meaningful activity, which provided structure to their day and facilitated opportunities for social interaction. The inconsistencies between individuals' beliefs about their health and the actual risk of harm associated with health-related behaviours present significant and ongoing challenges for the implementation of relevant

  3. Gender-specific increase in susceptibility to metabolic syndrome of offspring rats after prenatal caffeine exposure with post-weaning high-fat diet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Luo, Hanwen [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Wu, Yimeng; He, Zheng; Zhang, Li; Guo, Yu [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Ma, Lu [Department of Epidemiology & Health Statistics, Public Health School of Wuhan University, Wuhan 430071 (China); Magdalou, Jacques [UMR 7561 CNRS-NancyUniversité, Faculté de Médicine, Vandoeuvre-lès-Nancy (France); Chen, Liaobin [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071 (China); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan 430071 (China)

    2015-05-01

    Prenatal caffeine exposure (PCE) alters the hypothalamic–pituitary–adrenocortical (HPA) axis-associated neuroendocrine metabolic programming and induces an increased susceptibility to metabolic syndrome (MS) in intrauterine growth retardation (IUGR) offspring rats. High-fat diet (HFD) is one of the main environmental factors accounting for the incidence of MS. In this study, we aimed to clarify the gender-specific increase in susceptibility to MS in offspring rats after PCE with post-weaning HFD. Maternal Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. The offspring rats with normal diet or HFD were euthanized at postnatal week 24, and blood samples were collected. Results showed that PCE not only reduced serum adrenocorticotropic hormone (ACTH) and corticosterone levels, but also enhanced serum glucose, triglyceride and total cholesterol (TCH) concentrations in the offspring rats. Moreover, several interactions among PCE, HFD and gender were observed by a three-way ANOVA analysis. In PCE offspring, HFD could aggravate the degree of increased serum triglyceride level. Meanwhile, serum corticosterone levels of females were decreased more obviously than those of males in PCE offspring. The results also revealed interactions between HFD and gender in the levels of serum ACTH, triglyceride and TCH, which were changed more evidently in female HFD offspring. These results indicate that HFD could exacerbate the dysfunction of lipid metabolism and the susceptibility to MS induced by PCE, and the female offspring are more sensitive to HFD-induced neuroendocrine metabolic dysfunction than their male counterparts. - Highlights: • Caffeine induced HPA axis dysfunction in offspring rats fed by high-fat diet (HFD). • Caffeine induced an increased susceptibility to metabolic syndrome. • HFD aggravated susceptibility to metabolic syndrome induced by caffeine. • Female was more sensitive to HFD-induced neuroendocrine

  4. Gender-specific increase in susceptibility to metabolic syndrome of offspring rats after prenatal caffeine exposure with post-weaning high-fat diet

    International Nuclear Information System (INIS)

    Li, Jing; Luo, Hanwen; Wu, Yimeng; He, Zheng; Zhang, Li; Guo, Yu; Ma, Lu; Magdalou, Jacques; Chen, Liaobin; Wang, Hui

    2015-01-01

    Prenatal caffeine exposure (PCE) alters the hypothalamic–pituitary–adrenocortical (HPA) axis-associated neuroendocrine metabolic programming and induces an increased susceptibility to metabolic syndrome (MS) in intrauterine growth retardation (IUGR) offspring rats. High-fat diet (HFD) is one of the main environmental factors accounting for the incidence of MS. In this study, we aimed to clarify the gender-specific increase in susceptibility to MS in offspring rats after PCE with post-weaning HFD. Maternal Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. The offspring rats with normal diet or HFD were euthanized at postnatal week 24, and blood samples were collected. Results showed that PCE not only reduced serum adrenocorticotropic hormone (ACTH) and corticosterone levels, but also enhanced serum glucose, triglyceride and total cholesterol (TCH) concentrations in the offspring rats. Moreover, several interactions among PCE, HFD and gender were observed by a three-way ANOVA analysis. In PCE offspring, HFD could aggravate the degree of increased serum triglyceride level. Meanwhile, serum corticosterone levels of females were decreased more obviously than those of males in PCE offspring. The results also revealed interactions between HFD and gender in the levels of serum ACTH, triglyceride and TCH, which were changed more evidently in female HFD offspring. These results indicate that HFD could exacerbate the dysfunction of lipid metabolism and the susceptibility to MS induced by PCE, and the female offspring are more sensitive to HFD-induced neuroendocrine metabolic dysfunction than their male counterparts. - Highlights: • Caffeine induced HPA axis dysfunction in offspring rats fed by high-fat diet (HFD). • Caffeine induced an increased susceptibility to metabolic syndrome. • HFD aggravated susceptibility to metabolic syndrome induced by caffeine. • Female was more sensitive to HFD-induced neuroendocrine

  5. Short-term Effects of High-Dose Caffeine on Cardiac Arrhythmias in Patients With Heart Failure: A Randomized Clinical Trial.

    Science.gov (United States)

    Zuchinali, Priccila; Souza, Gabriela C; Pimentel, Maurício; Chemello, Diego; Zimerman, André; Giaretta, Vanessa; Salamoni, Joyce; Fracasso, Bianca; Zimerman, Leandro I; Rohde, Luis E

    2016-12-01

    The presumed proarrhythmic action of caffeine is controversial. Few studies have assessed the effect of high doses of caffeine in patients with heart failure due to left ventricular systolic dysfunction at high risk for ventricular arrhythmias. To compare the effect of high-dose caffeine or placebo on the frequency of supraventricular and ventricular arrhythmias, both at rest and during a symptom-limited exercise test. Double-blinded randomized clinical trial with a crossover design conducted at the heart failure and cardiac transplant clinic of a tertiary-care university hospital. The trial included patients with chronic heart failure with moderate-to-severe systolic dysfunction (left ventricular ejection fraction capsules, in addition to 5 doses of 100 mL decaffeinated coffee at 1-hour intervals, for a total of 500 mg of caffeine or placebo during a 5-hour protocol. After a 1-week washout period, the protocol was repeated. Number and percentage of ventricular and supraventricular premature beats assessed by continuous electrocardiographic monitoring. We enrolled 51 patients (37 [74%] male; mean [SD] age, 60.6 [10.9] years) with predominantly moderate-to-severe left ventricular systolic dysfunction (mean [SD] left ventricular ejection fraction, 29% [7%]); 31 [61%] had an implantable cardioverter-defibrillator device. No significant differences between the caffeine and placebo groups were observed in the number of ventricular (185 vs 239 beats, respectively; P = .47) and supraventricular premature beats (6 vs 6 beats, respectively; P = .44), as well as in couplets, bigeminal cycles, or nonsustained tachycardia during continuous electrocardiographic monitoring. Exercise test-derived variables, such as ventricular and supraventricular premature beats, duration of exercise, estimated peak oxygen consumption, and heart rate, were not influenced by caffeine ingestion. We observed no increases in ventricular premature beats (91 vs 223 vs 207 beats, respectively

  6. Contribution of caffeine to the homocysteine-raising effect of coffee: a randomized controlled trial in humans.

    Science.gov (United States)

    Verhoef, Petra; Pasman, Wilrike J; Van Vliet, Trinette; Urgert, Rob; Katan, Martijn B

    2002-12-01

    A high plasma total homocysteine concentration is associated with increased risk of cardiovascular disease. Consumption of unfiltered or filtered coffee raises total homocysteine concentrations in healthy volunteers. The responsible compound, however, is unknown. The objective was to determine whether caffeine explains the homocysteine-raising effect of coffee. Forty-eight subjects aged 19-65 y completed this randomized crossover study with 3 treatments, each lasting 2 wk. Subjects consumed 6 capsules providing 870 mg caffeine/d (test treatment), 0.9 L paper-filtered coffee providing approximately 870 mg caffeine/d, or 6 placebo capsules. Blood samples were drawn fasting and 4 h after consumption of 0.45 L coffee or 3 capsules. The mean fasting plasma homocysteine concentration after the placebo treatment was 9.6 +/- 3.1 micro mol/L. The caffeine and coffee treatments increased fasting homocysteine by 0.4 micro mol/L (95% CI: 0.1, 0.7; P = 0.04), or 5%, and by 0.9 micro mol/L (95% CI: 0.6, 1.2; P = 0.0001), or 11%, respectively, compared with placebo. The increase in homocysteine concentrations 4 h after consumption of 0.45 L coffee relative to consumption of 3 placebo capsules was 19% (P = 0.0001). Caffeine treatment had a much weaker acute effect on homocysteine (4%; P = 0.09). Effects of caffeine were stronger in women than in men, but the effects of coffee did not differ significantly between men and women. Caffeine is partly responsible for the homocysteine-raising effect of coffee. Coffee, but not caffeine, affects homocysteine metabolism within hours after intake, although the effect is still substantial after an overnight fast.

  7. Caffeine and sports performance.

    Science.gov (United States)

    Burke, Louise M

    2008-12-01

    Athletes are among the groups of people who are interested in the effects of caffeine on endurance and exercise capacity. Although many studies have investigated the effect of caffeine ingestion on exercise, not all are suited to draw conclusions regarding caffeine and sports performance. Characteristics of studies that can better explore the issues of athletes include the use of well-trained subjects, conditions that reflect actual practices in sport, and exercise protocols that simulate real-life events. There is a scarcity of field-based studies and investigations involving elite performers. Researchers are encouraged to use statistical analyses that consider the magnitude of changes, and to establish whether these are meaningful to the outcome of sport. The available literature that follows such guidelines suggests that performance benefits can be seen with moderate amounts (~3 mg.kg-1 body mass) of caffeine. Furthermore, these benefits are likely to occur across a range of sports, including endurance events, stop-and-go events (e.g., team and racquet sports), and sports involving sustained high-intensity activity lasting from 1-60 min (e.g., swimming, rowing, and middle and distance running races). The direct effects on single events involving strength and power, such as lifts, throws, and sprints, are unclear. Further studies are needed to better elucidate the range of protocols (timing and amount of doses) that produce benefits and the range of sports to which these may apply. Individual responses, the politics of sport, and the effects of caffeine on other goals, such as sleep, hydration, and refuelling, also need to be considered.

  8. The Safety of Ingested Caffeine: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Jennifer L. Temple

    2017-05-01

    Full Text Available Caffeine is the most widely consumed psychoactive drug in the world. Natural sources of caffeine include coffee, tea, and chocolate. Synthetic caffeine is also added to products to promote arousal, alertness, energy, and elevated mood. Over the past decade, the introduction of new caffeine-containing food products, as well as changes in consumption patterns of the more traditional sources of caffeine, has increased scrutiny by health authorities and regulatory bodies about the overall consumption of caffeine and its potential cumulative effects on behavior and physiology. Of particular concern is the rate of caffeine intake among populations potentially vulnerable to the negative effects of caffeine consumption: pregnant and lactating women, children and adolescents, young adults, and people with underlying heart or other health conditions, such as mental illness. Here, we review the research into the safety and safe doses of ingested caffeine in healthy and in vulnerable populations. We report that, for healthy adults, caffeine consumption is relatively safe, but that for some vulnerable populations, caffeine consumption could be harmful, including impairments in cardiovascular function, sleep, and substance use. We also identified several gaps in the literature on which we based recommendations for the future of caffeine research.

  9. Caffeine Use Disorder: A Review of the Evidence and Future Implications.

    Science.gov (United States)

    Addicott, Merideth A

    2014-09-01

    The latest edition of the Diagnostic and Statistical Manual (DSM-5) has introduced new provisions for caffeine-related disorders. Caffeine Withdrawal is now an officially recognized diagnosis, and criteria for caffeine use disorder have been proposed for additional study. caffeine use disorder is intended to be characterized by cognitive, behavioral, and physiological symptoms indicative of caffeine use despite significant caffeine-related problems, similar to other Substance Use Disorders. However, since nonproblematic caffeine use is so common and widespread, it may be difficult for some health professionals to accept that caffeine use can result in the same types of pathological behaviors caused by alcohol, cocaine, opiates, or other drugs of abuse. Yet there is evidence that some individuals are psychologically and physiologically dependent on caffeine, although the prevalence and severity of these problems is unknown. This article reviews the recent changes to the DSM, the concerns regarding these changes, and some potential impacts these changes could have on caffeine consumers.

  10. HPLC determination of caffeine in coffee beverage

    Science.gov (United States)

    Fajara, B. E. P.; Susanti, H.

    2017-11-01

    Coffee is the second largest beverage which is consumed by people in the world, besides the water. One of the compounds which contained in coffee is caffeine. Caffeine has the pharmacological effect such as stimulating the central nervous system. The purpose of this study is to determine the level of caffeine in coffee beverages with HPLC method. Three branded coffee beverages which include in 3 of Top Brand Index 2016 Phase 2 were used as samples. Qualitative analysis was performed by Parry method, Dragendorff reagent, and comparing the retention time between sample and caffeine standard. Quantitative analysis was done by HPLC method with methanol-water (95:5v/v) as mobile phase and ODS as stationary phasewith flow rate 1 mL/min and UV 272 nm as the detector. The level of caffeine data was statistically analyzed using Anova at 95% confidence level. The Qualitative analysis showed that the three samples contained caffeine. The average of caffeine level in coffee bottles of X, Y, and Z were 138.048 mg/bottle, 109.699 mg/bottle, and 147.669 mg/bottle, respectively. The caffeine content of the three coffee beverage samples are statistically different (pcoffee beverage samples were not meet the requirements set by the Indonesian Standard Agency of 50 mg/serving.

  11. Effects of Caffeine on Auditory Brainstem Response

    Directory of Open Access Journals (Sweden)

    Saleheh Soleimanian

    2008-06-01

    Full Text Available Background and Aim: Blocking of the adenosine receptor in central nervous system by caffeine can lead to increasing the level of neurotransmitters like glutamate. As the adenosine receptors are present in almost all brain areas like central auditory pathway, it seems caffeine can change conduction in this way. The purpose of this study was to evaluate the effects of caffeine on latency and amplitude of auditory brainstem response(ABR.Materials and Methods: In this clinical trial study 43 normal 18-25 years old male students were participated. The subjects consumed 0, 2 and 3 mg/kg BW caffeine in three different sessions. Auditory brainstem responses were recorded before and 30 minute after caffeine consumption. The results were analyzed by Friedman and Wilcoxone test to assess the effects of caffeine on auditory brainstem response.Results: Compared to control group the latencies of waves III,V and I-V interpeak interval of the cases decreased significantly after 2 and 3mg/kg BW caffeine consumption. Wave I latency significantly decreased after 3mg/kg BW caffeine consumption(p<0.01. Conclusion: Increasing of the glutamate level resulted from the adenosine receptor blocking brings about changes in conduction in the central auditory pathway.

  12. Caffeine and Your Child

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Caffeine KidsHealth / For Parents / Caffeine What's in this article? ... español La cafeína y su hijo What Is Caffeine? Caffeine is a natural stimulant found in coffee, ...

  13. The influence of CYP1A2 genotype in the blood pressure response to caffeine ingestion is affected by physical activity status and caffeine consumption level.

    Science.gov (United States)

    Soares, Rogerio Nogueira; Schneider, Augusto; Valle, Sandra Costa; Schenkel, Paulo Cavalheiro

    2018-03-06

    This study aimed to investigate whether the influence of CYP1A2 genotype in the blood pressure (BP) response to caffeine ingestion was affected by physical activity status and habitual caffeine consumption. Thirty-seven participants (19-50 years old) took place in the study and were categorized according to i) genotype: CYP1A2 (AA) "fast metabolizer", and CYP1A2 (AC) "slow metabolizer"; ii) physical activity level: sedentary (S) and physically active (A); and iii) caffeine consumption level: non-habitual caffeine consumer (NC) and habitual heavy caffeine consumer (C). All groups had BP assessed before (basal) and 1 hourh after (post) caffeine ingestion (6 mg·kg -1 ). It was observed that AC genotype individuals had increased basal-DBP and post-caffeine SBP when compared to AA individuals. Additionally, acute caffeine ingestion increased SBP only in the AC group. It was also found that physical activity only modulated the BP responses to acute caffeine ingestion in AC individuals. Furthermore, the results indicated that the habitual heavy caffeine consumers AC individuals had increased basal-DBP when compared to the AA ones. Our results suggest that the influence of CYP1A2 genotype in the basal and post-caffeine BP response to caffeine ingestion is modified by physical activity status and caffeine consumption level. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Subjective, behavioral, and physiological effects of acute caffeine in light, nondependent caffeine users.

    Science.gov (United States)

    Childs, Emma; de Wit, Harriet

    2006-05-01

    Caffeine produces mild psychostimulant effects that are thought to underlie its widespread use. However, the direct effects of caffeine are difficult to evaluate in regular users of caffeine because of tolerance and withdrawal. Indeed, some researchers hypothesize that the psychostimulant effects of caffeine are due largely to the reversal of withdrawal and question whether there are direct effects of caffeine consumption upon mood, alertness, or mental performance in nondependent individuals. This study investigated the physiological, subjective, and behavioral effects of 0, 50, 150, and 450 mg caffeine in 102 light, nondependent caffeine users. Using a within-subjects design, subjects participated in four experimental sessions, in which they received each of the four drug conditions in random order under double blind conditions. Participants completed subjective effects questionnaires and vital signs were measured before and at repeated time points after drug administration. Forty minutes after the capsules were ingested, subjects completed behavioral tasks that included tests of sustained attention, short-term memory, psychomotor performance, and behavioral inhibition. Caffeine significantly increased blood pressure, and produced feelings of arousal, positive mood, and high. Caffeine increased the number of hits and decreased reaction times in a vigilance task, but impaired performance on a memory task. We confirm that acute doses of caffeine, at levels typically found in a cup of coffee, produce stimulant-like subjective effects and enhance performance in light, nondependent caffeine users. These findings support the idea that the drug has psychoactive effects even in the absence of withdrawal.

  15. Beliefs, Behaviors, and Contexts of Adolescent Caffeine Use: A Focus Group Study.

    Science.gov (United States)

    Ludden, Alison B; O'Brien, Elizabeth M; Pasch, Keryn E

    2017-07-29

    Caffeinated products are widely available to adolescents, and consumption of caffeine products-energy drinks and coffee in particular-is on the rise in this age group (Branum, Rossen, & Schoendorf, 2014). Yet, little is known about the psychosocial context of caffeine use. Previous studies on adolescent caffeine use have focused on caffeine's acute physiological effects, rather than the psychosocial contexts and beliefs regarding different types of caffeinated beverages (e.g., coffee, energy drinks, soda). The current research examines the contexts and beliefs associated with adolescents' use of caffeinated beverages (e.g., coffee, energy drinks, soda) using a focus group approach. Eleven focus group interviews (49 total participants) addressed adolescents' motivations for and patterns of caffeine use; they were transcribed and axial coding was used to identify common themes. Coffee and energy drinks were perceived to be the most popular caffeinated beverages. Reasons for consuming caffeine included the effect of caffeine as a stimulant, the pleasant feelings experienced when drinking it, and the fact that caffeine was available. As for contexts, coffee was consumed in more diverse social contexts than other caffeinated beverages. Friends and sports were the most popular contexts for energy drink use. The present findings inform adolescent health promotion efforts and provide researchers and practitioners alike detailed information in adolescents' own words about how and why they use caffeine. Adolescents' beliefs about caffeinated products are not uniform; the reasons adolescents articulate regarding their use of coffee, soda, and energy drinks are different across contexts and beverage type.

  16. Effects of p-synephrine in combination with caffeine: a review

    Directory of Open Access Journals (Sweden)

    Stohs SJ

    2017-09-01

    Full Text Available Sidney J Stohs,1,2 Nicholas A Ratamess3 1School of Pharmacy and Health Professions, Creighton University, Omaha, NE, 2Kitsto Consulting LLC, Frisco, TX, 3Department of Health and Exercise Science, College of New Jersey, Ewing, NJ, USA Abstract: This review summarizes the current research involving p-synephrine in combination with caffeine. Over 30 clinical human studies with in excess of 700 subjects, and animal and in vitro studies have assessed the safety, efficacy, and mechanism of action of Citrus aurantium (bitter orange extract and its primary active constituent p-synephrine. Approximately 35% of these human subjects concurrently consumed caffeine, a stimulant thermogenic agent. In these clinical investigations, no serious adverse effects were reported or observed when using the combination of p-synephrine with caffeine. Animal studies with exceedingly high doses of p-synephrine in combination with caffeine support and affirm the human studies. The results of studies conducted to date indicate that p-synephrine does not augment the cardiovascular effects of caffeine or produce cardiovascular effects at commonly used doses. These observations can be explained on the basis of in vitro mechanistic studies. Keywords: caffeine, p-synephrine, bitter orange extract, Citrus aurantium, mechanisms, cardiovascular effects

  17. Taurine, caffeine, and energy drinks: Reviewing the risks to the adolescent brain.

    Science.gov (United States)

    Curran, Christine Perdan; Marczinski, Cecile A

    2017-12-01

    Energy drinks are emerging as a major component of the beverage market with sales projected to top $60 billion globally in the next five years. Energy drinks contain a variety of ingredients, but many of the top-selling brands include high doses of caffeine and the amino acid taurine. Energy drink consumption by children has raised concerns, due to potential caffeine toxicity. An additional risk has been noted among college-aged consumers of energy drinks who appear at higher risk of over-consumption of alcohol when the two drinks are consumed together. The differential and combinatorial effects of caffeine and taurine on the developing brain are reviewed here with an emphasis on the adolescent brain, which is still maturing. Key data from animal studies are summarized to highlight both reported benefits and adverse effects reported following acute and chronic exposures. The data suggest that age is an important factor in both caffeine and taurine toxicity. Although the aged or diseased brain might benefit from taurine or caffeine supplementation, it appears that adolescents are not likely to benefit from supplementation and may, in fact, suffer ill effects from chronic ingestion of high doses. Additional work is needed though to address gaps in our understanding of how taurine affects females, since the majority of animal studies focused exclusively on male subjects. © 2017 Wiley Periodicals, Inc.

  18. Increases in cerebrospinal fluid caffeine concentration are associated with favorable outcome after severe traumatic brain injury in humans

    Science.gov (United States)

    Sachse, Kathleen T; Jackson, Edwin K; Wisniewski, Stephen R; Gillespie, Delbert G; Puccio, Ava M; Clark, Robert SB; Dixon, C Edward; Kochanek, Patrick M

    2013-01-01

    Caffeine, the most widely consumed psychoactive drug and a weak adenosine receptor antagonist, can be neuroprotective or neurotoxic depending on the experimental model or neurologic disorder. However, its contribution to pathophysiology and outcome in traumatic brain injury (TBI) in humans is undefined. We assessed serial cerebrospinal fluid (CSF) concentrations of caffeine and its metabolites (theobromine, paraxanthine, and theophylline) by high-pressure liquid chromatography/ultraviolet in 97 ventricular CSF samples from an established bank, from 30 adults with severe TBI. We prospectively selected a threshold caffeine level of ≥1 μmol/L (194 ng/mL) as clinically significant. Demographics, Glasgow Coma Scale (GCS) score, admission blood alcohol level, and 6-month dichotomized Glasgow Outcome Scale (GOS) score were assessed. Mean time from injury to initial CSF sampling was 10.77±3.13 h. On initial sampling, caffeine was detected in 24 of 30 patients, and the threshold was achieved in 9 patients. Favorable GOS was seen more often in patients with CSF caffeine concentration ≥ versus theobromine and paraxanthine were also associated with favorable outcome (P = 0.018 and 0.056, respectively). Caffeine and its metabolites are commonly detected in CSF in patients with severe TBI and in an exploratory assessment are associated with favorable outcome. We speculate that caffeine may be neuroprotective by long-term upregulation of adenosine A1 receptors or acute inhibition of A2a receptors. PMID:17684518

  19. Method Development and Validation for the Determination of Caffeine: An Alkaloid from Coffea arabica by High-performance Liquid Chromatography Method.

    Science.gov (United States)

    Naveen, P; Lingaraju, H B; Deepak, M; Medhini, B; Prasad, K Shyam

    2018-01-01

    The present study was investigated to develop and validate a reversed phase high performance liquid chromatography method for the determination of caffeine from bean material of Coffee arabica. The separation was achieved on a reversed-phase C18 column using a mobile phase composed of water: methanol (50:50) at a flow rate of 1.0 mlmin-1. The detection was carried out on a UV detector at 272 nm. The developed method was validated according to the requirements for International Conference on Harmonisation (ICH) guidelines, which includes specificity, linearity, precision, accuracy, limit of detection and limit of quantitation. The developed method validates good linearity with excellent correlation coefficient (R2 > 0.999). In repeatability and intermediate precision, the percentage relative standard deviation (% RSD) of peak area was less than 1% shows high precision of the method. The recovery rate for caffeine was within 98.78% - 101.28% indicates high accuracy of the method. The low limit of detection and limit of quantitation of caffeine enable the detection and quantitation of caffeine from C. arabica at low concentrations. The developed HPLC method is a simple, rapid, precisely, accurately and widely accepted and it is recommended for efficient assays in routine work. A simple, accurate, and sensitive high-performance liquid chromatography (HPLC) method for caffeine from Coffea arabica has been developed and validated. The developed HPLC method was validated for linearity, specificity, precision, recovery, limits of detection, and limits of quantification by the International Conference on Harmonization guidelines. The results revealed that the proposed method is highly reliable. This method could be successfully applied for routine quality work analysis. Abbreviation Used: C. arabica : Coffee arabica, ICH: International Conference on Harmonisation, % RSD: Percentage Relative Standard Deviation, R2: Correlation Coefficient, ppm: Parts per million, LOD: Limits

  20. The Combined Effects of Alcohol, Caffeine and Expectancies on Subjective Experience, Impulsivity and Risk-Taking

    Science.gov (United States)

    Heinz, Adrienne J.; de Wit, Harriet; Lilje, Todd C.; Kassel, Jon D.

    2013-01-01

    Caffeinated alcoholic beverage (CAB) consumption is a rapidly growing phenomenon among young adults and is associated with a variety of health-risk behaviors. The current study examined whether either caffeinated alcohol or the expectation of receiving caffeinated alcohol altered affective, cognitive and behavioral outcomes hypothesized to contribute to risk behavior. Young adult social drinkers (N=146) participated in a single session where they received alcohol (peak Breath Alcohol Content = .088 g/dL, SD = .019; equivalent to about 4 standard drinks) and were randomly assigned to one of four further conditions 1) no caffeine, no caffeine expectancy, 2) caffeine and caffeine expectancy, 3) no caffeine but caffeine expectancy, 4) caffeine but no caffeine expectancy. Participants’ habitual CAB consumption was positively correlated with measures of impulsivity and risky behavior, independently of study drugs. Administration of caffeine (mean dose = 220 mg, SD = 38; equivalent to about 2.75 Red Bulls) in the study reduced subjective ratings of intoxication and reversed the decrease in desire to continue drinking, regardless of expectancy. Caffeine also reduced the effect of alcohol on inhibitory reaction time (faster incorrect responses). Participants not expecting caffeine were less attentive after alcohol, whereas participants expecting caffeine were not, regardless of caffeine administration. Alcohol decreased response accuracy in all participants except those who both expected and received caffeine. Findings suggest that CABs may elevate risk for continued drinking by reducing perceived intoxication, and by maintaining the desire to continue drinking. Simply expecting to consume caffeine may reduce the effects of alcohol on inattention, and either expecting or consuming caffeine may protect against other alcohol-related performance decrements. Caffeine, when combined with alcohol, has both beneficial and detrimental effects on mechanisms known to contribute to

  1. Determination of caffeine and identification of undeclared substances in dietary supplements and caffeine dietary exposure assessment.

    Science.gov (United States)

    Neves, Diana Brito da Justa; Caldas, Eloisa Dutra

    2017-07-01

    Caffeine is one of the most consumed stimulants in the world, and is a frequent ingredient of dietary supplements. The aims of this work were to validate a GC-MS method for the quantitation of caffeine and identification of other substances in supplements, mainly weight loss products, and to estimate the caffeine intake by consumers. Sample preparation included extraction with chloroform:water in ultrasonic bath, centrifugation and analysis of the organic layer for caffeine quantitation, and extraction with methanol for identification of other substances. A total of 213 samples of 52 supplement products not registered in Brazil and seized by the Brazilian Federal Police were analyzed. From the 109 samples that declared the amount of caffeine present, 26.6% contained more than 120% of the specified content. Considering the maximum recommended dose stated on the product labels, the consumption of 47.9% of the samples would lead to a daily intake of caffeine above the safe limit of 400 mg. Undeclared drugs, including sibutramine, phenolphthalein, amphepramone and femproporex were found in 28 samples. These results show that consumers of dietary supplements should be aware that these products might contain caffeine at levels that could represent potential health risks, in addition to undeclared pharmaceutical drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Caffeine protects against memory loss induced by high and non-anxiolytic dose of cannabidiol in adult zebrafish (Danio rerio).

    Science.gov (United States)

    Nazario, Luiza Reali; Antonioli, Régis; Capiotti, Katiucia Marques; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Crippa, José Alexandre S; Bonan, Carla Denise; da Silva, Rosane Souza

    2015-08-01

    Cannabidiol (CBD) has been investigated in a wide spectrum of clinical approaches due to its psychopharmacological properties. CBD has low affinity for cannabinoid neuroreceptors and agonistic properties to 5-HT receptors. An interaction between cannabinoid and purinergic receptor systems has been proposed. The purpose of this study is to evaluate CBD properties on memory behavioral and locomotor parameters and the effects of pre-treatment of adenosine receptor blockers on CBD impacts on memory using adult zebrafish. CBD (0.1, 0.5, 5, and 10mg/kg) was tested in the avoidance inhibitory paradigm and anxiety task. We analyzed the effect of a long-term caffeine pre-treatment (~20mg/L - four months). Also, acute block of adenosine receptors was performed in co-administration with CBD exposure in the memory assessment. CBD promoted an inverted U-shaped dose-response curve in the anxiety task; in the memory assessment, CBD in the dose of 5mg/Kg promoted the strongest effects without interfering with social and aggressive behavior. Caffeine treatment was able to prevent CBD (5mg/kg) effects on memory when CBD was given after the training session. CBD effects on memory were partially prevented by co-treatment with a specific A2A adenosine receptor antagonist when given prior to or after the training session, while CBD effects after the training session were fully prevented by adenosine A1 receptor antagonist. These results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention in a way dependent on adenosine. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Certification of caffeine reference material purity by ultraviolet/visible spectrophotometry and high-performance liquid chromatography with diode-array detection as two independent analytical methods.

    Science.gov (United States)

    Shehata, A B; Rizk, M S; Rend, E A

    2016-10-01

    Caffeine reference material certified for purity is produced worldwide, but no research work on the details of the certification process has been published in the literature. In this paper, we report the scientific details of the preparation and certification of pure caffeine reference materials. Caffeine was prepared by extraction from roasted and ground coffee by dichloromethane after heating in deionized water mixed with magnesium oxide. The extract was purified, dried, and bottled in dark glass vials. Stratified random selection was applied to select a number of vials for homogeneity and stability studies, which revealed that the prepared reference material is homogeneous and sufficiently stable. Quantification of caffeine purity % was carried out using a calibrated UV/visible spectrophotometer and a calibrated high-performance liquid chromatography with diode-array detection method. The results obtained from both methods were combined to drive the certified value and its associated uncertainty. The certified value of the reference material purity was found to be 99.86% and its associated uncertainty was ±0.65%, which makes the candidate reference material a very useful calibrant in food and drug chemical analysis. Copyright © 2016. Published by Elsevier B.V.

  4. Certification of caffeine reference material purity by ultraviolet/visible spectrophotometry and high-performance liquid chromatography with diode-array detection as two independent analytical methods

    Directory of Open Access Journals (Sweden)

    A.B. Shehata

    2016-10-01

    Full Text Available Caffeine reference material certified for purity is produced worldwide, but no research work on the details of the certification process has been published in the literature. In this paper, we report the scientific details of the preparation and certification of pure caffeine reference materials. Caffeine was prepared by extraction from roasted and ground coffee by dichloromethane after heating in deionized water mixed with magnesium oxide. The extract was purified, dried, and bottled in dark glass vials. Stratified random selection was applied to select a number of vials for homogeneity and stability studies, which revealed that the prepared reference material is homogeneous and sufficiently stable. Quantification of caffeine purity % was carried out using a calibrated UV/visible spectrophotometer and a calibrated high-performance liquid chromatography with diode-array detection method. The results obtained from both methods were combined to drive the certified value and its associated uncertainty. The certified value of the reference material purity was found to be 99.86% and its associated uncertainty was ±0.65%, which makes the candidate reference material a very useful calibrant in food and drug chemical analysis.

  5. Caffeine promotes wakefulness via dopamine signaling in Drosophila

    Science.gov (United States)

    Nall, Aleksandra H.; Shakhmantsir, Iryna; Cichewicz, Karol; Birman, Serge; Hirsh, Jay; Sehgal, Amita

    2016-01-01

    Caffeine is the most widely-consumed psychoactive drug in the world, but our understanding of how caffeine affects our brains is relatively incomplete. Most studies focus on effects of caffeine on adenosine receptors, but there is evidence for other, more complex mechanisms. In the fruit fly Drosophila melanogaster, which shows a robust diurnal pattern of sleep/wake activity, caffeine reduces nighttime sleep behavior independently of the one known adenosine receptor. Here, we show that dopamine is required for the wake-promoting effect of caffeine in the fly, and that caffeine likely acts presynaptically to increase dopamine signaling. We identify a cluster of neurons, the paired anterior medial (PAM) cluster of dopaminergic neurons, as the ones relevant for the caffeine response. PAM neurons show increased activity following caffeine administration, and promote wake when activated. Also, inhibition of these neurons abrogates sleep suppression by caffeine. While previous studies have focused on adenosine-receptor mediated mechanisms for caffeine action, we have identified a role for dopaminergic neurons in the arousal-promoting effect of caffeine. PMID:26868675

  6. Caffeine intake and fecundability: a follow-up study among 430 Danish couples planning their first pregnancy.

    Science.gov (United States)

    Jensen, T K; Henriksen, T B; Hjollund, N H; Scheike, T; Kolstad, H; Giwercman, A; Ernst, E; Bonde, J P; Skakkebaek, N E; Olsen, J

    1998-01-01

    Fecundability has been defined as the ability to achieve a recognized pregnancy. Several studies on caffeine and fecundability have been conducted but have been inconclusive. This may be explained partly by lack of stratification by smoking. Furthermore, few researchers have tried to separate the effect of caffeine from different sources (coffee, tea, cola, and chocolate). Clearly, the relationship between caffeine and fecundability needs further research, given the high prevalence of caffeine intake among women of childbearing age. We examined the independent and combined effects of smoking and caffeine intake from different sources on the probability of conception. From 1992 to 1995, a total of 430 couples were recruited after a nationwide mailing of a personal letter to 52,255 trade union members who were 20 to 35 years old, lived with a partner, and had no previous reproductive experience. At enrollment and in six cycles of follow-up, both partners filled out a questionnaire on different factors including smoking habits and their intake of coffee, tea, chocolate, cola beverages, and chocolate bars. In all, 1596 cycles and 423 couples were included in the analyses. The cycle-specific association between caffeine intake and fecundability was analyzed in a logistic regression model with the outcome at each cycle (pregnant or not pregnant) in a Cox discrete model calculating the fecundability odds-ratio (FR). Compared to nonsmoking women with caffeine intake less than 300 mg/d, nonsmoking women who consumed 300 to 700 mg/d caffeine had a FR of 0.88 [95% confidence interval (CI) 0.60-1.31], whereas women with a higher caffeine intake had a FR = 0.63 (95% CI 0.25-1.60) after adjusting for female body mass index and alcohol intake, diseases of the female reproductive organs, semen quality, and duration of menstrual cycle. No dose-response relationship was found among smokers. Among males, the same decline in point estimates of the FR was present. Smoking women whose

  7. Differential cognitive effects of energy drink ingredients: caffeine, taurine, and glucose.

    Science.gov (United States)

    Giles, Grace E; Mahoney, Caroline R; Brunyé, Tad T; Gardony, Aaron L; Taylor, Holly A; Kanarek, Robin B

    2012-10-01

    Energy drinks containing caffeine, taurine, and glucose may improve mood and cognitive performance. However, there are no studies assessing the individual and interactive effects of these ingredients. We evaluated the effects of caffeine, taurine, and glucose alone and in combination on cognitive performance and mood in 24-hour caffeine-abstained habitual caffeine consumers. Using a randomized, double-blind, mixed design, 48 habitual caffeine consumers (18 male, 30 female) who were 24-hour caffeine deprived received one of four treatments (200 mg caffeine/0 mg taurine, 0 mg caffeine/2000 mg taurine, 200 mg caffeine/2000 mg taurine, 0 mg caffeine/0 mg taurine), on each of four separate days, separated by a 3-day wash-out period. Between-participants treatment was a glucose drink (50 g glucose, placebo). Salivary cortisol, mood and heart rate were measured. An attention task was administered 30-minutes post-treatment, followed by a working memory and reaction time task 60-minutes post-treatment. Caffeine enhanced executive control and working memory, and reduced simple and choice reaction time. Taurine increased choice reaction time but reduced reaction time in the working memory tasks. Glucose alone slowed choice reaction time. Glucose in combination with caffeine, enhanced object working memory and in combination with taurine, enhanced orienting attention. Limited glucose effects may reflect low task difficulty relative to subjects' cognitive ability. Caffeine reduced feelings of fatigue and increased tension and vigor. Taurine reversed the effects of caffeine on vigor and caffeine-withdrawal symptoms. No effects were found for salivary cortisol or heart rate. Caffeine, not taurine or glucose, is likely responsible for reported changes in cognitive performance following consumption of energy drinks, especially in caffeine-withdrawn habitual caffeine consumers. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Exercise and Sport Performance with Low Doses of Caffeine

    OpenAIRE

    Spriet, Lawrence L.

    2014-01-01

    Caffeine is a popular work-enhancing supplement that has been actively researched since the 1970s. The majority of research has examined the effects of moderate to high caffeine doses (5–13 mg/kg body mass) on exercise and sport. These caffeine doses have profound effects on the responses to exercise at the whole-body level and are associated with variable results and some undesirable side effects. Low doses of caffeine (

  9. Effects of anxiety sensitivity and expectations on the modulation of the startle eyeblink response during a caffeine challenge.

    Science.gov (United States)

    Benke, Christoph; Blumenthal, Terry D; Modeß, Christiane; Hamm, Alfons O; Pané-Farré, Christiane A

    2015-09-01

    The way in which the tendency to fear somatic arousal sensations (anxiety sensitivity), in interaction with the created expectations regarding arousal induction, might affect defensive responding to a symptom provocation challenge is not yet understood. The present study investigated the effect of anxiety sensitivity on autonomic arousal, startle eyeblink responses, and reported arousal and alertness to expected vs. unexpected caffeine consumption. To create a match/mismatch of expected and experienced arousal, high and low anxiety sensitive participants received caffeine vs. no drug either mixed in coffee (expectation of arousal induction) or in bitter lemon soda (no expectation of arousal induction) on four separate occasions. Autonomic arousal (heart rate, skin conductance level), respiration (end-tidal CO2, minute ventilation), defensive reflex responses (startle eyeblink), and reported arousal and alertness were recorded prior to, immediately and 30 min after beverage ingestion. Caffeine increased ventilation, autonomic arousal, and startle response magnitudes. Both groups showed comparable levels of autonomic and respiratory responses. The startle eyeblink responses were decreased when caffeine-induced arousal occurred unexpectedly, e.g., after administering caffeine in bitter lemon. This effect was more accentuated in high anxiety sensitive persons. Moreover, in high anxiety sensitive persons, the expectation of arousal (coffee consumption) led to higher subjective alertness when administering caffeine and increased arousal even if no drug was consumed. Unexpected symptom provocation leads to increased attention allocation toward feared arousal sensations in high anxiety sensitive persons. This finding broadens our understanding of modulatory mechanisms in defensive responding to bodily symptoms.

  10. Anaphylaxis due to caffeine

    OpenAIRE

    Sugiyama, Kumiya; Cho, Tatsurai; Tatewaki, Masamitsu; Onishi, Shogo; Yokoyama, Tatsuya; Yoshida, Naruo; Fujimatsu, Takayoshi; Hirata, Hirokuni; Fukuda, Takeshi; Fukushima, Yasutsugu

    2015-01-01

    We report a rare case of anaphylaxis due to caffeine intake. A 27-year-old woman suffered her first episode of anaphylaxis and a positive skin prick test suggested that the anaphylaxis was due to an IgE-mediated hypersensitivity reaction to caffeine. She was diagnosed with caffeine allergy and has not had an allergic reaction after avoiding foods and drinks containing caffeine. Although caffeine is known to have antiallergic effects, this case shows that caffeine can be an allergen and cause ...

  11. [Caffeine--common ingredient in a diet and its influence on human health].

    Science.gov (United States)

    Wierzejska, Regina

    2012-01-01

    Caffeine is widely consumed by people of all ages. In the last period a market of caffeine-containing products, particularly energy drinks and food supplements increased. Caffeine for years is under discussion, whether has positive whether adverse impact on health. Children are a group of special anxieties. Caffeine is a stimulant of central nervous system and therefore is probably the most commonly used psychoactive substance in the world. The physiological effect of caffeine and the lack of nutrition value causes a great interest its impact on health, especially with reference to the risk of cardiovascular diseases. Results of scientific research are not clear. The influence of caffeine on the human body is conditioned with the individual metabolism of caffeine which also depends on many endogenic and environmental factors. According to the current knowledge moderate caffeine intake by healthy adults at a dose level of 400 mg a day is not associated with adverse effects, but it also depends on other health determinants of a lifestyle. Excessive caffeine consumption can cause negative health consequences such as psychomotor agitation, insomnia, headache, gastrointestinal complaints. Adverse effect of caffeine intoxication is classified in World Health Organization's International Classification of Diseases (ICD-10). Metabolism of caffeine by pregnant woman is slowed down. Caffeine and its metabolites pass freely across the placenta into a fetus. For this reason pregnant women should limit caffeine intake. Children and adolescents should also limit daily caffeine consumption. It results from the influence of caffeine on the central nervous system in the period of rapid growth and the final stage of brain development, calcium balance and sleep duration. Average daily caffeine consumption in European countries ranging from 280-490 mg. The highest caffeine intake is in Scandinavian countries what results from the great consumption of the coffee. As far as caffeine

  12. Caffeine deprivation affects vigilance performance and mood.

    Science.gov (United States)

    Lane, J D; Phillips-Bute, B G

    1998-08-01

    The effects of brief caffeine deprivation on vigilance performance, mood, and symptoms of caffeine withdrawal were studied in habitual coffee drinkers. Thirty male and female coffee drinkers were tested twice at midday (1130 to 1330 hours) after mornings in which they either consumed caffeinated beverages ad lib or abstained. Vigilance performance was tested with a 30-min computerized visual monitoring task. Mood and withdrawal symptom reports were collected by questionnaires. Caffeine deprivation was associated with impaired vigilance performance characterized by a reduction in the percentage of targets detected and an increase in response time, and by subjective reports of decreased vigor and increased fatigue and symptoms characterized by sleepiness, headache, and reduced ability to work. Even short periods of caffeine deprivation, equivalent in length to skipping regular morning coffee, can produce deficits in sustained attention and noticeable unpleasant caffeine-withdrawal symptoms in habitual coffee drinkers. Such symptoms may be a common side-effect of habitual caffeine consumption that contributes to the maintenance of this behavior.

  13. Use pattern and predictors of use of highly caffeinated energy drinks among South Korean adolescents: a study using the Health Belief Model.

    Science.gov (United States)

    Ha, Dongmun; Song, Inmyung; Jang, Gyeongil; Lee, Eui-Kyung; Shin, Ju-Young

    2017-09-24

    Concerns about the use of highly caffeinated energy drinks among Korean adolescents remains. We compared adolescents' perceptions regarding the use of drinks to their behaviours and factors. A structured questionnaire based on the Health Belief Model was administered to 850 freshmen and sophomores at three high schools in Bucheon, South Korea. Benefits were defined as beneficial effects from the use of highly caffeinated energy drinks (eg, awakening from sleepiness) and harms as adverse effects of the drinks (eg, cardiac palpitation). Likelihood of action represents the likelihood of taking actions that are perceived to be more beneficial after comparison of the benefits and harms of caffeine use. Descriptive analysis was used to quantify the relationship between their beliefs about highly caffeinated energy drinks and their use. We conducted hierarchical logistic regression to compute ORs and 95% CIs for: (1) demographic factors, (2) health threat, (3) likelihood of action and (4) cues to act. Altogether, 833 students responded to the questionnaire (effective response rate=98.0%). About 63.0% reported use of highly caffeinated energy drinks and 35.2% had used them as needed and habitually. The more susceptible the respondents perceived themselves to be to the risk of using these drinks, the less likely they were to use them (OR: 0.73, 95% CI 0.50 to 1.06). The more severe the perception of a health threat, the less that perception was associated with use (OR: 0.44, 95% CI 0.29 to 0.67). Likelihood of action was the strongest predictor of use, explaining 12.5% in use. Benefits and harms (OR: 4.43, 95% CI 2.77 to 7.09; OR: 1.86, 95% CI 1.16 to 2.99) also were significant predictors. Enhancing adolescents' perceptions of benefits and harms regarding using highly caffeinated energy drinks could be an effective way to influence the use of these drinks. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All

  14. The impact of caffeine use across the lifespan on cognitive performance in elderly women.

    Science.gov (United States)

    Perry, Clinton S; Thomas, Ayanna K; Taylor, Holly A; Jacques, Paul F; Kanarek, Robin B

    2016-12-01

    Habitual caffeine consumption has often been associated with decreasing age-related cognitive decline. However, whether habitual caffeine use preferentially spares different cognitive processes is unclear. Furthermore, whether basing habitual caffeine consumption patterns on current consumption or on a lifetime measure better represents an individual's use remains unclear. In the present study, we collected information from women, aged 56-83, about their current caffeine consumption patterns and history of use, including age they began consuming caffeine. Regression models assessed the relationship between caffeine consumption and performance on batteries designed to probe speed of processing, inhibition, memory, and executive function. While we found no direct associations between caffeine exposure and cognitive performance, we found that caffeine consumption and participant BMI interacted for inhibitory function and speed of processing performance. We discuss possible protective effects of long term caffeine use as well as the possibility of dose dependent effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Influence of caffeine consumption on 7,12-dimethylbenz(a)anthracene-induced mammary gland tumorigenesis in female rats fed a chemically defined diet containing standard and high levels of unsaturated fat.

    Science.gov (United States)

    Welsch, C W; DeHoog, J V

    1988-04-15

    The effect of caffeine (430-500 mg/liter of drinking water) on the initiation and promotion phases of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary gland tumorigenesis in female Sprague-Dawley rats fed a chemically defined diet containing standard (5%) or high (20%) levels of fat (corn oil) was examined. In the initiation studies, caffeine and the standard or high fat diet treatments were provided for 34 days, from 24-29 days of age to 58-63 days of age. Three days prior to termination of caffeine-fat diet treatments, each rat received a single dose of DMBA. In the promotion studies, caffeine and the standard or high fat diets were provided commencing 3 days after a single dose of DMBA (at 56-61 days of age) and until termination of the study. Caffeine consumption, during the initiation phase significantly (P less than 0.05) reduced mammary carcinoma multiplicity (number of tumors/rat), in rats fed either a standard or high fat diet. In the promotion studies, prolonged consumption of caffeine in rats fed either a standard or high fat diet did not significantly effect mammary carcinoma multiplicity. In the early stages of promotion, an apparent increase in mammary carcinoma multiplicity was observed; this increase in mammary carcinoma multiplicity did not, however, reach the 5% level of statistical probability. When caffeine was administered during both the initiation and promotion phases, no significant effect on mammary carcinoma multiplicity was observed. Treatment of rats during the initiation or promotion phases with caffeinated coffee (via drinking water) mimicked the mammary tumor modulating activities of caffeine. Decaffeinated coffee consumption did not effect either the initiation or promotion phases of this tumorigenic process. In both the initiation and promotion studies, caffeine and/or coffee consumption did not significantly affect the incidence of mammary carcinomas (percentage of rats bearing mammary carcinomas) or the mean latency period of

  16. Degradation of exogenous caffeine by Populus alba and its effects on endogenous caffeine metabolism.

    Science.gov (United States)

    Pierattini, Erika C; Francini, Alessandra; Raffaelli, Andrea; Sebastiani, Luca

    2016-04-01

    This is the first study reporting the presence of endogenous caffeine, theobromine, and theophylline in all organs of poplar plants. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used in order to evaluate the uptake, translocation, and metabolism of caffeine-(trimethyl-(13)C) in Populus alba L. Villafranca clone grown in hydroponic conditions. We investigated the remediation of caffeine since it is one of the most widely consumed drugs and it is frequently detected in wastewater treatment plant effluents, surface water, and groundwater worldwide. Our results demonstrated that poplar can absorb and degrade exogenous caffeine without negative effects on plant health. Data showed that concentrations of all endogenous compounds varied depending on caffeine-(trimethyl-(13)C) treatments. In particular, in control conditions, endogenous caffeine, theobromine, and theophylline were mainly distributed in roots. On the other hand, once caffeine-(trimethyl-(13)C) was provided, this compound and its dimethy-(13)C metabolites are mainly localized at leaf level. In conclusion, our results support the possible use of Villafranca clone in association with other water treatment systems in order to complete the process of caffeine remediation.

  17. Acute Effect of Caffeine on Amplitude of Accommodation and Near ...

    African Journals Online (AJOL)

    Caffeine is widely consumed in kola nuts and in other products in Sub-Saharan Africa. We examined the acute effect of caffeine on the amplitude of accommodation and near point of convergence of healthy Nigerians. Forty volunteers between ages of 20 and 27 years with refractive power± 0.50 DS were employed.

  18. Caffeine adsorption of montmorillonite in coffee extracts.

    Science.gov (United States)

    Shiono, Takashi; Yamamoto, Kenichiro; Yotsumoto, Yuko; Yoshida, Aruto

    2017-08-01

    The growth in health-conscious consumers continues to drive the demand for a wide variety of decaffeinated beverages. We previously developed a new technology using montmorillonite (MMT) in selective decaffeination of tea extract. This study evaluated and compared decaffeination of coffee extract using MMT and activated carbon (AC). MMT adsorbed caffeine without significant adsorption of caffeoylquinic acids (CQAs), feruloylquinic acids (FQAs), dicaffeoylquinic acids (di-CQAs), or caffeoylquinic lactones (CQLs). AC adsorbed caffeine, chlorogenic acids (CGAs) and CQLs simultaneously. The results suggested that the adsorption selectivity for caffeine in coffee extract is higher in MMT than AC. The caffeine adsorption isotherms of MMT in coffee extract fitted well to the Langmuir adsorption model. The adsorption properties in coffee extracts from the same species were comparable, regardless of roasting level and locality of growth. Our findings suggest that MMT is a useful adsorbent in the decaffeination of a wide range of coffee extracts.

  19. Aspirin, Butalbital, and Caffeine

    Science.gov (United States)

    The combination of aspirin, butalbital, and caffeine comes as a capsule and tablet to take by mouth. It usually is taken every 4 ... explain any part you do not understand. Take aspirin, butalbital, and caffeine exactly as directed. Do not ...

  20. Caffeine in Pregnancy

    Science.gov (United States)

    ... Global Map Premature Birth Report Cards Careers Archives Pregnancy Before or between pregnancies Nutrition, weight & fitness Prenatal ... Nutrition, weight & fitness > Caffeine in pregnancy Caffeine in pregnancy E-mail to a friend Please fill in ...

  1. The Combined Effect of Caffeine and Ornithine on the Mood of Healthy Office Workers

    Science.gov (United States)

    Misaizu, Akane; Kokubo, Takeshi; Tazumi, Kyoko; Kanayama, Masaya; Miura, Yutaka

    2014-01-01

    Caffeine is widely consumed and well known for stimulating the central nervous system. When developing new foods and beverages that contain caffeine, it is important to explore the potential synergistic effects of consuming amino acids and other food ingredients with caffeine on humans. Given the physiological pathways affected by the amino acid ornithine, consumption of ornithine with caffeine may have synergistic effects. The purpose of the present study was to examine the effect of consuming caffeine with ornithine in humans. The study used a randomized, placebo-controlled, double-blinded crossover design. The subjects were all healthy office workers who ingested the placebo, 100 mg caffeine, or 100 mg caffeine plus 200 mg ornithine in the morning and completed questionnaires about their mood. Office workers who consumed the combination of caffeine and ornithine had higher mood ratings 8 h after consumption than office workers who consumed caffeine alone. The results of the present study suggest that there is a unique synergistic effect between caffeine and ornithine on the mood of healthy office workers and that ornithine may potentiate the effects of caffeine. PMID:25580405

  2. Creatine and Caffeine: Considerations for Concurrent Supplementation.

    Science.gov (United States)

    Trexler, Eric T; Smith-Ryan, Abbie E

    2015-12-01

    Nutritional supplementation is a common practice among athletes, with creatine and caffeine among the most commonly used ergogenic aids. Hundreds of studies have investigated the ergogenic potential of creatine supplementation, with consistent improvements in strength and power reported for exercise bouts of short duration (≤ 30 s) and high intensity. Caffeine has been shown to improve endurance exercise performance, but results are mixed in the context of strength and sprint performance. Further, there is conflicting evidence from studies comparing the ergogenic effects of coffee and caffeine anhydrous supplementation. Previous research has identified independent mechanisms by which creatine and caffeine may improve strength and sprint performance, leading to the formulation of multi-ingredient supplements containing both ingredients. Although scarce, research has suggested that caffeine ingestion may blunt the ergogenic effect of creatine. While a pharmacokinetic interaction is unlikely, authors have suggested that this effect may be explained by opposing effects on muscle relaxation time or gastrointestinal side effects from simultaneous consumption. The current review aims to evaluate the ergogenic potential of creatine and caffeine in the context of high-intensity exercise. Research directly comparing coffee and caffeine anhydrous is discussed, along with previous studies evaluating the concurrent supplementation of creatine and caffeine.

  3. Caffeine Use and Extroversion.

    Science.gov (United States)

    Landrum, R. Eric; Meliska, Charles J.

    Some research on the stimulant effect of caffeine suggests that the amount of behavioral enhancement produced by caffeine may depend on subjects' prior experience with the task and the drug. A study was undertaken to test whether prior experience with a task while under the influence of caffeine would facilitate performance of that task. Male…

  4. Caffeine, fatigue, and cognition

    NARCIS (Netherlands)

    Lorist, M.M.; Tops, M.

    2003-01-01

    Effects of caffeine and fatigue are discussed with special attention to adenosine-dopamine interactions. Effects of caffeine on human cognition are diverse. Behavioural measurements indicate a general improvement in the efficiency of information processing after caffeine, while the EEG data support

  5. Effect of caffeine on vestibular evoked myogenic potential: a systematic review with meta-analysis.

    Science.gov (United States)

    Souza, Maria Eduarda Di Cavalcanti Alves de; Costa, Klinger Vagner Teixeira da; Menezes, Pedro de Lemos

    2017-12-24

    Caffeine can be considered the most consumed drug by adults worldwide, and can be found in several foods, such as chocolate, coffee, tea, soda and others. Overall, caffeine in moderate doses, results in increased physical and intellectual productivity, increases the capacity of concentration and reduces the time of reaction to sensory stimuli. On the other hand, high doses can cause noticeable signs of mental confusion and error induction in intellectual tasks, anxiety, restlessness, muscle tremors, tachycardia, labyrinthine changes, and tinnitus. Considering that the vestibular evoked myogenic potential is a clinical test that evaluates the muscular response of high intensity auditory stimulation, the present systematic review aimed to analyze the effects of caffeine on vestibular evoked myogenic potential. This study consisted of the search of the following databases: MEDLINE, CENTRAL, ScienceDirect, Scopus, Web of Science, LILACS, SciELO and ClinicalTrials.gov. Additionally, the gray literature was also searched. The search strategy included terms related to intervention (caffeine or coffee consumption) and the primary outcome (vestibular evoked myogenic potential). Based on the 253 potentially relevant articles identified through the database search, only two full-text publications were retrieved for further evaluation, which were maintained for qualitative analysis. Analyzing the articles found, caffeine has no effect on vestibular evoked myogenic potential in normal individuals. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  6. Caffeine Use among Active Duty Navy and Marine Corps Personnel

    Science.gov (United States)

    Knapik, Joseph J.; Trone, Daniel W.; McGraw, Susan; Steelman, Ryan A.; Austin, Krista G.; Lieberman, Harris R.

    2016-01-01

    Data from the National Health and Nutrition Examination Survey (NHANES) indicate 89% of Americans regularly consume caffeine, but these data do not include military personnel. This cross-sectional study examined caffeine use in Navy and Marine Corps personnel, including prevalence, amount of daily consumption, and factors associated with use. A random sample of Navy and Marine Corps personnel was contacted and asked to complete a detailed questionnaire describing their use of caffeine-containing substances, in addition to their demographic, military, and lifestyle characteristics. A total of 1708 service members (SMs) completed the questionnaire. Overall, 87% reported using caffeinated beverages ≥1 time/week, with caffeine users consuming a mean ± standard error of 226 ± 5 mg/day (242 ± 7 mg/day for men, 183 ± 8 mg/day for women). The most commonly consumed caffeinated beverages (% users) were coffee (65%), colas (54%), teas (40%), and energy drinks (28%). Multivariable logistic regression modeling indicated that characteristics independently associated with caffeine use (≥1 time/week) included older age, white race/ethnicity, higher alcohol consumption, and participating in less resistance training. Prevalence of caffeine use in these SMs was similar to that reported in civilian investigations, but daily consumption (mg/day) was higher. PMID:27735834

  7. Caffeine Use among Active Duty Navy and Marine Corps Personnel

    Directory of Open Access Journals (Sweden)

    Joseph J. Knapik

    2016-10-01

    Full Text Available Data from the National Health and Nutrition Examination Survey (NHANES indicate 89% of Americans regularly consume caffeine, but these data do not include military personnel. This cross-sectional study examined caffeine use in Navy and Marine Corps personnel, including prevalence, amount of daily consumption, and factors associated with use. A random sample of Navy and Marine Corps personnel was contacted and asked to complete a detailed questionnaire describing their use of caffeine-containing substances, in addition to their demographic, military, and lifestyle characteristics. A total of 1708 service members (SMs completed the questionnaire. Overall, 87% reported using caffeinated beverages ≥1 time/week, with caffeine users consuming a mean ± standard error of 226 ± 5 mg/day (242 ± 7 mg/day for men, 183 ± 8 mg/day for women. The most commonly consumed caffeinated beverages (% users were coffee (65%, colas (54%, teas (40%, and energy drinks (28%. Multivariable logistic regression modeling indicated that characteristics independently associated with caffeine use (≥1 time/week included older age, white race/ethnicity, higher alcohol consumption, and participating in less resistance training. Prevalence of caffeine use in these SMs was similar to that reported in civilian investigations, but daily consumption (mg/day was higher.

  8. The perinatal effects of maternal caffeine intake on fetal and neonatal brain levels of testosterone, estradiol, and dihydrotestosterone in rats.

    Science.gov (United States)

    Karaismailoglu, S; Tuncer, M; Bayrak, S; Erdogan, G; Ergun, E L; Erdem, A

    2017-08-01

    Testosterone, estradiol, and dihydrotestosterone are the main sex steroid hormones responsible for the organization and sexual differentiation of brain structures during early development. The hypothalamo-pituitary-adrenocortical axis, adrenal cells, and gonads play a key role in the production of sex steroids and express adenosine receptors. Caffeine is a non-selective adenosine antagonist; therefore, it can modulate metabolic pathways in these tissues. Besides, the proportion of pregnant women that consume caffeine is ∼60%. That is why the relationship between maternal caffeine consumption and fetal development is important. Therefore, we aimed to investigate this modulatory effect of maternal caffeine consumption on sex steroids in the fetal and neonatal brain tissues. Pregnant rats were treated with a low (0.3 g/L) or high (0.8 g/L) dose of caffeine in their drinking water during pregnancy and lactation. The testosterone, estradiol, and dihydrotestosterone levels in the frontal cortex and hypothalamus were measured using radioimmunoassay at embryonic day 19 (E19), birth (PN0), and postnatal day 4 (PN4). The administration of low-dose caffeine increased the body weight in PN4 male and female rats and anogenital index in PN4 males. The administration of high-dose caffeine decreased the adrenal weight in E19 male rats and increased testosterone levels in the frontal cortex of E19 female rats and the hypothalamus of PN0 male rats. Maternal caffeine intake during pregnancy affects sex steroid levels in the frontal cortex and hypothalamus of the offspring. This concentration changes of the sex steroids in the brain may influence behavioral and neuroendocrine functions at some point in adult life.

  9. Psychostimulant and other effects of caffeine in 9- to 11-year-old children.

    Science.gov (United States)

    Heatherley, Susan V; Hancock, Katie M F; Rogers, Peter J

    2006-02-01

    Recent research on adults suggests that "beneficial" psychostimulant effects of caffeine are found only in the context of caffeine deprivation; that is, caffeine improves psychomotor and cognitive performance in habitual caffeine consumers following caffeine withdrawal. Furthermore, no net benefit is gained because performance is merely restored to "baseline" levels. The effects of caffeine in children is an under-researched area, with only a handful of studies being carried out in the US where children's consumption of caffeine appears to be lower on average than in the UK. Twenty-six children aged between 9 and 11 years completed a double-blind, placebo-controlled study. Habitual caffeine consumers (mean daily caffeine intake = 109 mg) and non/low-consumers (12 mg) were tested on two separate days following overnight caffeine abstinence. On each day measures of cognitive performance (a number search task), and self-rated mood and physical symptoms, including alertness and headache, were taken before and after administration of 50 mg of caffeine, or placebo. At baseline (before treatment), the habitual consumers showed poorer performance on the cognitive test than did the non/low-consumers, although no significant differences in mood or physical symptoms were found between the two groups. There were significant habit by treatment (caffeine vs. placebo) interactions for accuracy of performance and headache, and a significant main effect of treatment for alertness. Post hoc comparisons showed that caffeine administration improved the consumers' accuracy on the cognitive test (to near the level displayed by the non/low-consumers at baseline), but that it had no significant effect on the non/low-consumers' performance. In the consumers, caffeine prevented an increase in headache that occurred after placebo, and it increased alertness relative to placebo. Again, however, caffeine did not significantly affect levels of headache or alertness in the non/low-consumers

  10. Quantitative HPLC Analysis of an Analgesic/Caffeine Formulation: Determination of Caffeine

    Science.gov (United States)

    Ferguson, Glenda K.

    1998-04-01

    A modern high performance liquid chromatography (HPLC) laboratory experiment which entails the separation of acetaminophen, aspirin, and caffeine and the quantitative assay of caffeine in commercial mixtures of these compounds has been developed. Our HPLC protocol resolves these compounds in only three minutes with a straightforward chromatographic apparatus which consists of a C-18 column, an isocratic mobile phase, UV detection at 254 nm, and an integrator; an expensive, sophisticated system is not required. The separation is both repeatable and rapid. Moreover, the experiment can be completed in a single three-hour period. The experiment is appropriate for any chemistry student who has completed a minimum of one year of general chemistry and is ideal for an analytical or instrumental analysis course. The experiment detailed herein involves the determination of caffeine in Goody's Extra Strength Headache Powders, a commercially available medication which contains acetaminophen, aspirin, and caffeine as active ingredients. However, the separation scheme is not limited to this brand of medication nor is it limited to caffeine as the analyte. With only minor procedural modifications, students can simultaneously quantitate all of these compounds in a commercial mixture. In our procedure, students prepare a series of four caffeine standard solutions as well as a solution from a pharmaceutical analgesic/caffeine mixture, chromatographically analyze each solution in quadruplicate, and plot relative average caffeine standard peak area versus concentration. From the mathematical relationship that results, the concentration of caffeine in the commercial formulation is obtained. Finally, the absolute standard deviation of the mean concentration is calculated.

  11. A review of caffeine's effects on cognitive, physical and occupational performance.

    Science.gov (United States)

    McLellan, Tom M; Caldwell, John A; Lieberman, Harris R

    2016-12-01

    Caffeine is consumed by over 80% of U.S. adults. This review examines the effects caffeine has on cognitive and physical function, since most real-world activities require complex decision making, motor processing and movement. Caffeine exerts its effects by blocking adenosine receptors. Following low (∼40mg or ∼0.5mgkg -1 ) to moderate (∼300mg or 4mgkg -1 ) caffeine doses, alertness, vigilance, attention, reaction time and attention improve, but less consistent effects are observed on memory and higher-order executive function, such as judgment and decision making. Effects on physical performance on a vast array of physical performance metrics such as time-to-exhaustion, time-trial, muscle strength and endurance, and high-intensity sprints typical of team sports are evident following doses that exceed about 200mg (∼3mgkg -1 ). Many occupations, including military, first responders, transport workers and factory shift workers, require optimal physical and cognitive function to ensure success, workplace safety and productivity. In these circumstances, that may include restricted sleep, repeated administration of caffeine is an effective strategy to maintain physical and cognitive capabilities. Published by Elsevier Ltd.

  12. Medical students' use of caffeine for 'academic purposes' and their ...

    African Journals Online (AJOL)

    Third-year students were the heaviest consumers of coffee for academic purposes. .... Caffeine can, however, only reliably affect cognitive performance and mood if the ... decreased alertness, drowsiness, decreased contentedness, depressed.

  13. Caffeine: Friend or Foe?

    Science.gov (United States)

    Doepker, Candace; Lieberman, Harris R; Smith, Andrew Paul; Peck, Jennifer D; El-Sohemy, Ahmed; Welsh, Brian T

    2016-01-01

    The debate on the safety of and regulatory approaches for caffeine continues among various stakeholders and regulatory authorities. This decision-making process comes with significant challenges, particularly when considering the complexities of the available scientific data, making the formulation of clear science-based regulatory guidance more difficult. To allow for discussions of a number of key issues, the North American Branch of the International Life Sciences Institute (ILSI) convened a panel of subject matter experts for a caffeine-focused session entitled "Caffeine: Friend or Foe?," which was held during the 2015 ILSI Annual Meeting. The panelists' expertise covered topics ranging from the natural occurrence of caffeine in plants and interindividual metabolism of caffeine in humans to specific behavioral, reproductive, and cardiovascular effects related to caffeine consumption. Each presentation highlighted the potential risks, benefits, and challenges that inform whether caffeine exposure warrants concern. This paper aims to summarize the key topics discussed during the session.

  14. Genetic polymorphism of the adenosine A2A receptor is associated with habitual caffeine consumption.

    Science.gov (United States)

    Cornelis, Marilyn C; El-Sohemy, Ahmed; Campos, Hannia

    2007-07-01

    Caffeine is the most widely consumed stimulant in the world, and individual differences in response to its stimulating effects may explain some of the variability in caffeine consumption within a population. We examined whether genetic variability in caffeine metabolism [cytochrome P450 1A2 (CYP1A2) -163A-->C] or the main target of caffeine action in the nervous system [adenosine A(2A) receptor (ADORA2A) 1083C-->T] is associated with habitual caffeine consumption. Subjects (n=2735) were participants from a study of gene-diet interactions and risk of myocardial infarction who did not have a history of hypertension. Genotype frequencies were examined among persons who were categorized according to their self-reported daily caffeine intake, as assessed with a validated food-frequency questionnaire. The ADORA2A, but not the CYP1A2, genotype was associated with different amounts of caffeine intake. Compared with persons consuming caffeine/d, the odds ratios for having the ADORA2A TT genotype were 0.74 (95% CI: 0.53, 1.03), 0.63 (95% CI: 0.48, 0.83), and 0.57 (95% CI: 0.42, 0.77) for those consuming 100-200, >200-400, and >400 mg caffeine/d, respectively. The association was more pronounced among current smokers than among nonsmokers (P for interaction = 0.07). Persons with the ADORA2A TT genotype also were significantly more likely to consume less caffeine (ie, caffeine consumption increases. This observation provides a biologic basis for caffeine consumption behavior and suggests that persons with this genotype may be less vulnerable to caffeine dependence.

  15. Determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography.

    Science.gov (United States)

    Oellig, Claudia; Schunck, Jacob; Schwack, Wolfgang

    2018-01-19

    Mate beer and Mate soft drinks are beverages produced from the dried leaves of Ilex paraguariensis (Yerba Mate). In Yerba Mate, the xanthine derivatives caffeine, theobromine and theophylline, also known as methylxanthines, are important active components. The presented method for the determination of caffeine, theobromine and theophylline in Mate beer and Mate soft drinks by high-performance thin-layer chromatography with ultraviolet detection (HPTLC-UV) offers a fully automated and sensitive determination of the three methylxanthines. Filtration of the samples was followed by degassing, dilution with acetonitrile in the case of Mate beers for protein precipitation, and centrifugation before the extracts were analyzed by HPTLC-UV on LiChrospher silica gel plates with fluorescence indicator and acetone/toluene/chloroform (4:3:3, v/v/v) as the mobile phase. For quantitation, the absorbance was scanned at 274nm. Limits of detection and quantitation were 1 and 4ng/zone, respectively, for caffeine, theobromine and theophylline. With recoveries close to 100% and low standard deviations reliable results were guaranteed. Experimental Mate beers as well as Mate beers and Mate soft drinks from the market were analyzed for their concentrations of methylxanthines. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Energy drinks and the neurophysiological impact of caffeine.

    Science.gov (United States)

    Persad, Leeana Aarthi Bagwath

    2011-01-01

    Caffeine is the most widely used psychoactive stimulant with prevalent use across all age groups. It is a naturally occurring substance found in the coffee bean, tea leaf, the kola nut, cocoa bean. Recently there has been an increase in energy drink consumption leading to caffeine abuse, with aggressive marketing and poor awareness on the consequences of high caffeine use. With caffeine consumption being so common, it is vital to know the impact caffeine has on the body, as its effects can influence cardio-respiratory, endocrine, and perhaps most importantly neurological systems. Detrimental effects have being described especially since an over consumption of caffeine has being noted. This review focuses on the neurophysiological impact of caffeine and its biochemical pathways in the human body.

  17. Energy drinks and the neurophysiological impacts of caffeine

    Directory of Open Access Journals (Sweden)

    Leeana eBagwath Persad

    2011-10-01

    Full Text Available Caffeine is the most widely used psychoactive stimulant with prevalent use across all age groups. It is a naturally occurring substance found in the coffee bean, tea leaf, the kola nut, cocoa bean. Recently there has been an increase in energy drink consumption leading to caffeine abuse, with aggressive marketing and poor awareness on the consequences of high caffeine use. With caffeine consumption being so common, it is vital to know the impact caffeine has on the body, as its effects can influence cardio-respiratory, endocrine and perhaps most importantly neurological systems. Detrimental effects have being described especially since an over consumption of caffeine has being noted. This review focuses on the neurophysiological impact of caffeine and its biochemical pathways in the human body.

  18. Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine.

    Science.gov (United States)

    Beaumont, Ross; Cordery, Philip; Funnell, Mark; Mears, Stephen; James, Lewis; Watson, Phillip

    2017-10-01

    This study examined effects of 4 weeks of caffeine supplementation on endurance performance. Eighteen low-habitual caffeine consumers (caffeine (1.5-3.0 mg · kg -1 day -1 ; titrated) or placebo for 28 days. Groups were matched for age, body mass, V̇O 2peak and W max (P > 0.05). Before supplementation, all participants completed one V̇O 2peak test, one practice trial and 2 experimental trials (acute 3 mg · kg -1 caffeine [precaf] and placebo [testpla]). During the supplementation period a second V̇O 2peak test was completed on day 21 before a final, acute 3 mg · kg -1 caffeine trial (postcaf) on day 29. Trials consisted of 60 min cycle exercise at 60% V̇O 2peak followed by a 30 min performance task. All participants produced more external work during the precaf trial than testpla, with increases in the caffeine (383.3 ± 75 kJ vs. 344.9 ± 80.3 kJ; Cohen's d effect size [ES] = 0.49; P = 0.001) and placebo (354.5 ± 55.2 kJ vs. 333.1 ± 56.4 kJ; ES = 0.38; P = 0.004) supplementation group, respectively. This performance benefit was no longer apparent after 4 weeks of caffeine supplementation (precaf: 383.3 ± 75.0 kJ vs. postcaf: 358.0 ± 89.8 kJ; ES = 0.31; P = 0.025), but was retained in the placebo group (precaf: 354.5 ± 55.2 kJ vs. postcaf: 351.8 ± 49.4 kJ; ES = 0.05; P > 0.05). Circulating caffeine, hormonal concentrations and substrate oxidation did not differ between groups (all P > 0.05). Chronic ingestion of a low dose of caffeine develops tolerance in low-caffeine consumers. Therefore, individuals with low-habitual intakes should refrain from chronic caffeine supplementation to maximise performance benefits from acute caffeine ingestion.

  19. D-ribose--an additive with caffeine.

    Science.gov (United States)

    Herrick, Jim; Shecterle, L M; St Cyr, J A

    2009-05-01

    Caffeine acts as a stimulant, in which approximately 90% of people in the United States consume daily. Besides its beneficial effects, many individuals have experienced unpleasant reactions following the consumption of caffeine: such as insomnia, an increase in heart rate, feelings of nervousness, headaches, occasional lightheadedness, a state of "jitters," and a potential "crash" state following its metabolism. Researchers have proposed mechanisms responsible for caffeine's interactions, which include its blocking capacity of adenosine receptors, its role with the pituitary gland, increasing levels of dopamine, and its role with the intracellular release of calcium from the sarcoplasmic reticulum, which is dependent on intracellular adenosine triphosphate levels. Specific substrates have been investigated to lessen the undesirable effects of caffeine and still preserve its stimulatory benefits. The results of these investigations have produced no positive consensus. However, D-ribose, an important pentose carbohydrate in the energy molecule of adenosine triphosphate, as well as our genetic code and other cellular processes, could offer such a solution to this problem. D-ribose could potentially aid in maintaining or potentially lowering extra-cellular adenosine concentrations, aid in the flux of intracellular calcium, aid in intracellular energy production, and potentially lessen the perceived "crash" state felt by many. Every cell requires adequate levels of energy to maintain its integrity and function. Caffeine has the potential to task this energy equilibrium. D-ribose with caffeine may be the substrate to aid in the potential intracellular energy demand, aid in lessening the perceived unpleasant side effects of caffeine, and still preserving the desired benefits of this stimulant consumed by all of us daily.

  20. Caffeinated drinks, alcohol consumption and hangover severity

    NARCIS (Netherlands)

    Penning, R.; de Haan, L.; Verster, J.C.

    2011-01-01

    This study examined the relationship between consumption of caffeinated beverages and alcohol, and effects on next day hangover severity. In 2010, a survey funded by Utrecht University was conducted among N=549 Dutch students. Beverages consumed on their latest drinking session that produced a

  1. Acute effects of theanine, caffeine and theanine-caffeine combination on attention.

    Science.gov (United States)

    Kahathuduwa, Chanaka N; Dassanayake, Tharaka L; Amarakoon, A M Tissa; Weerasinghe, Vajira S

    2017-07-01

    l-theanine is a constituent of tea which is claimed to enhance cognitive functions. We aimed to determine whether theanine and theanine-caffeine combination have acute positive effects on cognitive and neurophysiological measures of attention, compared to caffeine (a positive control) and a placebo in healthy individuals. In a placebo-controlled, five-way crossover trial in 20 healthy male volunteers, we compared the effects of l-theanine (200 mg), caffeine (160 mg), their combination, black tea (one cup) and a placebo (distilled water) on cognitive (simple [SVRT] and recognition visual reaction time [RVRT]) and neurophysiological (event-related potentials [ERPs]) measures of attention. We also recorded visual (VEPs) and motor evoked potentials (MEPs) to examine any effects of treatments on peripheral visual and motor conduction, respectively. Mean RVRT was significantly improved by theanine (P = 0.019), caffeine (P = 0.043), and theanine-caffeine combination (P = 0.001), but not by tea (P = 0.429) or placebo (P = 0.822). VEP or MEP latencies or SVRT did not show significant inter-treatment differences. Theanine (P = 0.001) and caffeine (P = 0.001) elicited significantly larger mean peak-to-peak N2-P300 ERP amplitudes than the placebo, whereas theanine-caffeine combination elicited a significantly larger mean N2-P300 amplitude than placebo (P caffeine (P = 0.005). No significant theanine × caffeine interaction was observed for RVRT or N2-P300 amplitude. A dose of theanine equivalent of eight cups of back tea improves cognitive and neurophysiological measures of selective attention, to a degree that is comparable with that of caffeine. Theanine and caffeine seem to have additive effects on attention in high doses.

  2. [Caffeine: a nutrient, a drug or a drug of abuse].

    Science.gov (United States)

    Pardo Lozano, Ricardo; Alvarez García, Yolanda; Barral Tafalla, Diego; Farré Albaladejo, Magí

    2007-01-01

    Coffee, tea, chocolate and caffeinated drinks are the main sources of caffeine, which is consumed in almost all ages and socioeconomic levels. Caffeine acts as a non-selective adenosine receptor antagonist in the central nervous system. Its main effects are as psychostimulant, acting in addition on the respiratory, muscular and cardiovascular systems. Basically, caffeine is metabolized by the hepatic cytochrome P-450 1A2 enzymes (CYP1A2). Several drugs can interact with its metabolism. The observed interindividual differences of its effects can be explained by variations in its metabolism. The main therapeutic use of caffeine is bronchodilator in respiratory diseases. Other possible uses are under investigation. Acute or chronic consumption of caffeine can induce several adverse effects, including intoxication that can be lethal. Finally, caffeine can be considered a drug of abuse. It has positive reinforcing actions, produces tolerance, and a withdrawal syndrome after stopping its consumption. Caffeine can cause different mental disorders such as dependence, which is not included in the DSM-IV-R, withdrawal syndrome and intoxication. Depending on its use, caffeine can be considered a nutrient, a drug or a drug of abuse.

  3. Regulation of cerebrospinal fluid production by caffeine consumption

    Directory of Open Access Journals (Sweden)

    Yoon Sik

    2009-09-01

    Full Text Available Abstract Background Caffeine is the most commonly consumed psycho-stimulant in the world. The effects of caffeine on the body have been extensively studied; however, its effect on the structure of the brain has not been investigated to date. Results In the present study we found that the long-term consumption of caffeine can induce ventriculomegaly; this was observed in 40% of the study rats. In the caffeine-treated rats with ventriculomegaly, there was increased production of CSF, associated with the increased expression of Na+, K+-ATPase and increased cerebral blood flow (CBF. In contrast to the chronic effects, acute treatment with caffeine decreased the production of CSF, suggesting 'effect inversion' associated with caffeine, which was mediated by increased expression of the A1 adenosine receptor, in the choroid plexus of rats chronically treated with caffeine. The involvement of the A1 adenosine receptor in the effect inversion of caffeine was further supported by the induction of ventriculomegaly and Na+, K+-ATPase, in A1 agonist-treated rats. Conclusion The results of this study show that long-term consumption of caffeine can induce ventriculomegaly, which is mediated in part by increased production of CSF. Moreover, we also showed that adenosine receptor signaling can regulate the production of CSF by controlling the expression of Na+, K+-ATPase and CBF.

  4. Caffeine use and dependence in adolescents: one-year follow-up.

    Science.gov (United States)

    Oberstar, Joel V; Bernstein, Gail A; Thuras, Paul D

    2002-01-01

    The objectives were to conduct a 1-year follow-up of daily caffeine-using adolescents to further describe caffeine dependence symptoms and to determine whether caffeine dependence is associated with other substance dependence disorders. Twenty-one of 36 (58.3%) adolescents who participated in a study of caffeine dependence returned for follow-up. The previous study was a case series of adolescents who consumed caffeine daily and met some Diagnostic and Statistical Manual of Mental Disorders (fourth edition) substance dependence criteria as applied to caffeine. At follow-up, caffeine consumption from beverages was 179.9 +/- 151.8 mg/day. Of the 21 teenagers, 23.8% (n = 5) met criteria for caffeine dependence. Four of these participants developed caffeine dependence during the follow-up period. Other substance dependence disorders were not overrepresented in the caffeine dependent group compared to the caffeine nondependent group. The most commonly reported withdrawal symptoms in dependent teenagers (at baseline and follow-up combined) were feeling drowsy/tired, fatigued, or sluggish/slowed down (83.3% each) and headache (75.0%). Caffeine dependence occurs in some adolescents who drink caffeine daily and is marked by symptoms similar to those found in adults.

  5. Caffeine and cognition in functional magnetic resonance imaging.

    Science.gov (United States)

    Koppelstaetter, Florian; Poeppel, Thorsten D; Siedentopf, Christian M; Ischebeck, Anja; Kolbitsch, Christian; Mottaghy, Felix M; Felber, Stephan R; Jaschke, Werner R; Krause, Bernd J

    2010-01-01

    Caffeine has been consumed since ancient times due to its beneficial effects on attention, psychomotor function, and memory. Caffeine exerts its action mainly through an antagonism of cerebral adenosine receptors, although there are important secondary effects on other neurotransmitter systems. Recently, functional MRI (fMRI) entered the field of neuropharmacology to explore the intracerebral sites and mechanisms of action of pharmacological agents. However, as caffeine possesses vasoconstrictive properties it may interfere with the mechanisms underlying the functional contrast in fMRI. Yet, only a limited number of studies dealt with the effect of caffeine on measures in fMRI. Even fewer neuroimaging studies examined the effects that caffeine exerts on cognition: Portas and colleagues used fMRI in an attentional task under different levels of arousal (sleep deprivation or caffeine administration), concluding that the thalamus is involved in mediating the interaction of attention and arousal. Bendlin and colleagues found caffeine to stabilize the extent of neuronal activation in repetitive word stem completion, counteracting the general task practice effect. Recently, Koppelstaetter and colleagues assessed the effect of caffeine on verbal working memory demonstrating a modulatory effect of caffeine on brain regions (medial frontopolar and anterior cingulate cortex) that have been associated with attentional and executive functions. This review surveys and discusses neuroimaging findings on 1) how caffeine affects the contrast underlying fMRI techniques, particularly the blood oxygen level dependent contrast (BOLD fMRI), and 2) how caffeine operates on neuronal activity underlying cognition, to understand the effect of caffeine on behavior and its neurobiological underpinnings.

  6. Improving the quality of pork and pork products for the consumer : development of innovative, integrated, and sustainable food production chains of high quality pork products matching consumer demands

    NARCIS (Netherlands)

    Heimann, B.; Christensen, M.; Rosendal Rasmussen, S.; Bonneau, M.; Grunert, K.G.; Arnau, J.; Trienekens, J.H.; Oksbjerg, N.; Greef, de K.H.; Petersen, B.

    2012-01-01

    Improving the quality of pork and pork products for the consumer: development of innovative, integrated, and sustainable food production chains of high quality pork products matching consumer demands.

  7. Caffeine, fatigue, and cognition.

    Science.gov (United States)

    Lorist, Monicque M; Tops, Mattie

    2003-10-01

    Effects of caffeine and fatigue are discussed with special attention to adenosine-dopamine interactions. Effects of caffeine on human cognition are diverse. Behavioural measurements indicate a general improvement in the efficiency of information processing after caffeine, while the EEG data support the general belief that caffeine acts as a stimulant. Studies using ERP measures indicate that caffeine has an effect on attention, which is independent of specific stimulus characteristics. Behavioural effects on response related processes turned out to be mainly related to more peripheral motor processes. Recent insights in adenosine and dopamine physiology and functionality and their relationships with fatigue point to a possible modulation by caffeine of mechanisms involved in the regulation of behavioural energy expenditure.

  8. Effects of carbohydrate mouth rinse and caffeine on high-intensity interval running in a fed state.

    Science.gov (United States)

    Devenney, Simon; Mangan, Shane; Shortall, Marcus; Collins, Kieran

    2018-05-01

    The current study aims to identify if mouth rinsing with a 6% carbohydrate mouth-rinse (CMR) solution and mouth rinsing and ingestion of caffeine (CMR+CAFF) can affect exercise performance during steady-state (SS) running and high-intensity intervals (HIIT) in comparison with a 0% control solution (PLA) when in a fed state. Eight recreationally trained males completed 3 trials (CMR, CMR+CAFF, and PLA) of 45 min SS running and an HIIT protocol (90% peak treadmill velocity) until fatigue in a double blinded, repeated-measures study. Participants ingested a capsule of either CAFF or PLA before and after SS. Participants received a 25-mL bolus of carbohydrate solution (CMR and CMR+CAFF trials) or taste-matched PLA (PLA trial) prior to HIIT protocol and after every second effort. Heart rate and lactate responses were recorded throughout the SS and HIIT protocol. CMR+CAFF was significantly different when compared with PLA (p = 0.001; Cohens d = 1.34) and CMR (p = 0.031; Cohens d = 0.87) in relation to distance covered before fatigue. Although there was no significant difference between CMR and PLA, there was a small benefit for CMR (p = 0.218; Cohens d = 0.46). Results indicate that CMR and ingestion of CAFF leads to improvements in performance during interval sessions while participants were in a fed state. These findings indicate that the regular use of CMR can decrease the risk of gastrointestinal distress reported by athletes, which can be applicable to athletes in a real-world setting.

  9. Reinforcing effects of caffeine and theobromine as found in chocolate.

    Science.gov (United States)

    Smit, Hendrik J; Blackburn, Rachel J

    2005-08-01

    Although in a previous study we showed that caffeine and theobromine were the main psychopharmacologically active constituents in a 50-g bar of chocolate, mere activity does not guarantee a role in our liking for the food. Our aim was to see if liking for a drink repeatedly paired with these amounts of caffeine and theobromine would increase compared to a placebo-paired drink. Participants (n=64) consumed a 'novel' drink + treatment capsule on six non-consecutive mornings using a double-blind, placebo-controlled independent-sample design. Aspects of liking and intensity of various sensory descriptors for these drinks were measured at every drink collection. Treatment capsules contained either an ecologically relevant dose combination of 19-mg caffeine and 250-mg theobromine or a placebo. Liking for the drink paired with the methylxanthine-containing capsules increased over time compared to the placebo-paired drink. This highly significant effect was confirmed by subjective, retrospective changes in liking for the drink. Methylxanthines in amounts found in 50-g chocolate may well contribute to our liking for chocolate, especially to the more acquired taste for dark chocolate.

  10. Caffeine for asthma

    OpenAIRE

    Welsh, EJ; Bara, A; Barley, E; Cates, CJ

    2010-01-01

    Background\\ud \\ud Caffeine has a variety of pharmacological effects; it is a weak bronchodilator and it also reduces respiratory muscle fatigue. It is chemically related to the drug theophylline which is used to treat asthma. It has been suggested that caffeine may reduce asthma symptoms and interest has been expressed in its potential role as an asthma treatment. A number of studies have explored the effects of caffeine in asthma, this is the first review to systematically examine and summar...

  11. The effect of caffeine on working memory load-related brain activation in middle-aged males

    NARCIS (Netherlands)

    Klaassen, E.B.; de Groot, R.H.M.; Evers, E.A.T.; Snel, J.; Veerman, E.C.I.; Ligtenberg, A.J.M.; Jolles, J.; Veltman, D.J.

    2013-01-01

    Caffeine is commonly consumed in an effort to enhance cognitive performance. However, little is known about the usefulness of caffeine with regard to memory enhancement, with previous studies showing inconsistent effects on memory performance. We aimed to determine the effect of caffeine on working

  12. Caffeine in tea Camellia sinensis--content, absorption, benefits and risks of consumption.

    Science.gov (United States)

    Gramza-Michałowska, A

    2014-01-01

    Therapeutic properties of tea Camellia sinensis are of particular interest since it has been consumed for ages and was always regarded as safe beverage. Tea is most popular beverage in the world because of its attractive aroma, exceptional taste, health promoting and pharmaceutical potential. Current results showed that antioxidative, antibacterial and other health effects are attributed to its caffeine content and caffeine - polyphenols interactions. An overview is given on caffeine content in different tea leaves beverage. Special attention is drawn to caffeine physiological effect on human organism. Controversies concerning the possible caffeine influence on human physical and psychological health are briefly summarized and presented.

  13. Caffeine-containing beverages, total fluid consumption, and premenstrual syndrome.

    Science.gov (United States)

    Rossignol, A M; Bonnlander, H

    1990-09-01

    The main objective of this study was to evaluate whether daily consumption of caffeine-containing beverages is related to the prevalence and severity of premenstrual syndrome apart from any effects of daily total fluid consumption. A secondary objective was to determine whether daily total fluid consumption itself is related to premenstrual syndrome. The study is based on 841 responses to a questionnaire probing menstrual and premenstrual health, and daily fluid consumption, which was mailed to female university students in Oregon. Analysis of the data revealed that consumption of caffeine-containing beverages was strongly related to the prevalence of premenstrual syndrome. Among women with more severe symptoms, the relation between consumption of caffeine-containing beverages and premenstrual syndrome was dose-dependent, with prevalence odds ratios equal to 1.3 for consumers of one cup of a caffeine-containing beverage per day and increasing steadily to 7.0 for consumers of eight to 10 cups per day. The effects were apparent among both caffeine-containing tea/coffee consumers and caffeine-containing soda consumers. The observed effects were only slightly reduced when daily total fluid consumption was controlled. Daily total fluid consumption also was related to the prevalence of premenstrual symptoms although the effects were large only for consumers of 13-19 cups of fluid per day (the largest amount studied).

  14. Energy drinks available in Ireland: a description of caffeine and sugar content.

    Science.gov (United States)

    Keaver, Laura; Gilpin, Susannah; Fernandes da Silva, Joana Caldeira; Buckley, Claire; Foley-Nolan, Cliodhna

    2017-06-01

    To describe the caffeine and sugar content of all energy drinks available on the island of Ireland. Two retail outlets were selected from each of: multinational, convenience and discount stores in Northern Ireland and the Republic of Ireland, and all available single-serve energy drinks were purchased. The cross-sectional survey was conducted in February 2015 and brand name, price, volume, caffeine and sugar content were recorded for each product. Descriptive analysis was performed. Seventy-eight products were identified on the island of Ireland (regular, n 59; diet/sugar-free/light, n 19). Caffeine and sugar content was in the range of 14-35 mg and 2·9-15·6 g per 100 ml, respectively. Mean caffeine content of 102·2 mg per serving represents 25·6 % of the maximum intake advised for adults by the European Food Safety Authority. Per serving, mean sugar content of regular energy drinks was 37 g. This exceeds WHO recommendations for maximum daily sugar intake of energy intake (25 g for adults consuming 8368 kJ (2000 kcal) diet). If displaying front-of-pack labelling, fifty-seven of the fifty-nine regular energy drinks would receive a Food Standards Agency 'red' colour-coded label for sugar. Energy drinks are freely available on the island of Ireland and all products surveyed can be defined as highly caffeinated products. This has potential health issues particularly for children and adolescents where safe limits of caffeine have not been determined. Energy drinks surveyed also contained high levels of sugar and could potentially contribute to weight gain and adverse dental health effects.

  15. Inducing somatic meiosis-like reduction at high frequency by caffeine in root-tip cells of Vicia faba.

    Science.gov (United States)

    Chen, Y; Zhang, L; Zhou, Y; Geng, Y; Chen, Z

    2000-07-20

    Germinated seeds of Vicia faba were treated in caffeine solutions of different concentration for different durations to establish the inducing system of somatic meiosis-like reduction. The highest frequency of somatic meiosis-like reduction could reach up to 54.0% by treating the root tips in 70 mmol/l caffeine solution for 2 h and restoring for 24 h. Two types of somatic meiosis-like reduction were observed. One was reductional grouping, in which the chromosomes in a cell usually separated into two groups, and the role of spindle fibers did not show. The other type was somatic meiosis, which was analogous to meiosis presenting in gametogenesis, and chromosome pairing and chiasmata were visualized.

  16. Improved high-performance liquid chromatography method to determine theobromine and caffeine in cocoa and cocoa products.

    Science.gov (United States)

    Pura Naik, J

    2001-08-01

    At present, the commonly used HPLC method for the analysis of caffeine and theobromine contents in aqueous cocoa extracts employs direct application of the extracts on the column. This practice gradually reduces the efficiency of the column and shortens its life. Also, this method gives inflated values due to interfering substances and difficulty in achieving baseline resolution. In the improved method, the interfering cocoa pigments are effectively removed by passing the aqueous extract through a Sep-pak C(18) cartridge. Subsequent injection on a C(18) reverse-phase column employing acetonitrile and water (20:80) as the mobile phase reduces the analysis time without affecting either resolution of the peak or the accuracy of caffeine and theobromine determination or achieving baseline resolution. Therefore, this method is ideally suited for rapid routine analysis of cocoa and its products.

  17. Intake of caffeine from all sources and reasons for use by college students.

    Science.gov (United States)

    Mahoney, Caroline R; Giles, Grace E; Marriott, Bernadette P; Judelson, Daniel A; Glickman, Ellen L; Geiselman, Paula J; Lieberman, Harris R

    2018-04-10

    Caffeine intake in a convenience sample of U.S. college students (N = 1248) was surveyed at five geographically-dispersed United States (U.S.) universities. Intake from coffee, tea, soft drinks, energy drinks, gums, and medications was assessed. Associations between caffeine intake and demographic variables including sex, age, race/ethnicity, family income, general health, exercise, weight variables and tobacco use were examined. Reasons for use of caffeine-containing products were assessed. Caffeine, in any form, was consumed by 92% of students in the past year. Mean daily caffeine consumption for all students, including non-consumers, was 159 mg/d with a mean intake of 173 mg/d among caffeine users. Coffee was the main source of caffeine intake in male (120 mg/d) and female (111 mg/d) consumers. Male and female students consumed 53 vs. 30 mg/d of caffeine in energy drinks, respectively, and 28% consumed energy drinks with alcohol on at least one occasion. Students provided multiple reasons for caffeine use including: to feel awake (79%); enjoy the taste (68%); the social aspects of consumption (39%); improve concentration (31%); increase physical energy (27%); improve mood (18%); and alleviate stress (9%). As in the general U.S. population, coffee is the primary source of caffeine intake among the college students surveyed. Energy drinks provide less than half of total daily caffeine intake but more than among the general population. Students, especially women, consume somewhat more caffeine than the general population of individuals aged 19-30 y but less than individuals aged 31-50 y. Published by Elsevier Ltd.

  18. Simultaneous determination of caffeine, paracetamol, and ibuprofen in pharmaceutical formulations by high-performance liquid chromatography with UV detection and by capillary electrophoresis with conductivity detection.

    Science.gov (United States)

    Cunha, Rafael R; Chaves, Sandro C; Ribeiro, Michelle M A C; Torres, Lívia M F C; Muñoz, Rodrigo A A; Dos Santos, Wallans T P; Richter, Eduardo M

    2015-05-01

    Paracetamol, caffeine and ibuprofen are found in over-the-counter pharmaceutical formulations. In this work, we propose two new methods for simultaneous determination of paracetamol, caffeine and ibuprofen in pharmaceutical formulations. One method is based on high-performance liquid chromatography with diode-array detection and the other on capillary electrophoresis with capacitively coupled contactless conductivity detection. The separation by high-performance liquid chromatography with diode-array detection was achieved on a C18 column (250×4.6 mm(2), 5 μm) with a gradient mobile phase comprising 20-100% acetonitrile in 40 mmol L(-1) phosphate buffer pH 7.0. The separation by capillary electrophoresis with capacitively coupled contactless conductivity detection was achieved on a fused-silica capillary (40 cm length, 50 μm i.d.) using 10 mmol L(-1) 3,4-dimethoxycinnamate and 10 mmol L(-1) β-alanine with pH adjustment to 10.4 with lithium hydroxide as background electrolyte. The determination of all three pharmaceuticals was carried out in 9.6 min by liquid chromatography and in 2.2 min by capillary electrophoresis. Detection limits for caffeine, paracetamol and ibuprofen were 4.4, 0.7, and 3.4 μmol L(-1) by liquid chromatography and 39, 32, and 49 μmol L(-1) by capillary electrophoresis, respectively. Recovery values for spiked samples were between 92-107% for both proposed methods. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Heritability of caffeine metabolism

    DEFF Research Database (Denmark)

    Matthaei, Johannes; Tzvetkov, Mladen V; Strube, Jakob

    2016-01-01

    Heritability of caffeine pharmacokinetics and CYP1A2 activity is controversial. Here we analyzed the pharmacokinetics of caffeine, an in vivo probe drug for CYP1A2 and arylamine N-acetyltransferase 2 (NAT2) activity, in monozygotic and dizygotic twins. In the entire group, common and unique...... environmental effects explained most variation in caffeine AUC. Apparently, smoking and hormonal contraceptives masked the genetic effects on CYP1A2 activity. However, when excluding smokers and users of hormonal contraceptives, 89% of caffeine AUC variation was due to genetic effects and even in the entire...... group, 8% of caffeine AUC variation could be explained by a CYP1A1/1A2 promotor polymorphism (rs2470893). In contrast, nearly all of the variation (99%) of NAT2 activity was explained by genetic effects. This study illustrates two very different situations in pharmacogenetics, from an almost exclusively...

  20. Spectrophotometric Analysis of Caffeine

    Directory of Open Access Journals (Sweden)

    Showkat Ahmad Bhawani

    2015-01-01

    Full Text Available The nature of caffeine reveals that it is a bitter white crystalline alkaloid. It is a common ingredient in a variety of drinks (soft and energy drinks and is also used in combination with various medicines. In order to maintain the optimum level of caffeine, various spectrophotometric methods have been developed. The monitoring of caffeine is very important aspect because of its consumption in higher doses that can lead to various physiological disorders. This paper incorporates various spectrophotometric methods used in the analysis of caffeine in various environmental samples such as pharmaceuticals, soft and energy drinks, tea, and coffee. A range of spectrophotometric methodologies including chemometric techniques and derivatization of spectra have been used to analyse the caffeine.

  1. Effect of Coffee and Caffeine Ingestion on Resistance Exercise Performance.

    Science.gov (United States)

    Richardson, Darren L; Clarke, Neil D

    2016-10-01

    Richardson, DL and Clarke, ND. Effect of coffee and caffeine ingestion on resistance exercise performance. J Strength Cond Res 30(10): 2892-2900, 2016-The aim of the present study was to determine the effect of ingesting caffeine dose-matched anhydrous caffeine, coffee, or decaffeinated coffee plus anhydrous caffeine during resistance exercise on performance. Nine resistance-trained men (mean ± SD: age, 24 ± 2 years; weight, 84 ± 8 kg; height, 180 ± 8 cm) completed a squat and bench press exercise protocol at 60% 1 repetition maximum until failure on 5 occasions consuming 0.15 g·kg caffeinated coffee (COF), 0.15 g·kg decaffeinated coffee (DEC), 0.15 g·kg decaffeinated coffee plus 5 mg·kg anhydrous caffeine (D + C), 5 mg·kg anhydrous caffeine (CAF), or a placebo (PLA). Felt arousal and rating of perceived exertion (RPE) were used to assess perceptual variables and heart rate (HR) to assess physiological responses between trials. There were significant differences in total weight lifted for the squat between conditions (p caffeine have the ability to improve performance during a resistance exercise protocol, although possibly not over multiple bouts.

  2. Sucrose or sucrose and caffeine differentially impact memory and anxiety-like behaviours, and alter hippocampal parvalbumin and doublecortin.

    Science.gov (United States)

    Xu, Tanya J; Reichelt, Amy C

    2018-04-11

    Caffeinated sugar-sweetened "energy" drinks are a subset of soft drinks that are popular among young people worldwide. High sucrose diets impair cognition and alter aspects of emotional behaviour in rats, however, little is known about sucrose combined with caffeine. Rats were allocated to 2 h/day 10% sucrose (Suc), 10% sucrose plus 0.04% caffeine (CafSuc) or control (water) conditions. The addition of caffeine to sucrose appeared to increase the rewarding aspect of sucrose, as the CafSuc group consumed more solution than the Suc group. After 14 days of intermittent Suc or CafSuc access, anxiety was assessed in the elevated plus maze (EPM) prior to their daily solution access, whereby CafSuc and Suc rats spent more time in the closed arms, indicative of increased anxiety. Following daily solution access, CafSuc, but not Suc, rats showed reduced anxiety-like behaviour in the open-field. Control and CafSuc rats displayed intact place and long-term object memory, while Suc showed impaired memory performance. Sucrose reduced parvalbumin immunoreactivity in the hippocampus, but no differences were observed between Control and CafSuc conditions. Parvalbumin reactivity in the basolateral amygdala did not differ between conditions. Reduced doublecortin immunoreactivity in the dentate gyrus relative to controls was seen in the CafSuc, but not Suc, treatment conditions. These findings indicate that the addition of caffeine to sucrose attenuated cognitive deficits. However, the addition of caffeine to sucrose evoked anxiety-like responses under certain testing conditions, suggesting that frequent consumption of caffeinated energy drinks may promote emotional alterations and brain changes compared to standard soft drinks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Consumption and foraging behaviors for common stimulants (nicotine, caffeine).

    Science.gov (United States)

    Phillips, James G; Currie, Jonathan; Ogeil, Rowan P

    2016-01-01

    Models are needed to understand the emerging capability to track consumers' movements. Therefore, we examined the use of legal and readily available stimulants that vary in their addictive potential (nicotine, caffeine). One hundred sixty-six participants answered the Kessler Psychological Distress Scale (K10), the Severity of Dependence Scale for nicotine and caffeine, and reported the number of times and locations stimulants were purchased and used. On average, nicotine dependent individuals made their purchases from 2 locations, while caffeine dependent individuals consumed caffeine at 2 locations, but some people exhibited a greater range and intensity of use. Stimulant foraging behavior could be described by power laws, and is exacerbated by dependency. The finding has implications for attempts to control substance use.

  4. Caffeine delays autonomic recovery following acute exercise.

    Science.gov (United States)

    Bunsawat, Kanokwan; White, Daniel W; Kappus, Rebecca M; Baynard, Tracy

    2015-11-01

    Impaired autonomic recovery of heart rate (HR) following exercise is associated with an increased risk of sudden death. Caffeine, a potent stimulator of catecholamine release, has been shown to augment blood pressure (BP) and sympathetic nerve activity; however, whether caffeine alters autonomic function after a bout of exercise bout remains unclear. In a randomized, crossover study, 18 healthy individuals (26 ± 1 years; 23.9 ± 0.8 kg·m(-2)) ingested caffeine (400 mg) or placebo pills, followed by a maximal treadmill test to exhaustion. Autonomic function and ventricular depolarization/repolarization were determined using heart rate variability (HRV) and corrected QT interval (QTc), respectively, at baseline, 5, 15, and 30 minutes post-exercise. Maximal HR (HRmax) was greater with caffeine (192 ± 2 vs. 190 ± 2 beat·min(-1), p < 0.05). During recovery, HR, mean arterial pressure (MAP), and diastolic blood pressure (DBP) remained elevated with caffeine (p < 0.05). Natural log transformation of low-to-high frequency ratio (LnLF/LnHF) of HRV was increased compared with baseline at all time points in both trials (p < 0.05), with less of an increase during 5 and 15 minutes post-exercise in the caffeine trial (p < 0.05). QTc increased from baseline at all time points in both trials, with greater increases in the caffeine trial (p < 0.05). Caffeine ingestion disrupts post-exercise autonomic recovery because of increased sympathetic nerve activity. The prolonged sympathetic recovery time could subsequently hinder baroreflex function during recovery and disrupt the stability of autonomic function, potentiating a pro-arrhythmogenic state in young adults. © The European Society of Cardiology 2014.

  5. Methylxanthine Content in Commonly Consumed Foods in Spain and Determination of Its Intake during Consumption

    Directory of Open Access Journals (Sweden)

    Juan M. Sanchez

    2017-12-01

    Full Text Available Methylxanthines present psychostimulant effects. These compounds have low toxicity and their consumption at moderate levels presents some beneficial health effects, whereas some significant risk appears at high levels. Samples of common types of methylxanthine-containing beverages and foods consumed in Spain were analyzed to determine their content. Caffeine was the methylxanthine that was most found in the samples investigated. Instant coffees gave the highest caffeine percentage (18–44 mg·g−1. Green and scented teas were found to have a caffeine dry-weight content (8–26 mg·g−1 equivalent to ground coffees (13–23 mg·g−1, but black and pu-erh teas (18–30 mg·g−1 had a higher caffeine content. The evaluation of the most conventional methods for preparing espresso coffees showed that an espresso contains between 88–116 mg of caffeine. In the case of tea beverages, the amount of caffeine present was 2–3 times smaller than in espresso coffees. Energy drinks showed a similar caffeine content (80–106 mg as espresso coffees. Chocolates had the lowest caffeine content. It has been found that none of the foods evaluated reach the recommended daily intake limit of 400 mg of caffeine with a single dose. This limit can be reached with 4–5 doses in the case of coffees and energy drinks. In the case of chocolates, the methylxanthine compound detected at large levels was theobromine, with amounts ranging from 4 to 10 mg·g−1 for dark chocolates.

  6. Caffeine levels in beverages from Argentina's market: application to caffeine dietary intake assessment.

    Science.gov (United States)

    Olmos, V; Bardoni, N; Ridolfi, A S; Villaamil Lepori, E C

    2009-03-01

    The caffeine content of different beverages from Argentina's market was measured. Several brands of coffees, teas, mates, chocolate milks, soft and energy drinks were analysed by high-performance liquid chromatography (HPLC) with ultraviolet detection. The highest concentration level was found in short coffee (1.38 mg ml(-1)) and the highest amount per serving was found in instant coffee (95 mg per serving). A consumption study was also carried out among 471 people from 2 to 93 years of age to evaluate caffeine total dietary intake by age and to identify the sources of caffeine intake. The mean caffeine intake among adults was 288 mg day(-1) and mate was the main contributor to that intake. The mean caffeine intake among children of 10 years of age and under was 35 mg day(-1) and soft drinks were the major contributors to that intake. Children between 11 and 15 years old and teenagers (between 16 and 20 years) had caffeine mean intakes of 120 and 240 mg day(-1), respectively, and mate was the major contributor to those intakes. Drinking mate is a deep-rooted habit among Argentine people and it might be the reason for their elevated caffeine mean daily intake.

  7. Variation in caffeine concentration in single coffee beans.

    Science.gov (United States)

    Fox, Glen P; Wu, Alex; Yiran, Liang; Force, Lesleigh

    2013-11-13

    Twenty-eight coffee samples from around the world were tested for caffeine levels to develop near-infrared reflectance spectroscopy (NIRS) calibrations for whole and ground coffee. Twenty-five individual beans from five of those coffees were used to develop a NIRS calibration for caffeine concentration in single beans. An international standard high-performance liquid chromatography method was used to analyze for caffeine content. Coffee is a legal stimulant and possesses a number of heath properties. However, there is variation in the level of caffeine in brewed coffee and other caffeinated beverages. Being able to sort beans on the basis of caffeine concentration will improve quality control in the level of caffeine in those beverages. The range in caffeine concentration was from 0.01 mg/g (decaffeinated coffee) to 19.9 mg/g (Italian coffee). The majority of coffees were around 10.0-12.0 mg/g. The NIRS results showed r(2) values for bulk unground and ground coffees were >0.90 with standard errors coffee beans. One application of this calibration could be sorting beans on caffeine concentration to provide greater quality control for high-end markets. Furthermore, bean sorting may open new markets for novel coffee products.

  8. Alcohol and caffeine consumption and decreased fertility.

    Science.gov (United States)

    Hakim, R B; Gray, R H; Zacur, H

    1998-10-01

    To examine the effects of alcohol and caffeine on conception. Prospective observational study. Healthy volunteers in two manufacturing facilities. One hundred twenty-four women who provided daily urine samples for measurement of steroid hormones and hCG, and prospective information about alcohol and caffeine consumption. Probability of conception per 100 menstrual cycles. There was >50% reduction in the probability of conception during a menstrual cycle during which participants consumed alcohol. Caffeine consumption did not independently affect the probability of conception but may enhance alcohol's negative effect. Women who abstained from alcohol and consumed less than one cup of coffee or its equivalent per day conceived 26.9 pregnancies per 100 menstrual cycles compared with 10.5 per 100 menstrual cycles among those who consumed any alcohol and more than one cup of coffee per day. This study revealed an independent dose-related negative effect of alcohol consumption on the ability to conceive. Our results suggest that women who are attempting to conceive should abstain from consuming alcohol.

  9. The effects of caffeine abstinence on sleep: a pilot study.

    Science.gov (United States)

    Ho, Shuk Ching; Chung, Joanne Wai Yee

    2013-05-01

    The aim of this study was to examine whether caffeine abstinence in the evening could improve the sleep quality of those who habitually consume coffee. A double-blind control group design (caffeine and caffeine-free groups). A university. A convenience sampling of 10 students (mean age 21.4 years). It was a 14-day experiment. For the first 7 days, all participants consumed caffeinated coffee. In the following 7 days, subjects consumed caffeinated or decaffeinated coffee according to their assigned group. Sleep-wake parameters, self-reported sleep quality and level of refreshment. There were no significant differences (p>.05) among the data of the two groups identified. No significant changes (p>.05) were found in the sleep quality of either group during the study. This study confirms that caffeine abstinence in the evening might not be helpful in sleep promotion. It highlights the need to implement evidence-based practice in health promotion. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Determination of Caffeine Content in Non-Alcoholic Beverages and ...

    African Journals Online (AJOL)

    It was found that Burn®, XL energy drink® and Red Bull® had the highest amount of caffeine. It was however noted that though most of the non-alcoholic beverages had high caffeine content they had no label claim. Key Words: Reverse Phase High Performance Liquid chromatography (HPLC), Ultra violet visible (UV/VIS), ...

  11. Determination of theobromine, theophylline, and caffeine in by-products of cupuacu and cacao seeds by high-performance liquid chromatography.

    Science.gov (United States)

    Lo Coco, F; Lanuzza, F; Micali, G; Cappellano, G

    2007-01-01

    Theobromine, theophylline, and caffeine are determined simultaneously by a rapid and selective reversed-phase high-performance liquid chromatography (HPLC) method with UV detection in by-products of cupuacu and cacao seeds. The determination is carried out in the raw and roasted ground cupuacu seeds and in the corresponding powders obtained after pressure treatment. The by-products of both cupuacu seeds and cacao seeds are obtained under the same technological conditions. The HPLC method uses isocratic elution with a mobile phase of methanol-water-acetic acid (80:19:1) (v/v) at a flow rate of 1 mL/min and UV absorbance detection at 275 nm. Total elution time for these analytes is less than 10 min, and the detection limit for all analytes is 0.1 mg/g. The amounts of theobromine and caffeine found in all the cupuacu samples are one or more orders of magnitude lower than those from cacao. Theophylline is found in all cacao samples except for the roasted ground paste, and it is only found in the roasted ground paste in the cupuacu samples.

  12. Caffeine Enhances Memory Performance in Young Adults during Their Non-optimal Time of Day

    OpenAIRE

    Sherman, Stephanie M.; Buckley, Timothy P.; Baena, Elsa; Ryan, Lee

    2016-01-01

    Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not impl...

  13. Caffeine Content in Popular Energy Drinks and Energy Shots.

    Science.gov (United States)

    Attipoe, Selasi; Leggit, Jeffrey; Deuster, Patricia A

    2016-09-01

    The use of energy beverages is high among the general population and military personnel. Previous studies have reported discrepancies between the actual amount of caffeine in products and the amount of caffeine on stated labels. Thus, the purpose of this study was to examine the content of caffeine listed on the labels of various energy drinks and energy shots. Top-selling energy drinks (n = 9) and energy shots (n = 5) were purchased from retail stores. Three of each of the 14 products were purchased and analyzed for caffeine content by an independent laboratory. Of the 14 products tested, 5 did not provide caffeine amounts on their facts panel-of those, 3 listed caffeine as an ingredient and 2 listed caffeine as part of a proprietary blend. The remaining 9 (of 14) products stated the amounts of caffeine on their labels, all of which were within 15% of the amount indicated on the label. In this study, although the energy beverages that indicated the amount of caffeine it contained had values within ±15% of the amount listed on the label, a potentially acceptable range, this finding is not acceptable with regard to current labeling regulations, which require added ingredients to total 100%. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

  14. Caffeine, creatine, GRIN2A and Parkinson's disease progression.

    Science.gov (United States)

    Simon, David K; Wu, Cai; Tilley, Barbara C; Lohmann, Katja; Klein, Christine; Payami, Haydeh; Wills, Anne-Marie; Aminoff, Michael J; Bainbridge, Jacquelyn; Dewey, Richard; Hauser, Robert A; Schaake, Susen; Schneider, Jay S; Sharma, Saloni; Singer, Carlos; Tanner, Caroline M; Truong, Daniel; Wei, Peng; Wong, Pei Shieen; Yang, Tianzhong

    2017-04-15

    Caffeine is neuroprotective in animal models of Parkinson's disease (PD) and caffeine intake is inversely associated with the risk of PD. This association may be influenced by the genotype of GRIN2A, which encodes an NMDA-glutamate-receptor subunit. In two placebo-controlled studies, we detected no association of caffeine intake with the rate of clinical progression of PD, except among subjects taking creatine, for whom higher caffeine intake was associated with more rapid progression. We now have analyzed data from 420 subjects for whom DNA samples and caffeine intake data were available from a placebo-controlled study of creatine in PD. The GRIN2A genotype was not associated with the rate of clinical progression of PD in the placebo group. However, there was a 4-way interaction between GRIN2A genotype, caffeine, creatine and the time since baseline. Among subjects in the creatine group with high levels of caffeine intake, but not among those with low caffeine intake, the GRIN2A T allele was associated with more rapid progression (p=0.03). These data indicate that the deleterious interaction between caffeine and creatine with respect to rate of progression of PD is influenced by GRIN2A genotype. This example of a genetic factor interacting with environmental factors illustrates the complexity of gene-environment interactions in the progression of PD. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Are energy Drinks Scapegoats? Decomposing Teenagers' Caffeine intake from Energy Drinks and Soda Beverages.

    Science.gov (United States)

    Turel, Ofir

    2018-02-22

    Energy drinks have been repeatedly blamed for contributing to caffeine intake among teenagers. This study aimed to estimate and compare the caffeine intake of US teenagers from soda drinks versus energy drinks and shots. Data were taken from a 2015 nationally representative survey (Monitoring the Future) of 8th and 10th graders in the US (47.2% 8th grade; 51.1% female). Participants reported their numbers of consumed sodas, diet sodas, energy drinks, and energy shots per day. These were converted into mg caffeine/day and were contrasted with common guidelines for healthy caffeine intake, stratified by age group and sex. Error-bar charts, ANOVA and ROC curves were used for contrasting caffeine intake from soda drinks and energy drinks, as well as their contribution to exceeding recommended caffeine intake cutoffs. First, in both sexes and grades the intake from soda drinks was significantly higher than the intake from energy drinks. The soda and energy drink intake for males was higher than the intake for females; intake for 8th graders was higher than this of 10th graders. Second, caffeine intake from soda drinks was significantly higher even in those who exceeded the recommended maximum caffeine intake. Third, caffeine intakes from soda and energy drinks were efficacious in explaining the exceeding of the recommended threshold for daily caffeine intake, but the explanatory power of soda drinks was larger. From a caffeine consumption standpoint, health professionals should emphasize reduction in both soda and energy drinks.

  16. “Clozapine makes me quite drowsy, so when I wake up in the morning those first cups of coffee are really handy”: an exploratory qualitative study of excessive caffeine consumption among individuals with schizophrenia

    Science.gov (United States)

    2014-01-01

    Background Research has shown that individuals with schizophrenia use caffeine at higher rates than the general population; however, no qualitative research has been undertaken investigating problematic caffeine use and its effects on this population. This article explores the role of caffeine consumption in the lives of people with schizophrenia through a narrative analysis of the attitudes and beliefs associated with this practice, and how these, in turn, influence caffeine consumption. Methods A qualitative study was undertaken with individuals who had previously scored in either a ‘moderate’ or ‘high’ risk category for caffeine use on the Alcohol, Smoking and Substance Involvement Screening Tool (ASSIST). In-depth interviews were undertaken with 20 individuals, and transcripts were analysed thematically to identify prominent perspectives. Results Consistent with previous literature, participants’ caffeine consumption was driven largely by its stimulating properties; however, participants also identified ‘cravings’ as an important motivating factor. Participants’ behaviours related to caffeine consumption seemed to be tempered by their previous experiences of consumption; if participants had experienced positive effects such as alertness or relaxation in the past, their use was maintained at a similar level or increased. Conversely, participants who anticipated negative consequences often altered their patterns of caffeine consumption; for example, by substituting caffeinated drinks that minimised or ceased their experience of negative side effects for those that directly caused such impacts. Overall, participants largely identified caffeine consumption as a highly meaningful activity, which provided structure to their day and facilitated opportunities for social interaction. Conclusions The inconsistencies between individuals’ beliefs about their health and the actual risk of harm associated with health-related behaviours present significant

  17. Adolescent caffeine consumption increases adulthood anxiety-related behavior and modifies neuroendocrine signaling

    Science.gov (United States)

    O’Neill, Casey E.; Newsom, Ryan J.; Stafford, Jacob; Scott, Talia; Archuleta, Solana; Levis, Sophia C.; Spencer, Robert L.; Campeau, Serge; Bachtell, Ryan K.

    2016-01-01

    Caffeine is a commonly used psychoactive substance and consumption by children and adolescents continues to rise. Here, we examine the lasting effects of adolescent caffeine consumption on anxiety-related behaviors and several neuroendocrine measures in adulthood. Adolescent male Sprague-Dawley rats consumed caffeine (0.3 g/L) for 28 consecutive days from postnatal day 28 (P28) to P55. Age-matched control rats consumed water. Behavioral testing for anxiety-related behavior began in adulthood (P62) 7 days after removal of caffeine. Adolescent caffeine consumption enhanced anxiety-related behavior in an open field, social interaction test, and elevated plus maze. Similar caffeine consumption in adult rats did not alter anxiety-related behavior after caffeine removal. Characterization of neuroendocrine measures was next assessed to determine whether the changes in anxiety were associated with modifications in the HPA axis. Blood plasma levels of corticosterone (CORT) were assessed throughout the caffeine consumption procedure in adolescent rats. Adolescent caffeine consumption elevated plasma CORT 24 h after initiation of caffeine consumption that normalized over the course of the 28-day consumption procedure. CORT levels were also elevated 24 h after caffeine removal and remained elevated for 7 days. Despite elevated basal CORT in adult rats that consumed caffeine during adolescence, the adrenocorticotropic hormone (ACTH) and CORT response to placement on an elevated pedestal (a mild stressor) was significantly blunted. Lastly, we assessed changes in basal and stress-induced c-fos and corticotropin-releasing factor (Crf) mRNA expression in brain tissue collected at 7 days withdrawal from adolescent caffeine. Adolescent caffeine consumption increased basal c-fos mRNA in the paraventricular nucleus of the hypothalamus. Adolescent caffeine consumption had no other effects on the basal or stress-induced c-fos mRNA changes. Caffeine consumption during adolescence

  18. Adolescent caffeine consumption increases adulthood anxiety-related behavior and modifies neuroendocrine signaling.

    Science.gov (United States)

    O'Neill, Casey E; Newsom, Ryan J; Stafford, Jacob; Scott, Talia; Archuleta, Solana; Levis, Sophia C; Spencer, Robert L; Campeau, Serge; Bachtell, Ryan K

    2016-05-01

    Caffeine is a commonly used psychoactive substance and consumption by children and adolescents continues to rise. Here, we examine the lasting effects of adolescent caffeine consumption on anxiety-related behaviors and several neuroendocrine measures in adulthood. Adolescent male Sprague-Dawley rats consumed caffeine (0.3g/L) for 28 consecutive days from postnatal day 28 (P28) to P55. Age-matched control rats consumed water. Behavioral testing for anxiety-related behavior began in adulthood (P62) 7 days after removal of caffeine. Adolescent caffeine consumption enhanced anxiety-related behavior in an open field, social interaction test, and elevated plus maze. Similar caffeine consumption in adult rats did not alter anxiety-related behavior after caffeine removal. Characterization of neuroendocrine measures was next assessed to determine whether the changes in anxiety were associated with modifications in the HPA axis. Blood plasma levels of corticosterone (CORT) were assessed throughout the caffeine consumption procedure in adolescent rats. Adolescent caffeine consumption elevated plasma CORT 24h after initiation of caffeine consumption that normalized over the course of the 28-day consumption procedure. CORT levels were also elevated 24h after caffeine removal and remained elevated for 7 days. Despite elevated basal CORT in adult rats that consumed caffeine during adolescence, the adrenocorticotropic hormone (ACTH) and CORT response to placement on an elevated pedestal (a mild stressor) was significantly blunted. Lastly, we assessed changes in basal and stress-induced c-fos and corticotropin-releasing factor (Crf) mRNA expression in brain tissue collected at 7 days withdrawal from adolescent caffeine. Adolescent caffeine consumption increased basal c-fos mRNA in the paraventricular nucleus of the hypothalamus. Adolescent caffeine consumption had no other effects on the basal or stress-induced c-fos mRNA changes. Caffeine consumption during adolescence increased

  19. HIGHER SERUM CAFFEINE IN SMOKERS WITH SCHIZOPHRENIA COMPARED TO SMOKING CONTROLS

    OpenAIRE

    Gandhi, Kunal K; Williams, Jill M; Menza, Matthew; Galazyn, Magdalena; Benowitz, Neal L.

    2010-01-01

    Previous studies of high dietary caffeine intake in individuals with schizophrenia have not demonstrated biological evidence of higher intake or controlled smoking behavior. This study aimed to examine differences in serum caffeine levels in 104 smokers with schizophrenia/schizoaffective disorder (SCZ/SA) and compare them to 63 smokers without any mental illness (CON). Since we were interested in measuring caffeine levels, we excluded all non caffeine users from the study. Blood draws were st...

  20. Caffeine intake and semen quality in a population of 2,554 young Danish men

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Swan, Shanna H; Skakkebaek, Niels E

    2010-01-01

    The authors examined the association between semen quality and caffeine intake among 2,554 young Danish men recruited when they were examined to determine their fitness for military service in 2001-2005. The men delivered a semen sample and answered a questionnaire including information about...... caffeine intake from various sources, from which total caffeine intake was calculated. Moderate caffeine and cola intakes (101-800 mg/day and semen quality. High cola (>14 0.5-L bottles...

  1. [birthweight And Caffeine Consumption].

    OpenAIRE

    Bicalho, Gladys Gripp; Barros Filho, Antônio de Azevedo

    2015-01-01

    To assess the association between maternal caffeine consumption during pregnancy and low birth weight, prematurity and intrauterine growth retardation. A case-control was carried out and 354 newborns of single labor with birthweight 3,000 g (controls) were analyzed. Caffeine consumption was calculated based on daily consumption of coffee, soft drinks and tea. Results were adjusted using multiple logistic regression for the following confounders: mother's age, schooling, income, marital status...

  2. The effects of a pre-workout supplement containing caffeine, creatine, and amino acids during three weeks of high-intensity exercise on aerobic and anaerobic performance.

    Science.gov (United States)

    Smith, Abbie E; Fukuda, David H; Kendall, Kristina L; Stout, Jeffrey R

    2010-02-15

    A randomized, single-blinded, placebo-controlled, parallel design study was used to examine the effects of a pre-workout supplement combined with three weeks of high-intensity interval training (HIIT) on aerobic and anaerobic running performance, training volume, and body composition. Twenty-four moderately-trained recreational athletes (mean +/- SD age = 21.1 +/- 1.9 yrs; stature = 172.2 +/- 8.7 cm; body mass = 66.2 +/- 11.8 kg, VO2max = 3.21 +/- 0.85 l.min-1, percent body fat = 19.0 +/- 7.1%) were assigned to either the active supplement (GT, n = 13) or placebo (PL, n = 11) group. The active supplement (Game Time(R), Corr-Jensen Laboratories Inc., Aurora, CO) was 18 g of powder, 40 kcals, and consisted of a proprietary blend including whey protein, cordyceps sinensis, creatine, citrulline, ginseng, and caffeine. The PL was also 18 g of powder, 40 kcals, and consisted of only maltodextrin, natural and artificial flavors and colors. Thirty minutes prior to all testing and training sessions, participants consumed their respective supplements mixed with 8-10 oz of water. Both groups participated in a three-week HIIT program three days per week, and testing was conducted before and after the training. Cardiovascular fitness (VO2max) was assessed using open circuit spirometry (Parvo-Medics TrueOne(R) 2400 Metabolic Measurement System, Sandy, UT) during graded exercise tests on a treadmill (Woodway, Pro Series, Waukesha, WI). Also, four high-speed runs to exhaustion were conducted at 110, 105, 100, and 90% of the treadmill velocity recorded during VO2max, and the distances achieved were plotted over the times-to-exhaustion. Linear regression was used to determine the slopes (critical velocity, CV) and y-intercepts (anaerobic running capacity, ARC) of these relationships to assess aerobic and anaerobic performances, respectively. Training volumes were tracked by summing the distances achieved during each training session for each subject. Percent body fat (%BF) and lean

  3. The effects of a pre-workout supplement containing caffeine, creatine, and amino acids during three weeks of high-intensity exercise on aerobic and anaerobic performance

    Directory of Open Access Journals (Sweden)

    Kendall Kristina L

    2010-02-01

    Full Text Available Abstract Background A randomized, single-blinded, placebo-controlled, parallel design study was used to examine the effects of a pre-workout supplement combined with three weeks of high-intensity interval training (HIIT on aerobic and anaerobic running performance, training volume, and body composition. Methods Twenty-four moderately-trained recreational athletes (mean ± SD age = 21.1 ± 1.9 yrs; stature = 172.2 ± 8.7 cm; body mass = 66.2 ± 11.8 kg, VO2max = 3.21 ± 0.85 l·min-1, percent body fat = 19.0 ± 7.1% were assigned to either the active supplement (GT, n = 13 or placebo (PL, n = 11 group. The active supplement (Game Time®, Corr-Jensen Laboratories Inc., Aurora, CO was 18 g of powder, 40 kcals, and consisted of a proprietary blend including whey protein, cordyceps sinensis, creatine, citrulline, ginseng, and caffeine. The PL was also 18 g of powder, 40 kcals, and consisted of only maltodextrin, natural and artificial flavors and colors. Thirty minutes prior to all testing and training sessions, participants consumed their respective supplements mixed with 8-10 oz of water. Both groups participated in a three-week HIIT program three days per week, and testing was conducted before and after the training. Cardiovascular fitness (VO2max was assessed using open circuit spirometry (Parvo-Medics TrueOne® 2400 Metabolic Measurement System, Sandy, UT during graded exercise tests on a treadmill (Woodway, Pro Series, Waukesha, WI. Also, four high-speed runs to exhaustion were conducted at 110, 105, 100, and 90% of the treadmill velocity recorded during VO2max, and the distances achieved were plotted over the times-to-exhaustion. Linear regression was used to determine the slopes (critical velocity, CV and y-intercepts (anaerobic running capacity, ARC of these relationships to assess aerobic and anaerobic performances, respectively. Training volumes were tracked by summing the distances achieved during each training session for each subject

  4. The Effects of Caffeine on Memory for Word Lists.

    Science.gov (United States)

    Erikson, George; And Others

    Research has suggested that behavioral differences may account for the effects of caffeine on information processing. To investigate the effects of caffeine on memory for supraspan word lists, 107 college students (47 males, 60 females), divided into 12 groups by high and low impulsivity scores on the Eysenck Personality Inventory, participated in…

  5. Correlation between caffeine contents of green coffee beans and ...

    African Journals Online (AJOL)

    A moderate negative correlation (R = 0.5463) was found between the caffeine contents of green coffee beans and the altitudes at which the coffee plants were grown. The caffeine contents of 9 of the green coffee bean samples analyzed by high performance liquid chromatography (HPLC) provided comparable results in the ...

  6. Effects of theobromine and caffeine on mood and vigilance.

    Science.gov (United States)

    Judelson, Daniel A; Preston, Amy G; Miller, Debra L; Muñoz, Colleen X; Kellogg, Mark D; Lieberman, Harris R

    2013-08-01

    Like caffeine, theobromine crosses the blood-brain barrier and binds to adenosine receptors, suggesting it might share caffeine's beneficial effects on mood and vigilance. Therefore, the purpose of this study was to assess the effect of theobromine doses commonly found in foods on mood and vigilance parameters sensitive to caffeine. Caffeine was tested as a positive control. Twenty-four men (age, 23 [3] years) completed 6 double-blind trials during which they consumed experimental beverages, assessed their mood using standardized self-report questionnaires, and completed a 2-hour visual vigilance task. Three experimental doses (100, 200, and 400 mg theobromine) were delivered in a cocoa-based beverage; 3 matched control treatments (0 mg theobromine, 400 mg theobromine, and 100 mg caffeine) were delivered in a non-cocoa beverage. Mean salivary concentrations of theobromine exhibited significant dose-dependent differences (400 mg trials > 200 mg trial > 100 mg trial > 0 mg trials; P affect mood state or vigilance (P > 0.05), but 100-mg caffeine significantly decreased lethargy/fatigue and increased vigor (P = 0.006 and 0.011, respectively). These findings indicate theobromine does not influence mood and vigilance when administered in nutritionally relevant doses, despite sharing many of caffeine's structural characteristics.

  7. Acute personalized habitual caffeine doses improve attention and have selective effects when considering the fractionation of executive functions.

    Science.gov (United States)

    Lanini, Juliana; Galduróz, José Carlos Fernandes; Pompéia, Sabine

    2016-01-01

    Caffeine is widely used, often consumed with food, and improves simple and complex/executive attention under fasting conditions. We investigated whether these cognitive effects are observed when personalized habitual doses of caffeine are ingested by caffeine consumers, whether they are influenced by nutriments and if various executive domains are susceptible to improvement. This was a double-blind, placebo-controlled study including 60 young, healthy, rested males randomly assigned to one of four treatments: placebo fasting, caffeine fasting, placebo meal and caffeine meal. Caffeine doses were individualized for each participant based on their self-reported caffeine consumption at the time of testing (morning). The test battery included measures of simple and sustained attention, executive domains (inhibiting, updating, shifting, dual tasking, planning and accessing long-term memory), control measures of subjective alterations, glucose and insulin levels, skin conductance, heart rate and pupil dilation. Regardless of meal intake, acute habitual doses of caffeine decreased fatigue, and improved simple and sustained attention and executive updating. This executive effect was not secondary to the habitual weekly dose consumed, changes in simple and sustained attention, mood, meal ingestion and increases in cognitive effort. We conclude that the morning caffeine "fix" has positive attentional effects and selectively improved executive updating whether or not caffeine is consumed with food. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Caffeine Enhances Real-World Language Processing: Evidence from a Proofreading Task

    Science.gov (United States)

    Brunye, Tad T.; Mahoney, Caroline R.; Rapp, David N.; Ditman, Tali; Taylor, Holly A.

    2012-01-01

    Caffeine has become the most prevalently consumed psychostimulant in the world, but its influences on daily real-world functioning are relatively unknown. The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a commonplace language task that required readers to identify and correct 4 error types in extended…

  9. Effects of caffeine on alcohol reinforcement: Beverage choice, self-administration, and subjective ratings

    Science.gov (United States)

    Sweeney, Mary M.; Meredith, Steven E.; Evatt, Daniel P.; Griffiths, Roland R.

    2017-01-01

    Rationale Combining alcohol and caffeine is associated with increased alcohol consumption, but no prospective experimental studies have examined whether added caffeine increases alcohol consumption. Objectives This study examined how caffeine alters alcohol self-administration and subjective reinforcing effects in healthy adults. Methods Thirty-one participants completed six double-blind alcohol self-administration sessions: three sessions with alcohol only (e.g., Beverage A) and three sessions with alcohol and caffeine (e.g., Beverage B). Participants chose which beverage to consume on a subsequent session (e.g., Beverage A or B). Effects of caffeine on overall beverage choice, number of self-administered drinks, subjective ratings (e.g., Biphasic Alcohol Effects Scale), and psychomotor performance were examined. Results A majority of participants (65%) chose to drink the alcohol beverage containing caffeine on their final self-administration session. Caffeine did not increase the number of self-administered drinks. Caffeine significantly increased stimulant effects, decreased sedative effects, and attenuated decreases in psychomotor performance attributable to alcohol. Relative to nonchoosers, caffeine choosers reported overall lower stimulant ratings, and reported greater drinking behavior prior to the study. Conclusions Although caffeine did not increase the number of self-administered drinks, most participants chose the alcohol beverage containing caffeine. Given the differences in subjective ratings and pre-existing differences in self-reported alcohol consumption for caffeine choosers and nonchoosers, these data suggest decreased stimulant effects of alcohol and heavier self-reported drinking may predict subsequent choice of combined caffeine and alcohol beverages. These predictors may identify individuals who would benefit from efforts to reduce risk behaviors associated with combining alcohol and caffeine. PMID:28108773

  10. Artificial sweeteners, caffeine, and alcohol intoxication in bar patrons.

    Science.gov (United States)

    Rossheim, Matthew E; Thombs, Dennis L

    2011-10-01

    Previous laboratory research on alcohol absorption has found that substitution of artificially sweetened alcohol mixers for sucrose-based mixers has a marked effect on the rate of gastric emptying, resulting in elevated blood alcohol concentrations. Studies conducted in natural drinking settings, such as bars, have indicated that caffeine ingestion while drinking is associated with higher levels of intoxication. To our knowledge, research has not examined the effects of alcohol mixers that contain both an artificial sweetener and caffeine, that is, diet cola. Therefore, we assessed the event-specific association between diet cola consumption and alcohol intoxication in bar patrons. We sought to determine whether putative increases in blood alcohol, produced by accelerated gastric emptying following diet cola consumption, as identified in the laboratory, also appear in a natural setting associated with impaired driving. We conducted a secondary analysis of data from 2 nighttime field studies that collected anonymous information from 413 randomly selected bar patrons in 2008 and 2010. Data sets were merged and recoded to distinguish between energy drink, regular cola, diet cola, and noncaffeinated alcohol mixers. Caffeinated alcohol mixers were consumed by 33.9% of the patrons. Cola-caffeinated mixed drinks were much more popular than those mixed with energy drinks. A large majority of regular cola-caffeinated mixed drink consumers were men (75%), whereas diet cola-caffeinated mixed drink consumers were more likely to be women (57%). After adjusting for the number of drinks consumed and other potential confounders, number of diet cola mixed drinks had a significant association with patron intoxication (β = 0.233, p 0.05). Caffeine's effect on intoxication may be most pronounced when mixers are artificially sweetened, that is, lack sucrose which slows the rate of gastric emptying of alcohol. Risks associated with on-premise drinking may be reduced by greater

  11. Cytochrome P450-Dependent Metabolism of Caffeine in Drosophila melanogaster

    Science.gov (United States)

    Coelho, Alexandra; Fraichard, Stephane; Le Goff, Gaëlle; Faure, Philippe; Artur, Yves; Ferveur, Jean-François; Heydel, Jean-Marie

    2015-01-01

    Caffeine (1, 3, 7-trimethylxanthine), an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents). A transcriptomic screen of Drosophila flies exposed to caffeine revealed the coordinated variation of a large set of genes that encode xenobiotic-metabolizing proteins, including several cytochromes P450s (CYPs) that were highly overexpressed. Flies treated with metyrapone—an inhibitor of CYP enzymes—showed dramatically decreased caffeine metabolism, indicating that CYPs are involved in this process. Using interference RNA genetic silencing, we measured the metabolic and transcriptomic effect of three candidate CYPs. Silencing of CYP6d5 completely abolished theobromine synthesis, whereas CYP6a8 and CYP12d1 silencing induced different consequences on metabolism and gene expression. Therefore, we characterized several metabolic products and some enzymes potentially involved in the degradation of caffeine. In conclusion, this pioneer approach to caffeine metabolism in insects opens novel perspectives for the investigation of the physiological effects of caffeine metabolites. It also indicates that caffeine could be used as a biomarker to evaluate CYP phenotypes in Drosophila and other insects. PMID:25671424

  12. Cytochrome P450-dependent metabolism of caffeine in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Alexandra Coelho

    Full Text Available Caffeine (1, 3, 7-trimethylxanthine, an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents. A transcriptomic screen of Drosophila flies exposed to caffeine revealed the coordinated variation of a large set of genes that encode xenobiotic-metabolizing proteins, including several cytochromes P450s (CYPs that were highly overexpressed. Flies treated with metyrapone--an inhibitor of CYP enzymes--showed dramatically decreased caffeine metabolism, indicating that CYPs are involved in this process. Using interference RNA genetic silencing, we measured the metabolic and transcriptomic effect of three candidate CYPs. Silencing of CYP6d5 completely abolished theobromine synthesis, whereas CYP6a8 and CYP12d1 silencing induced different consequences on metabolism and gene expression. Therefore, we characterized several metabolic products and some enzymes potentially involved in the degradation of caffeine. In conclusion, this pioneer approach to caffeine metabolism in insects opens novel perspectives for the investigation of the physiological effects of caffeine metabolites. It also indicates that caffeine could be used as a biomarker to evaluate CYP phenotypes in Drosophila and other insects.

  13. Caffeine, extraversion and working memory.

    Science.gov (United States)

    Smith, Andrew P

    2013-01-01

    Research has shown that extraverts performing a working memory task benefit more from caffeine than do introverts. The present study aimed to replicate this and extend our knowledge by using a lower dose of caffeine (65 mg) and a range of tasks related to different components of working memory. In addition, tasks assessing psychomotor speed and the encoding of new information were included to determine whether caffeine-extraversion interactions were restricted to working memory tasks. A double-blind design was used, with 128 participants being randomly assigned to caffeinated or de-caffeinated coffee conditions. The results showed that caffeine interacted with extraversion in the predicted direction for serial recall and running memory tasks. Caffeine improved simple reaction time and the speed of encoding of new information, effects which were not modified by extraversion. These results suggest possible biological mechanisms underlying effects of caffeine on cognitive performance.

  14. Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males.

    Science.gov (United States)

    Higgins, Matthew F; Wilson, Susie; Hill, Cameron; Price, Mike J; Duncan, Mike; Tallis, Jason

    2016-04-01

    This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg(-1)·min(-1)) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg(-1) body mass sodium bicarbonate (BIC), (ii) 5 mg·kg(-1) body mass caffeine plus 0.1 g·kg(-1) body mass sodium chloride (CAF), (iii) 0.3 g·kg(-1) body mass sodium bicarbonate plus 5 mg·kg(-1) body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg(-1) body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3(-)]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350-415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333-402 s; P = 0.028; r = 0.6) compared with BIC (313: 284-448 s) although not compared with PLA (358; 290-433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted.

  15. Caffeine use in sports. A pharmacological review.

    Science.gov (United States)

    Sinclair, C J; Geiger, J D

    2000-03-01

    Caffeine is the most widely ingested psychoactive drug in the world. As many know, chronic use of caffeine leads to dependence, tolerance, drug craving, and upon abrupt cessation unpleasant withdrawal symptoms. Thus, caffeine fulfills pharmacological criteria by which agents are classified as drugs of abuse. Nevertheless, its use is legal and only at high, but readily attainable, levels is it banned from sport. Its use is widespread by athletes as young as 11 years of age who are seeking athletic advantage over fellow competitors. It is likely that its use will not decline any time soon because it is inexpensive, readily available, medically quite safe, socially acceptable, and by most measures legal. However, at levels allowed in sport, caffeine through its wide-ranging physiological and psychological effects increases endurance in well-trained athletes. If the goal of drug-testing and education programs in sport is to protect the health of athletes, prevent unfair advantage (cheating) and encourage ethical behavior then it seems obvious that the allowable levels of caffeine ingestion should be decreased. The alternative is to continue with policies designed largely to punish only those that get caught.

  16. Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women.

    Science.gov (United States)

    Lovallo, William R; Farag, Noha H; Vincent, Andrea S; Thomas, Terrie L; Wilson, Michael F

    2006-03-01

    Caffeine elevates cortisol secretion, and caffeine is often consumed in conjunction with exercise or mental stress. The interactions of caffeine and stress on cortisol secretion have not been explored adequately in women. We measured cortisol levels at eight times on days when healthy men and women consumed caffeine (250 mg x 3) and underwent either mental stress or dynamic exercise protocols, followed by a midday meal, in a double blind, placebo-controlled, crossover design. Men and women had similar cortisol levels at the predrug baselines, but they responded differently to mental stress and exercise. The cortisol response to mental stress was smaller in women than in men (p=.003). Caffeine acted in concert with mental stress to further increase cortisol levels (p=.011), the effect was similar in men and women. Exercise alone did not increase cortisol, but caffeine taken before exercise elevated cortisol in both men and women (psrelease in response to stress and caffeine therefore appears to be a function of the type of stressor and the sex of the subject. However, repeated caffeine doses increased cortisol levels across the test day without regard to the sex of the subject or type of stressor employed (p<.00001). Caffeine may elevate cortisol by stimulating the central nervous system in men but may interact with peripheral metabolic mechanisms in women.

  17. Separate and joint effects of alcohol and caffeine on conflict monitoring and adaptation.

    Science.gov (United States)

    Bailey, Kira; Amlung, Michael T; Morris, David H; Price, Mason H; Von Gunten, Curtis; McCarthy, Denis M; Bartholow, Bruce D

    2016-04-01

    Caffeine is commonly believed to offset the acute effects of alcohol, but some evidence suggests that cognitive processes remain impaired when caffeine and alcohol are coadministered. No previous study has investigated the separate and joint effects of alcohol and caffeine on conflict monitoring and adaptation, processes thought to be critical for self-regulation. This was the purpose of the current study. Healthy, young adult social drinkers recruited from the community completed a flanker task after consuming one of four beverages in a 2 × 2 experimental design: Alcohol + caffeine, alcohol + placebo caffeine, placebo alcohol + caffeine, or placebo alcohol + placebo caffeine. Accuracy, response time, and the amplitude of the N2 component of the event-related potential (ERP), a neural index of conflict monitoring, were examined as a function of whether or not conflict was present (i.e., whether or not flankers were compatible with the target) on both the previous trial and the current trial. Alcohol did not abolish conflict monitoring or adaptation. Caffeine eliminated conflict adaptation in sequential trials but also enhanced neural conflict monitoring. The combined effect of alcohol and caffeine was apparent only in how previous conflict affected the neural conflict monitoring response. Together, the findings suggest that caffeine leads to exaggeration of attentional resource utilization, which could provide short-term benefits but lead to problems conserving resources for when they are most needed.

  18. Caffeine effects on learning, performance, and anxiety in normal school-age children.

    Science.gov (United States)

    Bernstein, G A; Carroll, M E; Crosby, R D; Perwien, A R; Go, F S; Benowitz, N L

    1994-01-01

    The purpose of this investigation was to study the acute effects of caffeine on learning, performance, and anxiety in normal prepubertal children. Twenty-one children were evaluated in a double-blind, placebo-controlled crossover design. Subjects were studied during four sessions, 1 week apart, under the following conditions: baseline, placebo, 2.5 mg/kg caffeine, and 5.0 mg/kg caffeine. Subjects were randomized to order of placebo and the two dosages of caffeine. Dependent measures included tests of attention, manual dexterity, short-term memory, and processing speed. Anxiety rating scales were also administered. Saliva samples were analyzed for caffeine levels. Caffeine improved performance on two of four measures of the Test of Variables of Attention and on a test of manual dexterity in the dominant hand. There was a trend toward increased current level of self-reported anxiety after caffeine on a visual analogue measure of anxiety. Children reported feeling significantly less "sluggish" after caffeine ingestion than after placebo ingestion. In a small sample size, there was indication that caffeine enhanced performance on a test of attention and on a motor task. Children also reported feeling less "sluggish" but somewhat more anxious. Because caffeine is so widely available and frequently consumed by children, these results are important and need replication.

  19. Pregnancy-Induced Changes in the Pharmacokinetics of Caffeine and Its Metabolites

    Science.gov (United States)

    Yu, Tian; Campbell, Sarah C.; Stockmann, Chris; Tak, Casey; Schoen, Katherine; Clark, Erin A. S.; Varner, Michael W.; Spigarelli, Michael G.; Sherwin, Catherine M. T.

    2017-01-01

    This study sought to assess the pharmacokinetic (PK) changes of caffeine and its CYP1A2 metabolites across the 3 trimesters of pregnancy. A prospective, multicenter PK study was conducted among 59 pregnant women (93.2% white) who were studied once during a trimester. One beverage with 30–95 mg caffeine was consumed, and a blood/urine sample was collected within 1 hour postingestion. Concentrations of caffeine and its primary metabolites were quantified from serum and urine by LC-MS/MS. There was a significant increase in dose-normalized caffeine serum and urine concentrations between the first and third trimesters (Ptheobromine concentrations. This study identified decreased caffeine metabolism and an increase in the active metabolite theophylline concentrations during pregnancy, especially in the third trimester, revealing evidence of the large role that pregnancy plays in influencing caffeine metabolism. PMID:26358647

  20. DETERMINATION OF CAFFEINE CONTENTS OF COFFEE BRANDS IN THE VIETNAMESE MARKET

    Directory of Open Access Journals (Sweden)

    Stanislav Kráčmar

    2012-02-01

    Full Text Available In this study, the caffeine contents in five certain Vietnamese coffee (Dak Tin, Di Linh, Nam Nguyen, Origin and Vinacafe found in the Vietnamese market were determined using UV/vis spectrophotometry. The quantification of caffeine sample was calculated by standard addition method. Our results showed that the caffeine contents in coffee brewing were influenced by temperature of water used to brew, time of brewing, and independent on the volume of water, respectively. In general, higher concentrations of caffeine were found in all samples prepared at temperature 100°C for 5 minutes. The order of caffeine contents in coffee samples was Dak Tin, Di Linh, Nam Nguyen, Origin and Vinacafe, respectively. This study can contribute to a better knowledge of caffeine contents in Vietnamese coffee of Vietnamese consumers.

  1. Reprint of "Caffeine protects against memory loss induced by high and non-anxiolytic dose of cannabidiol in adult zebrafish (Danio rerio)".

    Science.gov (United States)

    Nazario, Luiza Reali; Antonioli, Régis Junior; Capiotti, Katiucia Marques; Hallak, Jaime Eduardo Cecílio; Zuardi, Antonio Waldo; Crippa, José Alexandre S; Bonan, Carla Denise; da Silva, Rosane Souza

    2015-12-01

    Cannabidiol (CBD) has been investigated in a wide spectrum of clinical approaches due to its psychopharmacological properties. CBD has low affinity for cannabinoid neuroreceptors and agonistic properties to 5-HT receptors. An interaction between cannabinoid and purinergic receptor systems has been proposed. The purpose of this study is to evaluate CBD properties on memory behavioral and locomotor parameters and the effects of pre-treatment of adenosine receptor blockers on CBD impacts on memory using adult zebrafish. CBD (0.1, 0.5, 5, and 10mg/kg) was tested in the avoidance inhibitory paradigm and anxiety task. We analyzed the effect of a long-term caffeine pre-treatment (~20mg/L - four months). Also, acute block of adenosine receptors was performed in co-administration with CBD exposure in the memory assessment. CBD promoted an inverted U-shaped dose-response curve in the anxiety task; in the memory assessment, CBD in the dose of 5mg/Kg promoted the strongest effects without interfering with social and aggressive behavior. Caffeine treatment was able to prevent CBD (5mg/kg) effects on memory when CBD was given after the training session. CBD effects on memory were partially prevented by co-treatment with a specific A2A adenosine receptor antagonist when given prior to or after the training session, while CBD effects after the training session were fully prevented by adenosine A1 receptor antagonist. These results indicated that zebrafish have responses to CBD anxiolytic properties that are comparable to other animal models, and high doses changed memory retention in a way dependent on adenosine. Copyright © 2015. Published by Elsevier Inc.

  2. Enhancement of High-Intensity Actions and Physical Performance During a Simulated Brazilian Jiu-Jitsu Competition With a Moderate Dose of Caffeine.

    Science.gov (United States)

    Diaz-Lara, Francisco Javier; Del Coso, Juan; Portillo, Javier; Areces, Francisco; García, Jose Manuel; Abián-Vicén, Javier

    2016-10-01

    Although caffeine is one of the most commonly used substances in combat sports, information about its ergogenic effects on these disciplines is very limited. To determine the effectiveness of ingesting a moderate dose of caffeine to enhance overall performance during a simulated Brazilian jiu-jitsu (BJJ) competition. Fourteen elite BJJ athletes participated in a double-blind, placebo-controlled experimental design. In a random order, the athletes ingested either 3 mg/kg body mass of caffeine or a placebo (cellulose, 0 mg/kg) and performed 2 simulated BJJ combats (with 20 min rest between them), following official BJJ rules. Specific physical tests such as maximal handgrip dynamometry, maximal height during a countermovement jump, permanence during a maximal static-lift test, peak power in a bench-press exercise, and blood lactate concentration were measured at 3 specific times: before the first combat and immediately after the first and second combats. The combats were video-recorded to analyze fight actions. After the caffeine ingestion, participants spent more time in offensive actions in both combats and revealed higher blood lactate values (P Performance in all physical tests carried out before the first combat was enhanced with caffeine (P caffeine and placebo. Caffeine might be an effective ergogenic aid for improving intensity and physical performance during successive elite BJJ combats.

  3. TYPES OF CONSUMER LOYALTY IN THE UKRAINIAN HIGH TECHNOLOGY PRODUCTS MARKET

    Directory of Open Access Journals (Sweden)

    V. Zhurylo

    2017-01-01

    Full Text Available The study addresses the problem of the formation of customer loyalty in the market of high-tech products. It examines existing approaches to defining the determinants that influence the formation of loyalty in the consumer market. On the basis of generalization of existing approaches it is proposed to divide the determinants of such groups: behavioral, perceptual, marketing and individual determinants of customers loyalty. Marketing research was conducted to identify the features of the market behavior of Ukrainian consumers of high-tech products. As the result, the main tends of consumers behavior, external and individual factors of actualization and influence on the consumers motivation were determined. Ukrainian consumers' loyalty was sorted depending on the reasons to buying high-tech products and consumer involvement in this process. Each type of market behavior of consumers corresponds to a certain type of consumer loyalty. Cognitive, agreement, demonstrative loyalty are formed in the case of high consumer involvement in the buying process. Active, perceptual loyalty and loyalty of convenience are observed in the case of low involvement.

  4. Caffeine intake and fecundability

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Henriksen, T B; Hjollund, N H

    1998-01-01

    and caffeine intake from different sources on the probability of conception. From 1992 to 1995, a total of 430 couples were recruited after a nationwide mailing of a personal letter to 52,255 trade union members who were 20 to 35 years old, lived with a partner, and had no previous reproductive experience...... of menstrual cycle. No dose-response relationship was found among smokers. Among males, the same decline in point estimates of the FR was present. Smoking women whose only source of caffeine was coffee (>300 mg/d) had a reduced fecundability odds-ratio (FR = 0.34; 95% CI 0.12-0.98). An interaction between...

  5. Could caffeine have some vaso protective effect?

    International Nuclear Information System (INIS)

    Buitrago, Lorena; Barrera, Gladys; Zuniga, Carolina and others

    2004-01-01

    Coffee is the most consumed hot drink in the world. it is part of the current and cultural diet of our society. There is a myth around coffee, considering it injurious based on clinical studies, whose results have been contradictory and without a solid scientific support. Nevertheless, in the last few years, there have been studies that describe the kindness of the coffee upon convecting, digestive and cardiovascular system. We want to present the vasodilator effect of caffeine in a experimental model that used aorta rings of normal and hipercholesterolemic rabbits, mounted in a organ bath system (Kent scientific corporation, Litchfield CT containing krebs, solution. The solution was kept at 37 Celsius degrade and aerated continuously with a 95% o 2 5% CO 2 gas mixture. The rings were pre contracted with norepinephrine (-5.5 log m) and relaxed with nitroglycerin (endothelium independent relaxation), acetylcholine (endothelium dependant relaxation) and caffeine

  6. Analysis of the Consumption of Caffeinated Energy Drinks among Polish Adolescents.

    Science.gov (United States)

    Nowak, Dariusz; Jasionowski, Artur

    2015-07-10

    Energy drinks (EDs) are extremely popular among adults and adolescents. Regular intake of EDs may lead to an overdose of caffeine, loss of bone mass, overweight, hypertension and, in older age, osteoporosis and cardiovascular diseases. Some people mix EDs with alcohol, which adversely affects their health. The objective of this study was to analyze the consumption of EDs by adolescents. The study consisted of a questionnaire surveying amounts of drinks, preferences and product awareness among younger consumers. The study was carried out in junior and senior high schools in Poland (n = 2629). EDs were consumed by 67% of students (quite frequently by 16%). Students who practiced sports were more willing to drink EDs. Also, boys drank them more often than girls. When selecting a particular ED, young people looked at the taste, price and effect. Most respondents consumed one ED (250 mL) daily, although there were individuals consuming two or more drinks daily. Most respondents knew the ingredients of EDs, and 24% admitted to mixing EDs with alcohol. EDs are extremely popular among adolescents. Young people drinking EDs every day are potentially at risk of taking an overdose of caffeine.

  7. Analysis of the Consumption of Caffeinated Energy Drinks among Polish Adolescents

    Science.gov (United States)

    Nowak, Dariusz; Jasionowski, Artur

    2015-01-01

    Background: Energy drinks (EDs) are extremely popular among adults and adolescents. Regular intake of EDs may lead to an overdose of caffeine, loss of bone mass, overweight, hypertension and, in older age, osteoporosis and cardiovascular diseases. Some people mix EDs with alcohol, which adversely affects their health. The objective of this study was to analyze the consumption of EDs by adolescents. Methods: The study consisted of a questionnaire surveying amounts of drinks, preferences and product awareness among younger consumers. The study was carried out in junior and senior high schools in Poland (n = 2629). Results: EDs were consumed by 67% of students (quite frequently by 16%). Students who practiced sports were more willing to drink EDs. Also, boys drank them more often than girls. When selecting a particular ED, young people looked at the taste, price and effect. Most respondents consumed one ED (250 mL) daily, although there were individuals consuming two or more drinks daily. Most respondents knew the ingredients of EDs, and 24% admitted to mixing EDs with alcohol. Conclusions: EDs are extremely popular among adolescents. Young people drinking EDs every day are potentially at risk of taking an overdose of caffeine. PMID:26184263

  8. Analysis of the Consumption of Caffeinated Energy Drinks among Polish Adolescents

    Directory of Open Access Journals (Sweden)

    Dariusz Nowak

    2015-07-01

    Full Text Available Background: Energy drinks (EDs are extremely popular among adults and adolescents. Regular intake of EDs may lead to an overdose of caffeine, loss of bone mass, overweight, hypertension and, in older age, osteoporosis and cardiovascular diseases. Some people mix EDs with alcohol, which adversely affects their health. The objective of this study was to analyze the consumption of EDs by adolescents. Methods: The study consisted of a questionnaire surveying amounts of drinks, preferences and product awareness among younger consumers. The study was carried out in junior and senior high schools in Poland (n = 2629. Results: EDs were consumed by 67% of students (quite frequently by 16%. Students who practiced sports were more willing to drink EDs. Also, boys drank them more often than girls. When selecting a particular ED, young people looked at the taste, price and effect. Most respondents consumed one ED (250 mL daily, although there were individuals consuming two or more drinks daily. Most respondents knew the ingredients of EDs, and 24% admitted to mixing EDs with alcohol. Conclusions: EDs are extremely popular among adolescents. Young people drinking EDs every day are potentially at risk of taking an overdose of caffeine.

  9. Effect of caffeine on information processing: evidence from stroop task.

    Science.gov (United States)

    Dixit, Abhinav; Goyal, Abhishek; Thawani, Rajat; Vaney, Neelam

    2012-07-01

    Caffeine is a pyschostimulant present in various beverages and known to alter alertness and performance by acting on the central nervous system. Its effects on central nervous system have been studied using EEG, evoked potentials, fMRI, and neuropsychological tests. The Stroop task is a widely used tool in psychophysiology to understand the attention processes and is based on the principle that processing of two different kinds of information (like the word or colour) is parallel and at different speeds with a common response channel. To study the effect of caffeine on classical color word Stroop task. This study was conducted on 30 male undergraduate students by performing a test before and 40 minutes after consuming 3 mg/Kg caffeine and evaluating the effect of caffeine on Stroop interference and facilitation. The results revealed that practice has no effect on the performance in a Stroop task. However, there was reduction in Stroop interference and increase in facilitation after consumption of caffeine as was evident by changes in the reaction times in response to neutral, incongruent, and congruent stimuli. We hypothesize that caffeine led to faster processing of relevant information.

  10. Information in launch messages : stimulating the adoption of new high-tech consumer products

    NARCIS (Netherlands)

    Talke, K.S.S.; Snelders, Dirk

    2013-01-01

    This research investigates how the adoption of new high-tech consumer products can be stimulated by communicating product-related information in launch messages. In an initial pilot study, the authors find that for making an adoption decision, consumers require different types of product-related

  11. Maternal Caffeine Consumption and Infant Nighttime Waking: Prospective Cohort Study

    Science.gov (United States)

    Santos, Iná S.; Matijasevich, Alicia

    2012-01-01

    OBJECTIVE: Coffee and other caffeinated beverages are commonly consumed in pregnancy. In adults, caffeine may interfere with sleep onset and have a dose-response effect similar to those seen during insomnia. In infancy, nighttime waking is a common event. With this study, we aimed to investigate if maternal caffeine consumption during pregnancy and lactation leads to frequent nocturnal awakening among infants at 3 months of age. METHODS: All children born in the city of Pelotas, Brazil, during 2004 were enrolled on a cohort study. Mothers were interviewed at delivery and after 3 months to obtain information on caffeine drinking consumption, sociodemographic, reproductive, and behavioral characteristics. Infant sleeping pattern in the previous 15 days was obtained from a subsample. Night waking was defined as an episode of infant arousal that woke the parents during nighttime. Multivariable analysis was performed by using Poisson regression. RESULTS: The subsample included 885 of the 4231 infants born in 2004. All but 1 mother consumed caffeine in pregnancy. Nearly 20% were heavy consumers (≥300 mg/day) during pregnancy and 14.3% at 3 months postpartum. Prevalence of frequent nighttime awakeners (>3 episodes per night) was 13.8% (95% confidence interval: 11.5%–16.0%). The highest prevalence ratio was observed among breastfed infants from mothers consuming ≥300 mg/day during the whole pregnancy and in the postpartum period (1.65; 95% confidence interval: 0.86–3.17) but at a nonsignificant level. CONCLUSIONS: Caffeine consumption during pregnancy and by nursing mothers seems not to have consequences on sleep of infants at the age of 3 months. PMID:22473365

  12. Mood, music, and caffeine

    NARCIS (Netherlands)

    Jolij, Jacob; Lorist, Monicque

    2014-01-01

    What we see is affected by how we feel: in positive moods, we are more sensitive to positive stimuli, such as happy faces, but in negative moods we are more sensitive to negative stimuli, such as sad faces. Caffeine is known to affect mood - a cup of coffee results in a more positive mood, but also

  13. Replicative bypass repair of ultraviolet damage to DNA of mammalian cells: caffeine sensitive and caffeine resistant mechanism

    International Nuclear Information System (INIS)

    Fujiwara, Y.; Tatsumi, M.

    1976-01-01

    Replicative bypass repair of UV damage to DNA was studied in a wide variaty of human, mouse and hamster cells in culture. Survival curve analysis revealed that in established cell lines (mouse L, Chinese hamster V79, HeLa S3 and SV40-transformed xeroderma pigmentosum (XP), post-UV caffeine treatment potentiated cell killing by reducing the extrapolation number and mean lethal UV fluence (Do). In the Do reduction as the result of random inactivation by caffeine of sensitive repair there were marked clonal differences among such cell lines, V79 being most sensitive to caffeine potentiation. However, other diploid cell lines (normal human, excision-defective XP and Syrian hamster) exhibited no obvious reduction in Do by caffeine. In parallel, alkaline sucrose sedimentation results showed that the conversion of initially smaller segments of DNA synthesized after irradiation with 10 J/m 2 to high-molecular-weight DNA was inhibited by caffeine in transformed XP cells, but not in the diploid human cell lines. Exceptionally, diploid XP variants had a retarded ability of bypass repair which was drastically prevented by caffeine, so that caffeine enhanced the lethal effect of UV. Neutral CsCl study on the bypass repair mechanism by use of bromodeoxyuridine for DNA synthesis on damaged template suggests that the pyrimodine dimer acts as a block to replication and subsequently it is circumvented presumably by a new process involving replicative bypassing following strand displacement, rather than by gap-filling de novo. This mechanism worked similarly in normal and XP cells, whether or not caffeine was present, indicating that excision of dimer is not always necessary. However, replicative bypassing became defective in XP variant and transformed XP cells when caffeine was present. It appears, therefore, that the replicative bypass repair process is either caffeine resistant or sensitive, depending on the cell type used, but not necessarily on the excision repair capability

  14. Caffeine Supplementation as an Ergogenic Aid for Muscular Strength and Endurance: A Recommendation for Coaches and Athletes

    OpenAIRE

    Brooks, Joseph H.; Wyld, Kevin; Chrismas, Bryna C.R.

    2016-01-01

    Caffeine (1, 3, 7-trimethylxanthine) which can be ubiquitously found in energy drinks, sodas, coffee, and supplements, is one of the principal legal drugs consumed worldwide. Caffeine based ergogenic aids are utilized prolifically within training and competition for an ergogenic benefit to enhance sporting performance by both recreational and elite athletes. The evidence of caffeine's ability to enhance endurance performance is well established, however, evidence of an er...

  15. Effect of meal glycemic load and caffeine consumption on prolonged monotonous driving performance.

    Science.gov (United States)

    Bragg, Christopher; Desbrow, Ben; Hall, Susan; Irwin, Christopher

    2017-11-01

    Monotonous driving involves low levels of stimulation and high levels of repetition and is essentially an exercise in sustained attention and vigilance. The aim of this study was to determine the effects of consuming a high or low glycemic load meal on prolonged monotonous driving performance. The effect of consuming caffeine with a high glycemic load meal was also examined. Ten healthy, non-diabetic participants (7 males, age 51±7yrs, mean±SD) completed a repeated measures investigation involving 3 experimental trials. On separate occasions, participants were provided one of three treatments prior to undertaking a 90min computer-based simulated drive. The 3 treatment conditions involved consuming: (1) a low glycemic load meal+placebo capsules (LGL), (2) a high glycemic load meal+placebo capsules (HGL) and (3) a high glycemic load meal+caffeine capsules (3mgkg -1 body weight) (CAF). Measures of driving performance included lateral (standard deviation of lane position (SDLP), average lane position (AVLP), total number of lane crossings (LC)) and longitudinal (average speed (AVSP) and standard deviation of speed (SDSP)) vehicle control parameters. Blood glucose levels, plasma caffeine concentrations and subjective ratings of sleepiness, alertness, mood, hunger and simulator sickness were also collected throughout each trial. No difference in either lateral or longitudinal vehicle control parameters or subjective ratings were observed between HGL and LGL treatments. A significant reduction in SDLP (0.36±0.20m vs 0.41±0.19m, p=0.004) and LC (34.4±31.4 vs 56.7±31.5, p=0.018) was observed in the CAF trial compared to the HGL trial. However, no differences in AVLP, AVSP and SDSP or subjective ratings were detected between these two trials (p>0.05). Altering the glycemic load of a breakfast meal had no effect on measures of monotonous driving performance in non-diabetic adults. Individuals planning to undertake a prolonged monotonous drive following consumption of a

  16. Spontaneous Abortion and a Diet Drug Containing Caffeine and Ephedrine

    DEFF Research Database (Denmark)

    Howards, Penelope P; Hertz-Picciotto, Irva; Bech, Bodil H

    2012-01-01

    BACKGROUND: Medications may be consumed periconceptionally before a woman knows she is pregnant. In this study, the authors evaluate the association of a prescription diet drug (Letigen) containing ephedrine (20 mg) and caffeine (200 mg) with spontaneous abortion (SAB) in the Danish National Birth...

  17. Caffeine exposure during rat brain development causes memory impairment in a sex selective manner that is offset by caffeine consumption throughout life.

    Science.gov (United States)

    Ardais, Ana Paula; Rocha, Andréia S; Borges, Maurício Felisberto; Fioreze, Gabriela T; Sallaberry, Cássia; Mioranzza, Sabrina; Nunes, Fernanda; Pagnussat, Natália; Botton, Paulo Henrique S; Cunha, Rodrigo A; Porciúncula, Lisiane de Oliveira

    2016-04-15

    Caffeine is the psychostimulant most consumed worldwide. In moderate doses, it affords a beneficial effect in adults and upon aging, but has a deleterious effect during brain development. We now tested if caffeine consumption by rats (0.1, 0.3, 1.0 g/L in the drinking water, only during active cycle and weekdays) during adulthood could revert the potentially negative effects of caffeine during early life. Thus, we compared caffeine intake starting 15 days before mating and lasting either up to weaning (development) or up to adulthood, on behavior and synaptic proteins in male and female rats. Recognition memory was impaired only in female rats receiving caffeine (0.3 and 1.0 g/L) during development, coincident with increased proBDNF and unchanged BDNF levels in the hippocampus. Caffeine in both treatment regimens caused hyperlocomotion only in male rats, whereas anxiety-related behavior was attenuated in both sexes by caffeine (1.0 g/L) throughout life. Both caffeine treatment regimens decreased GFAP (as an astrocyte marker) and SNAP-25 (as a nerve terminals marker) in the hippocampus from male rats. TrkB receptor was decreased in the hippocampus from both sexes and treatment regimens. These findings revealed that caffeine intake during a specific time window of brain development promotes sex-dependent behavioral outcomes related to modification in BDNF signaling. Furthermore, caffeine throughout life can overcome the deleterious effects of caffeine on recognition memory during brain development in female rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. ASSOCIATION OF CAFFEINE INTAKE AND LIVER FIBROSIS IN PATIENTS WITH CHRONIC HEPATITIS C

    Directory of Open Access Journals (Sweden)

    Kalinca da Silva OLIVEIRA

    2015-03-01

    Full Text Available Background Caffeine consumption has been associated to decreased levels of liver enzymes and lower risk of fibrosis in patients with hepatitis C virus. Objectives This study aimed to evaluate the association between caffeine consumption and inflammatory activity or degree of liver fibrosis in patients with hepatitis C virus infection. Methods A cross-sectional study of patients with chronic hepatitis C virus infection treated in an outpatient Gastroenterology Unit of Santa Casa Hospital (Porto Alegre - Brasil. Patients were interviewed regarding the consumption of caffeine and anthropometric assessment was performed. Liver biopsy was performed in a maximum period of 36 months before inclusion in the study Results There were 113 patients, 67 (59.3% females, 48 (42.5% were aged between 52 and 62 years, and 101 (89.4% were white. The average caffeine consumption was 251.41 ± 232.32 mg/day, and 70 (62% patients consumed up to 250 mg/day of caffeine. There was no association between caffeine consumption and inflammatory activity on liver biopsy. On the other hand, when evaluating the caffeine consumption liver fibrosis an inverse association was observed. Conclusions The greater consumption of caffeine was associated with lower liver fibrosis. There was no association between caffeine consumption and inflammatory activity.

  19. Effects of a single, oral 60 mg caffeine dose on attention in healthy adult subjects.

    Science.gov (United States)

    Wilhelmus, Micha Mm; Hay, Justin L; Zuiker, Rob Gja; Okkerse, Pieter; Perdrieu, Christelle; Sauser, Julien; Beaumont, Maurice; Schmitt, Jeroen; van Gerven, Joop Ma; Silber, Beata Y

    2017-02-01

    Caffeine induces positive effects on sustained attention, although studies assessing the acute effects of low caffeine dose (caffeine on sustained attention in tests lasting up to 45 minutes using 82 low or non-caffeine-consuming healthy male ( n=41) and female ( n=41) adults aged between 40 and 60 years. Vigilance was measured using Mackworth Clock test, Rapid Visual Information Processing Test, adaptive tracking test, saccadic eye movement and attention switch test. Effects on mood and fatigue were analysed using Bond and Lader and Caffeine Research visual analogue scales, and Samn-Perelli questionnaire. Saliva sampling was performed for both compliance and caffeine pharmacokinetic analysis. Administration of a 60 mg caffeine dose resulted in a significant improvement in sustained attention compared with the placebo. Also a significantly improved peak saccadic velocity and reaction time performance was found, and decreased error rate. Significantly increased feelings of alertness, contentment and overall mood after caffeine treatment compared with placebo were observed. This study demonstrated that in healthy adult subjects oral administration of a single 60 mg caffeine dose elicited a clear enhancement of sustained attention and alertness, measured both in multiple objective performances and in subjective scales.

  20. Coinciding exercise with peak serum caffeine does not improve cycling performance.

    Science.gov (United States)

    Skinner, Tina L; Jenkins, David G; Taaffe, Dennis R; Leveritt, Michael D; Coombes, Jeff S

    2013-01-01

    To investigate whether coinciding peak serum caffeine concentration with the onset of exercise enhances subsequent endurance performance. Randomised, double-blind, crossover. In this randomised, placebo-controlled, double-blind crossover study, 14 male trained cyclists and triathletes (age 31±5year, body mass 75.4±5.7 kg, VO₂max 69.5±6.1 mL kg⁻¹ min⁻¹ and peak power output 417±35W, mean±SD) consumed 6 mg kg(-1) caffeine or a placebo either 1h (C(1h)) prior to completing a 40 km time trial or when the start of exercise coincided with individual peak serum caffeine concentrations (C(peak)). C(peak) was determined from a separate 'caffeine profiling' session that involved monitoring caffeine concentrations in the blood every 30 min over a 4h period. Following caffeine ingestion, peak serum caffeine occurred 120 min in 12 participants and 150 min in 2 participants. Time to complete the 40 km time trial was significantly faster (2.0%; p=0.002) in C(1h) compared to placebo. No statistically significant improvement in performance was noted in the C(peak) trial versus placebo (1.1%; p=0.240). Whilst no differences in metabolic markers were found between C(peak) and placebo conditions, plasma concentrations of glucose (p=0.005), norepinephrine and epinephrine (p≤0.002) were higher in the C(1h) trial 6 min post-exercise versus placebo. In contrast to coinciding peak serum caffeine concentration with exercise onset, caffeine consumed 60 min prior to exercise resulted in significant improvements in 40 km time trial performance. The ergogenic effect of caffeine was not found to be related to peak caffeine concentration in the blood at the onset of endurance exercise. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Effects of caffeinated chewing gum on muscle pain during submaximal isometric exercise in individuals with fibromyalgia.

    Science.gov (United States)

    Umeda, Masataka; Kempka, Laura; Weatherby, Amy; Greenlee, Brennan; Mansion, Kimberly

    2016-04-01

    Physical activity is important to manage symptom of fibromyalgia (FM); however, individuals with FM typically experience augmented muscle pain during exercise. This study examined the effects of caffeinated chewing gum on exercise-induced muscle pain in individuals with FM. This study was conducted with a double-blind, placebo-controlled, cross-over design. Twenty-three patients with FM completed a caffeine condition where they consumed a caffeinated chewing gum that contains 100mg of caffeine, and a placebo condition where they consumed a non-caffeinated chewing gum. They completed isometric handgrip exercise at 25% of their maximal strength for 3 min, and muscle pain rating (MPR) was recorded every 30s during exercise. Clinical pain severity was assessed in each condition using a pain questionnaire. The order of the two conditions was randomly determined. MPR increased during exercise, but caffeinated chewing gum did not attenuate the increase in MPR compared to placebo gum. Clinical pain severity was generally associated with the average MPR and the caffeine effects on MPR, calculated as difference in the average MPR between the two conditions. The results suggest that more symptomatic individuals with FM may experience greater exercise-induced muscle pain, but benefit more from caffeinated chewing gum to reduce exercise-induced muscle pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Chronic caffeine exposure attenuates blast-induced memory deficit in mice.

    Science.gov (United States)

    Ning, Ya-Lei; Yang, Nan; Chen, Xing; Zhao, Zi-Ai; Zhang, Xiu-Zhu; Chen, Xing-Yun; Li, Ping; Zhao, Yan; Zhou, Yuan-Guo

    2015-01-01

    To investigate the effects of three different ways of chronic caffeine administration on blast- induced memory dysfunction and to explore the underlying mechanisms. Adult male C57BL/6 mice were used and randomly divided into five groups: control: without blast exposure, con-water: administrated with water continuously before and after blast-induced traumatic brain injury (bTBI), con-caffeine: administrated with caffeine continuously for 1 month before and after bTBI, pre-caffeine: chronically administrated with caffeine for 1 month before bTBI and withdrawal after bTBI, post-caffeine: chronically administrated with caffeine after bTBI. After being subjected to moderate intensity of blast injury, mice were recorded for learning and memory performance using Morris water maze (MWM) paradigms at 1, 4, and 8 weeks post-blast injury. Neurological deficit scoring, glutamate concentration, proinflammatory cytokines production, and neuropathological changes at 24 h, 1, 4, and 8 weeks post-bTBI were examined to evaluate the brain injury in early and prolonged stages. Adenosine A1 receptor expression was detected using qPCR. All of the three ways of chronic caffeine exposure ameliorated blast-induced memory deficit, which is correlated with the neuroprotective effects against excitotoxicity, inflammation, astrogliosis and neuronal loss at different stages of injury. Continuous caffeine treatment played positive roles in both early and prolonged stages of bTBI; pre-bTBI and post-bTBI treatment of caffeine tended to exert neuroprotective effects at early and prolonged stages of bTBI respectively. Up-regulation of adenosine A1 receptor expression might contribute to the favorable effects of chronic caffeine consumption. Since caffeinated beverages are widely consumed in both civilian and military personnel and are convenient to get, the results may provide a promising prophylactic strategy for blast-induced neurotrauma and the consequent cognitive impairment.

  3. Radioprotective and antioxidant action of caffeine: mechanistic considerations

    International Nuclear Information System (INIS)

    Devasagayam, T.P.A.; Kesavan, P.C.

    1996-01-01

    Caffeine, a major constituent of coffee and other beverages has significant abilities to scavenge highly reactive free radicals and excited states of oxygen and to protect crucial biological molecules against these species. This is one of the possible reasons why caffeine acts as a radioprotector against oxygen-dependent (oxic) pathway of radiation damage and as an anti mutagen/anti carcinogen under certain conditions. The possible physicochemical and molecular mechanisms of caffeine action are briefly reviewed in the light of the recent finding. (author). 69 refs., 1 fig

  4. Caffeine in an Urbanized Estuary: Past and Present Influence ...

    Science.gov (United States)

    Caffeine has been identified by previous research as a potential tracer of sanitary wastewater. To further assess the utility of caffeine as a tracer of wastewater sources, samples from 25 sites throughout Boston Harbor were collected and analyzed for caffeine by LC-MS/MS. Caffeine concentrations in Boston Harbor ranged from 15 ng/L in the outer harbor to a high of 185 ng/L in the inner harbor; mean concentrations and median concentrations were 51 ng/L were 33 ng/L respectively. These data were visualized by a simple inverse distance weighting model to improve the understanding of transport and fate dynamics of wastewater derived contaminants. Elevated concentrations of caffeine in the inner harbor during the sampling period were determined to be the result of a combined sewage overflow (CSO) event as well as illicit discharge of sanitary sewage into municipal storm drains. A comparison of contemporary results to data from 1998 to 1999 shows significant reductions in caffeine levels within the harbor. For instance, concentrations were reduced by a factor of approximately 20 at the site of the former wastewater effluent discharge outfall in Boston Harbor. Lower present-day concentrations throughout the harbor were attributed to the relocation of effluent discharge from within the harbor to Massachusetts Bay, and a reduction in the number and discharge volume of CSOs. Spatial distributions of caffeine identified CSOs as the major contemporary source of con

  5. Caffeine as an indicator for the quantification of untreated wastewater in karst systems.

    Science.gov (United States)

    Hillebrand, Olav; Nödler, Karsten; Licha, Tobias; Sauter, Martin; Geyer, Tobias

    2012-02-01

    Contamination from untreated wastewater leakage and related bacterial contamination poses a threat to drinking water quality. However, a quantification of the magnitude of leakage is difficult. The objective of this work is to provide a highly sensitive methodology for the estimation of the mass of untreated wastewater entering karst aquifers with rapid recharge. For this purpose a balance approach is adapted. It is based on the mass flow of caffeine in spring water, the load of caffeine in untreated wastewater and the daily water consumption per person in a spring catchment area. Caffeine is a source-specific indicator for wastewater, consumed and discharged in quantities allowing detection in a karst spring. The methodology was applied to estimate the amount of leaking and infiltrating wastewater to a well investigated karst aquifer on a daily basis. The calculated mean volume of untreated wastewater entering the aquifer was found to be 2.2 ± 0.5 m(3) d(-1) (undiluted wastewater). It corresponds to approximately 0.4% of the total amount of wastewater within the spring catchment. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Evaluation of the Reproductive and Developmental Risks of Caffeine

    Science.gov (United States)

    Brent, Robert L; Christian, Mildred S; Diener, Robert M

    2011-01-01

    A risk analysis of in utero caffeine exposure is presented utilizing epidemiological studies and animal studies dealing with congenital malformation, pregnancy loss, and weight reduction. These effects are of interest to teratologists, because animal studies are useful in their evaluation. Many of the epidemiology studies did not evaluate the impact of the “pregnancy signal,” which identifies healthy pregnancies and permits investigators to identify subjects with low pregnancy risks. The spontaneous abortion epidemiology studies were inconsistent and the majority did not consider the confounding introduced by not considering the pregnancy signal. The animal studies do not support the concept that caffeine is an abortafacient for the wide range of human caffeine exposures. Almost all the congenital malformation epidemiology studies were negative. Animal pharmacokinetic studies indicate that the teratogenic plasma level of caffeine has to reach or exceed 60 µg/ml, which is not attainable from ingesting large amounts of caffeine in foods and beverages. No epidemiological study described the “caffeine teratogenic syndrome.” Six of the 17 recent epidemiology studies dealing with the risk of caffeine and fetal weight reduction were negative. Seven of the positive studies had growth reductions that were clinically insignificant and none of the studies cited the animal literature. Analysis of caffeine's reproductive toxicity considers reproducibility and plausibility of clinical, epidemiological, and animal data. Moderate or even high amounts of beverages and foods containing caffeine do not increase the risks of congenital malformations, miscarriage or growth retardation. Pharmacokinetic studies markedly improve the ability to perform the risk analyses. Birth Defects Res (Part B) 92:152–187, 2011. © 2011 Wiley-Liss, Inc. PMID:21370398

  7. The effect of caffeine on working memory load-related brain activation in middle-aged males.

    Science.gov (United States)

    Klaassen, Elissa B; de Groot, Renate H M; Evers, Elisabeth A T; Snel, Jan; Veerman, Enno C I; Ligtenberg, Antoon J M; Jolles, Jelle; Veltman, Dick J

    2013-01-01

    Caffeine is commonly consumed in an effort to enhance cognitive performance. However, little is known about the usefulness of caffeine with regard to memory enhancement, with previous studies showing inconsistent effects on memory performance. We aimed to determine the effect of caffeine on working memory (WM) load-related activation during encoding, maintenance and retrieval phases of a WM maintenance task using functional magnetic resonance imaging (fMRI). 20 healthy, male, habitual caffeine consumers aged 40-61 years were administered 100 mg of caffeine in a double-blind placebo-controlled crossover design. Participants were scanned in a non-withdrawn state following a workday during which caffeinated products were consumed according to individual normal use (range = 145-595 mg). Acute caffeine administration was associated with increased load-related activation compared to placebo in the left and right dorsolateral prefrontal cortex during WM encoding, but decreased load-related activation in the left thalamus during WM maintenance. These findings are indicative of an effect of caffeine on the fronto-parietal network involved in the top-down cognitive control of WM processes during encoding and an effect on the prefrontal cortico-thalamic loop involved in the interaction between arousal and the top-down control of attention during maintenance. Therefore, the effects of caffeine on WM may be attributed to both a direct effect of caffeine on WM processes, as well as an indirect effect on WM via arousal modulation. Behavioural and fMRI results were more consistent with a detrimental effect of caffeine on WM at higher levels of WM load, than caffeine-related WM enhancement. This article is part of a Special Issue entitled 'Cognitive Enhancers'. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Caffeine accelerates recovery from general anesthesia via multiple pathways.

    Science.gov (United States)

    Fong, Robert; Khokhar, Suhail; Chowdhury, Atif N; Xie, Kelvin G; Wong, Josiah Hiu-Yuen; Fox, Aaron P; Xie, Zheng

    2017-09-01

    Various studies have explored different ways to speed emergence from anesthesia. Previously, we have shown that three drugs that elevate intracellular cAMP (forskolin, theophylline, and caffeine) accelerate emergence from anesthesia in rats. However, our earlier studies left two main questions unanswered. First, were cAMP-elevating drugs effective at all anesthetic concentrations? Second, given that caffeine was the most effective of the drugs tested, why was caffeine more effective than forskolin since both drugs elevate cAMP? In our current study, emergence time from anesthesia was measured in adult rats exposed to 3% isoflurane for 60 min. Caffeine dramatically accelerated emergence from anesthesia, even at the high level of anesthetic employed. Caffeine has multiple actions including blockade of adenosine receptors. We show that the selective A 2a adenosine receptor antagonist preladenant or the intracellular cAMP ([cAMP] i )-elevating drug forskolin, accelerated recovery from anesthesia. When preladenant and forskolin were tested together, the effect on anesthesia recovery time was additive indicating that these drugs operate via different pathways. Furthermore, the combination of preladenant and forskolin was about as effective as caffeine suggesting that both A 2A receptor blockade and [cAMP] i elevation play a role in caffeine's ability to accelerate emergence from anesthesia. Because anesthesia in rodents is thought to be similar to that in humans, these results suggest that caffeine might allow for rapid and uniform emergence from general anesthesia in humans at all anesthetic concentrations and that both the elevation of [cAMP] i and adenosine receptor blockade play a role in this response. NEW & NOTEWORTHY Currently, there is no method to accelerate emergence from anesthesia. Patients "wake" when they clear the anesthetic from their systems. Previously, we have shown that caffeine can accelerate emergence from anesthesia. In this study, we show that

  9. Consumption of Caffeinated Products and Cardiac Ectopy.

    Science.gov (United States)

    Dixit, Shalini; Stein, Phyllis K; Dewland, Thomas A; Dukes, Jonathan W; Vittinghoff, Eric; Heckbert, Susan R; Marcus, Gregory M

    2016-01-26

    Premature cardiac contractions are associated with increased morbidity and mortality. Though experts associate premature atrial contractions (PACs) and premature ventricular contractions (PVCs) with caffeine, there are no data to support this relationship in the general population. As certain caffeinated products may have cardiovascular benefits, recommendations against them may be detrimental. We studied Cardiovascular Health Study participants with a baseline food frequency assessment, 24-hour ambulatory electrocardiography (Holter) monitoring, and without persistent atrial fibrillation. Frequencies of habitual coffee, tea, and chocolate consumption were assessed using a picture-sort food frequency survey. The main outcomes were PACs/h and PVCs/hour. Among 1388 participants (46% male, mean age 72 years), 840 (61%) consumed ≥1 caffeinated product per day. The median numbers of PACs and PVCs/h and interquartile ranges were 3 (1-12) and 1 (0-7), respectively. There were no differences in the number of PACs or PVCs/h across levels of coffee, tea, and chocolate consumption. After adjustment for potential confounders, more frequent consumption of these products was not associated with ectopy. In examining combined dietary intake of coffee, tea, and chocolate as a continuous measure, no relationships were observed after multivariable adjustment: 0.48% fewer PACs/h (95% CI -4.60 to 3.64) and 2.87% fewer PVCs/h (95% CI -8.18 to 2.43) per 1-serving/week increase in consumption. In the largest study to evaluate dietary patterns and quantify cardiac ectopy using 24-hour Holter monitoring, we found no relationship between chronic consumption of caffeinated products and ectopy. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  10. Sustained-release of caffeine from a polymeric tablet matrix: An in vitro and pharmacokinetic study

    International Nuclear Information System (INIS)

    Tan, Donna; Zhao Bin; Moochhala, Shabbir; Yang Yiyan

    2006-01-01

    Caffeine is utilized as a stimulant to impart a desired level of alertness during certain working hours. Usually, a single dose of caffeine induces 2-3 h of alertness coupled with side effects whereas a longer effect of 8-12 h is very useful for both daily life and military action. Thus, there is a need to deliver the stimulant continuously to an individual at one time to impart an increased level of alertness for the period stated after administration. This study aimed to design a polymeric microparticle system for sustained delivery of caffeine using a polymeric matrix. Poly(ethylene oxide) (PEO) was used as the erodible matrix material and the caffeine polymeric tablets were fabricated by compression using a Graseby Specac hydraulic press. In vitro release profiles as well as the pharmacokinetics studies data were obtained. Caffeine tablets fabricated using various polymers showed a high initial burst release type profile as compared to the caffeine-PEO-tablet. The PK studies showed sustained delivery of caffeine resulted in two expected phenomena: a reduction in the initial high rate of caffeine release (burst release) as well as a reduction in the change in caffeine concentration in the systemic circulation. A simple two-component system for sustained-release caffeine formulation therefore has been achieved

  11. Consumption of an acute dose of caffeine reduces acquisition but not memory in the honey bee.

    Science.gov (United States)

    Mustard, Julie A; Dews, Lauren; Brugato, Arlana; Dey, Kevin; Wright, Geraldine A

    2012-06-15

    Caffeine affects several molecules that are also involved in the processes underlying learning and memory such as cAMP and calcium. However, studies of caffeine's influence on learning and memory in mammals are often contradictory. Invertebrate model systems have provided valuable insight into the actions of many neuroactive compounds including ethanol and cocaine. We use the honey bee (Apis mellifera) to investigate how the ingestion of acute doses of caffeine before, during, and after conditioning influences performance in an appetitive olfactory learning and memory task. Consumption of caffeine doses of 0.01 M or greater during or prior to conditioning causes a significant reduction in response levels during acquisition. Although bees find the taste of caffeine to be aversive at high concentrations, the bitter taste does not explain the reduction in acquisition observed for bees fed caffeine before conditioning. While high doses of caffeine reduced performance during acquisition, the response levels of bees given caffeine were the same as those of the sucrose only control group in a recall test 24h after conditioning. In addition, caffeine administered after conditioning had no affect on recall. These results suggest that caffeine specifically affects performance during acquisition and not the processes involved in the formation of early long term memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Sustained-release of caffeine from a polymeric tablet matrix: An in vitro and pharmacokinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Donna [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Zhao Bin [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Moochhala, Shabbir [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore)]. E-mail: mshabbir@dso.org.sg; Yang Yiyan [Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, 04-01, The Nanos, Singapore 138669 (Singapore)

    2006-07-25

    Caffeine is utilized as a stimulant to impart a desired level of alertness during certain working hours. Usually, a single dose of caffeine induces 2-3 h of alertness coupled with side effects whereas a longer effect of 8-12 h is very useful for both daily life and military action. Thus, there is a need to deliver the stimulant continuously to an individual at one time to impart an increased level of alertness for the period stated after administration. This study aimed to design a polymeric microparticle system for sustained delivery of caffeine using a polymeric matrix. Poly(ethylene oxide) (PEO) was used as the erodible matrix material and the caffeine polymeric tablets were fabricated by compression using a Graseby Specac hydraulic press. In vitro release profiles as well as the pharmacokinetics studies data were obtained. Caffeine tablets fabricated using various polymers showed a high initial burst release type profile as compared to the caffeine-PEO-tablet. The PK studies showed sustained delivery of caffeine resulted in two expected phenomena: a reduction in the initial high rate of caffeine release (burst release) as well as a reduction in the change in caffeine concentration in the systemic circulation. A simple two-component system for sustained-release caffeine formulation therefore has been achieved.

  13. Consumer acceptance of high-pressure processing and pulsed-electric-field

    DEFF Research Database (Denmark)

    Olsen, Nina Veflen; Grunert, Klaus G.; Sonne, Anne-Mette

    2010-01-01

    New products and new processing techniques are continuously developed in the food industry. While food scientists may focus on the technical novelty and applaud the progress of science, consumers are often conservative and sceptical towards changes. The advantages that a new processing technology...... has to offer, do not necessarily guarantee the success of a product in the market place. Consumer acceptance depends on whether consumers perceive that there are specific benefits associated with the product. This review focuses specifically on how high-pressure processing (HPP) and pulsed...

  14. On the interaction of caffeine with nucleic acids. 4

    International Nuclear Information System (INIS)

    Fritzsche, H.; Lang, H.; Sprinz, H.; Pohle, W.

    1980-01-01

    The DNA-caffeine interaction at high concentration of caffeine (Cf) leads to an arrangement of Cf molecules outside of the DNA double helix with an orientation parallel to the bases both in the A and B form as demonstrated by infrared linear dichroism. Addition of DNA broadens the 1 H NMR lines of Cf in aqueous solution indicating a specific binding. Intercalation is not the predominant mechanism, the deuterium relaxation time T 1 = (38 +- 7) ms and the estimated reorientation correlation time tausub(cb) = 0.17 ns of caffeine-8-[ 2 H] in the Cf-DNA complex suggest an outside stacking of the ligand. According to the results a model on the DNA-Cf complex at high Cf concentration (binding process II) is suggested including the caffeine-induced reorientation of the hydration shell of DNA. (Auth.)

  15. Caffeine Enhances Memory Performance in Young Adults during Their Non-optimal Time of Day.

    Science.gov (United States)

    Sherman, Stephanie M; Buckley, Timothy P; Baena, Elsa; Ryan, Lee

    2016-01-01

    Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in physiological arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students' non-optimal time of day - early morning. These findings have real-world implications for students taking morning exams.

  16. Caffeine enhances memory performance in young adults during their non-optimal time of day

    Directory of Open Access Journals (Sweden)

    Stephanie M Sherman

    2016-11-01

    Full Text Available Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated, college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1. During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students’ non-optimal time of day – early morning. These findings have real-world implications for students taking morning exams.

  17. Caffeine and REM sleep deprivation: Effect on basal levels of signaling molecules in area CA1.

    Science.gov (United States)

    Alkadhi, Karim A; Alhaider, Ibrahim A

    2016-03-01

    We have investigated the neuroprotective effect of chronic caffeine treatment on basal levels of memory-related signaling molecules in area CA1 of sleep-deprived rats. Animals in the caffeine groups were treated with caffeine in drinking water (0.3g/l) for four weeks before they were REM sleep-deprived for 24h in the Modified Multiple Platforms paradigm. Western blot analysis of basal protein levels of plasticity- and memory-related signaling molecules in hippocampal area CA1 showed significant down regulation of the basal levels of phosphorylated- and total-CaMKII, phosphorylated- and total-CREB as well as those of BDNF and CaMKIV in sleep deprived rats. All these changes were completely prevented in rats that chronically consumed caffeine. The present findings suggest an important neuroprotective property of caffeine in sleep deprivation. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Maternal Caffeine Consumption during Pregnancy and Behavioral Disorders in 11-Year-Old Offspring: A Danish National Birth Cohort Study.

    Science.gov (United States)

    Hvolgaard Mikkelsen, Susanne; Obel, Carsten; Olsen, Jørn; Niclasen, Janni; Bech, Bodil Hammer

    2017-10-01

    To examine the association between maternal caffeine consumption from coffee and tea during pregnancy and offspring behavioral disorders. We studied 47 491 children enrolled in the Danish National Birth Cohort between 1996 and 2002. Data on maternal coffee and tea consumption was collected at 15 and 30 weeks of gestation. When the child was 11 years old, the Strength and Difficulties Questionnaire was filled in by children, parents, and teachers. We estimated risk ratios (RRs) for offspring behavioral disorders. At 15 weeks of gestation 3% and 4% of the pregnant women consumed ≥8 cups/d of coffee or tea, respectively. Maternal coffee consumption ≥8 cups/d at 15 weeks of gestation was associated with increased risk of hyperactivity-inattention disorder (RR 1.47; 95% CI 1.18-1.83), conduct-oppositional disorders (RR 1.22; 95% CI 1.01-1.48), and any psychiatric disorder (RR 1.23; 95% CI 1.08-1.40). Maternal tea consumption ≥8 cups/d at 15 weeks of gestation was associated with increased risk of anxiety-depressive disorders (RR 1.28; 95% CI 1.09-1.52) and any psychiatric disorder (RR 1.24; 95% CI 1.11-1.40). An increased risk of hyperactivity-inattention disorder was observed with increasing daily caffeine consumption at 15 weeks of gestation. High maternal caffeine consumption from coffee and tea at 15 weeks of gestation was associated with behavioral disorders in 11-year-old offspring. We hypothesize that caffeine exposure may affect the fetal brain and program for behavioral disorders later in life. The fetal brain seems to be more sensitive to caffeine exposure at 15 weeks of pregnancy compared with 30 weeks of gestation. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Stimulation of Intestinal Cl- Secretion Through CFTR by Caffeine Intake in Salt-Sensitive Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Xiao Wei

    2018-03-01

    Full Text Available Background/Aims: High salt consumption is a major risk factor for hypertension, and sodium homeostasis is regulated by both intestinal sodium absorption and urinary sodium excretion. Chronic caffeine intake has been reported to attenuate salt-sensitive hypertension by promoting urinary sodium excretion; however, its exact role in intestinal sodium absorption remains unknown. Here, we investigated whether and how chronic caffeine consumption antagonizes salt-sensitive hypertension by inhibiting intestinal sodium absorption. Methods: Dahl salt-sensitive rats were fed 8% NaCl chow and 0.1% caffeine in their drinking water for 15 days. The blood pressure and fecal sodium content were measured. The effect of caffeine on the movement of Cl- in enterocyte cells was determined with the Ussing chamber assay. Results: Rats that were treated with caffeine displayed significantly lower mean blood pressure and higher fecal sodium content than the controls. Consistent with these findings, caffeine intake decreased fluid absorption by the intestine in the fluid perfusion experiment. Further, the results from the Ussing chamber assay indicated that caffeine promoted Cl- secretion through enterocyte apical cystic fibrosis transmembrane conductance regulator (CFTR, and thus inhibited sodium absorption. Moreover, depletion of cAMP or inhibition of CFTR completely abolished the effect of caffeine on Cl- secretion. Conclusion: The results indicate that chronic caffeine consumption reduces sodium absorption by promoting CFTR-mediated Cl- secretion in the intestine, which contributes to the anti-hypertensive effect of caffeine in salt-sensitive rats.

  20. INFLUENCE OF MARKETING COMMUNICATIVE STRATEGIES ON CONSUMER BEHAVIOUR: A CASE OF THE HIGH-TECHNOLOGY MARKET OF UKRAINE

    OpenAIRE

    Victoria Zhurylo; Olga Prygara

    2017-01-01

    The purpose of the study is to research consumer behaviour types and to develop marketing strategies of communicative influence on the consumer in the high-technology goods market. Methodology. Marketing research in Ukrainian market of high-tech goods is conducted to define motivations of the consumers and the peculiarities of their market behaviour. The profiles of target customers are developed and the typology of consumer behaviour is formed, based on the reasons of purchasing of high-tech...

  1. No Enhancement of 24-Hour Visuomotor Skill Retention by Post-Practice Caffeine Administration.

    Directory of Open Access Journals (Sweden)

    Sara J Hussain

    Full Text Available Caffeine is widely consumed throughout the world and appears to indirectly facilitate learning and memory through effects on attention and motivation. Animal work indicates that post-training caffeine administration augments inhibitory avoidance memory, spatial memory, and object memory. In humans, post-training caffeine administration enhances the ability to discern between familiar images and new, similar images. However, the effect of post-training caffeine administration on motor memory has not been examined. Therefore, we tested two groups of low caffeine consumers (average weekly consumption ≤500 mg in a double-blind, placebo-controlled study involving acquisition of a continuous isometric visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150 repetitions of training on the continuous isometric visuomotor skill and subsequently ingested either 200 mg of caffeine or placebo. On day 2, subjects completed an additional 5 blocks of training. Day 1 mean performance and performance variability were both similar between groups, suggesting that both groups acquired the motor skill similarly. For mean performance on Day 2, patterns of re-learning, mean performance learning magnitudes, mean performance learning rates, and mean performance retention magnitudes were all similar between groups. For performance variability on Day 2, there was a small trend towards increased variability in the caffeine group during re-learning, but performance variability learning magnitudes and performance variability retention magnitudes did not differ between groups. Because motor skill acquisition can also be conceptualized as a reduction in performance variability, these results suggest that there may be a small negative effect of post-practice caffeine administration on memory of a newly-learned visuomotor skill. Overall, we found no evidence to suggest that post-training caffeine administration enhances 24-hour retention of a newly

  2. No Enhancement of 24-Hour Visuomotor Skill Retention by Post-Practice Caffeine Administration.

    Science.gov (United States)

    Hussain, Sara J; Cole, Kelly J

    2015-01-01

    Caffeine is widely consumed throughout the world and appears to indirectly facilitate learning and memory through effects on attention and motivation. Animal work indicates that post-training caffeine administration augments inhibitory avoidance memory, spatial memory, and object memory. In humans, post-training caffeine administration enhances the ability to discern between familiar images and new, similar images. However, the effect of post-training caffeine administration on motor memory has not been examined. Therefore, we tested two groups of low caffeine consumers (average weekly consumption ≤500 mg) in a double-blind, placebo-controlled study involving acquisition of a continuous isometric visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150 repetitions) of training on the continuous isometric visuomotor skill and subsequently ingested either 200 mg of caffeine or placebo. On day 2, subjects completed an additional 5 blocks of training. Day 1 mean performance and performance variability were both similar between groups, suggesting that both groups acquired the motor skill similarly. For mean performance on Day 2, patterns of re-learning, mean performance learning magnitudes, mean performance learning rates, and mean performance retention magnitudes were all similar between groups. For performance variability on Day 2, there was a small trend towards increased variability in the caffeine group during re-learning, but performance variability learning magnitudes and performance variability retention magnitudes did not differ between groups. Because motor skill acquisition can also be conceptualized as a reduction in performance variability, these results suggest that there may be a small negative effect of post-practice caffeine administration on memory of a newly-learned visuomotor skill. Overall, we found no evidence to suggest that post-training caffeine administration enhances 24-hour retention of a newly-learned continuous visuomotor

  3. No Enhancement of 24-Hour Visuomotor Skill Retention by Post-Practice Caffeine Administration

    Science.gov (United States)

    Hussain, Sara J.; Cole, Kelly J.

    2015-01-01

    Caffeine is widely consumed throughout the world and appears to indirectly facilitate learning and memory through effects on attention and motivation. Animal work indicates that post-training caffeine administration augments inhibitory avoidance memory, spatial memory, and object memory. In humans, post-training caffeine administration enhances the ability to discern between familiar images and new, similar images. However, the effect of post-training caffeine administration on motor memory has not been examined. Therefore, we tested two groups of low caffeine consumers (average weekly consumption ≤500 mg) in a double-blind, placebo-controlled study involving acquisition of a continuous isometric visuomotor tracking skill. On Day 1, subjects completed 5 blocks (150 repetitions) of training on the continuous isometric visuomotor skill and subsequently ingested either 200 mg of caffeine or placebo. On day 2, subjects completed an additional 5 blocks of training. Day 1 mean performance and performance variability were both similar between groups, suggesting that both groups acquired the motor skill similarly. For mean performance on Day 2, patterns of re-learning, mean performance learning magnitudes, mean performance learning rates, and mean performance retention magnitudes were all similar between groups. For performance variability on Day 2, there was a small trend towards increased variability in the caffeine group during re-learning, but performance variability learning magnitudes and performance variability retention magnitudes did not differ between groups. Because motor skill acquisition can also be conceptualized as a reduction in performance variability, these results suggest that there may be a small negative effect of post-practice caffeine administration on memory of a newly-learned visuomotor skill. Overall, we found no evidence to suggest that post-training caffeine administration enhances 24-hour retention of a newly-learned continuous visuomotor

  4. Dose-response study of caffeine effects on cerebral functional activity with a specific focus on dependence.

    Science.gov (United States)

    Nehlig, A; Boyet, S

    2000-03-06

    Caffeine is a behavioral stimulant consumed on a worldwide basis. The question of whether caffeine is addictive has been debated for over a decade. Caffeine acts as a mild positive reinforcer but is not consistently self-administered in humans or animals. With [14C]2-deoxyglucose autoradiography, we studied the effects of increasing doses of caffeine on cerebral glucose utilization in rats. At 1 mg/kg, caffeine activated the caudate nucleus mediating locomotion, and the raphe nuclei and locus coeruleus involved with mood and sleep. After 2.5 and 5 mg/kg caffeine, metabolic activation spread to other components of the nigrostriatal dopaminergic system, the thalamus, ventral tegmental area and amygdala. The functional activation of the shell of the nucleus accumbens, an area involved in addiction and reward, was only induced by the highest dose of caffeine, 10 mg/kg. At this dose, the activation of the shell of the nucleus accumbens occurred together with that of the core of the nucleus accumbens and of most other brain regions. These data correlate well with the known sensitivity of locomotion, mood and sleep to low doses of caffeine. They also show that low doses of caffeine which reflect the usual human level of consumption fail to activate reward circuits in the brain and thus provide functional evidence of the very low addictive potential of caffeine.

  5. Exercise-Induced Fatigue and Caffeine Supplementation Affect Psychomotor Performance but Not Covert Visuo-Spatial Attention

    Science.gov (United States)

    Connell, Charlotte J. W.; Thompson, Benjamin; Kuhn, Gustav; Gant, Nicholas

    2016-01-01

    Fatigue resulting from strenuous exercise can impair cognition and oculomotor control. These impairments can be prevented by administering psychostimulants such as caffeine. This study used two experiments to explore the influence of caffeine administered at rest and during fatiguing physical exercise on spatial attention—a cognitive function that is crucial for task-based visually guided behavior. In independent placebo-controlled studies, cohorts of 12 healthy participants consumed caffeine and rested or completed 180 min of stationary cycling. Covert attentional orienting was measured in both experiments using a spatial cueing paradigm. We observed no alterations in attentional facilitation toward spatial cues suggesting that covert attentional orienting is not influenced by exercise fatigue or caffeine supplementation. Response times were increased (impaired) after exercise and this deterioration was prevented by caffeine supplementation. In the resting experiment, response times across all conditions and cues were decreased (improved) with caffeine. Covert spatial attention was not influenced by caffeine. Together, the results of these experiments suggest that covert attentional orienting is robust to the effects of fatiguing exercise and not influenced by caffeine. However, exercise fatigue impairs response times, which can be prevented by caffeine, suggesting that pre-motor planning and execution of the motor responses required for performance of the cueing task are sensitive to central nervous system fatigue. Caffeine improves response time in both fatigued and fresh conditions, most likely through action on networks controlling motor function. PMID:27768747

  6. Exercise-Induced Fatigue and Caffeine Supplementation Affect Psychomotor Performance but Not Covert Visuo-Spatial Attention.

    Directory of Open Access Journals (Sweden)

    Charlotte J W Connell

    Full Text Available Fatigue resulting from strenuous exercise can impair cognition and oculomotor control. These impairments can be prevented by administering psychostimulants such as caffeine. This study used two experiments to explore the influence of caffeine administered at rest and during fatiguing physical exercise on spatial attention-a cognitive function that is crucial for task-based visually guided behavior. In independent placebo-controlled studies, cohorts of 12 healthy participants consumed caffeine and rested or completed 180 min of stationary cycling. Covert attentional orienting was measured in both experiments using a spatial cueing paradigm. We observed no alterations in attentional facilitation toward spatial cues suggesting that covert attentional orienting is not influenced by exercise fatigue or caffeine supplementation. Response times were increased (impaired after exercise and this deterioration was prevented by caffeine supplementation. In the resting experiment, response times across all conditions and cues were decreased (improved with caffeine. Covert spatial attention was not influenced by caffeine. Together, the results of these experiments suggest that covert attentional orienting is robust to the effects of fatiguing exercise and not influenced by caffeine. However, exercise fatigue impairs response times, which can be prevented by caffeine, suggesting that pre-motor planning and execution of the motor responses required for performance of the cueing task are sensitive to central nervous system fatigue. Caffeine improves response time in both fatigued and fresh conditions, most likely through action on networks controlling motor function.

  7. Exercise-Induced Fatigue and Caffeine Supplementation Affect Psychomotor Performance but Not Covert Visuo-Spatial Attention.

    Science.gov (United States)

    Connell, Charlotte J W; Thompson, Benjamin; Kuhn, Gustav; Gant, Nicholas

    2016-01-01

    Fatigue resulting from strenuous exercise can impair cognition and oculomotor control. These impairments can be prevented by administering psychostimulants such as caffeine. This study used two experiments to explore the influence of caffeine administered at rest and during fatiguing physical exercise on spatial attention-a cognitive function that is crucial for task-based visually guided behavior. In independent placebo-controlled studies, cohorts of 12 healthy participants consumed caffeine and rested or completed 180 min of stationary cycling. Covert attentional orienting was measured in both experiments using a spatial cueing paradigm. We observed no alterations in attentional facilitation toward spatial cues suggesting that covert attentional orienting is not influenced by exercise fatigue or caffeine supplementation. Response times were increased (impaired) after exercise and this deterioration was prevented by caffeine supplementation. In the resting experiment, response times across all conditions and cues were decreased (improved) with caffeine. Covert spatial attention was not influenced by caffeine. Together, the results of these experiments suggest that covert attentional orienting is robust to the effects of fatiguing exercise and not influenced by caffeine. However, exercise fatigue impairs response times, which can be prevented by caffeine, suggesting that pre-motor planning and execution of the motor responses required for performance of the cueing task are sensitive to central nervous system fatigue. Caffeine improves response time in both fatigued and fresh conditions, most likely through action on networks controlling motor function.

  8. Separating neural and vascular effects of caffeine using simultaneous EEG–FMRI: Differential effects of caffeine on cognitive and sensorimotor brain responses

    Science.gov (United States)

    Diukova, Ana; Ware, Jennifer; Smith, Jessica E.; Evans, C. John; Murphy, Kevin; Rogers, Peter J.; Wise, Richard G.

    2012-01-01

    The effects of caffeine are mediated through its non-selective antagonistic effects on adenosine A1 and A2A adenosine receptors resulting in increased neuronal activity but also vasoconstriction in the brain. Caffeine, therefore, can modify BOLD FMRI signal responses through both its neural and its vascular effects depending on receptor distributions in different brain regions. In this study we aim to distinguish neural and vascular influences of a single dose of caffeine in measurements of task-related brain activity using simultaneous EEG–FMRI. We chose to compare low-level visual and motor (paced finger tapping) tasks with a cognitive (auditory oddball) task, with the expectation that caffeine would differentially affect brain responses in relation to these tasks. To avoid the influence of chronic caffeine intake, we examined the effect of 250 mg of oral caffeine on 14 non and infrequent caffeine consumers in a double-blind placebo-controlled cross-over study. Our results show that the task-related BOLD signal change in visual and primary motor cortex was significantly reduced by caffeine, while the amplitude and latency of visual evoked potentials over occipital cortex remained unaltered. However, during the auditory oddball task (target versus non-target stimuli) caffeine significantly increased the BOLD signal in frontal cortex. Correspondingly, there was also a significant effect of caffeine in reducing the target evoked response potential (P300) latency in the oddball task and this was associated with a positive potential over frontal cortex. Behavioural data showed that caffeine also improved performance in the oddball task with a significantly reduced number of missed responses. Our results are consistent with earlier studies demonstrating altered flow-metabolism coupling after caffeine administration in the context of our observation of a generalised caffeine-induced reduction in cerebral blood flow demonstrated by arterial spin labelling (19

  9. Caffeinated beverage intake and reproductive hormones among premenopausal women in the BioCycle Study.

    Science.gov (United States)

    Schliep, Karen C; Schisterman, Enrique F; Mumford, Sunni L; Pollack, Anna Z; Zhang, Cuilin; Ye, Aijun; Stanford, Joseph B; Hammoud, Ahmad O; Porucznik, Christina A; Wactawski-Wende, Jean

    2012-02-01

    Caffeinated beverages are widely consumed among women of reproductive age, but their association with reproductive hormones, and whether race modifies any such associations, is not well understood. We assessed the relation between caffeine and caffeinated beverage intake and reproductive hormones in healthy premenopausal women and evaluated the potential effect modification by race. Participants (n = 259) were followed for up to 2 menstrual cycles and provided fasting blood specimens for hormonal assessment at up to 8 visits per cycle and four 24-h dietary recalls per cycle. Weighted linear mixed models and nonlinear mixed models with harmonic terms were used to estimate associations between caffeine and hormone concentrations, adjusted for age, adiposity, physical activity, energy and alcohol intakes, and perceived stress. On the basis of a priori assumptions, an interaction between race and caffeine was tested, and stratified results are presented. Caffeine intake ≥200 mg/d was inversely associated with free estradiol concentrations among white women (β = -0.15; 95% CI: -0.26, -0.05) and positively associated among Asian women (β = 0.61; 95% CI: 0.31, 0.92). Caffeinated soda intake and green tea intake ≥1 cup/d (1 cup = 240 mL) were positively associated with free estradiol concentrations among all races: β = 0.14 (95% CI: 0.06, 0.22) and β = 0.26 (95% CI: 0.07, 0.45), respectively. Moderate consumption of caffeine was associated with reduced estradiol concentrations among white women, whereas caffeinated soda and green tea intakes were associated with increased estradiol concentrations among all races. Further research is warranted on the association between caffeine and caffeinated beverages and reproductive hormones and whether these relations differ by race.

  10. Caffeinated beverage intake and reproductive hormones among premenopausal women in the BioCycle Study123

    Science.gov (United States)

    Schisterman, Enrique F; Mumford, Sunni L; Pollack, Anna Z; Zhang, Cuilin; Ye, Aijun; Stanford, Joseph B; Hammoud, Ahmad O; Porucznik, Christina A; Wactawski-Wende, Jean

    2012-01-01

    Background: Caffeinated beverages are widely consumed among women of reproductive age, but their association with reproductive hormones, and whether race modifies any such associations, is not well understood. Objective: We assessed the relation between caffeine and caffeinated beverage intake and reproductive hormones in healthy premenopausal women and evaluated the potential effect modification by race. Design: Participants (n = 259) were followed for up to 2 menstrual cycles and provided fasting blood specimens for hormonal assessment at up to 8 visits per cycle and four 24-h dietary recalls per cycle. Weighted linear mixed models and nonlinear mixed models with harmonic terms were used to estimate associations between caffeine and hormone concentrations, adjusted for age, adiposity, physical activity, energy and alcohol intakes, and perceived stress. On the basis of a priori assumptions, an interaction between race and caffeine was tested, and stratified results are presented. Results: Caffeine intake ≥200 mg/d was inversely associated with free estradiol concentrations among white women (β = −0.15; 95% CI: −0.26, −0.05) and positively associated among Asian women (β = 0.61; 95% CI: 0.31, 0.92). Caffeinated soda intake and green tea intake ≥1 cup/d (1 cup = 240 mL) were positively associated with free estradiol concentrations among all races: β = 0.14 (95% CI: 0.06, 0.22) and β = 0.26 (95% CI: 0.07, 0.45), respectively. Conclusions: Moderate consumption of caffeine was associated with reduced estradiol concentrations among white women, whereas caffeinated soda and green tea intakes were associated with increased estradiol concentrations among all races. Further research is warranted on the association between caffeine and caffeinated beverages and reproductive hormones and whether these relations differ by race. PMID:22237060

  11. Caffeine, Diabetes, Cognition, and Dementia

    NARCIS (Netherlands)

    Biessels, Geert Jan

    2010-01-01

    People with diabetes mellitus are at increased risk of cognitive dysfunction. This review explores the relation between caffeine intake, diabetes, cognition and dementia, focusing on type 2 diabetes (T2DM). Epidemiological studies on caffeine/coffee intake and T2DM risk are reviewed. Next, the

  12. Caffeine and the kidney: what evidence right now?

    Science.gov (United States)

    Bolignano, Davide; Coppolino, Giuseppe; Barillà, Antonio; Campo, Susanna; Criseo, Manila; Tripodo, Donatella; Buemi, Michele

    2007-07-01

    Caffeine, or 1, 3, 7-trimethylxanthine, is one of the most frequently consumed active drugs worldwide. Its main mechanisms of action include inhibiting the phosphodiesteratic enzyme and adenosine receptors and activating the ryanodine receptors with several actions on all organs. What effect does caffeine have on the kidney? Is caffeine beneficial or dangerous? A review of the current literature reveals conflicting opinions regarding the prolithiasic effect of this substance, whereas its diuretic action is least disputed and more easily observed. Caffeine may have a toxic or preventive effect in some physiologic or pathologic conditions. Some of these incongruences may depend on several factors, such as dosage, prior chronic exposure, genetic-enzymatic axes, and concomitant drug consumption. While awaiting further insight from forthcoming studies on the issue, we may reach a preliminary conclusion that, as yet, there is no evidence contraindicating the consumption of the equivalent of 3 to 4 cups of coffee per day in healthy or nephropathic subjects. However, particular attention should be paid to the elderly, children, and patients on concomitant treatment with analgesics or diuretics, whereas in subjects with a family or clinical history of calcium lithiasis a moderate caffeine consumption should be associated with an adequate fluid intake. Further in-depth studies are required to investigate whether this beverage is beneficial to patients on hemodialysis.

  13. Caffeine intake is associated with pupil dilation and enhanced accommodation.

    Science.gov (United States)

    Abokyi, S; Owusu-Mensah, J; Osei, K A

    2017-04-01

    PurposeIt is purported that caffeine, an autonomic stimulant, affects visual performance. This study sought to assess whether caffeine intake was associated with changes in pupil size and/or amplitude of accommodation.Patients and methodsA double-masked, crossover study was conducted in 50 healthy subjects of age range 19 to 25 years. Subjects were randomized to treatments such that subjects consumed either 250 mg caffeine drink or vehicle on separate days. Amplitude of accommodation was measured by the push-up technique, and pupil size using a millimeter ruler fixed to a slit lamp biomicroscope in dim illumination (5 lux). Amplitude of accommodation and pupil size were taken at baseline, and at 30, 60 and 90 min time points post treatment. Repeated measures one-way ANOVA and paired t-test were used in analyzing data.ResultsAmplitude of accommodation and pupil size after caffeine intake were significantly greater than vehicle (Pcaffeine beverage was associated with significant increases in amplitude of accommodation and pupil size with time (Pcaffeine. This study suggests caffeine may have some influence on visual functions.

  14. Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: High seafood consumers, high freshwater fish consumers and pregnant women

    International Nuclear Information System (INIS)

    Yamada, A.; Bemrah, N.; Veyrand, B.; Pollono, C.; Merlo, M.; Desvignes, V.; Sirot, V.

    2014-01-01

    Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC–MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values < LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg −1 bw.d −1 ), PFUnA (1.3 ng.kg −1 bw.d −1 ), PFDA (0.4 ng.kg −1 bw.d −1 ) and PFHpS (0.03 ng.kg −1 bw.d −1 ) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg −1 bw.d −1 ), PFNA (0.2 ng.kg −1 bw.d −1 ) and PFHxS (0.06 ng.kg −1 bw.d −1 ). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals. - Highlights: • The dietary exposure was estimated for 15 perfluoroalkyl acids. • Despite the overestimation, the FFQ remains useful to evaluate the whole diet. • The high fish consumers are the most dietary exposed population. • Fishery products are the main exposure contributors under LB hypothesis

  15. Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: High seafood consumers, high freshwater fish consumers and pregnant women

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, A., E-mail: ami.s.yamada@gmail.com [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Bemrah, N., E-mail: nawel.bemrah@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Veyrand, B., E-mail: bruno.veyrand@oniris-nantes.fr [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes 44307 (France); Pollono, C., E-mail: charles.pollono@oniris-nantes.fr [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes 44307 (France); Merlo, M., E-mail: mathilde.merlo@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Desvignes, V., E-mail: virginie.desvignes@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Sirot, V., E-mail: sirotv@gmail.com [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); and others

    2014-09-01

    Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC–MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values < LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg{sup −1} bw.d{sup −1}), PFUnA (1.3 ng.kg{sup −1} bw.d{sup −1}), PFDA (0.4 ng.kg{sup −1} bw.d{sup −1}) and PFHpS (0.03 ng.kg{sup −1} bw.d{sup −1}) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg{sup −1} bw.d{sup −1}), PFNA (0.2 ng.kg{sup −1} bw.d{sup −1}) and PFHxS (0.06 ng.kg{sup −1} bw.d{sup −1}). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals. - Highlights: • The dietary exposure was estimated for 15 perfluoroalkyl acids. • Despite the overestimation, the FFQ remains useful to evaluate the whole diet. • The high fish consumers are the most dietary exposed population. • Fishery products are the main exposure contributors under LB hypothesis.

  16. Nearly half of the adolescents in an Italian school-based study exceeded the recommended upper limits for daily caffeine consumption.

    Science.gov (United States)

    Santangelo, Barbara; Lapolla, Rosa; Rutigliano, Irene; Pettoello Mantovani, Massimo; Campanozzi, Angelo

    2018-06-01

    No data are available on caffeine consumption among Italian adolescents. We investigated caffeine intake from coffee, soft drinks and energy drinks in a sample of Italian adolescents and determined if they exceeded the recommended limits. The study comprised 1213 adolescents with a mean age of 15.1 years (range 12-19) from four schools in Foggia, southern Italy. Caffeine intake was assessed using an anonymous self-reported questionnaire during the 2013/2014 school year. We calculated the percentage of daily caffeine consumers, their mean intake of caffeine from beverages and the contribution of each beverage category to the total caffeine intake. Approximately 76% of the sample consumed caffeine every day, amounting to 125.5 ± 69.2 mg/day and 2.1 ± 1.2 mg/kg/day. When we applied the reference values from the Academy of Pediatrics, we found that 46% of the adolescents exceeded the recommended upper limits. Coffee was the most frequently consumed caffeinated drink and the main contributor to daily caffeine intake. More than three quarters (76%) of the Italian adolescents in our study drank coffee on a daily basis and nearly half (46%) exceeded the recommended upper limits. Strategies are needed to reduce caffeine consumption by adolescents. ©2018 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  17. Effects of 2 adenosine antagonists, quercetin and caffeine, on vigilance and mood.

    Science.gov (United States)

    Olson, Craig A; Thornton, Jennifer A; Adam, Gina E; Lieberman, Harris R

    2010-10-01

    Quercetin, a phenolic flavonoid found in small quantities in some fruits and vegetables, is an adenosine receptor antagonist in vitro marketed as a dietary supplement for purported caffeine-like effects. A double-blind, placebo-controlled, between-subjects study was conducted to compare the behavioral effects of quercetin to a central adenosine receptor antagonist, caffeine. Fifty-seven volunteers received either 2000 mg of quercetin dihydrate (a dose estimated based on in vitro receptor binding to be equivalent in potency to 200 mg of caffeine), placebo, or 200 mg of caffeine. One hour later, a 45-minute visual vigilance task was administered. The Profile of Mood States questionnaire was completed before treatment and immediately after vigilance testing. On the vigilance task, caffeine increased the number of stimuli detected (P mood disturbance Profile of Mood States scores compared with placebo. Quercetin did not significantly alter any parameter, but values were typically intermediate between caffeine and placebo on those tests affected by caffeine. Quercetin is unlikely to have any effects when consumed by humans in quantities present in the diet or in dietary supplements. Caffeine (200 mg) administration resulted in the expected effects on vigilance and mood.

  18. Glucose and caffeine effects on sustained attention: an exploratory fMRI study.

    Science.gov (United States)

    Serra-Grabulosa, Josep M; Adan, Ana; Falcón, Carles; Bargalló, Núria

    2010-11-01

    Caffeine and glucose can have beneficial effects on cognitive performance. However, neural basis of these effects remain unknown. Our objective was to evaluate the effects of caffeine and glucose on sustained attention, using functional magnetic resonance imaging (fMRI). Forty young right-handed, healthy, low caffeine-consuming subjects participated in the study. In a double-blind, randomised design, subjects received one of the following beverages: vehicle (water, 150 ml); vehicle plus 75 g of glucose; vehicle plus 75 mg of caffeine; vehicle plus 75 g of glucose and 75 mg of caffeine. Participants underwent two scanning fMRI sessions (before and 30 min after of the administration of the beverage). A continuous performance test was used to assess sustained attention. Participants who received combined caffeine and glucose had similar performance to the others but had a decrease in activation in the bilateral parietal and left prefrontal cortex. Since these areas have been related to the sustained attention and working memory processes, results would suggest that combined caffeine and glucose could increase the efficiency of the attentional system. However, more studies using larger samples and different levels of caffeine and glucose are necessary to better understand the combined effects of both substances. Copyright © 2010 John Wiley & Sons, Ltd.

  19. Caffeine Content of Tea and Coffee

    African Journals Online (AJOL)

    1974-03-13

    Mar 13, 1974 ... The xanthines (caffeine, theophylline, and theobromine) occur in plants widely distributed throughout the world. Best known for the preparation of beverages are coffee beans which contain caffeine, tea leaves which contain caffeine and theophylline, and cocoa seeds which contain caffeine and ...

  20. CORRELATION BETWEEN CAFFEINE CONTENTS OF GREEN ...

    African Journals Online (AJOL)

    KEY WORDS: Green coffee beans, Caffeine, Correlation between caffeine content and altitude of coffee plant,. UV-Vis .... The extraction of caffeine from green coffee bean samples in to water was carried out by the reported method ..... caffeine in proposed green tea standard reference materials by liquid chromatography.

  1. Sources of Caffeine in Diets of US Children and Adults: Trends by Beverage Type and Purchase Location

    Science.gov (United States)

    Drewnowski, Adam; Rehm, Colin D.

    2016-01-01

    New sources of caffeine, besides coffee and tea, have been introduced into the US food supply. Data on caffeine consumption age and purchase location can help guide public health policy. National Health and Nutrition Examination Surveys (NHANES) were used to estimate population-level caffeine intakes, using data from 24-h dietary recall. First, caffeine intakes by age-group and beverage type were estimated using the most recent 2011–2012 data (n = 7456). Second, fourteen years trends in caffeine consumption, overall and by beverage type, were evaluated for adults and children. Trend analyses were conducted by age groups. Last, trends in caffeine intakes by purchase location and beverage type were estimated. In 2011–2012, children aged four to eight years consumed the least caffeine (15 mg/day), and adults aged 51–70 years consumed the most (213 mg/day). The population mean (age ≥ four years) was 135 mg/day, driven largely by coffee (90 mg/day), tea (25 mg/day), and soda (21 mg/day). For the 14–19 years and 20–34 years age-groups, energy drinks contributed 6 mg/day (9.9%) and 5 mg/day (4.5%), respectively. The bulk of caffeine came from store-bought coffee and tea. Among both children and adults combined, caffeine intakes declined from 175 mg/day (1999–2000) to 142 mg/day (2011–2012), largely driven by a drop in caffeine from soda (41 mg/day to 21 mg/day). Store-bought coffee and tea remain principal drivers of caffeine intake in the US. Sodas and energy drinks make minor contributions to overall caffeine intakes. PMID:26978391

  2. Sources of Caffeine in Diets of US Children and Adults: Trends by Beverage Type and Purchase Location.

    Science.gov (United States)

    Drewnowski, Adam; Rehm, Colin D

    2016-03-10

    New sources of caffeine, besides coffee and tea, have been introduced into the US food supply. Data on caffeine consumption age and purchase location can help guide public health policy. National Health and Nutrition Examination Surveys (NHANES) were used to estimate population-level caffeine intakes, using data from 24-h dietary recall. First, caffeine intakes by age-group and beverage type were estimated using the most recent 2011-2012 data (n = 7456). Second, fourteen years trends in caffeine consumption, overall and by beverage type, were evaluated for adults and children. Trend analyses were conducted by age groups. Last, trends in caffeine intakes by purchase location and beverage type were estimated. In 2011-2012, children aged four to eight years consumed the least caffeine (15 mg/day), and adults aged 51-70 years consumed the most (213 mg/day). The population mean (age ≥ four years) was 135 mg/day, driven largely by coffee (90 mg/day), tea (25 mg/day), and soda (21 mg/day). For the 14-19 years and 20-34 years age-groups, energy drinks contributed 6 mg/day (9.9%) and 5 mg/day (4.5%), respectively. The bulk of caffeine came from store-bought coffee and tea. Among both children and adults combined, caffeine intakes declined from 175 mg/day (1999-2000) to 142 mg/day (2011-2012), largely driven by a drop in caffeine from soda (41 mg/day to 21 mg/day). Store-bought coffee and tea remain principal drivers of caffeine intake in the US. Sodas and energy drinks make minor contributions to overall caffeine intakes.

  3. Sources of Caffeine in Diets of US Children and Adults: Trends by Beverage Type and Purchase Location

    Directory of Open Access Journals (Sweden)

    Adam Drewnowski

    2016-03-01

    Full Text Available New sources of caffeine, besides coffee and tea, have been introduced into the US food supply. Data on caffeine consumption age and purchase location can help guide public health policy. National Health and Nutrition Examination Surveys (NHANES were used to estimate population-level caffeine intakes, using data from 24-h dietary recall. First, caffeine intakes by age-group and beverage type were estimated using the most recent 2011–2012 data (n = 7456. Second, fourteen years trends in caffeine consumption, overall and by beverage type, were evaluated for adults and children. Trend analyses were conducted by age groups. Last, trends in caffeine intakes by purchase location and beverage type were estimated. In 2011–2012, children aged four to eight years consumed the least caffeine (15 mg/day, and adults aged 51–70 years consumed the most (213 mg/day. The population mean (age ≥ four years was 135 mg/day, driven largely by coffee (90 mg/day, tea (25 mg/day, and soda (21 mg/day. For the 14–19 years and 20–34 years age-groups, energy drinks contributed 6 mg/day (9.9% and 5 mg/day (4.5%, respectively. The bulk of caffeine came from store-bought coffee and tea. Among both children and adults combined, caffeine intakes declined from 175 mg/day (1999–2000 to 142 mg/day (2011–2012, largely driven by a drop in caffeine from soda (41 mg/day to 21 mg/day. Store-bought coffee and tea remain principal drivers of caffeine intake in the US. Sodas and energy drinks make minor contributions to overall caffeine intakes.

  4. Consumer Preferences for High Welfare Meat in Germany: Self-service Counter or Service Counter?

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2015-01-01

    Full Text Available Many people view animal welfare standards in the agricultural industry as critical and some consumers would prefer to buy high welfare meat. In order to successfully introduce high welfare meat products onto the market, some important marketing decisions must be made. Due to limited shelf space in retail outlets, niche products like high welfare meat cannot be placed both at the self-service counter and at the service counter. In order to analyze where to place it best an online survey of 642 German consumers was conducted. By means of factor and cluster analyses, consumers’ animal welfare attitudes and their preference for a point of purchase were combined. The different target groups were joint using cross tabulation analysis. The results reveal that consumers in the target group show a more positive attitude to the service counter.

  5. The Use of Caffeine to Enhance Cognitive Performance, Reaction Time, Vigilance, Rifle Marksmanship and Mood States in Sleep-Deprived Navy SEAL (BUD/S) Trainees

    National Research Council Canada - National Science Library

    Tharion, William

    1997-01-01

    Caffeine has been shown to improve tasks with a vigilance component. The purpose of this study was to determine the effectiveness of caffeine in sleep-deprived individuals exposed to high levels of operational and environmental stress...

  6. Beneficial Role of Coffee and Caffeine in Neurodegenerative Diseases: A Minireview

    OpenAIRE

    Yenisetti SC; Muralidhara

    2016-01-01

    Coffee is among the most widespread and healthiest beverages in the world. Coffee typically contains more caffeine than most other beverages, and is widely and frequently consumed. Thus, it contributes significantly to the overall caffeine consumption within the general population, particularly in adults. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health-promoting potential. Several lines of evidence have highlighted th...

  7. Caffeine antagonism of alcohol-induced driving impairment.

    Science.gov (United States)

    Liguori, A; Robinson, J H

    2001-07-01

    The extent to which caffeine antagonizes alcohol-induced impairment of simulated automobile driving at the current lowest legal American limit (0.08% BrAC) was the focus of this study. Fifteen adults swallowed a capsule (0, 200, or 400 mg caffeine) then drank a beverage (0.0 or 0.6 g/kg ethanol) in a within-subject, double-blind, randomized procedure. Forty-five minutes later, participants completed a test battery of subjective effects scales, dynamic posturography, critical flicker fusion (CFF), choice reaction time (CRT), divided attention (Stroop test), and simulated driving. Alcohol alone increased ratings of 'dizzy', 'drug effect', and 'high', slowed CRT and brake latency, and increased body sway. Caffeine alone increased ratings of 'alert' and 'jittery', but did not significantly affect body sway or psychomotor performance. Both caffeine doses comparably counteracted alcohol impairment of brake latency but not CRT or body sway. Brake latency with either alcohol-caffeine combination remained significantly longer than that with placebo. Stroop and CFF performance were unaffected by any drug condition. The results suggest that caffeine may increase alertness and improve reaction time after alcohol use but will not completely counteract alcohol impairment in a driver.

  8. Antioxidant and prooxidant properties of caffeine, theobromine and xanthine.

    Science.gov (United States)

    Azam, Sonish; Hadi, Naghma; Khan, Nizam Uddin; Hadi, Sheikh Mumtaz

    2003-09-01

    Caffeine, along with its catabolic products theobromine and xanthine, is a key component of tea and coffee. These compounds are structurally similar to uric acid, a known antioxidant which is present in blood at relatively high concentrations, but also shows prooxidant activity. In view of the structural similarity between uric acid and caffeine and its metabolites, we studied the antioxidant and prooxidant properties of these compounds. Antioxidant activity was determined by measuring the quenching effect of the compounds on oxidative DNA degradation by a hydroxyl radical generating system. Prooxidant activity was studied by measuring the ability of the compounds to oxidatively degrade DNA in the presence of copper ions. Caffeine, theobromine and xanthine have a quenching effect on the production of hydroxyl radicals, as well as on oxidative DNA breakage by hydroxyl radicals. Consistent with previous observations that many known antioxidants of plant origin are also capable of prooxidant action, the purine alkaloids also show oxidative DNA breakage in the presence of transition metal ions. The alkaloid caffeine and its catabolic products theobromine and xanthine exhibit both antioxidant and prooxidant properties. The results lead to the observation that caffeine and its metabolites may also contribute to the overall antioxidant and chemopreventive properties of caffeine-bearing beverages, such as tea.

  9. Caffeine-catalyzed gels.

    Science.gov (United States)

    DiCiccio, Angela M; Lee, Young-Ah Lucy; Glettig, Dean L; Walton, Elizabeth S E; de la Serna, Eva L; Montgomery, Veronica A; Grant, Tyler M; Langer, Robert; Traverso, Giovanni

    2018-07-01

    Covalently cross-linked gels are utilized in a broad range of biomedical applications though their synthesis often compromises easy implementation. Cross-linking reactions commonly utilize catalysts or conditions that can damage biologics and sensitive compounds, producing materials that require extensive post processing to achieve acceptable biocompatibility. As an alternative, we report a batch synthesis platform to produce covalently cross-linked materials appropriate for direct biomedical application enabled by green chemistry and commonly available food grade ingredients. Using caffeine, a mild base, to catalyze anhydrous carboxylate ring-opening of diglycidyl-ether functionalized monomers with citric acid as a tri-functional crosslinking agent we introduce a novel poly(ester-ether) gel synthesis platform. We demonstrate that biocompatible Caffeine Catalyzed Gels (CCGs) exhibit dynamic physical, chemical, and mechanical properties, which can be tailored in shape, surface texture, solvent response, cargo release, shear and tensile strength, among other potential attributes. The demonstrated versatility, low cost and facile synthesis of these CCGs renders them appropriate for a broad range of customized engineering applications including drug delivery constructs, tissue engineering scaffolds, and medical devices. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Awareness and use of caffeine by athletes competing at the 2005 Ironman Triathlon World Championships.

    Science.gov (United States)

    Desbrow, Ben; Leveritt, Michael

    2006-10-01

    This study assessed the knowledge, prevalence, and quantity of caffeine use by athletes competing at the 2005 Ironman Triathlon World Championships. Caffeine-related questionnaires were self-administered to 140 (105 male and 35 female, 40.3 +/- 10.7 y) athletes representing 16 countries. Fifty of these athletes further consented to immediate post-race blood samples for analysis of plasma caffeine and paraxanthine using high-performance liquid chromatography (HPLC). Seventy-two percent of 70 athletes correctly identified caffeine as being an unrestricted substance in triathlon. The majority of athletes [125 (89%)] were planning on using a caffeinated substance immediately prior to or throughout the race. Cola drinks (78%), caffeinated gels (42%), coffee (usually pre-race) (37%), energy drinks (13%), and NoDoz tablets (9%) were the most popular caffeinated choices. Mean +/- standard deviation (and range) post race plasma caffeine and paraxanthine levels were 22.3 +/- 20 micromol/L (1.7 to 98.4) and 9.4 +/- 6 micromol/L (1.8 to 28.9), respectively. Seven athletes (14%) finished with plasma caffeine levels > or = 40 micromol/L. Plasma values from elite athletes did not differ from age group competitors. Despite the prevalence of its consumption and the training experience of this athletic group, over one quarter of athletes remained either confused or uninformed about caffeine's legality. Levels of plasma caffeine taken immediately post race indicated that athletes typically finish with quantities of caffeine that have been shown to improve endurance performance (i.e., approximately 20 micromol/L or a dose of > or = 3 mg/kg body weight).

  11. Determining the market value of high-rise residential buildings based on evaluation of consumer properties

    Directory of Open Access Journals (Sweden)

    Kolobova Svetlana

    2018-01-01

    Full Text Available As you know, high-rise construction is an indicator of the practical implementation of advanced innovative technologies in the construction industry of the country. High-rise building inevitably comes to the big cities, in connection with the shortage and value of land. The life cycle of any construction project, including high-rise buildings consists of chains: of engineering survey - design-construction-operation. In the process of operation of a tall building, decisions about major repairs or reconstruction of a building are made for decision-making on further use. This article describes methods of assessing the consumer quality of high-rise residential buildings and the establishment of prices based on consumer characteristics of a tall residential building. It is proposed to assess the premises under their quality characteristics. The study was conducted to establish the influence of individual, comprehensive and integral indicators of comparable quality for effective quality living spaces. Simultaneously, there was established a relationship of quality with the consumer cost of housing, ultimately with the potential needs of owners, tenants of the home, lessor dwelling, or buyers of residential properties and other participants in the residential real estate market. This relationship further creates consumer requirements to quality standard of premises at a certain stage of socio-economic development.

  12. Determining the market value of high-rise residential buildings based on evaluation of consumer properties

    Science.gov (United States)

    Kolobova, Svetlana

    2018-03-01

    As you know, high-rise construction is an indicator of the practical implementation of advanced innovative technologies in the construction industry of the country. High-rise building inevitably comes to the big cities, in connection with the shortage and value of land. The life cycle of any construction project, including high-rise buildings consists of chains: of engineering survey - design-construction-operation. In the process of operation of a tall building, decisions about major repairs or reconstruction of a building are made for decision-making on further use. This article describes methods of assessing the consumer quality of high-rise residential buildings and the establishment of prices based on consumer characteristics of a tall residential building. It is proposed to assess the premises under their quality characteristics. The study was conducted to establish the influence of individual, comprehensive and integral indicators of comparable quality for effective quality living spaces. Simultaneously, there was established a relationship of quality with the consumer cost of housing, ultimately with the potential needs of owners, tenants of the home, lessor dwelling, or buyers of residential properties and other participants in the residential real estate market. This relationship further creates consumer requirements to quality standard of premises at a certain stage of socio-economic development.

  13. Wake up and smell the coffee. Caffeine, coffee, and the medical consequences.

    Science.gov (United States)

    Chou, T

    1992-11-01

    Caffeine is a methylxanthine whose primary biologic effect is antagonism of the adenosine receptor. Its presence in coffee, tea, soda beverages, chocolate, and many prescription and over-the-counter drugs makes it the most commonly consumed stimulant drug. Initially caffeine increases blood pressure, plasma catecholamine levels, plasma renin activity, serum free fatty acid levels, urine production, and gastric acid secretion. Its long-term effects have been more difficult to substantiate. Most of the caffeine consumed in the United States is in coffee, which contains many other chemicals that may have other biologic actions. The consumption of coffee is a self-reinforcing behavior, and caffeine dependence and addiction are common. Coffee and caffeine intake have been linked to many illnesses, but definitive correlations have been difficult to substantiate. Initial trials showing coffee's association with coronary disease and myocardial infarction have been difficult to reproduce and have many confounding variables. Recent studies showing a larger effect over long follow-up periods and with heavy coffee consumption have again brought the question of the role of coffee in disease states to the fore. Caffeine in average dosages does not seem to increase the risk of arrhythmia. At present there is no convincing evidence that caffeine or coffee consumption increases the risk for any solid tumor. The intake of coffee and caffeine has clearly been decreasing in this country over the past two decades, largely brought about by the increasing health consciousness of Americans. Although there have been many studies that hint that the fears of increased disease with coffee drinking may be warranted, many questions have yet to be answered about the health effects of coffee and caffeine use.

  14. Biochemical effects of heat shock and caffeine on post-irradiation oxic and anoxic damage in barley seeds of low and high water content

    International Nuclear Information System (INIS)

    Singh, S.P.; Kesavan, P.C.

    1991-01-01

    Wet heat shock (60 o C, 90s) and caffeine (3.8 x 10 -4 M) afford significant radioprotection against post-irradiation O 2 -dependent damage which develops in seeds of ∼ 3.5% moisture content. The damage was assessed in terms of seedling injury on the eighth day of growth. An increase in seedling injury is clearly seen, associated with a parallel increase in the peroxidase activity. There is a concomitant decrease in the content of total peroxides. Both these post-irradiation treatments potentiate the O 2 -independent component of seedling injury, irrespective of the seed moisture content. Analysis of the peroxidase activity in the seedlings using non-denaturing polyacrylamide gel electrophoresis reveals that two additional bands appear with the post-irradiation oxic damage. Radioprotection against this damage by caffeine, heat shock and O 2 -free post-irradiation hydration is accompanied by the disappearance of these two additional bands. (author)

  15. THE IMPORTANCE OF AFFECT TO BUILD CONSUMER TRUST IN HIGH-CONSEQUENCES EXCHANGES

    Directory of Open Access Journals (Sweden)

    Mellina da Silva Terres

    2012-12-01

    Full Text Available The present article investigates the importance of affect displayed by service provider to build consumer trust in high consequence exchanges. High-consequence exchanges are difficult situations in which the choices present a dilemma that can cause stress and severe emotional reactions (KAHN; LUCE, 2003. In this specific case, trust based on affect seems to become important; mainly because consumers may not have ability to evaluate the cognitive aspects of the situation, and moreover, a medical services failure can be highly problematic or even fatal (LEISEN; HYMAN, 2004. On the other hand, in low-consequence choices, we are predicting that cognition will be more important than affect in building trust. In this kind of situation, patients are more self-confident, less sensitive, and don’t perceive a high probability of loss (KUNREUTHER et al., 2002, and therefore focuses more on the rational outcomes.

  16. Effects of caffeine on X-irradiated synchronous, asynchronous and plateau phase mouse ascites cells: the importance of progression through the cell cycle for caffeine enhancement of killing

    International Nuclear Information System (INIS)

    Iliakis, G.; Nuesse, M.

    1983-01-01

    Caffeine potentiated the killing effect of X-rays on exponentially growing cells giving rise to exponential curves (D 0 =(0.8+-0.05)Gy) at 4mM and 14 hours treatment. Irradiated plateau phase cells were less sensitive. Exponentially growing cells also became less sensitive to the effects of caffeine when they were incubated in the conditioned medium of plateau phase cells(C-medium) in which cell growth was considerably inhibited. Low caffeine concentrations(2mM) enhanced X-ray induced killing of cells irradiated in G 1 -,G 1 /S- or S-phase, but more effectively G 2 -phase cells. High caffeine concentrations (6mM) enhanced killing of cells in all phases of the cell cycle. Incubation of synchronized populations in C-medium during treatment with caffeine (2mM and 6mM) resulted in less potentiation than in cells treated in fresh medium. The expression of X-ray induced potentially lethal damage caused by 6mM caffeine in cells irradiated in various phases resulted in an exponential survival curve with a mean lethal dose of (0.8+-0.05)Gy, but the time of caffeine treatment necessary to reach this curve was different for cells irradiated in different phases. PLD repair, measured as loss of sensitivity to 6mM caffeine (4 hours treatment) was of 1-2 hours duration. (author)

  17. Cigarette, alcohol, and caffeine consumption

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2003-01-01

    OBJECTIVE: To study the association between cigarette, alcohol, and caffeine consumption and the occurrence of spontaneous abortion. METHODS: The study population consisted of 330 women with spontaneous abortion and 1168 pregnant women receiving antenatal care. A case-control design was utilized;...... units alcohol per week and 375 mg or more caffeine per day during pregnancy may increase the risk of spontaneous abortion.......OBJECTIVE: To study the association between cigarette, alcohol, and caffeine consumption and the occurrence of spontaneous abortion. METHODS: The study population consisted of 330 women with spontaneous abortion and 1168 pregnant women receiving antenatal care. A case-control design was utilized......; cases were defined as women with a spontaneous abortion in gestational week 6-16 and controls as women with a live fetus in gestational week 6-16. The variables studied comprise age, parity, occupational situation, cigarette, alcohol, and caffeine consumption. The association between cigarette, alcohol...

  18. EFFECT OF CAFFEINE ON THE HUMAN BODY: A REVIEW

    Directory of Open Access Journals (Sweden)

    Sadia Hafeez Kazi

    2015-06-01

    Full Text Available Caffeine (1,3,7-trimethylxanthine is the widely consumed substance all over the world. It is found in coffee, tea, cocoa, etc. Caffeine (CF is rapidly and completely absorbed from the gastrointestinal tract; peak plasma concentration reaches in about 15 to 120 min after oral ingestion in humans without any significant first-pass effect. There are some drugs which are responsible for the inhibition of metabolism of CF. It also exerts its effect in higher doses on different body organs like neuro, gastrointestinal, renal, respiration, skeletal muscle, cardiovascular systems. Those who are regular consumer of tea, coffee, or CF containing beverages are at the higher risk for the development of CF toxicity which can lead even to death of an individual. The dependence and withdrawal side effects of CF include anxiety, insomnia, restlessness, nervousness, tremors, gastrointestinal upset, tachycardia, psychomotor agitation, etc.

  19. Influence of acute consumption of caffeine vs. placebo over Bia-derived measurements of body composition: a randomized, double-blind, crossover design.

    Science.gov (United States)

    Williamson, Cassie M; Nickerson, Brett S; Bechke, Emily E; McLester, Cherilyn N; Kliszczewicz, Brian M

    2018-01-01

    Bioelectrical impedance analysis (BIA) is often used to estimate total body water (TBW), intracellular body water (ICW), extracellular body water (ECW), and body fat percentage (BF%). A common restriction for BIA analysis is abstinence from caffeine 12-h prior to testing. However, research has yet to determine whether the consumption of caffeine influences BIA testing results. The purpose of this study was to determine if the consumption of caffeine influences BIA-derived BF% and body water values in habitual caffeine users. Twenty apparently healthy males (26.6 ± 4.1 years) identified as habitual caffeine consumers (≥ one 95 mg serving per day ≥ four days per week) participated in this study. Participants came to the lab on three occasions, the first visit serving as the control (CON) with no supplementation. The remaining two visits were performed in a randomized double-blind, cross-over fashion. Participants consumed 200 mg of dextrose (PLA) or caffeine (CAF) in capsule form. During each visit, seven multi-frequency BIA measurements were conducted before (PRE) and after (15-min, 30-min, 45-min, 60-min, 75-min, 90-min) consumption. Repeated measures ANOVA revealed BF% for CAF was lower than the CON and PLA conditions at PRE and 15-min ( p  Caffeine consumption in habitual users produced trivial changes in TBW, ECW, ICW, or BF%. Therefore, the pre-testing guidelines for caffeine consumption may not be necessary in habitual caffeine consumers.

  20. Annual electricity consumption forecasting by neural network in high energy consuming industrial sectors

    International Nuclear Information System (INIS)

    Azadeh, A.; Ghaderi, S.F.; Sohrabkhani, S.

    2008-01-01

    This paper presents an artificial neural network (ANN) approach for annual electricity consumption in high energy consumption industrial sectors. Chemicals, basic metals and non-metal minerals industries are defined as high energy consuming industries. It is claimed that, due to high fluctuations of energy consumption in high energy consumption industries, conventional regression models do not forecast energy consumption correctly and precisely. Although ANNs have been typically used to forecast short term consumptions, this paper shows that it is a more precise approach to forecast annual consumption in such industries. Furthermore, the ANN approach based on a supervised multi-layer perceptron (MLP) is used to show it can estimate the annual consumption with less error. Actual data from high energy consuming (intensive) industries in Iran from 1979 to 2003 is used to illustrate the applicability of the ANN approach. This study shows the advantage of the ANN approach through analysis of variance (ANOVA). Furthermore, the ANN forecast is compared with actual data and the conventional regression model through ANOVA to show its superiority. This is the first study to present an algorithm based on the ANN and ANOVA for forecasting long term electricity consumption in high energy consuming industries

  1. Compound list: caffeine [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available caffeine CAF 00097 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/caffeine....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/caffeine....Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Single/caffeine...-tggates/LATEST/Rat/in_vivo/Liver/Repeat/caffeine.Rat.in_vivo.Liver.Repeat.zip ftp://ftp.biosciencedbc.jp/ar...chive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/caffeine.Rat.in_vivo.Kidney.Single.zip ftp://ftp.bioscie

  2. Caffeine, exercise and the brain.

    Science.gov (United States)

    Meeusen, Romain; Roelands, Bart; Spriet, Lawrence L

    2013-01-01

    Caffeine can improve exercise performance when it is ingested at moderate doses (3-6 mg/kg body mass). Caffeine also has an effect on the central nervous system (CNS), and it is now recognized that most of the performance-enhancing effect of caffeine is accomplished through the antagonism of the adenosine receptors, influencing the dopaminergic and other neurotransmitter systems. Adenosine and dopamine interact in the brain, and this might be one mechanism to explain how the important components of motivation (i.e. vigor, persistence and work output) and higher-order brain processes are involved in motor control. Caffeine maintains a higher dopamine concentration especially in those brain areas linked with 'attention'. Through this neurochemical interaction, caffeine improves sustained attention, vigilance, and reduces symptoms of fatigue. Other aspects that are localized in the CNS are a reduction in skeletal muscle pain and force sensation, leading to a reduction in perception of effort during exercise and therefore influencing the motivational factors to sustain effort during exercise. Because not all CNS aspects have been examined in detail, one should consider that a placebo effect may also be present. Overall, it appears that the performance-enhancing effects of caffeine reside in the brain, although more research is necessary to reveal the exact mechanisms through which the CNS effect is established. Copyright © 2013 Nestec Ltd., Vevey/S. Karger AG, Basel.

  3. Caffeine and the olfactory bulb.

    Science.gov (United States)

    Hadfield, M G

    1997-08-01

    Caffeine, a popular CNS stimulant, is the most widely used neuroactive drug. Present in coffee, tea, chocolate, and soft drinks as well as over-the-counter and prescription medications, it influences millions of users. This agent has achieved recent notoriety because its dependency consequences and addictive potential have been re-examined and emphasized. Caffeine's central actions are thought to be mediated through adenosine (A) receptors and monoamine neurotransmitters. The present article suggests that the olfactory bulb (OB) may be an important site in the brain that is responsible for caffeine's central actions in several species. This conclusion is based on the extraordinarily robust and selective effects of caffeine on norepinephrine (NE), dopamine (DA), and particularly serotonin (5HT) utilization in the OB of mice. We believe that these phenomena should be given appropriate consideration as a basis for caffeine's central actions, even in primates. Concurrently, we review a rich rodent literature concerned with A, 5HT, NE, and DA receptors in the OB and related structures along with other monoamine parameters. We also review a more limited literature concerned with the primate OB. Finally, we cite the literature that treats the dependency and addictive effects of caffeine in humans, and relate the findings to possible olfactory mechanisms.

  4. Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee Comparação de métodos por eletroforese capilar e cromatografia líquida de alta eficiência para a determinação de cafeína em café descafeinado

    Directory of Open Access Journals (Sweden)

    Carolina Schaper Bizzotto

    2013-03-01

    Full Text Available Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE and high performance liquid chromatography (HPLC methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE method proved to be a valuable analytical tool for this type of analysis.O comércio de café descafeinado constitui 10% das vendas mundiais de café, sendo preferido pelos consumidores que não desejam ou são sensíveis aos efeitos da cafeína. Este artigo apresenta uma comparação analítica de métodos por eletroforese capilar (CE e cromatografia líquida de alta eficiência (HPLC para a quantificação de cafeína residual em café descafeinado, quanto aos parâmetros de validação, custos, tempo de análise, composição e tratamento dos resíduos gerados, bem como quantificação de cafeína em 20 amostras comerciais. Ambos os métodos apresentaram parâmetros de validação adequados. O teor de cafeína não diferiu estatisticamente pelos dois métodos. A vantagem do método por HPLC foi o limite de detecção 42 vezes mais baixo. Não obstante, o

  5. The effect of caffeine on skeletal muscle anabolic signaling and hypertrophy.

    Science.gov (United States)

    Moore, Timothy M; Mortensen, Xavier M; Ashby, Conrad K; Harris, Alexander M; Kump, Karson J; Laird, David W; Adams, Aaron J; Bray, Jeremy K; Chen, Ting; Thomson, David M

    2017-06-01

    Caffeine is a widely consumed stimulant with the potential to enhance physical performance through multiple mechanisms. However, recent in vitro findings have suggested that caffeine may block skeletal muscle anabolic signaling through AMP-activated protein kinase (AMPK)-mediated inhibition of mechanistic target of rapamycin (mTOR) signaling pathway. This could negatively affect protein synthesis and the capacity for muscle growth. The primary purpose of this study was to assess the effect of caffeine on in vivo AMPK and mTOR pathway signaling, protein synthesis, and muscle growth. In cultured C2C12 muscle cells, physiological levels of caffeine failed to impact mTOR activation or myoblast proliferation or differentiation. We found that caffeine administration to mice did not significantly enhance the phosphorylation of AMPK or inhibit signaling proteins downstream of mTOR (p70S6k, S6, or 4EBP1) or protein synthesis after a bout of electrically stimulated contractions. Skeletal muscle-specific knockout of LKB1, the primary AMPK activator in skeletal muscle, on the other hand, eliminated AMPK activation by contractions and enhanced S6k, S6, and 4EBP1 activation before and after contractions. In rats, the addition of caffeine did not affect plantaris hypertrophy induced by the tenotomy of the gastrocnemius and soleus muscles. In conclusion, caffeine administration does not impair skeletal muscle load-induced mTOR signaling, protein synthesis, or muscle hypertrophy.

  6. Effects of caffeine on the electrophysiological, cognitive and motor responses of the central nervous system.

    Science.gov (United States)

    Deslandes, A C; Veiga, H; Cagy, M; Piedade, R; Pompeu, F; Ribeiro, P

    2005-07-01

    Caffeine is the most consumed psychoactive substance in the world. The effects of caffeine have been studied using cognitive and motor measures, quantitative electroencephalography (qEEG) and event-related potentials. However, these methods are not usually employed in combination, a fact that impairs the interpretation of the results. The objective of the present study was to analyze changes in electrophysiological, cognitive and motor variables with the ingestion of caffeine, and to relate central to peripheral responses. For this purpose we recorded event-related potentials and eyes-closed, resting EEG, applied the Stroop test, and measured reaction time. Fifteen volunteers took caffeine (400 mg) or placebo in a randomized, crossover, double-blind design. A significant reduction of alpha absolute power over the entire scalp and of P300 latency at the Fz electrode were observed after caffeine ingestion. These results are consistent with a stimulatory effect of caffeine, although there was no change in the attention (Stroop) test or in reaction time. The qEEG seems to be the most sensitive index of the changes produced by caffeine in the central nervous system since it proved to be capable of detecting changes that were not evident in the tests of cognitive or motor performance.

  7. Effects of coffee/caffeine on brain health and disease: What should I tell my patients?

    Science.gov (United States)

    Nehlig, Astrid

    2016-04-01

    Over the last decade, Food Regulation Authorities have concluded that coffee/caffeine consumption is not harmful if consumed at levels of 200 mg in one sitting (around 2½ cups of coffee) or 400 mg daily (around 5 cups of coffee). In addition, caffeine has many positive actions on the brain. It can increase alertness and well-being, help concentration, improve mood and limit depression. Caffeine may disturb sleep, but only in sensitive individuals. It may raise anxiety in a small subset of particularly sensitive people. Caffeine does not seem to lead to dependence, although a minority of people experience withdrawal symptoms. Caffeine can potentiate the effect of regular analgesic drugs in headache and migraine. Lifelong coffee/caffeine consumption has been associated with prevention of cognitive decline, and reduced risk of developing stroke, Parkinson's disease and Alzheimer's disease. Its consumption does not seem to influence seizure occurrence. Thus, daily coffee and caffeine intake can be part of a healthy balanced diet; its consumption does not need to be stopped in elderly people. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  8. Caffeine consumption and exacerbations of chronic obstructive pulmonary disease: Retrospective study

    Directory of Open Access Journals (Sweden)

    P.O. Lopes

    2015-09-01

    Full Text Available Background: The modulation of adenosine receptors has been proposed as new therapeutic target for chronic obstructive pulmonary disease, but studies in humans were negative. Caffeine is widely consumed and acts by non-selective modulation of these receptors, allowing for a non-interventional evaluation of the purinergic effects on COPD. We evaluated the effects of chronic caffeine consumption on the risk for COPD exacerbations. Methods: Retrospective study including patients with COPD. The total number of exacerbations during a three-year period and the mean daily caffeine consumption in the last twenty years were evaluated. A univariate and multiple regression analysis were performed for evaluation of the significant predictors of exacerbations. Results: A total of 90 patients were included. Most were males (82.2% and had a mean forced expiratory volume in the first second (FEV1 of 57.0 ± 17.1% predicted. The mean daily caffeine consumption was 149.7 ± 140.9 mg. There was no correlation between the mean caffeine consumption and exacerbations (p > 0.05. Discussion: Our results suggest that caffeine has no significant effect on the frequency of COPD exacerbations. These conclusions are limited by the sample size and the retrospective nature of the study. Keywords: COPD, Caffeine, Disease exacerbation, Purines, Pharmacology, Coffee, Respiratory Tract Diseases

  9. Effects of caffeine on the electrophysiological, cognitive and motor responses of the central nervous system

    Directory of Open Access Journals (Sweden)

    Deslandes A.C.

    2005-01-01

    Full Text Available Caffeine is the most consumed psychoactive substance in the world. The effects of caffeine have been studied using cognitive and motor measures, quantitative electroencephalography (qEEG and event-related potentials. However, these methods are not usually employed in combination, a fact that impairs the interpretation of the results. The objective of the present study was to analyze changes in electrophysiological, cognitive and motor variables with the ingestion of caffeine, and to relate central to peripheral responses. For this purpose we recorded event-related potentials and eyes-closed, resting EEG, applied the Stroop test, and measured reaction time. Fifteen volunteers took caffeine (400 mg or placebo in a randomized, crossover, double-blind design. A significant reduction of alpha absolute power over the entire scalp and of P300 latency at the Fz electrode were observed after caffeine ingestion. These results are consistent with a stimulatory effect of caffeine, although there was no change in the attention (Stroop test or in reaction time. The qEEG seems to be the most sensitive index of the changes produced by caffeine in the central nervous system since it proved to be capable of detecting changes that were not evident in the tests of cognitive or motor performance.

  10. Caffeine Intake from Food and Beverage Sources and Trends among Children and Adolescents in the United States: Review of National Quantitative Studies from 1999 to 201112345

    Science.gov (United States)

    Ahluwalia, Namanjeet; Herrick, Kirsten

    2015-01-01

    There is increasing concern about potential adverse effects of caffeine in children. Our understanding of caffeine intake relies on studies dating to the late 1990s. This article synthesizes information from national studies since then to describe caffeine consumption, its association with sociodemographic factors, key dietary sources including caffeine-containing energy drinks (CCEDs), and trends in caffeine intake and sources among US children. Findings from the Kanter Worldpanel (KWP) Beverage Consumption Panel and the NHANES showed that caffeine consumption prevalence was generally consistent across studies and over time; more than one-half of 2- to 5-y-olds and ∼75% of older children (>5 y) consumed caffeine. The usual intakes of caffeine were 25 and 50 mg/d for children and adolescents aged 2–11 and 12–17 y, respectively (NHANES 2007–2010). Caffeine consumption correlated with age and was higher in non-Hispanic white children. The key sources of caffeine were soda and tea as well as flavored dairy (for children aged caffeine intake was noted in children overall during the 10- to 12-y period examined; intakes remained stable among older children (≥12 y). A significant increasing trend in CCED and coffee consumption and a decline in soda intake were noted (1999–2010). In 2009–2010, 10% of 12- to 19-y-olds and 10–25% of caffeine consumers (aged 12–19 y) had intakes exceeding Canadian maximal guidelines. Continued monitoring can help better understand changes in caffeine consumption patterns of youth. PMID:25593149

  11. Sensory analysis and consumer acceptance of 140 high-quality extra virgin olive oils.

    Science.gov (United States)

    Valli, Enrico; Bendini, Alessandra; Popp, Martin; Bongartz, Annette

    2014-08-01

    Sensory analysis is a crucial tool for evaluating the quality of extra virgin olive oils. One aim of such an investigation is to verify if the sensory attributes themselves - which are strictly related to volatile and phenolic compounds - may permit the discrimination of high-quality products obtained by olives of different cultivars and/or grown in various regions. Moreover, a crucial topic is to investigate the interdependency between relevant parameters determining consumer acceptance and objective sensory characteristics evaluated by the panel test. By statistically analysing the sensory results, a grouping - but not discriminatory - effect was shown for some cultivars and some producing areas. The preference map shows that the most appreciated samples by consumers were situated in the direction of the 'ripe fruity' and 'sweet' axis and opposite to the 'bitter' and 'other attributes' (pungent, green fruity, freshly cut grass, green tomato, harmony, persistency) axis. Extra virgin olive oils produced from olives of the same cultivars and grown in the same areas shared similar sensorial attributes. Some differences in terms of expectation and interpretation of sensory characteristics of extra virgin olive oils might be present for consumers and panellists: most of the consumers appear unfamiliar with positive sensorial attributes, such as bitterness and pungency. © 2013 Society of Chemical Industry.

  12. Inhibiting c-Jun N-terminal kinase partially attenuates caffeine-dependent cell death without alleviating the caffeine-induced reduction in mitochondrial respiration in C2C12 skeletal myotubes

    International Nuclear Information System (INIS)

    Downs, R.M.; Hughes, M.A.; Kinsey, S.T.; Johnson, M.C.; Baumgarner, B.L.

    2016-01-01

    Caffeine is a widely consumed stimulant that has previously been shown to promote cytotoxic stress and even cell death in numerous mammalian cell lines. Thus far there is little information available regarding the toxicity of caffeine in skeletal muscle cells. Our preliminary data revealed that treating C2C12 myotubes with 5 mM caffeine for 6 h increased nuclear fragmentation and reduced basal and maximal oxygen consumption rate (OCR) in skeletal myotubes. The purpose of this study was to further elucidate the pathways by which caffeine increased cell death and reduced mitochondrial respiration. We specifically examined the role of c-Jun N-terminal kinase (JNK), which has previously been shown to simultaneously increase caspase-dependent cell death and reduce mitochondrial respiration in other mammalian cell lines. We found that caffeine promoted a dose-dependent increase in cell death in multinucleated myotubes but did not in mononucleated myoblasts. The addition of 10 μM Z-DEVD-FMK, a specific inhibitor of executioner caspases, completely inhibited caffeine-dependent cell death. Further, the addition of 400 μM dantrolene, a specific ryanodine receptor (RYR) inhibitor, prevented the caffeine-dependent increase in cell death and the reduction in basal and maximal OCR. We also discovered that caffeine treatment significantly increased the phosphorylation of JNK and that the addition of 30 μM SP600125 (JNKi), a specific JNK inhibitor, partially attenuated caffeine-induced cell death without preventing the caffeine-dependent reduction in basal and maximal OCR. Our results suggest that JNK partially mediates the increase in caspase-dependent cell death but does not contribute to reduced mitochondrial respiration in caffeine-treated skeletal muscle cells. We conclude that caffeine increased cell death and reduced mitochondrial respiration in a calcium-dependent manner by activating the RYR and promoting reticular calcium release. - Highlights: • Caffeine

  13. Monitoring of caffeine consumption effect on skin blood properties by diffuse reflectance spectroscopy

    Science.gov (United States)

    Milanic, Matija; Marin, Ana; Stergar, Jost; Verdel, Nina; Majaron, Boris

    2017-07-01

    Caffeine is the most widely consumed psychoactive substance in the world. It affects many tissues and organs, in particular central nervous system, heart, and blood vessels. The effect of caffeine on vascular smooth muscle cells is an initial transient contraction followed by significant vasodilatation. In this study we investigate the use of diffuse reflectance spectroscopy (DRS) for monitoring of vascular changes in human skin induced by caffeine consumption. DRS spectra were recorded on volar sides of the forearms of ten healthy volunteers at time delays of 0, 30, 60, 120, and 180 minutes after consumption of caffeine, while one subject served as a negative control. Analytical diffusion approximation solutions for diffuse reflectance from three-layer structures were used to assess skin composition (e.g., dermal blood volume fraction and oxygen saturation) by fitting to experimental data. The results demonstrate that cutaneous vasodynamics induced by caffeine consumption can be monitored by DRS, while changes in the control subject not consuming caffeine were insignificant.

  14. Profiling the high frequency wine consumer by price segmentation in the US market

    Directory of Open Access Journals (Sweden)

    Liz Thach

    2015-06-01

    Full Text Available Heavy users of consumer products are important to marketers as a profitable target segment. This is equally true in the wine industry, but with the added precaution of encouraging responsible consumption. This study examines the attributes and behaviors of 681 high frequency (heavy-user wine consumers in the US, based on a price segmentation of High, Moderate, and Low Spenders. For this study, price segmentation was defined as the price typically paid for a bottle of wine for home consumption. Significant differences were discovered based on gender, age, income, wine involvement, shopping channel, ecommerce/social media usage and other key areas. Implications for marketing managers as well as areas of future research are described.

  15. L-theanine and caffeine improve task switching but not intersensory attention or subjective alertness.

    Science.gov (United States)

    Einöther, Suzanne J L; Martens, Vanessa E G; Rycroft, Jane A; De Bruin, Eveline A

    2010-04-01

    Tea ingredients L-theanine and caffeine have repeatedly been shown to deliver unique cognitive benefits when consumed in combination. The current randomized, placebo-controlled, double-blind, cross-over study compared a combination of L-theanine (97 mg) and caffeine (40 mg) to a placebo on two attention tasks and a self-report questionnaire before, and 10 and 60 min after consumption. The combination of L-theanine and caffeine significantly improved attention on a switch task as compared to the placebo, while subjective alertness and intersensory attention were not improved significantly. The results support previous evidence that L-theanine and caffeine in combination can improve attention. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Caffeine Consumption among Medical Interns and Association with GPA in Makkah Region

    Directory of Open Access Journals (Sweden)

    Alsharif Mohammed H

    2016-12-01

    Full Text Available The Vagarious amount of caffeine may become harmful in frequent use, it increased among medical interns in Makkah region. The caffeine becomes a daily routine for medical interns without attention for their side harmful effect. The purpose of our study was to evaluate the educational level of awareness of the harmful effect of caffeine consumption. This was a cross-sectional study from August to October 2016. A total number 437 of participants with GPA groups, Group I (GPA 1.5-2, Group II (GPA 2.1- 3 and Group III (GPA 3.1- 3.5. The higher percentages were the group II and female consumed caffeine frequently more than male.

  17. Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

    Science.gov (United States)

    Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

    2017-03-01

    The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO 2 max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO 2

  18. THE EFFECT OF CAFFEINE ON TEAR FORMATION

    African Journals Online (AJOL)

    improvement in physical performance and other. Caffeine is of ... function is also influenced by other factors like age, menopause ... influence of such drugs on the lacrimal gland function .... Pharmacokinetic profile on caffeine in premature ...

  19. Effect of Carbohydrate, Caffeine, and Carbohydrate + Caffeine Mouth Rinsing on Intermittent Running Performance in Collegiate Male Lacrosse Athletes.

    Science.gov (United States)

    Dolan, Patrick; Witherbee, Kyle E; Peterson, Kimi M; Kerksick, Chad M

    2017-09-01

    Dolan, P, Witherbee, KE, Peterson, KM, and Kerksick, CM. Effect of carbohydrate, caffeine, and carbohydrate + caffeine mouth rinsing on intermittent running performance in collegiate male lacrosse athletes. J Strength Cond Res 31(9): 2473-2479, 2017-Recently, an interest has developed in the potential to rinse the oral cavity with key nutrients to impact various types of exercise and presumably sporting performance. Although multiple studies examining carbohydrate mouth rinsing have been completed, conflicting evidence surrounding caffeine mouth rinsing persists, and no research has explored its ability to impact high-intensity, intermittent running performance. This study investigated the independent and synergistic ability of carbohydrate and caffeine mouth rinsing to improve intermittent running performance. The Yo-Yo Intermittent Recovery Test-Level 1 (Yo-Yo Level 1) was completed in 10 collegiate (National Collegiate Athletic Association [NCAA] Division II) male lacrosse players after a 10-second mouth rinse with a solution of either carbohydrate (CHO), caffeine (CAF), carbohydrate + caffeine (CHO + CAF), placebo (H2O), or a no rinse control (CON). No significant improvements in Yo-Yo IRT-1 performance were found (p > 0.05). Perceptual indications of effort (i.e., rating of their perceived exertion [RPE]) were significantly lower (p ≤ 0.05) in CHO and CHO + CAF when compared with CON after speed level 11. Interestingly, RPE levels were nonsignificantly lower in all but one level of the Yo-Yo Level 1 for CHO in comparison with other groups. Carbohydrate and caffeine mouth rinsing seems to exert no impact on running performance before maximal intermittent running in a group of male collegiate lacrosse players.

  20. Having a Coffee Break: The Impact of Caffeine Consumption on Microglia-Mediated Inflammation in Neurodegenerative Diseases.

    Science.gov (United States)

    Madeira, Maria H; Boia, Raquel; Ambrósio, António F; Santiago, Ana R

    2017-01-01

    Caffeine is the major component of coffee and the most consumed psychostimulant in the world and at nontoxic doses acts as a nonselective adenosine receptor antagonist. Epidemiological evidence suggests that caffeine consumption reduces the risk of several neurological and neurodegenerative diseases. However, despite the beneficial effects of caffeine consumption in human health and behaviour, the mechanisms by which it impacts the pathophysiology of neurodegenerative diseases still remain to be clarified. A promising hypothesis is that caffeine controls microglia-mediated neuroinflammatory response associated with the majority of neurodegenerative conditions. Accordingly, it has been already described that the modulation of adenosine receptors, namely, the A 2A receptor, affords neuroprotection through the control of microglia reactivity and neuroinflammation. In this review, we will summarize the main effects of caffeine in the modulation of neuroinflammation in neurodegenerative diseases.

  1. Having a Coffee Break: The Impact of Caffeine Consumption on Microglia-Mediated Inflammation in Neurodegenerative Diseases

    Directory of Open Access Journals (Sweden)

    Maria H. Madeira

    2017-01-01

    Full Text Available Caffeine is the major component of coffee and the most consumed psychostimulant in the world and at nontoxic doses acts as a nonselective adenosine receptor antagonist. Epidemiological evidence suggests that caffeine consumption reduces the risk of several neurological and neurodegenerative diseases. However, despite the beneficial effects of caffeine consumption in human health and behaviour, the mechanisms by which it impacts the pathophysiology of neurodegenerative diseases still remain to be clarified. A promising hypothesis is that caffeine controls microglia-mediated neuroinflammatory response associated with the majority of neurodegenerative conditions. Accordingly, it has been already described that the modulation of adenosine receptors, namely, the A2A receptor, affords neuroprotection through the control of microglia reactivity and neuroinflammation. In this review, we will summarize the main effects of caffeine in the modulation of neuroinflammation in neurodegenerative diseases.

  2. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2015. Scientific Opinion on the safety of caffeine

    DEFF Research Database (Denmark)

    Tetens, Inge

    2015-01-01

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies was asked to deliver a scientific opinion on the safety of caffeine, providing advice on caffeine intakes, from all dietary sources that do not give rise to concerns about adverse health...... not give rise to safety concerns. The same amount does not give rise to safety concerns when consumed .../L of caffeine, taurine and d-glucurono-γ-lactone, respectively), as well as alcohol at doses up to about 0.65 g/kg bw, would not affect the safety of single doses of caffeine up to 200 mg. Habitual caffeine consumption up to 400 mg per day does not give rise to safety concerns for non-pregnant adults. Habitual...

  3. Effects of caffeine, time of day and user history on study-related performance.

    Science.gov (United States)

    Mitchell, P J; Redman, J R

    1992-01-01

    The individual and interactive effects of caffeine, time of day and history of caffeine consumption on several study-related tasks were investigated in 25 subjects (6 males, 19 females). Performance was measured on short term memory (STM), mental arithmetic (MA), reading comprehension, serial search (SS) and verbal reasoning (VR). Subjects attended eight experimental sessions, at four times of day (0100, 0700, 1300 and 1900 hours), after ingesting caffeine (4 mg/kg) or placebo. Subjects were assigned to a low, moderate or high user group on the basis of a caffeine consumption questionnaire. Reading comprehension was affected by time of day, while caffeine improved performance on all mental speed-related tasks. High caffeine users performed more poorly than other groups on the verbal reasoning task. Several interactions between the three independent variables were observed on a number of tasks, supporting the contention that different processes underlying various types of cognitive performance are differentially, and often jointly, affected by caffeine, time of day and user history. Implications of caffeine usage on academic performance were discussed.

  4. Metabolic and hormonal effects of caffeine: randomized, double-blind, placebo-controlled crossover trial.

    Science.gov (United States)

    MacKenzie, Todd; Comi, Richard; Sluss, Patrick; Keisari, Ronit; Manwar, Simone; Kim, Janice; Larson, Robin; Baron, John A

    2007-12-01

    In short-term studies, caffeine has been shown to increase insulin levels, reduce insulin sensitivity, and increase cortisol levels. However, epidemiological studies have indicated that long-term consumption of beverages containing caffeine such as coffee and green tea is associated with a reduced risk of type 2 diabetes mellitus. There is a paucity of randomized studies addressing the metabolic and hormonal effects of consuming caffeine over periods of more than 1 day. We evaluated the effect of oral intake of 200 mg of caffeine taken twice a day for 7 days on glucose metabolism, as well as on serum cortisol, dehydroepiandrosterone (DHEA), and androstenedione, and on nighttime salivary melatonin. A double-blind, randomized, placebo-controlled crossover study with periods of 7 days and washouts of 5 days comparing caffeine with placebo capsules was conducted. Participants were 16 healthy adults aged 18 to 22 years with a history of caffeine consumption. Blood samples from each subject were assayed for glucose, insulin, serum cortisol, DHEA, and androstenedione on the eighth day of each period after an overnight fast. Nighttime salivary melatonin was also measured. Insulin levels were significantly higher (by 1.80 microU/mL; 95% confidence interval, 0.33-3.28) after caffeine intake than after placebo. The homeostasis model assessment index of insulin sensitivity was reduced by 35% (95% confidence interval, 7%-62%) by caffeine. There were no differences in glucose, DHEA, androstenedione, and melatonin between treatment periods. This study provides evidence that daily caffeine intake reduces insulin sensitivity; the effect persists for at least a week and is evident up to 12 hours after administration.

  5. Chronic caffeine consumption prevents memory disturbance in different animal models of memory decline.

    Science.gov (United States)

    Cunha, Rodrigo A; Agostinho, Paula M

    2010-01-01

    Caffeine, the most widely consumed psychoactive drug, enhances attention/vigilance, stabilizes mood, and might also independently enhance cognitive performance. Notably, caffeine displays clearer and more robust beneficial effects on memory performance when memory is perturbed by stressful or noxious stimuli either in human or animal studies. Thus, caffeine restores memory performance in sleep-deprived or aged human individuals, a finding replicated in rodent animal models. Likewise, in animal models of Alzheimer's disease (AD), caffeine alleviates memory dysfunction, which is in accordance with the tentative inverse correlation between caffeine intake and the incidence of AD in different (but not all) cohorts. Caffeine also affords beneficial effects in animal models of conditions expected to impair memory performance such as Parkinson's disease, chronic stress, type 2 diabetes, attention deficit and hyperactivity disorder, early life convulsions, or alcohol-induced amnesia. Thus, caffeine should not be viewed as a cognitive enhancer but instead as a cognitive normalizer. Interestingly, these beneficial effects of caffeine on stress-induced memory disturbance are mimicked by antagonists of adenosine A2A receptors. This prominent role of A2A receptors in preventing memory deterioration is probably related to the synaptic localization of this receptor in limbic areas and its ability to control glutamatergic transmission, especially NMDA receptor-dependent plasticity, and to control apoptosis, brain metabolism, and the burden of neuroinflammation. This opens the real and exciting possibility that caffeine consumption might be a prophylactic strategy and A2A receptor antagonists may be a novel therapeutic option to manage memory dysfunction both in AD and in other chronic neurodegenerative disorders where memory deficits occur.

  6. Biodegradation of Caffeine by Trichosporon asahii Isolated from Caffeine Contaminated Soil

    OpenAIRE

    LAKSHMI V.; NILANJANA DAS

    2011-01-01

    Studies were carried out on caffeine degradation using Trichosporon asahii, a yeast species isolated from caffeine contaminated soil. There was 100 % degradation of caffeine at 54 h by the yeast cells acclimated to the medium containing caffeine and sucrose both. Experiments with T. asahii growing on caffeine in the presenceof 1 mM 1-aminobenzotriazole (ABT), an inhibitor of the cytochrome P-450 enzyme system, resulted inhibition of biomass production relative to positive control implicating ...

  7. The metabolic and performance effects of caffeine compared to coffee during endurance exercise.

    Science.gov (United States)

    Hodgson, Adrian B; Randell, Rebecca K; Jeukendrup, Asker E

    2013-01-01

    There is consistent evidence supporting the ergogenic effects of caffeine for endurance based exercise. However, whether caffeine ingested through coffee has the same effects is still subject to debate. The primary aim of the study was to investigate the performance enhancing effects of caffeine and coffee using a time trial performance test, while also investigating the metabolic effects of caffeine and coffee. In a single-blind, crossover, randomised counter-balanced study design, eight trained male cyclists/triathletes (Mean ± SD: Age 41 ± 7 y, Height 1.80 ± 0.04 m, Weight 78.9 ± 4.1 kg, VO2 max 58 ± 3 ml • kg(-1) • min(-1)) completed 30 min of steady-state (SS) cycling at approximately 55% VO2max followed by a 45 min energy based target time trial (TT). One hour prior to exercise each athlete consumed drinks consisting of caffeine (5 mg CAF/kg BW), instant coffee (5 mg CAF/kg BW), instant decaffeinated coffee or placebo. The set workloads produced similar relative exercise intensities during the SS for all drinks, with no observed difference in carbohydrate or fat oxidation. Performance times during the TT were significantly faster (~5.0%) for both caffeine and coffee when compared to placebo and decaf (38.35 ± 1.53, 38.27 ± 1.80, 40.23 ± 1.98, 40.31 ± 1.22 min respectively, pperformance times were similar for both caffeine and coffee. Average power for caffeine and coffee during the TT was significantly greater when compared to placebo and decaf (294 ± 21 W, 291 ± 22 W, 277 ± 14 W, 276 ± 23 W respectively, pcaffeine (5 mg/kg/BW) and coffee (5 mg/kg/BW) consumed 1 h prior to exercise can improve endurance exercise performance.

  8. Caffeine provokes adverse interactions with 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’) and related psychostimulants: mechanisms and mediators

    Science.gov (United States)

    Vanattou-Saïfoudine, N; McNamara, R; Harkin, A

    2012-01-01

    Concomitant consumption of caffeine with recreational psychostimulant drugs of abuse can provoke severe acute adverse reactions in addition to longer term consequences. The mechanisms by which caffeine increases the toxicity of psychostimulants include changes in body temperature regulation, cardiotoxicity and lowering of the seizure threshold. Caffeine also influences the stimulatory, discriminative and reinforcing effects of psychostimulant drugs. In this review, we consider our current understanding of such caffeine-related drug interactions, placing a particular emphasis on an adverse interaction between caffeine and the substituted amphetamine, 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’), which has been most recently described and characterized. Co-administration of caffeine profoundly enhances the acute toxicity of MDMA in rats, as manifested by high core body temperature, tachycardia and increased mortality. In addition, co-administration of caffeine enhances the long-term serotonergic neurotoxicity induced by MDMA. Observations to date support an interactive model of drug-induced toxicity comprising MDMA-related enhancement of dopamine release coupled to a caffeine-mediated antagonism of adenosine receptors in addition to inhibition of PDE. These experiments are reviewed together with reports of caffeine-related drug interactions with cocaine, d-amphetamine and ephedrine where similar mechanisms are implicated. Understanding the underlying mechanisms will guide appropriate intervention strategies for the management of severe reactions and potential for increased drug-related toxicity, resulting from concomitant caffeine consumption. PMID:22671762

  9. Influence of caffeine on blood pressure and platelet aggregation

    Directory of Open Access Journals (Sweden)

    José Wilson S. Cavalcante

    2000-08-01

    Full Text Available OBJECTIVE: Studies have demonstrated that methylxanthines, such as caffeine, are A1 and A2 adenosine receptor antagonists found in the brain, heart, lungs, peripheral vessels, and platelets. Considering the high consumption of products with caffeine in their composition, in Brazil and throughout the rest of the world, the authors proposed to observe the effects of this substance on blood pressure and platelet aggregation. METHODS: Thirteen young adults, ranging from 21 to 27 years of age, participated in this study. Each individual took 750mg/day of caffeine (250mg tid, over a period of seven days. The effects on blood pressure were analyzed through the pressor test with handgrip, and platelet aggregation was analyzed using adenosine diphosphate, collagen, and adrenaline. RESULTS: Diastolic pressure showed a significant increase 24 hours after the first intake (p<0.05. This effect, however, disappeared in the subsequent days. The platelet aggregation tests did not reveal statistically significant alterations, at any time during the study. CONCLUSION: The data suggest that caffeine increases diastolic blood pressure at the beginning of caffeine intake. This hypertensive effect disappears with chronic use. The absence of alterations in platelet aggregation indicates the need for larger randomized studies.

  10. Graphene platforms for the detection of caffeine in real samples

    Energy Technology Data Exchange (ETDEWEB)

    Khoo, Weslie Yu Heng; Pumera, Martin; Bonanni, Alessandra, E-mail: a.bonanni@ntu.edu.sg

    2013-12-04

    Graphical abstract: -- Highlights: •Commercial caffeine was detected on different chemically modified graphenes. •Electrochemically reduced graphene (ERGO) provided the best performance. •ERGO was then employed for the detection of caffeine in real samples. -- Abstract: The analysis of food components is of high importance due to food safety and security. Here the electrochemical detection of caffeine was performed on different chemically modified graphene (CMG) surfaces carrying diverse amount of defects and oxygen functionalities. The analytical performances of graphite oxide (GPO), graphene oxide (GO), and electrochemically reduced graphene oxide (ERGO) were compared for the first time for the detection of caffeine. It was found that ERGO showed the most favourable analytical parameters, such as lower oxidation potential, sensitivity, linearity and reproducibility of the response. ERGO was then used for the analysis of real samples. Caffeine levels of soluble coffee, teas and energetic drinks were measured without the need of any sample pre-treatment. Our findings are very important to gain more insight into the applicability of different graphene materials to real samples for sense-and-act analysis.

  11. Graphene platforms for the detection of caffeine in real samples

    International Nuclear Information System (INIS)

    Khoo, Weslie Yu Heng; Pumera, Martin; Bonanni, Alessandra

    2013-01-01

    Graphical abstract: -- Highlights: •Commercial caffeine was detected on different chemically modified graphenes. •Electrochemically reduced graphene (ERGO) provided the best performance. •ERGO was then employed for the detection of caffeine in real samples. -- Abstract: The analysis of food components is of high importance due to food safety and security. Here the electrochemical detection of caffeine was performed on different chemically modified graphene (CMG) surfaces carrying diverse amount of defects and oxygen functionalities. The analytical performances of graphite oxide (GPO), graphene oxide (GO), and electrochemically reduced graphene oxide (ERGO) were compared for the first time for the detection of caffeine. It was found that ERGO showed the most favourable analytical parameters, such as lower oxidation potential, sensitivity, linearity and reproducibility of the response. ERGO was then used for the analysis of real samples. Caffeine levels of soluble coffee, teas and energetic drinks were measured without the need of any sample pre-treatment. Our findings are very important to gain more insight into the applicability of different graphene materials to real samples for sense-and-act analysis

  12. Caffeine, sleep and quality of life

    NARCIS (Netherlands)

    Lorist, M.M.; Snel, J.; Verster, J.C.; Pandi-Perumal, S.R.; Streiner, D.L.

    2008-01-01

    Caffeine is regarded as a mild stimulant acting on the central nervous system that is responsible for a significant portion of the behavioural and physiological effects of coffee and tea. Motives why people take caffeine are reflected in consumption patterns. Early in the morning caffeine might help

  13. 21 CFR 182.1180 - Caffeine.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Caffeine. 182.1180 Section 182.1180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1180 Caffeine. (a) Product. Caffeine. (b) Tolerance. 0.02 percent. (c) Limitations, restrictions, or...

  14. Associations of Urinary Caffeine and Caffeine Metabolites With Arterial Stiffness in a Large Population-Based Study.

    Science.gov (United States)

    Ponte, Belen; Pruijm, Menno; Ackermann, Daniel; Ehret, Georg; Ansermot, Nicolas; Staessen, Jan A; Vogt, Bruno; Pechère-Bertschi, Antoinette; Burnier, Michel; Martin, Pierre-Yves; Eap, Chin B; Bochud, Murielle; Guessous, Idris

    2018-05-01

    To assess the influence of caffeine on arterial stiffness by exploring the association of urinary excretion of caffeine and its related metabolites with pulse pressure (PP) and pulse wave velocity (PWV). Families were randomly selected from the general population of 3 Swiss cities from November 25, 2009, through April 4, 2013. Pulse pressure was defined as the difference between the systolic and diastolic blood pressures obtained by 24-hour ambulatory monitoring. Carotid-femoral PWV was determined by applanation tonometry. Urinary caffeine, paraxanthine, theophylline, and theobromine excretions were measured in 24-hour urine collections. Multivariate linear and logistic mixed models were used to explore the associations of quartiles of urinary caffeine and metabolite excretions with PP, high PP, and PWV. We included 863 participants with a mean ± SD age of 47.1±17.6 years, 24-hour PP of 41.9±9.2 mm Hg, and PWV of 8.0±2.3 m/s. Mean (SE) brachial PP decreased from 43.5 (0.5) to 40.5 (0.6) mm Hg from the lowest to the highest quartiles of 24-hour urinary caffeine excretion (P<.001). The odds ratio (95% CI) of high PP decreased linearly from 1.0 to 0.52 (0.31-0.89), 0.38 (0.22-0.65), and 0.31 (0.18-0.55) from the lowest to the highest quartile of 24-hour urinary caffeine excretion (P<.001). Mean (SE) PWV in the highest caffeine excretion quartile was significantly lower than in the lowest quartile (7.8 [0.1] vs 8.1 [0.1] m/s; P=.03). Similar associations were found for paraxanthine and theophylline, whereas no associations were found with theobromine. Urinary caffeine, paraxanthine, and theophylline excretions were associated with decreased parameters of arterial stiffness, suggesting a protective effect of caffeine intake beyond its blood pressure-lowering effect. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  15. Slow crack growth in post-consumer recycled high-density polyethylene

    OpenAIRE

    Sciammarella, Cesar A.; Yang, Y.

    2015-01-01

    An experimental study of slow crack growth behavior of post-consumer recycled high-density polyethylene blended with virgin high-density polyethylene copolymer has been done. The study has been performed under constant load and in baths of distilled water at 40, 60, 80°C. The specimen used is notched with side grooves. The test results of crack growth have been analyzed using linear fracture mechanics and the rate process theory. The results show that the resistance to crack growth increases ...

  16. Ethanol and Caffeine effects on social interaction and recognition in mice: Involvement of adenosine A2A and A1 receptors

    Directory of Open Access Journals (Sweden)

    Laura López-Cruz

    2016-11-01

    Full Text Available Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A1/A2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A1 and A2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg increasing social contact and higher doses (1.0-1.5 g/kg reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg, and even blocked social preference at higher doses (30.0-60.0 mg/kg. The A1 antagonist CPT (3-9 mg/kg did not modify social contact or preference on its own, and the A2A antagonist MSX-3 (1.5-6 mg/kg increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg. Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the formation of social

  17. Ethanol and Caffeine Effects on Social Interaction and Recognition in Mice: Involvement of Adenosine A2A and A1 Receptors.

    Science.gov (United States)

    López-Cruz, Laura; San-Miguel, Noemí; Bayarri, Pilar; Baqi, Younis; Müller, Christa E; Salamone, John D; Correa, Mercé

    2016-01-01

    Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A 1 /A 2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A 1 and A 2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0-1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg), and even blocked social preference at higher doses (30.0-60.0 mg/kg). The A 1 antagonist Cyclopentyltheophylline (CPT; 3-9 mg/kg) did not modify social contact or preference on its own, and the A 2A antagonist MSX-3 (1.5-6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the

  18. Caffeine intake and semen quality in a population of 2,554 young Danish men

    DEFF Research Database (Denmark)

    Jensen, Tina Kold; Swan, Shanna H; Skakkebaek, Niels E

    2010-01-01

    The authors examined the association between semen quality and caffeine intake among 2,554 young Danish men recruited when they were examined to determine their fitness for military service in 2001-2005. The men delivered a semen sample and answered a questionnaire including information about...... caffeine intake from various sources, from which total caffeine intake was calculated. Moderate caffeine and cola intakes (101-800 mg/day and 14 0.5-L bottles....../week) and/or caffeine (>800 mg/day) intake was associated with reduced sperm concentration and total sperm count, although only significant for cola. High-intake cola drinkers had an adjusted sperm concentration and total sperm count of 40 mill/mL (95% confidence interval (CI): 32, 51) and 121 mill (95% CI...

  19. The effect of caffeine on glucose kinetics in humans - influence of adrenaline

    DEFF Research Database (Denmark)

    Battram, Danielle S.; Graham, Terry E.; Richter, Erik

    2005-01-01

    While caffeine impedes insulin-mediated glucose disposal in humans, its effect on endo-genous glucose production (EGP) remains unknown. In addition, the mechanism involved in these effects is unclear, but may be due to the accompanying increase in adrenaline concentration. We studied the effect...... of caffeine on EGP and glucose infusion rates (GIR), and whether or not adrenaline can account for all of caffeine's effects. Subjects completed three isoglycaemic-hyperinsulinaemic clamps (with 3-[3H]glucose infusion) 30 min after ingesting: (1) placebo capsules (n= 12); (2) caffeine capsules (5 mg kg-1) (n......= 12); and either (3) placebo plus a high-dose adrenaline infusion (HAdr; adrenaline concentration, 1.2 nM; n= 8) or (4) placebo plus a low-dose adrenaline infusion (LAdr; adrenaline concentration, 0.75 nM; n= 6). With caffeine, adrenaline increased to 0.6 nM but no effect on EGP was observed. While...

  20. Voltammetric sensor for caffeine based on a glassy carbon electrode modified with Nafion and graphene oxide

    International Nuclear Information System (INIS)

    Zhao, F.; Wang, F.; Zhao, W.; Zhou, J.; Liu, Y.; Zou, L.; Ye, B.

    2011-01-01

    We report on a voltammetric sensor for caffeine that is based on a glassy carbon electrode modified with Nafion and graphene oxide (GO). It exhibits a good affinity for caffeine (resulting from the presence of Nafion), and excellent electrochemical response (resulting from the pressence of GO) for the oxidation of caffeine. The electrode enables the determination of caffeine in the range from 4.0 x 10 -7 to 8.0 x 10 -5 mol L -1 , with a detection limit of 2.0 x 10 -7 mol L -1 . The sensor displays good stability, reproducibility, and high sensitivity. It was successfully applied to the quantitative determination of caffeine in beverages. (author)

  1. Biochemical effects of heat shock and caffeine on post-irradiation oxic and anoxic damage in barley seeds of low and high water content

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P.; Kesavan, P.C. (Jawaharlal Nehru Univ., New Delhi (India). School of Life Sciences)

    1991-05-01

    Wet heat shock (60{sup o}C, 90s) and caffeine (3.8 x 10{sup -4}M) afford significant radioprotection against post-irradiation O{sub 2}-dependent damage which develops in seeds of {similar to} 3.5% moisture content. The damage was assessed in terms of seedling injury on the eighth day of growth. An increase in seedling injury is clearly seen, associated with a parallel increase in the peroxidase activity. There is a concomitant decrease in the content of total peroxides. Both these post-irradiation treatments potentiate the O{sub 2}-independent component of seedling injury, irrespective of the seed moisture content. Analysis of the peroxidase activity in the seedlings using non-denaturing polyacrylamide gel electrophoresis reveals that two additional bands appear with the post-irradiation oxic damage. Radioprotection against this damage by caffeine, heat shock and O{sub 2}-free post-irradiation hydration is accompanied by the disappearance of these two additional bands. (author).

  2. Caffeine May Reduce Perceived Sweet Taste in Humans, Supporting Evidence That Adenosine Receptors Modulate Taste.

    Science.gov (United States)

    Choo, Ezen; Picket, Benjamin; Dando, Robin

    2017-09-01

    Multiple recent reports have detailed the presence of adenosine receptors in sweet sensitive taste cells of mice. These receptors are activated by endogenous adenosine in the plasma to enhance sweet signals within the taste bud, before reporting to the primary afferent. As we commonly consume caffeine, a powerful antagonist for such receptors, in our daily lives, an intriguing question we sought to answer was whether the caffeine we habitually consume in coffee can inhibit the perception of sweet taste in humans. 107 panelists were randomly assigned to 2 groups, sampling decaffeinated coffee supplemented with either 200 mg of caffeine, about the level found in a strong cup of coffee, or an equally bitter concentration of quinine. Participants subsequently performed sensory testing, with the session repeated in the alternative condition in a second session on a separate day. Panelists rated both the sweetened coffee itself and subsequent sucrose solutions as less sweet in the caffeine condition, despite the treatment having no effect on bitter, sour, salty, or umami perception. Panelists were also unable to discern whether they had consumed the caffeinated or noncaffeinated coffee, with ratings of alertness increased equally, but no significant improvement in reaction times, highlighting coffee's powerful placebo effect. This work validates earlier observations in rodents in a human population. © 2017 Institute of Food Technologists®.

  3. DNA of HeLa cells during caffeine-promoted recovery from X-ray induced G2 arrest

    International Nuclear Information System (INIS)

    Bases, R.; Mendez, F.; Liebeskind, D.; Elequin, F.; Neubort, S.

    1980-01-01

    Progression of X-irradiated HeLa cells from G2 arrest through mitosis was promoted by 1mM caffeine. Caffeine promoted the return from abnormally high levels of radiation-induced immunoreactivity to antinucleoside antibodies, which indicates persistent DNA strand separation, to the low levels normally found in G2. With caffeine, the irradiated cells progressed through mitosis, producing daughter cells with the normal G1 content of DNA. Without caffeine, the DNA content of individual radiation-arrested cells retained G2 values and the abnormally high levels of immunoreactivity to antinucleoside antibodies. (author)

  4. Prediction of Caffeine Content in Java Preanger Coffee Beans by NIR Spectroscopy Using PLS and MLR Method

    Science.gov (United States)

    Budiastra, I. W.; Sutrisno; Widyotomo, S.; Ayu, P. C.

    2018-05-01

    Caffeine is one of important components in coffee that contributes to the coffee beverages flavor. Caffeine concentration in coffee bean is usually determined by chemical method which is time consuming and destructive method. A nondestructive method using NIR spectroscopy was successfully applied to determine the caffeine concentration of Arabica gayo coffee bean. In this study, NIR Spectroscopy was assessed to determine the caffeine concentration of java preanger coffee bean. A hundred samples, each consist of 96 g coffee beans were prepared for reflectance and chemical measurement. Reflectance of the sample was measured by FT-NIR spectrometer in the wavelength of 1000-2500 nm (10000-4000 cm-1) followed by determination of caffeine content using LCMS method. Calibration of NIR spectra and the caffeine content was carried out using PLS and MLR methods. Several spectra data processing was conducted to increase the accuracy of prediction. The result of the study showed that caffeine content could be determined by PLS model using 7 factors and spectra data processing of combination of the first derivative and MSC of spectra absorbance (r = 0.946; CV = 1.54 %; RPD = 2.28). A lower accuracy was obtained by MLR model consisted of three caffeine and other four absorption wavelengths (r = 0.683; CV = 3.31%; RPD = 1.18).

  5. Consumer Awareness and Willingness to Pay for High-Pressure Processing of Ready-to-Eat Food

    Science.gov (United States)

    Hicks, Doris T.; Pivarnik, Lori F.; McDermott, Ryan; Richard, Nicole; Hoover, Dallas G.; Kniel, Kalmia E.

    2009-01-01

    Commercial, nonthermal processing of food, such as high hydrostatic-pressure processing (HPP), has increased. The safety and quality of foods produced by HPP has not been well communicated to the public. An online, nationwide consumer survey was implemented to assess awareness of alternative food processing technologies, consumer food safety…

  6. Possible health effects of caffeinated coffee consumption on Alzheimer's disease and cardiovascular disease.

    Science.gov (United States)

    You, Dong-Chul; Kim, Young-Soon; Ha, Ae-Wha; Lee, Yu-Na; Kim, Soo-Min; Kim, Chun-Heum; Lee, Seung-Ha; Choi, Dalwoong; Lee, Jae-Min

    2011-03-01

    Coffee has been known to have both beneficial and harmful effects upon health. Coffee is one of the most widely consumed beverages, worldwide. Dementia/Alzheimer's disease (AD) and cardiovascular disease (CVD) are public health problems that are rapidly increasing in the aging population. Due to the high consumption of coffee, even small effects on an individual's health could have a large effect on public health.The aim of this review article is to provide an overview of previously published studies of coffee consumption on health. Herein, we focus on epidemiological and experimental findings to investigate whether coffee-drinking habits, and/or the quantity of coffee consumption, have any relationship to CVD, dementia/AD, and other chronic diseases. Although the underlying mechanisms are not fully understood, when comparing coffee drinkers with non-drinkers, moderate doses of caffeine showed protective effects against CVD and AD. We hypothesized that caffeine may be a novel therapy to treat CVD and dementia/AD.

  7. Effect of Melatonin and Caffeine Interaction on Caffeine Induced ...

    African Journals Online (AJOL)

    Chigo Okwuosa

    Caffeine Induced Oxidative Stress and Sleep Disorders. Obochi G. O., Amali ... pregnancy, and use of oral contraceptives slow the ..... a shaking water bath at 37oC for 48 hours. The tubes .... availability and delivery of energy to all cells of the.

  8. Caffeine Increases Hippocampal Sharp Waves in Vitro.

    Science.gov (United States)

    Watanabe, Yusuke; Ikegaya, Yuji

    2017-01-01

    Caffeine promotes memory consolidation. Memory consolidation is thought to depend at least in part on hippocampal sharp waves (SWs). In the present study, we investigated the effect of bath-application of caffeine in spontaneously occurring SWs in mouse acute hippocampal slices. Caffeine induced an about 100% increase in the event frequency of SWs at concentrations of 60 and 200 µM. The effect of caffeine was reversible after washout of caffeine and was mimicked by an adenosine A 1 receptor antagonist, but not by an A 2A receptor antagonist. Caffeine increased SWs even in dentate-CA3 mini-slices without the CA2 regions, in which adenosine A 1 receptors are abundantly expressed in the hippocampus. Thus, caffeine facilitates SWs by inhibiting adenosine A 1 receptors in the hippocampal CA3 region or the dentate gyrus.

  9. Nonfatal and fatal intoxications with pure caffeine - report of three different cases.

    Science.gov (United States)

    Magdalan, Jan; Zawadzki, Marcin; Skowronek, Rafał; Czuba, Magdalena; Porębska, Barbara; Sozański, Tomasz; Szpot, Paweł

    2017-09-01

    Caffeine is not usually perceived as a drug by most people because it is found in many foods and drinks, including caffeinated energy drinks, as well as in over the counter analgesics and cold preparations. Recently in Poland it has become increasingly common to take pure caffeine, bought through online stores, as a psychoanaleptic. This creates a much higher risk of severe and even fatal poisoning in comparison with the risk associated with the abuse of food products and non-prescription medicines containing low doses of caffeine. This paper presents three different cases of poisoning that occurred when pure caffeine was taken as psychostimulant; in cases 1 and 2 poisoning was the result of a single overdose, while in the case 3 poisoning resulted from a cumulative overdose. In the case 1 there was a severe intoxication (persistent vomiting, hypotension, tremor), and the concentration of caffeine in the blood was found to be 80.16 μg/mL. The patient was treated using hemodialysis, which caused a rapid decrease in blood levels of caffeine and relief of the clinical symptoms of poisoning. Cases 2 and 3 were fatal poisonings, and recorded levels of caffeine in post mortem blood samples were 140.64 μg/mL and 613.0 μg/mL. In case 2 the patient died 10 min after admission to hospital as a result of sudden cardiac arrest, which was preceded by an attack of convulsions, and in case 3 death occurred in home and was also sudden in nature. Taking pure caffeine as a stimulant is associated with a high risk of overdose and the development of serious and even fatal poisoning, and those using pure caffeine are generally completely unaware of these risks. In such cases, death is usually sudden due to functional mechanisms.

  10. The Role of Clomipramine in Potentiating the Teratogenic Effects of Caffeine in Pregnant Rats: A Histopathological Study

    Directory of Open Access Journals (Sweden)

    Vahid Nikoui

    2013-01-01

    Full Text Available Since little is known about the teratogenic effects of clomipramine used concurrently with caffeine during the organogenesis period, the aim of this study was to test the teratogenic effects of a coadministration of caffeine and clomipramine on rat fetuses. We divided 42 pregnant rats into seven groups, randomly. The first group (control received 0.5 mL of normal saline. Clomipramine was injected at 40 mg/kg and 80 mg/kg to the second and third groups, respectively. The fourth and fifth groups received caffeine in doses of 60 mg/kg and 120 mg/kg, respectively. The sixth group received a combination of 40 mg/kg clomipramine and 60 mg/kg caffeine, and the seventh group was given clomipramine and caffeine at 80 mg/kg and 120 mg/kg, respectively. The fetuses were removed on the 17th day of pregnancy and studied in terms of microscopic and macroscopic morphological features. Fetuses of rats receiving high doses of caffeine or combinations of caffeine and clomipramine showed a significant rate of cleft palate development, open eyelids, mortality, torsion anomalies, shrinkage of skin, and subcutaneous haemorrhage (P≤0.001. This study concludes that caffeine in high doses or the simultaneous administration of caffeine and clomipramine leads to teratogenicity.

  11. Early-life exposure to caffeine affects the construction and activity of cortical networks in mice.

    Science.gov (United States)

    Fazeli, Walid; Zappettini, Stefania; Marguet, Stephan Lawrence; Grendel, Jasper; Esclapez, Monique; Bernard, Christophe; Isbrandt, Dirk

    2017-09-01

    The consumption of psychoactive drugs during pregnancy can have deleterious effects on newborns. It remains unclear whether early-life exposure to caffeine, the most widely consumed psychoactive substance, alters brain development. We hypothesized that maternal caffeine ingestion during pregnancy and the early postnatal period in mice affects the construction and activity of cortical networks in offspring. To test this hypothesis, we focused on primary visual cortex (V1) as a model neocortical region. In a study design mimicking the daily consumption of approximately three cups of coffee during pregnancy in humans, caffeine was added to the drinking water of female mice and their offspring were compared to control offspring. Caffeine altered the construction of GABAergic neuronal networks in V1, as reflected by a reduced number of somatostatin-containing GABA neurons at postnatal days 6-7, with the remaining ones showing poorly developed dendritic arbors. These findings were accompanied by increased synaptic activity in vitro and elevated network activity in vivo in V1. Similarly, in vivo hippocampal network activity was altered from the neonatal period until adulthood. Finally, caffeine-exposed offspring showed increased seizure susceptibility in a hyperthermia-induced seizure model. In summary, our results indicate detrimental effects of developmental caffeine exposure on mouse brain development. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Caffeine-Related Deaths: Manner of Deaths and Categories at Risk.

    Science.gov (United States)

    Cappelletti, Simone; Piacentino, Daria; Fineschi, Vittorio; Frati, Paola; Cipolloni, Luigi; Aromatario, Mariarosaria

    2018-05-14

    Caffeine is the most widely consumed psychoactive compound worldwide. It is mostly found in coffee, tea, energizing drinks and in some drugs. However, it has become really easy to obtain pure caffeine (powder or tablets) on the Internet markets. Mechanisms of action are dose-dependent. Serious toxicities such as seizure and cardiac arrhythmias, seen with caffeine plasma concentrations of 15 mg/L or higher, have caused poisoning or, rarely, death; otherwise concentrations of 3⁻6 mg/kg are considered safe. Caffeine concentrations of 80⁻100 mg/L are considered lethal. The aim of this systematic review, performed following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement for the identification and selection of studies, is to review fatal cases in which caffeine has been recognized as the only cause of death in order to identify potential categories at risk. A total of 92 cases have been identified. These events happened more frequently in infants, psychiatric patients, and athletes. Although caffeine intoxication is relatively uncommon, raising awareness about its lethal consequences could be useful for both clinicians and pathologists to identify possible unrecognized cases and prevent related severe health conditions and deaths.

  13. Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials.

    Science.gov (United States)

    Clark, Ian; Landolt, Hans Peter

    2017-02-01

    Caffeine is the most widely consumed psychoactive substance in the world. It is readily available in coffee and other foods and beverages, and is used to mitigate sleepiness, enhance performance, and treat apnea in premature infants. This review systematically explores evidence from epidemiological studies and randomized controlled trials as to whether coffee and caffeine have deleterious effects on sleep. Caffeine typically prolonged sleep latency, reduced total sleep time and sleep efficiency, and worsened perceived sleep quality. Slow-wave sleep and electroencephalographic (EEG) slow-wave activity were typically reduced, whereas stage-1, wakefulness, and arousals were increased. Dose- and timing-response relationships were established. The sleep of older adults may be more sensitive to caffeine compared to younger adults. Pronounced individual differences are also present in young people, and genetic studies isolated functional polymorphisms of genes implicated in adenosine neurotransmission and metabolism contributing to individual sensitivity to sleep disruption by caffeine. Most studies were conducted in male adults of Western countries, which limits the generalizability of the findings. Given the importance of good sleep for general health and functioning, longitudinal investigations aimed at establishing possible causal relationships among coffee- and caffeine-induced changes in sleep quality and health development are warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Nutrition and Healthy Eating: Caffeine

    Science.gov (United States)

    Healthy Lifestyle Nutrition and healthy eating By Mayo Clinic Staff If you're like most adults, caffeine is a part of ... US adults: 2001-2010. American Journal of Clinical Nutrition. 2015;101:1081. 2015-2020 Dietary Guidelines for ...

  15. Caffeine Modulates Attention Network Function

    Science.gov (United States)

    Brunye, Tad T.; Mahoney, Caroline R.; Lieberman, Harris R.; Taylor, Holly A.

    2010-01-01

    The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a flanker task designed to test Posner's three visual attention network functions: alerting, orienting, and executive control [Posner, M. I. (2004). "Cognitive neuroscience of attention". New York, NY: Guilford Press]. In a placebo-controlled, double-blind…

  16. Caffeine Induces the Stress Response and Up-Regulates Heat Shock Proteins in Caenorhabditis elegans.

    Science.gov (United States)

    Al-Amin, Mohammad; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2016-02-01

    Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

  17. INFLUENCE OF MARKETING COMMUNICATIVE STRATEGIES ON CONSUMER BEHAVIOUR: A CASE OF THE HIGH-TECHNOLOGY MARKET OF UKRAINE

    Directory of Open Access Journals (Sweden)

    Victoria Zhurylo

    2017-11-01

    Full Text Available The purpose of the study is to research consumer behaviour types and to develop marketing strategies of communicative influence on the consumer in the high-technology goods market. Methodology. Marketing research in Ukrainian market of high-tech goods is conducted to define motivations of the consumers and the peculiarities of their market behaviour. The profiles of target customers are developed and the typology of consumer behaviour is formed, based on the reasons of purchasing of high-tech goods and on the level of consumer involvement in the purchasing process. Results showed that Highly Rational, Cautious, and Demonstrative behaviours can be observed in case of high consumer involvement in the buying process. Rationally-Confident, Comfortable, Adaptive behaviour can be observed in the case of low involvement. The peculiarities of communicative influence for each type of consumer behaviour in the market of high-tech goods are determined and the appropriate strategies of marketing communication are offered. Practical implementation. Strategies of communicative influence and communication sources depend on consumer behavioural types and the stage of the process of adopting innovations. In case of highly rational consumer behaviour, generic strategy, benefit strategy, and unique technical advantage strategies are recommended to be used as the main communicative strategies. Benefit strategy, unique technical advantage strategy, positioning strategy should be used in the case of rationally confident behaviour. The technology of intrusion, intimidation, positioning strategy, affective strategy, and resonance strategy should be used in the case of cautious consumer behaviour. Brand strategy should be used in the case of demonstrative consumer behaviour. The communicative strategies of product positioning and the strategy of resonance can be used in the case of comfortable consumer behaviour. Brand strategy is the main communicative strategy in the

  18. Drivers of high-involvement consumers' intention to buy PDO wines: Valpolicella PDO case study.

    Science.gov (United States)

    Capitello, Roberta; Agnoli, Lara; Begalli, Diego

    2016-08-01

    This study investigates whether different sensory profiles of wines belonging to the same Protected Designation of Origin (PDO) are perceived as different products by consumers. It identifies the drivers of consumers' intention to buy preferred wines. Descriptive sensory analysis, consumer tests and consumer interviews were conducted to reach research aims. To perform the consumer tests and interviews, 443 consumers participated in the survey. The tasted wines comprised five samples representative of Valpolicella PDO wine. Analysis of variance tests, principal component analysis and linear and logit regressions were employed to verify the research hypotheses. The results demonstrated: (1) different sensory profiles exist within the Valpolicella PDO wine; (2) these sensory profiles result in consumers having the perception of diversified products; (3) the perception of differences was less marked for consumers than for trained assessors due to the different weight attributed to visual, aroma and the taste/mouthfeel hedonic dimensions; and (4) consumers' liking, as well as general perceptions, attitudes, preferences, wine knowledge and experience, contribute to consumers' intentions to buy more than the socio-demographic characteristics of consumers. The analysis of the drivers of consumers' intention to buy certain PDO wines provides new marketing insights into the roles of intrinsic quality, preferences and consumers' subjective characteristics in market segmentation. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  19. The preparation of 11C-labeled caffeine

    International Nuclear Information System (INIS)

    Denutte, H.R.; Cattoir, H.J.; Jonckheere, J.A.; Gelijkens, C.F.; Leenheer, A.P. de; Vandewalle, T.; Vandecasteele, C.; Slegers, G.

    1982-01-01

    A rapid and mild procedure for the preparation of [N-7-methyl- 11 C] caffeine is described. Gaseous 11 C-methyl iodide was led into dimethyl sulphoxide (DMSO), containing theophylline (1,3-dimethylxanthine) and sodium hydride. Purification of the reaction product was achieved by High Performance Liquid Chromatography (HPLC). (author)

  20. EFFECTS OF INSECT PEST INFESTATION ON THE CAFFEINE ...

    African Journals Online (AJOL)

    The caffeine content of nuts of Cola nitida and C. acuminata infested by insect pests in four major geographical zones of Nigeria have been determined and compared with the uninfested ones using high-performance liquid chromatography (HPLC). The findings showed that the infestation has no significant effect on the ...

  1. Caffeine synergizes with another coffee component to increase plasma GCSF: linkage to cognitive benefits in Alzheimer's mice.

    Science.gov (United States)

    Cao, Chuanhai; Wang, Li; Lin, Xiaoyang; Mamcarz, Malgorzata; Zhang, Chi; Bai, Ge; Nong, Jasson; Sussman, Sam; Arendash, Gary

    2011-01-01

    Retrospective and prospective epidemiologic studies suggest that enhanced coffee/caffeine intake during aging reduces risk of Alzheimer's disease (AD). Underscoring this premise, our studies in AD transgenic mice show that long-term caffeine administration protects against cognitive impairment and reduces brain amyloid-β levels/deposition through suppression of both β- and γ-secretase. Because coffee contains many constituents in addition to caffeine that may provide cognitive benefits against AD, we examined effects of caffeinated and decaffeinated coffee on plasma cytokines, comparing their effects to caffeine alone. In both AβPPsw+PS1 transgenic mice and non-transgenic littermates, acute i.p. treatment with caffeinated coffee greatly and specifically increased plasma levels of granulocyte-colony stimulating factor (GCSF), IL-10, and IL-6. Neither caffeine solution alone (which provided high plasma caffeine levels) or decaffeinated coffee provided this effect, indicating that caffeine synergized with some as yet unidentified component of coffee to selectively elevate these three plasma cytokines. The increase in GCSF is particularly important because long-term treatment with coffee (but not decaffeinated coffee) enhanced working memory in a fashion that was associated only with increased plasma GCSF levels among all cytokines. Since we have previously reported that long-term GCSF treatment enhances cognitive performance in AD mice through three possible mechanisms (e.g., recruitment of microglia from bone marrow, synaptogenesis, and neurogenesis), the same mechanisms could be complimentary to caffeine's established ability to suppress Aβ production. We conclude that coffee may be the best source of caffeine to protect against AD because of a component in coffee that synergizes with caffeine to enhance plasma GCSF levels, resulting in multiple therapeutic actions against AD.

  2. Population pharmacokinetics of caffeine and its metabolites theobromine, paraxanthine and theophylline after inhalation in combination with diacetylmorphine.

    Science.gov (United States)

    Zandvliet, Anthe S; Huitema, Alwin D R; de Jonge, Milly E; den Hoed, Rob; Sparidans, Rolf W; Hendriks, Vincent M; van den Brink, Wim; van Ree, Jan M; Beijnen, Jos H

    2005-01-01

    The stimulant effect of caffeine, as an additive in diacetylmorphine preparations for study purposes, may interfere with the pharmacodynamic effects of diacetylmorphine. In order to obtain insight into the pharmacology of caffeine after inhalation in heroin users, the pharmacokinetics of caffeine and its dimethylxanthine metabolites were studied. The objectives were to establish the population pharmacokinetics under these exceptional circumstances and to compare the results to published data regarding intravenous and oral administration in healthy volunteers. Diacetylmorphine preparations containing 100 mg of caffeine were used by 10 persons by inhalation. Plasma concentrations of caffeine, theobromine, paraxanthine and theophylline were measured by high performance liquid chromatography. Non-linear mixed effects modelling was used to estimate population pharmacokinetic parameters. The model was evaluated by the jack-knife procedure. Caffeine was rapidly and effectively absorbed after inhalation. Population pharmacokinetics of caffeine and its dimethylxanthine metabolites could adequately and simultaneously be described by a linear multi-compartment model. The volume of distribution for the central compartment was estimated to be 45.7 l and the apparent elimination rate constant of caffeine at 8 hr after inhalation was 0.150 hr(-1) for a typical individual. The bioavailability was approximately 60%. The presented model adequately describes the population pharmacokinetics of caffeine and its dimethylxanthine metabolites after inhalation of the caffeine sublimate of a 100 mg tablet. Validation proved the stability of the model. Pharmacokinetics of caffeine after inhalation and intravenous administration are to a large extent similar. The bioavailability of inhaled caffeine is approximately 60% in experienced smokers.

  3. Relationships Between Caffeine Intake and Risk for Probable Dementia or Global Cognitive Impairment: The Women's Health Initiative Memory Study.

    Science.gov (United States)

    Driscoll, Ira; Shumaker, Sally A; Snively, Beverly M; Margolis, Karen L; Manson, JoAnn E; Vitolins, Mara Z; Rossom, Rebecca C; Espeland, Mark A

    2016-12-01

    Nonhuman studies suggest a protective effect of caffeine on cognition. Although human literature remains less consistent, reviews suggest a possible favorable relationship between caffeine consumption and cognitive impairment or dementia. We investigated the relationship between caffeine intake and incidence of cognitive impairment or probable dementia in women aged 65 and older from the Women's Health Initiative Memory Study. All women with self-reported caffeine consumption at enrollment were included (N = 6,467). In 10 years or less of follow-up with annual assessments of cognitive function, 388 of these women received a diagnosis of probable dementia based on a 4-phase protocol that included central adjudication. We used proportional hazards regression to assess differences in the distributions of times until incidence of probable dementia or composite cognitive impairment among women grouped by baseline level of caffeine intake, adjusting for risk factors (hormone therapy, age, race, education, body mass index, sleep quality, depression, hypertension, prior cardiovascular disease, diabetes, smoking, and alcohol consumption). Women consuming above median levels (mean intake = 261mg) of caffeine intake for this group were less likely to develop incident dementia (hazard ratio = 0.74, 95% confidence interval [0.56, 0.99], p = .04) or any cognitive impairment (hazard ratio = 0.74, confidence interval [0.60, 0.91], p = .005) compared to those consuming below median amounts (mean intake = 64mg) of caffeine for this group. Our findings suggest lower odds of probable dementia or cognitive impairment in older women whose caffeine consumption was above median for this group and are consistent with the existing literature showing an inverse association between caffeine intake and age-related cognitive impairment. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e

  4. Caffeine, mental health, and psychiatric disorders.

    Science.gov (United States)

    Lara, Diogo R

    2010-01-01

    Caffeine intake is so common that its pharmacological effects on the mind are undervalued. Since it is so readily available, individuals can adjust their own dose, time of administration and dose intervals of caffeine, according to the perceived benefits and side effects of each dose. This review focuses on human studies of caffeine in subjects with and without psychiatric disorders. Besides the possibility of mild drug dependence, caffeine may bring benefits that contribute to its widespread use. These benefits seem to be related to adaptation of mental energy to the context by increasing alertness, attention, and cognitive function (more evident in longer or more difficult tasks or situations of low arousal) and by elevating mood. Accordingly, moderate caffeine intake (caffeine can induce psychotic and manic symptoms, and more commonly, anxiety. Patients with panic disorder and performance social anxiety disorder seem to be particularly sensitive to the anxiogenic effects of caffeine, whereas preliminary data suggests that it may be effective for some patients with obsessive compulsive disorder (OCD). The threshold for the anxiogenic effect of caffeine is influenced by a polymorphism of the A2A receptor. In summary, caffeine can be regarded as a pharmacological tool to increase energy and effortful behavior in daily activities. More populational (cross-sectional and prospective) and experimental studies are necessary to establish the role of caffeine intake in psychiatric disorders, especially its putative efficacy on depressive mood and cognitive/attentional disorders.

  5. Caffeine tolerance: behavioral, electrophysiological and neurochemical evidence

    International Nuclear Information System (INIS)

    Chou, D.T.; Khan, S.; Forde, J.; Hirsh, K.R.

    1985-01-01

    The development of tolerance to the stimulatory action of caffeine upon mesencephalic reticular neurons and upon spontaneous locomotor activity was evaluated in rats after two weeks of chronic exposure to low doses of caffeine (5-10 mg/kg/day via their drinking water). These doses are achievable through dietary intake of caffeine-containing beverages in man. Concomitant measurement of [ 3 H]-CHA binding in the mesencephalic reticular formation was also carried out in order to explore the neurochemical basis of the development of tolerance. Caffeine, 2.5 mg/kg i.v., markedly increased the firing rate of reticular neurons in caffeine naive rats but failed to modify the neuronal activity in a group exposed chronically to low doses of caffeine. In addition, in spontaneous locomotor activity studies, the data show a distinct shift to the right of the caffeine dose-response curve in caffeine pretreated rats. These results clearly indicate that tolerance develops to the stimulatory action of caffeine upon the reticular formation at the single neuronal activity level as well as upon spontaneous locomotor activity. Furthermore, in chronically caffeine exposed rats, an increase in the number of binding sites for [ 3 H]-CHA was observed in reticular formation membranes without any change in receptor affinity. 28 references, 4 figures

  6. Validation of different instruments for caffeine measurement among premenopausal women in the BioCycle study.

    Science.gov (United States)

    Schliep, Karen C; Schisterman, Enrique F; Mumford, Sunni L; Perkins, Neil J; Ye, Aijun; Pollack, Anna Z; Zhang, Cuilin; Porucznik, Christina A; VanDerslice, James A; Stanford, Joseph B; Wactawski-Wende, Jean

    2013-04-01

    Effects of caffeine on women's health are inconclusive, in part because of inadequate exposure assessment. In this study we determined 1) validity of a food frequency questionnaire compared with multiple 24-hour dietary recalls (24HDRs) for measuring monthly caffeine and caffeinated beverage intakes; and 2) validity of the 24HDR compared with the prior day's diary record for measuring daily caffeinated coffee intake. BioCycle Study (2005-2007) participants, women (n = 259) aged 18-44 years from western New York State, were followed for 2 menstrual cycles. Participants completed a food frequency questionnaire at the end of each cycle, four 24HDRs per cycle, and daily diaries. Caffeine intakes reported for the food frequency questionnaires were greater than those reported for the 24HDRs (mean = 114.1 vs. 92.6mg/day, P = 0.01) but showed high correlation (r = 0.73, P cups/day, P cup = 237 mL). Although caffeine and coffee exposures were highly correlated, absolute intakes differed significantly between measurement tools. These results highlight the importance of considering potential misclassification of caffeine exposure.

  7. Caffeine inheritance in interspecific hybrids of Coffea arabica x Coffea canephora (Gentianales, Rubiaceae

    Directory of Open Access Journals (Sweden)

    Regina H.G. Priolli

    2008-01-01

    Full Text Available Caffeine inheritance was investigated in F2 and BC1F1 generations between Coffea arabica var. Bourbon Vermelho (BV and Coffea canephora var. Robusta 4x (R4x. The caffeine content of seeds and leaves was determined during 2004 and 2005. Microsatellite loci-markers were used to deduce the meiotic pattern of chromosome pairing of tetraploid interspecific hybrids. Genetic analysis indicated that caffeine content in seeds was quantitatively inherited and controlled by genes with additive effects. The estimates of broad-sense heritability of caffeine content in seeds were high for both generations. In coffee leaves, the caffeine content (BSH from the same populations showed transgressive segregants with enhanced levels and high BSH. Segregation of loci-markers in BC1F1 populations showed that the ratios of the gametes genotype did not differ significantly from those expected assuming random associations and tetrasomic inheritance. The results confirm the existence of distinct mechanisms controlling the caffeine content in seeds and leaves, the gene exchange between the C. arabica BV and C. canephora R4x genomes and favorable conditions for improving caffeine content in this coffee population.

  8. Effects of caffeine on fractional flow reserve values measured using intravenous adenosine triphosphate.

    Science.gov (United States)

    Nakayama, Masafumi; Chikamori, Taishiro; Uchiyama, Takashi; Kimura, Yo; Hijikata, Nobuhiro; Ito, Ryosuke; Yuhara, Mikio; Sato, Hideaki; Kobori, Yuichi; Yamashina, Akira

    2018-04-01

    We investigated the effects of caffeine intake on fractional flow reserve (FFR) values measured using intravenous adenosine triphosphate (ATP) before cardiac catheterization. Caffeine is a competitive antagonist for adenosine receptors; however, it is unclear whether this antagonism affects FFR values. Patients were evenly randomized into 2 groups preceding the FFR study. In the caffeine group (n = 15), participants were given coffee containing 222 mg of caffeine 2 h before the catheterization. In the non-caffeine group (n = 15), participants were instructed not to take any caffeine-containing drinks or foods for at least 12 h before the catheterization. FFR was performed in patients with more than intermediate coronary stenosis using the intravenous infusion of ATP at 140 μg/kg/min (normal dose) and 170 μg/kg/min (high dose), and the intracoronary infusion of papaverine. FFR was followed for 30 s after maximal hyperemia. In the non-caffeine group, the FFR values measured with ATP infusion were not significantly different from those measured with papaverine infusion. However, in the caffeine group, the FFR values were significantly higher after ATP infusion than after papaverine infusion (P = 0.002 and P = 0.007, at normal and high dose ATP vs. papaverine, respectively). FFR values with ATP infusion were significantly increased 30 s after maximal hyperemia (P = 0.001 and P < 0.001 for normal and high dose ATP, respectively). The stability of the FFR values using papaverine showed no significant difference between the 2 groups. Caffeine intake before the FFR study affected FFR values and their stability. These effects could not be reversed by an increased ATP dose.

  9. The Cumulative Neurobehavioral and Physiological Effects of Chronic Caffeine Intake: Individual Differences and Implications for the Use of Caffeinated Energy Products

    Science.gov (United States)

    Spaeth, Andrea M; Goel, Namni; Dinges, David F

    2014-01-01

    The use of caffeine-containing energy products (CCEP) has increased worldwide in recent years and research shows that CCEP can improve cognitive and physical performance. All of the top-selling energy drinks contain caffeine, which is likely to be the primary psychoactive ingredient in CCEP. Presumably, individuals consume CCEP to counteract feelings of ‘low-energy’ in situations causing tiredness, fatigue, and/or reduced alertness. This review discusses the scientific evidence for sleep loss, circadian phase, sleep inertia and the time-on-task effect as causes of ‘low energy’ and summarizes research assessing the efficacy of caffeine to counteract decreased alertness and increased fatigue in such situations. The results of a placebo-controlled experiment on healthy adults undergoing three nights of total sleep deprivation (with or without 2 hour naps every 12 hours) are presented to illustrate the physiological and neurobehavioral effects of sustained low-dose caffeine. Individual differences, including genetic factors, in the response to caffeine and to sleep loss are discussed. We conclude with future directions for research on this important and evolving topic. PMID:25293542

  10. Prevalence of caffeine use in elite athletes following its removal from the World Anti-Doping Agency list of banned substances.

    Science.gov (United States)

    Del Coso, Juan; Muñoz, Gloria; Muñoz-Guerra, Jesús

    2011-08-01

    The aim of this investigation was to determine the use of caffeine by athletes after its removal from the World Anti-Doping Agency list. For this purpose, we measured the caffeine concentration in 20 686 urine samples obtained for doping control from 2004 to 2008. We utilized only urine samples obtained after official national and international competitions. Urine caffeine concentration was determined using alkaline extraction followed by gas chromatography-mass spectrometry. The limit of detection (LOD) was set at 0.1 µg·mL(-1). The percentage of urine samples below the LOD was 26.2%; the remaining 73.8% of the urine samples contained caffeine. Most urine samples (67.3%) had urinary caffeine concentrations below 5 µg·mL(-1). Only 0.6% of urine samples exceeded the former threshold for caffeine doping (12 µg·mL(-1)). Triathlon (3.3 ± 2.2 µg·mL(-1)), cycling (2.6 ± 2.0 µg·mL(-1)), and rowing (1.9 ± 1.4 µg·mL(-1)) were the sports with the highest levels of urine caffeine concentration; gymnastics was the sport with the lowest urine caffeine concentration (0.5 ± 0.4 µg·mL(-1)). Older competitors (>30 y) had higher levels of caffeine in their urine than younger competitors (<20 y; p < 0.05); there were no differences between males and females. In conclusion, 3 out of 4 athletes had consumed caffeine before or during sports competition. Nevertheless, only a small proportion of these competitors (0.6%) had a urine caffeine concentration higher than 12 µg·mL(-1). Endurance sports were the disciplines showing the highest urine caffeine excretion after competition.

  11. Caffeine metabolites not caffeine protect against riboflavin photosensitized oxidative damage related to skin and eye health

    DEFF Research Database (Denmark)

    Scurachio, R. S.; Mattiucci, F.; Santos, W. G.

    2016-01-01

    . Caffeine metabolites rather than caffeine seem accordingly important for the observed protective effect against cutaneous melanoma identified for drinkers of regular but not of decaffeinated coffee. The caffeine metabolites, but not caffeine, were by time resolved single photon counting found to quench...... singlet excited riboflavin through exothermic formation of ground-state precursor complexes indicating importance of hydrogen bounding through keto-enol tautomer's for protection of oxidizable substrates and sensitive structures against riboflavin photosensitization....

  12. Analysis of caffeine and heavy metal contents in branded and unbranded tea available in Pakistan

    International Nuclear Information System (INIS)

    Khan, S.R.; Inayat, A.; Chowdhry, M.N.; Waheed, A.

    2010-01-01

    In the investigation of caffeine and heavy metal contents in four branded and six unbranded tea samples collected from local markets of Lahore, Faisalabad and Peshawar, the amount of caffeine and heavy metals in all the branded tea samples were in agreement with the international standards. In unbranded tea samples, though the amount of caffeine was within standard limits but two of the samples collected from Peshawar had high concentrations of lead being, 13.69 and 15.78 mg/kg, consumption of which can lead to serious problems. (author)

  13. Caffeine, coffee, and appetite control: a review.

    Science.gov (United States)

    Schubert, Matthew M; Irwin, Christopher; Seay, Rebekah F; Clarke, Holly E; Allegro, Deanne; Desbrow, Ben

    2017-12-01

    Coffee and caffeine consumption has global popularity. However, evidence for the potential of these dietary constituents to influence energy intake, gut physiology, and appetite perceptions remains unclear. The purpose of this review was to examine the evidence regarding coffee and caffeine's influence on energy intake and appetite control. The literature was examined for studies that assessed the effects of caffeine and coffee on energy intake, gastric emptying, appetite-related hormones, and perceptual measures of appetite. The literature review indicated that coffee administered 3-4.5 h before a meal had minimal influence on food and macronutrient intake, while caffeine ingested 0.5-4 h before a meal may suppress acute energy intake. Evidence regarding the influence of caffeine and coffee on gastric emptying, appetite hormones, and appetite perceptions was equivocal. The influence of covariates such as genetics of caffeine metabolism and bitter taste phenotype remain unknown; longer controlled studies are needed.

  14. Multidrug resistance transporters Snq2p and Pdr5p mediate caffeine efflux in Saccharomyces cerevisiae.

    Science.gov (United States)

    Tsujimoto, Yoshiyuki; Shimizu, Yoshihiro; Otake, Kazuya; Nakamura, Tatsuya; Okada, Ryutaro; Miyazaki, Toshitaka; Watanabe, Kunihiko

    2015-01-01

    SNQ2 was identified as a caffeine-resistance gene by screening a genomic library of Saccharomyces cerevisiae in a multicopy vector YEp24. SNQ2 encodes an ATP-binding cassette transporter and is highly homologous to PDR5. Multicopy of PDR5 also conferred resistance to caffeine, while its resistance was smaller than that of SNQ2. Residual caffeine contents were analyzed after transiently exposing cells to caffeine. The ratios of caffeine contents were 21.3 ± 8.8% (YEp24-SNQ2) and 81.9 ± 8.7% (YEp24-PDR5) relative to control (YEp24, 100%). In addition, multicopies of SNQ2 or PDR5 conferred resistance to rhodamine 6G (R6G), which was widely used as a substrate for transport assay. R6G was exported by both transporters, and their efflux activities were inhibited by caffeine with half-maximal inhibitory concentrations of 5.3 ± 1.9 (YEp24-SNQ2) and 17.2 ± 9.6 mM (YEp24-PDR5). These results demonstrate that Snq2p is a more functional transporter of caffeine than Pdr5p in yeast cells.

  15. Effects of carbohydrate and caffeine ingestion on performance during a rugby union simulation protocol.

    Science.gov (United States)

    Roberts, Simon P; Stokes, Keith A; Trewartha, Grant; Doyle, Jenny; Hogben, Patrick; Thompson, Dylan

    2010-06-01

    In this study, we investigated the effect of ingesting carbohydrate alone or with caffeine on performance of a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced trial order, eight male rugby union forwards ingested either placebo or carbohydrate (1.2 g x kg(-1) body mass x h(-1)) before and during a rugby union-specific protocol, with pre-exercise caffeine ingestion (4 mg x kg(-1)) before one of the carbohydrate trials (carbohydrate + caffeine). The intermittent exercise protocol included walking, jogging, and cruising at pre-determined intensities, simulated contact events, a sustained high-intensity test of speed and agility (Performance Test), and a 15-m sprint. Ratings of perceived exertion (RPE) were recorded every 5 min and a motor skills test was performed after each 21-min block. Performance Test times were not significantly different between trials but the likelihood of 2% improvements for carbohydrate + caffeine over placebo and carbohydrate were 98% and 44%, respectively. For carbohydrate + caffeine, 15-m sprints were faster than for placebo (P=0.05) and the motor skills test was performed faster in the carbohydrate + caffeine trial than the carbohydrate and placebo trials (P benefit to rugby performance following co-ingestion of carbohydrate and caffeine.

  16. Effects of caffeine and alcohol on mood and performance changes following consumption of lager.

    Science.gov (United States)

    Smith, Andrew P

    2013-06-01

    The present study examined whether caffeine would modify the behavioural effects of alcohol. The aim of the study was to determine whether caffeine modifies the effects of alcohol on mood and psychomotor performance and to identify possible dose-response and temporal relationships. A double-blind study examined the effects of three successive lager drinks (330 ml each) in the early afternoon on mood and psychomotor performance assessed at 30-min intervals over a 2-h period. Participants carried out a baseline session and were then randomly assigned to one of six conditions formed by combining three different doses of caffeine (0, 62.5 and 125 mg per drink) with either no alcohol or 4.3 % alcohol. One hundred and forty-six young adults (65 male, 81 female; age range 18-30 years) participated in the study. Mood (alertness, hedonic tone and anxiety) was assessed before and after performing simple reaction time and choice reaction time tasks. Alcohol was associated with higher hedonic tone (p Caffeine had no modifying effect on hedonic tone or anxiety. However, the highest dose of caffeine did remove the effect of alcohol on alertness (p caffeine were found on the performance tasks (all p values caffeine does not remove the negative effects of alcohol on performance although high doses counteract the drop in subjective alertness produced by alcohol.

  17. Estimation of caffeine intake from analysis of caffeine metabolites in wastewater

    NARCIS (Netherlands)

    Gracia-Lor, E.; Rousis, N.I.; Zuccato, E.; Bade, R.; Baz-Lomba, J.A.; Castrignanò, E.; Causanilles Llanes, A.; Hernández, F.; Kasprzyk-Hordern, B.; Kinyua, J.; McCall, A.-K.; van Nuijs, A.L.N.; Plósz, B.G.; Ramin, P.; Ryu, Y.; Santos, M.M.; Thomas, K.; de Voogt, P.; Yang, Z.; Castiglioni, S.

    2017-01-01

    Caffeine metabolites in wastewater were investigated as potential biomarkers for assessing caffeine intake in a population. The main human urinary metabolites of caffeine were measured in the urban wastewater of ten European cities and the metabolic profiles in wastewater were compared with the

  18. Effect of Carbohydrate and Caffeine Ingestion on Badminton Performance.

    Science.gov (United States)

    Clarke, Neil D; Duncan, Michael J

    2016-01-01

    To investigate the effect of ingesting carbohydrate and caffeine solutions on measures that are central to success in badminton. Twelve male badminton players performed a badminton serve-accuracy test, coincidence-anticipation timing (CAT), and a choice reaction-time sprint test 60 min before exercise. Participants then consumed 7 mL/kg body mass of either water (PLA), 6.4% carbohydrate solution (CHO), a solution containing a caffeine dose of 4 mg/kg, or 6.4% carbohydrate and 4 mg/kg caffeine (C+C). All solutions were flavored with orange-flavored concentrate. During the 33-min fatigue protocol, participants were provided with an additional 3 mL/kg body mass of solution, which was ingested before the end of the protocol. As soon as the 33-min fatigue protocol was completed, all measures were recorded again. Short-serve accuracy was improved after the ingestion of CHO and C+C compared with PLA (P = .001, η(p)(2) = .50). Long-serve accuracy was improved after the ingestion of C+C compared with PLA (P badminton match can maintain serve accuracy, anticipation timing, and sprinting actions around the court.

  19. Role of adenosine receptors in caffeine tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Holtzman, S.G.; Mante, S.; Minneman, K.P. (Emory Univ. School of Medicine, Atlanta, GA (USA))

    1991-01-01

    Caffeine is a competitive antagonist at adenosine receptors. Receptor up-regulation during chronic drug treatment has been proposed to be the mechanism of tolerance to the behavioral stimulant effects of caffeine. This study reassessed the role of adenosine receptors in caffeine tolerance. Separate groups of rats were given scheduled access to drinking bottles containing plain tap water or a 0.1% solution of caffeine. Daily drug intake averaged 60-75 mg/kg and resulted in complete tolerance to caffeine-induced stimulation of locomotor activity, which could not be surmounted by increasing the dose of caffeine. 5'-N-ethylcarboxamidoadenosine (0.001-1.0 mg/kg) dose dependently decreased the locomotor activity of caffeine-tolerant rats and their water-treated controls but was 8-fold more potent in the latter group. Caffeine (1.0-10 mg/kg) injected concurrently with 5-N-ethylcarboxamidoadenosine antagonized the decreases in locomotor activity comparably in both groups. Apparent pA2 values for tolerant and control rats also were comparable: 5.05 and 5.11. Thus, the adenosine-antagonist activity of caffeine was undiminished in tolerant rats. The effects of chronic caffeine administration on parameters of adenosine receptor binding and function were measured in cerebral cortex. There were no differences between brain tissue from control and caffeine-treated rats in number and affinity of adenosine binding sites or in receptor-mediated increases (A2 adenosine receptor) and decreases (A1 adenosine receptor) in cAMP accumulation. These results are consistent with theoretical arguments that changes in receptor density should not affect the potency of a competitive antagonist. Experimental evidence and theoretical considerations indicate that up-regulation of adenosine receptors is not the mechanism of tolerance to caffeine-induced stimulation of locomotor activity.

  20. Role of adenosine receptors in caffeine tolerance

    International Nuclear Information System (INIS)

    Holtzman, S.G.; Mante, S.; Minneman, K.P.

    1991-01-01

    Caffeine is a competitive antagonist at adenosine receptors. Receptor up-regulation during chronic drug treatment has been proposed to be the mechanism of tolerance to the behavioral stimulant effects of caffeine. This study reassessed the role of adenosine receptors in caffeine tolerance. Separate groups of rats were given scheduled access to drinking bottles containing plain tap water or a 0.1% solution of caffeine. Daily drug intake averaged 60-75 mg/kg and resulted in complete tolerance to caffeine-induced stimulation of locomotor activity, which could not be surmounted by increasing the dose of caffeine. 5'-N-ethylcarboxamidoadenosine (0.001-1.0 mg/kg) dose dependently decreased the locomotor activity of caffeine-tolerant rats and their water-treated controls but was 8-fold more potent in the latter group. Caffeine (1.0-10 mg/kg) injected concurrently with 5-N-ethylcarboxamidoadenosine antagonized the decreases in locomotor activity comparably in both groups. Apparent pA2 values for tolerant and control rats also were comparable: 5.05 and 5.11. Thus, the adenosine-antagonist activity of caffeine was undiminished in tolerant rats. The effects of chronic caffeine administration on parameters of adenosine receptor binding and function were measured in cerebral cortex. There were no differences between brain tissue from control and caffeine-treated rats in number and affinity of adenosine binding sites or in receptor-mediated increases (A2 adenosine receptor) and decreases (A1 adenosine receptor) in cAMP accumulation. These results are consistent with theoretical arguments that changes in receptor density should not affect the potency of a competitive antagonist. Experimental evidence and theoretical considerations indicate that up-regulation of adenosine receptors is not the mechanism of tolerance to caffeine-induced stimulation of locomotor activity

  1. Caffeine in Boston Harbor past and present, assessing its utility as a tracer of wastewater contamination in an urban estuary

    Science.gov (United States)

    Sites throughout Boston Harbor were analyzed for caffeine to assess its utility as a tracer in identifying sources of sanitary wastewater. Caffeine ranged from 15 ng/L in the outer harbor to a high of 185 ng/L in the inner harbor. Inner harbor concentrations were a result of comb...

  2. Prenatal caffeine ingestion induces transgenerational neuroendocrine metabolic programming alteration in second generation rats

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hanwen [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Deng, Zixin; Liu, Lian; Shen, Lang; Kou, Hao; He, Zheng [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Ping, Jie; Xu, Dan [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China); Ma, Lu [Department of Epidemiology and Health Statistics, Public Health School of Wuhan University, Wuhan 430071 (China); Chen, Liaobin, E-mail: lbchen@whu.edu.cn [Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Wang, Hui, E-mail: wanghui19@whu.edu.cn [Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

    2014-02-01

    Our previous studies have demonstrated that prenatal caffeine ingestion induces an increased susceptibility to metabolic syndrome with alterations of glucose and lipid metabolic phenotypes in adult first generation (F1) of intrauterine growth retardation (IUGR) rats, and the underlying mechanism is originated from a hypothalamic–pituitary–adrenal (HPA) axis-associated neuroendocrine metabolic programming alteration in utero. This study aims to investigate the transgenerational effects of this programming alteration in adult second generation (F2). Pregnant Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. Four groups in F2 were set according to the cross-mating between control and caffeine-induced IUGR rats. F2 were subjected to a fortnight ice water swimming stimulus on postnatal month 4, and blood samples were collected before and after stress. Results showed that the majority of the activities of HPA axis and phenotypes of glucose and lipid metabolism were altered in F2. Particularly, comparing with the control group, caffeine groups had an enhanced corticosterone levels after chronic stress. Compared with before stress, the serum glucose levels were increased in some groups whereas the triglyceride levels were decreased. Furthermore, total cholesterol gain rates were enhanced but the high-density lipoprotein-cholesterol gain rates were decreased in most caffeine groups after stress. These transgenerational effects were characterized partially with gender and parental differences. Taken together, these results indicate that the reproductive and developmental toxicities and the neuroendocrine metabolic programming mechanism by prenatal caffeine ingestion have transgenerational effects in rats, which may help to explain the susceptibility to metabolic syndrome and associated diseases in F2. - Highlights: • Caffeine-induced neuroendocrine metabolic programming of HPA has hereditary effect. • Caffeine

  3. Prenatal caffeine ingestion induces transgenerational neuroendocrine metabolic programming alteration in second generation rats

    International Nuclear Information System (INIS)

    Luo, Hanwen; Deng, Zixin; Liu, Lian; Shen, Lang; Kou, Hao; He, Zheng; Ping, Jie; Xu, Dan; Ma, Lu; Chen, Liaobin; Wang, Hui

    2014-01-01

    Our previous studies have demonstrated that prenatal caffeine ingestion induces an increased susceptibility to metabolic syndrome with alterations of glucose and lipid metabolic phenotypes in adult first generation (F1) of intrauterine growth retardation (IUGR) rats, and the underlying mechanism is originated from a hypothalamic–pituitary–adrenal (HPA) axis-associated neuroendocrine metabolic programming alteration in utero. This study aims to investigate the transgenerational effects of this programming alteration in adult second generation (F2). Pregnant Wistar rats were administered with caffeine (120 mg/kg·d) from gestational day 11 until delivery. Four groups in F2 were set according to the cross-mating between control and caffeine-induced IUGR rats. F2 were subjected to a fortnight ice water swimming stimulus on postnatal month 4, and blood samples were collected before and after stress. Results showed that the majority of the activities of HPA axis and phenotypes of glucose and lipid metabolism were altered in F2. Particularly, comparing with the control group, caffeine groups had an enhanced corticosterone levels after chronic stress. Compared with before stress, the serum glucose levels were increased in some groups whereas the triglyceride levels were decreased. Furthermore, total cholesterol gain rates were enhanced but the high-density lipoprotein-cholesterol gain rates were decreased in most caffeine groups after stress. These transgenerational effects were characterized partially with gender and parental differences. Taken together, these results indicate that the reproductive and developmental toxicities and the neuroendocrine metabolic programming mechanism by prenatal caffeine ingestion have transgenerational effects in rats, which may help to explain the susceptibility to metabolic syndrome and associated diseases in F2. - Highlights: • Caffeine-induced neuroendocrine metabolic programming of HPA has hereditary effect. • Caffeine

  4. Coffee with co-workers: role of caffeine on evaluations of the self and others in group settings.

    Science.gov (United States)

    Unnava, Vasu; Singh, Amit Surendra; Unnava, H Rao

    2018-03-01

    This research explores the effect of consuming a moderate amount of commercially available caffeinated coffee on an individual's self-evaluated participation in a group activity and subsequent evaluations of the experience. Across two studies, results show that consuming a moderate amount of caffeinated coffee prior to indulging in a group activity enhances an individual's task-relevant participation in the group activity. In addition, subjective evaluations of the participation of other group members and oneself are also positively influenced. Finally, the positive impact of consuming a moderate amount of caffeinated coffee on the evaluation of participation of other group members and oneself is moderated by a sense of an increased level of alertness.

  5. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood.

    Science.gov (United States)

    Dodd, F L; Kennedy, D O; Riby, L M; Haskell-Ramsay, C F

    2015-07-01

    Evidence suggests interactive effects of the tea components caffeine and L-theanine on behaviour, yet no data exists exploring the impact of the two on cerebral blood flow (CBF). The current placebo-controlled, double-blind, counterbalanced, crossover study examined the effects of caffeine and L-theanine on CBF and extended previous cognitive and mood findings by using lower doses than previous studies of a similar methodology, which more closely reflect the ratios present in tea. Twelve habitual consumers and 12 non-habitual consumers of caffeine each received 75 mg caffeine, 50 mg L-theanine, 75 mg caffeine plus 50 mg L-theanine, and placebo in a counterbalanced order across four separate visits. CBF was measured via near-infrared spectroscopy with cognition and mood assessed at baseline and 30 min post-dose. Salivary caffeine and peripheral haemodynamics were co-monitored. Caffeine reduced oxygenated haemoglobin (oxy-Hb), increased deoxygenated haemoglobin (deoxy-Hb), improved performance on attention tasks and increased overall mood ratings. Increases in deoxy-Hb following caffeine were more pronounced in non-consumers. Some evidence for increased deoxy-Hb remained when caffeine was combined with L-theanine, but this effect was attenuated and the effects of caffeine on oxy-Hb, cognition and mood were eradicated. Combining L-theanine with caffeine, at levels and ratios equivalent to one to two cups of tea, eliminated the vasoconstrictive effect and behavioural effects of caffeine. This supports previous findings of an interaction between these substances, despite a lack of effects of L-theanine in isolation. However, at the levels tested here, this did not lead to a positive impact on behaviour.

  6. Vital signs : no end in sight to high revenues for producers (and headaches for consumers)

    International Nuclear Information System (INIS)

    Lunan, D.

    2001-01-01

    Prices for petroleum products in North America have been on a roller coaster ride for a while now, with prices remaining high for the normally more dormant summer season. Although it is beneficial to producers, consumers are not as happy about the situation. Refinery problems, growing demand and product proliferation have combined to create this situation. Refineries on the East Coast of the United States were forced to extend the required maintenance period in the spring since they had been running non-stop to meet the requirements of last winter. Canadian refiners benefited from the situation. They enjoy strong refining margins. Canadian refined-product exports jumped 22 per cent higher in February of 2001 when compared to February 2000. Heavy fuel oil exports in January and February were especially strong, as the industrial boilers in the United States were feeling the effects of the very high natural gas prices. A similar phenomenon was reflected in exports of gasoline and crude oil. The commissioning last year of the Alliance Pipeline and successful exploration programs in British Columbia ensured it led the pack. The crude production in Saskatchewan was up 11.4 per cent due to the widespread horizontal drilling and recovery programs. To ensure adequate winter peaking supplies, storage injections are lagging behind, which tends to indicate that gas prices will remain high for the remainder of the year. 7 tabs., 4 figs

  7. Direct-to-consumer television advertising exposure, diagnosis with high cholesterol, and statin use.

    Science.gov (United States)

    Niederdeppe, Jeff; Byrne, Sahara; Avery, Rosemary J; Cantor, Jonathan

    2013-07-01

    While statin drugs are recommended for secondary prevention of coronary heart disease (CHD), there is no medical consensus on whether or not a statin should be added to lifestyle change efforts for primary prevention of CHD. Previous research suggests that exposure to direct-to-consumer advertising (DTCA) increases drug demand among those at comparatively low risk. Research has yet to examine whether individual-level DTCA exposure may influence statin use among men and women at high, moderate, or low risk for future cardiac events. To determine the relationship between estimated exposure to DTCA for statin drugs and two clinical variables: diagnosis with high cholesterol and statin use. We used logistic regression to analyze repeated cross-sectional surveys of the United States population, merged with data on the frequency of DTCA appearances on national, cable, and local television, between 2001 and 2007. American adults (n=106,685) aged 18 and older. Levels of exposure to statin DTCA, based on ad appearances and TV viewing patterns; self-reports of whether or not a respondent has been diagnosed with high cholesterol, and whether or not a respondent took a statin in the past year. Adjusting for potential confounders, we estimate that exposure to statin ads increased the odds of being diagnosed with high cholesterol by 16 to 20 %, and increased statin use by 16 to 22 %, among both men and women (p<0.05). These associations were driven almost exclusively by men and women at low risk for future cardiac events. There was also evidence of a negative association between DTCA exposure and statin use among high-risk women (p<0.05) CONCLUSIONS: This study provides new evidence that DTCA may promote over-diagnosis of high cholesterol and over-treatment for populations where risks of statin use may outweigh potential benefits.

  8. Simple electrochemical sensor for caffeine based on carbon and Nafion-modified carbon electrodes.

    Science.gov (United States)

    Torres, A Carolina; Barsan, Madalina M; Brett, Christopher M A

    2014-04-15

    A simple, economic, highly sensitive and highly selective method for the detection of caffeine has been developed at bare and Nafion-modified glassy carbon electrodes (GCE). The electrochemical behaviour of caffeine was examined in electrolyte solutions of phosphate buffer saline, sodium perchlorate, and in choline chloride plus oxalic acid, using analytical determinations by fixed potential amperometry, phosphate buffer saline being the best. Modifications of the GCE surface with poly(3,4-ethylenedioxythiophene) (PEDOT), Nafion, and multi-walled carbon nanotubes were tested in order to evaluate possible sensor performance enhancements, Nafion giving the most satisfactory results. The effect of interfering compounds usually found in samples containing caffeine was examined at GCE without and with Nafion coating, to exclude interferences, and the sensors were successfully applied to determine the caffeine content in commercial beverages and drugs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Maternal caffeine intake during pregnancy is associated with birth weight but not with gestational length: results from a large prospective observational cohort study

    Science.gov (United States)

    2013-01-01

    Background Pregnant women consume caffeine daily. The aim of this study was to examine the association between maternal caffeine intake from different sources and (a) gestational length, particularly the risk for spontaneous preterm delivery (PTD), and (b) birth weight (BW) and the baby being small for gestational age (SGA). Methods This study is based on the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health. A total of 59,123 women with uncomplicated pregnancies giving birth to a live singleton were identified. Caffeine intake from different sources was self-reported at gestational weeks 17, 22 and 30. Spontaneous PTD was defined as spontaneous onset of delivery between 22+0 and 36+6 weeks (n = 1,451). As there is no consensus, SGA was defined according to ultrasound-based (Marsal, n = 856), population-based (Skjaerven, n = 4,503) and customized (Gardosi, n = 4,733) growth curves. Results The main caffeine source was coffee, but tea and chocolate were the main sources in women with low caffeine intake. Median pre-pregnancy caffeine intake was 126 mg/day (IQR 40 to 254), 44 mg/day (13 to 104) at gestational week 17 and 62 mg/day (21 to 130) at gestational week 30. Coffee caffeine, but not caffeine from other sources, was associated with prolonged gestation (8 h/100 mg/day, P caffeine was associated with spontaneous PTD risk. Caffeine intake from different sources, measured repeatedly during pregnancy, was associated with lower BW (Marsal-28 g, Skjaerven-25 g, Gardosi-21 g per 100 mg/day additional total caffeine for a baby with expected BW 3,600 g, P Caffeine intake of 200 to 300 mg/day increased the odds for SGA (OR Marsal 1.62, Skjaerven 1.44, Gardosi 1.27, P caffeine, consumption was associated with marginally increased gestational length but not with spontaneous PTD risk. Caffeine intake was consistently associated with decreased BW and increased odds of SGA. The association was strengthened by concordant results for

  10. A high-rise on Main Street: Hotelling with mobile consumers

    OpenAIRE

    Martin Richardson

    2004-01-01

    This note considers Hotelling’s (1929) model of locational choices by two firms and subsequent price competition in a setting where atomistic consumers locate first. It is shown that any equilibrium in pure strategies involves either one or two mass points with all surplus captured either by the consumers or by firms, respectively.

  11. High-efficiency VCSEL arrays for illumination and sensing in consumer applications

    Science.gov (United States)

    Seurin, Jean-Francois; Zhou, Delai; Xu, Guoyang; Miglo, Alexander; Li, Daizong; Chen, Tong; Guo, Baiming; Ghosh, Chuni

    2016-03-01

    There has been increased interest in vertical-cavity surface-emitting lasers (VCSELs) for illumination and sensing in the consumer market, especially for 3D sensing ("gesture recognition") and 3D image capture. For these applications, the typical wavelength range of interest is 830~950nm and power levels vary from a few milli-Watts to several Watts. The devices are operated in short pulse mode (a few nano-seconds) with fast rise and fall times for time-of-flight applications (ToF), or in CW/quasi-CW for structured light applications. In VCSELs, the narrow spectrum and its low temperature dependence allows the use of narrower filters and therefore better signal-to-noise performance, especially for outdoor applications. In portable devices (mobile devices, wearable devices, laptops etc.) the size of the illumination module (VCSEL and optics) is a primary consideration. VCSELs offer a unique benefit compared to other laser sources in that they are "surface-mountable" and can be easily integrated along with other electronics components on a printed circuit board (PCB). A critical concern is the power-conversion efficiency (PCE) of the illumination source operating at high temperatures (>50 deg C). We report on various VCSEL based devices and diffuser-integrated modules with high efficiency at high temperatures. Over 40% PCE was achieved in broad temperature range of 0-70 °C for either low power single devices or high power VCSEL arrays, with sub- nano-second rise and fall time. These high power VCSEL arrays show excellent reliability, with extracted mean-time-to-failure (MTTF) of over 500 years at 60 °C ambient temperature and 8W peak output.

  12. Effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance.

    Science.gov (United States)

    Glaister, Mark; Pattison, John R; Muniz-Pumares, Daniel; Patterson, Stephen D; Foley, Paul

    2015-01-01

    The aim of this study was to examine the acute supplementation effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. Using a randomized, counterbalanced, double-blind Latin-square design, 14 competitive female cyclists (age: 31 ± 7 years; height: 1.69 ± 0.07 m; body mass: 61.6 ± 6.0 kg) completed four 20-km time trials on a racing bicycle fitted to a turbo trainer. Approximately 2.5 hours before each trial, subjects consumed a 70-ml dose of concentrated beetroot juice containing either 0.45 g of dietary nitrate or with the nitrate content removed (placebo). One hour before each trial, subjects consumed a capsule containing either 5 mg·kg of caffeine or maltodextrin (placebo). There was a significant effect of supplementation on power output (p = 0.001), with post hoc tests revealing higher power outputs in caffeine (205 ± 21 W) vs. nitrate (194 ± 22 W) and placebo (194 ± 25 W) trials only. Caffeine-induced improvements in power output corresponded with significantly higher measures of heart rate (caffeine: 166 ± 12 b·min vs. placebo: 159 ± 15 b·min; p = 0.02), blood lactate (caffeine: 6.54 ± 2.40 mmol·L vs. placebo: 4.50 ± 2.11 mmol·L; p caffeine: 0.95 ± 0.04 vs. placebo: 0.91 ± 0.05; p = 0.03). There were no effects (p ≥ 0.05) of supplementation on cycling cadence, rating of perceived exertion, (Equation is included in full-text article.), or integrated electromyographic activity. The results of this study support the well-established beneficial effects of caffeine supplementation on endurance performance. In contrast, acute supplementation with dietary nitrate seems to have no effect on endurance performance and adds nothing to the benefits afforded by caffeine supplementation.

  13. Comparison of caffeine disposition following administration by oral solution (energy drink) and inspired powder (AeroShot) in human subjects.

    Science.gov (United States)

    Laizure, S Casey; Meibohm, Bernd; Nelson, Kembral; Chen, Feng; Hu, Zhe-Yi; Parker, Robert B

    2017-12-01

    To determine the disposition and effects of caffeine after administration using a new dosage form (AeroShot) that delivers caffeine by inspiration of a fine powder into the oral cavity and compare it to an equivalent dose of an oral solution (energy drink) as the reference standard. Healthy human subjects (n = 17) inspired a 100 mg caffeine dose using the AeroShot device or consumed an energy drink on separate study days. Heart rate, blood pressure and subject assessments of effects were measured over an 8-h period. Plasma concentrations of caffeine and its major metabolites were determined by liquid chromatography-mass spectrometry. Pharmacokinetic, cardiovascular and perceived stimulant effects were compared between AeroShot and energy drink phases using a paired t test and standard bioequivalency analysis. Caffeine disposition was similar after caffeine administration by the AeroShot device and energy drink: peak plasma concentration 1790 and 1939 ng ml -1 , and area under the concentration-time curve (AUC) 15 579 and 17 569 ng ml -1 × h, respectively, but they were not bioequivalent: AeroShot AUC of 80.3% (confidence interval 71.2-104.7%) and peak plasma concentration of 86.3% (confidence interval 62.8-102.8%) compared to the energy drink. Female subjects did have a significantly larger AUC compared to males after consumption of the energy drink. The heart rate and blood pressure were not significantly affected by the 100 mg caffeine dose, and there were no consistently perceived stimulant effects by the subjects using visual analogue scales. Inspiration of caffeine as a fine powder using the AeroShot device produces a similar caffeine profile and effects compared to administration of an oral solution (energy drink). © 2017 The British Pharmacological Society.

  14. Pharmacokinetics of Caffeine in the Lens Capsule/Epithelium After Peroral Intake: A Pilot Randomized Controlled Study.

    Science.gov (United States)

    Kronschläger, Martin; Stimpfl, Thomas; Ruiß, Manuel; Hirnschall, Nino; Leisser, Christoph; Findl, Oliver

    2018-04-01

    To determine the pharmacokinetics of perorally administered caffeine, a widely consumed and potent dietary antioxidant, in the anterior lens capsule and lens epithelial cells, a crucial cell monolayer for cataract development. Bilateral cataract patients were scheduled for cataract surgery with a caffeine abstinence of 1 week before surgery of each eye. At the day of surgery of the second eye patients were administered no drink (0-mg group) or coffee with 60-, 120-, or 180-mg caffeine. After capsulorhexis the lens capsule including lens epithelial cells was transferred to a test tube for analysis of caffeine concentration by gas chromatography-mass spectrometry (GC-MS/MS). Coffee consumption significantly (P < 0.05) increased caffeine levels of the lens capsule/epithelium in the 60-, 120-, and 180-mg group. Caffeine concentrations (caffeine ng/lens capsule/epithelium) measured as difference between 1st and 2nd eye were -0.52 ± 1.16 (0-mg group, n = 7), 1.88 ± 2.02 (60-mg group, n = 8), 2.09 ± 0.67 (120-mg group, n = 9), and 3.68 ± 1.86 (180-mg group, n = 9). The increase constant of caffeine in a linear regression model was estimated as a 95% CI 0.02 ± 0.0046 (degrees of freedom; 25; r = 0.85). Peroral intake of coffee significantly increased caffeine concentrations in the lens capsule and lens epithelial cells in a dose-dependent manner. This information is important for further investigations on preventing cataract.

  15. Chronic coffee and caffeine ingestion effects on the cognitive function and antioxidant system of rat brains.

    Science.gov (United States)

    Abreu, Renata Viana; Silva-Oliveira, Eliane Moretto; Moraes, Márcio Flávio Dutra; Pereira, Grace Schenatto; Moraes-Santos, Tasso

    2011-10-01

    Coffee is a popular beverage consumed worldwide and its effect on health protection has been well studied throughout literature. This study investigates the effect of chronic coffee and caffeine ingestion on cognitive behavior and the antioxidant system of rat brains. The paradigms of open field and object recognition were used to assess locomotor and exploratory activities, as well as learning and memory. The antioxidant system was evaluated by determining the activities of glutathione reductase (GR), glutathione peroxidase (GPx) and superoxide dismutase (SOD), as well as the lipid peroxidation and reduced glutathione content. Five groups of male rats were fed for approximately 80 days with different diets: control diet (CD), fed a control diet; 3% coffee diet (3%Co) and 6% coffee diet (6%Co), both fed a diet containing brewed coffee; 0.04% caffeine diet (0.04%Ca) and 0.08% caffeine diet (0.08%Ca), both fed a control diet supplemented with caffeine. The estimated caffeine intake was approximately 20 and 40 mg/kg per day, for the 3%Co-0.04%Ca and 6%Co-0.08%Ca treatments, respectively. At 90 days of life, the animals were subjected to the behavioral tasks and then sacrificed. The results indicated that the intake of coffee, similar to caffeine, improved long-term memory when tested with object recognition; however, this was not accompanied by an increase in locomotor and exploratory activities. In addition, chronic coffee and caffeine ingestion reduced the lipid peroxidation of brain membranes and increased the concentration of reduced-glutathione. The activities of the GR and SOD were similarly increased, but no change in GPx activity could be observed. Thus, besides improving cognitive function, our data show that chronic coffee consumption modulates the endogenous antioxidant system in the brain. Therefore, chronic coffee ingestion, through the protection of the antioxidant system, may play an important role in preventing age-associated decline in the cognitive

  16. The effects of Red Bull energy drink compared with caffeine on cycling time-trial performance.

    Science.gov (United States)

    Quinlivan, Alannah; Irwin, Christopher; Grant, Gary D; Anoopkumar-Dukie, Sheilandra; Skinner, Tina; Leveritt, Michael; Desbrow, Ben

    2015-10-01

    This study investigated the ergogenic effects of a commercial energy drink (Red Bull) or an equivalent dose of anhydrous caffeine in comparison with a noncaffeinated control beverage on cycling performance. Eleven trained male cyclists (31.7 ± 5.9 y 82.3 ± 6.1 kg, VO2max = 60.3 ± 7.8 mL · kg-1 · min-1) participated in a double-blind, placebo-controlled, crossover-design study involving 3 experimental conditions. Participants were randomly administered Red Bull (9.4 mL/kg body mass [BM] containing 3 mg/kg BM caffeine), anhydrous caffeine (3 mg/kg BM given in capsule form), or a placebo 90 min before commencing a time trial equivalent to 1 h cycling at 75% peak power output. Carbohydrate and fluid volumes were matched across all trials. Performance improved by 109 ± 153 s (2.8%, P = .039) after Red Bull compared with placebo and by 120 ± 172 s (3.1%, P = .043) after caffeine compared with placebo. No significant difference (P > .05) in performance time was detected between Red Bull and caffeine treatments. There was no significant difference (P > .05) in mean heart rate or rating of perceived exertion among the 3 treatments. This study demonstrated that a moderate dose of caffeine consumed as either Red Bull or in anhydrous form enhanced cycling time-trial performance. The ergogenic benefits of Red Bull energy drink are therefore most likely due to the effects of caffeine, with the other ingredients not likely to offer additional benefit.

  17. Role of Caffeine Intake on Erectile Dysfunction in US Men: Results from NHANES 2001-2004.

    Directory of Open Access Journals (Sweden)

    David S Lopez

    Full Text Available Caffeine is consumed by more than 85% of adults and little is known about its role on erectile dysfunction (ED in population-based studies. We investigated the association of caffeine intake and caffeinated beverages with ED, and whether these associations vary among comorbidities for ED.Data were analyzed for 3724 men (≥20 years old who participated in the National Health and Nutrition Examination Survey (NHANES. ED was assessed by a single question during a self-paced, computer-assisted self-interview. We analyzed 24-h dietary recall data to estimate caffeine intake (mg/day. Multivariable logistic regression analyses using appropriate sampling weights were conducted.We found that men in the 3rd (85-170 mg/day and 4th (171-303 mg/day quintiles of caffeine intake were less likely to report ED compared to men in the lowest 1st quintile (0-7 mg/day [OR: 0.58; 95% CI, 0.37-0.89; and OR: 0.61; 95% CI, 0.38-0.97, respectively], but no evidence for a trend. Similarly, among overweight/obese and hypertensive men, there was an inverse association between higher quintiles of caffeine intake and ED compared to men in the lowest 1st quintile, P≤0.05 for each quintile. However, only among men without diabetes we found a similar inverse association (Ptrend = 0.01.Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day. This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies.

  18. Caffeine-based food supplements and beverages: Trends of consumption for performance purposes and safety concerns.

    Science.gov (United States)

    Bessada, Sílvia M F; Alves, Rita C; Oliveira, M Beatriz P P

    2018-07-01

    Nowadays, daily food supplementation regarding the improvement of physical and mental performance is a growing trend in sport practitioners, young students and active people. Food supplements are foodstuffs, labeled under food law and not obliged to safety assessments before their commercialization. Several products are commercialized claiming ergogenic effects as marketing strategies. Caffeine is often one of their main ingredients, as it increases both physical performance and concentration. This manuscript presents a general overview of the current caffeine-based food supplements and energy drinks available in the Portuguese market, as well as the consuming trends regarding their ergogenic effects, performance purposes, and active ingredients. Product claims, recommended daily intakes, caffeine pharmacology, and safety concerns aspects are also discussed aspects. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Factors associated with consumption of caffeinated-beverage among Siriraj pre-clinical year medical students, A 2-year consecutive survey.

    Science.gov (United States)

    Pandejpong, Denla; Paisansudhi, Supalerg; Udompunthurak, Suthipol

    2014-03-01

    Previous studies showed that significant proportion of medical students consumed caffeine to face sleep-deprived daily schedules. To monitor the trend of caffeinated-beverage consumption among Siriraj medical students as well as to study possible factors associated with caffeine dependency. The questionnaire was distributed to a class of medical students for 2 consecutive years. Statistical analysis was performed for descriptive purpose. 269 (89.7%) and 225 (74.5%) questionnaires were returned in year 1 and year 2, respectively 16.2% refused to take caffeine-beverages totally. 13% of those who consumed caffeinated-beverages developed caffeine dependence. From logistical analysis, positive history of smoking-family member and female sex were the only other two factors associated with caffeine dependency (OR 2.19, 95% CI 1.04-4.61 and 1.76, 95% CI 1.01-3.07, respectively). Other investigated factors included: exercise (p = 0.08); sleep hours (p = 0.24); reading beverage labels (p = 0.87); alcohol consumption (p = 0.59); class performance (p = 0.87); family member coffee-drinking habits (p = 0.66);family member alcohol-drinking habits (p = 0.18); and family income (p = 0.06). Caffeinated-beverage consumption was common among Siriraj medical students. No significant change was detected in the pattern of caffeinated-beverage consumption within the study period. Positive history of smoking family members and female sex were found as the only other two factors correlated with caffeine dependency.

  20. Do High Consumers of Sugar-Sweetened Beverages Respond Differently to Price Changes? A Finite Mixture IV-Tobit Approach.

    Science.gov (United States)

    Etilé, Fabrice; Sharma, Anurag

    2015-09-01

    This study compares the impact of sugar-sweetened beverages (SSBs) tax between moderate and high consumers in Australia. The key methodological contribution is that price response heterogeneity is identified while controlling for censoring of consumption at zero and endogeneity of expenditure by using a finite mixture instrumental variable Tobit model. The SSB price elasticity estimates show a decreasing trend across increasing consumption quantiles, from -2.3 at the median to -0.2 at the 95th quantile. Although high consumers of SSBs have a less elastic demand for SSBs, their very high consumption levels imply that a tax would achieve higher reduction in consumption and higher health gains. Our results also suggest that an SSB tax would represent a small fiscal burden for consumers whatever their pre-policy level of consumption, and that an excise tax should be preferred to an ad valorem tax. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Caffeine: How Much Is Too Much?

    Science.gov (United States)

    Healthy Lifestyle Nutrition and healthy eating Caffeine has its perks, but it can pose problems too. Find out how much is too much and if you need to curb ... By Mayo Clinic Staff If you rely on caffeine to wake you up and keep you going, ...

  2. CORRELATION BETWEEN CAFFEINE CONTENTS OF GREEN ...

    African Journals Online (AJOL)

    AND ALTITUDES OF THE COFFEE PLANTS GROWN IN SOUTHWEST ETHIOPIA .... sublimation temperature of caffeine, during it only a small percentage of .... the tube and extracted for a second time with 5.00 mL of boiling water. ..... Sridevi, V.; Giridhar, P. Changes in caffeine content during fruit development in Coffea.

  3. Caffeinated Energy Drinks -- A Growing Problem

    Science.gov (United States)

    Reissig, Chad J.; Strain, Eric C.; Griffiths, Roland R.

    2009-01-01

    Since the introduction of Red Bull in Austria in 1987 and in the United States in 1997, the energy drink market has grown exponentially. Hundreds of different brands are now marketed, with caffeine content ranging from a modest 50 mg to an alarming 505 mg per can or bottle. Regulation of energy drinks, including content labeling and health warnings differs across countries, with some of the most lax regulatory requirements in the U.S. The absence of regulatory oversight has resulted in aggressive marketing of energy drinks, targeted primarily toward young males, for psychoactive, performance-enhancing and stimulant drug effects. There are increasing reports of caffeine intoxication from energy drinks, and it seems likely that problems with caffeine dependence and withdrawal will also increase. In children and adolescents who are not habitual caffeine users, vulnerability to caffeine intoxication may be markedly increased due to an absence of pharmacological tolerance. Genetic factors may also contribute to an individual’s vulnerability to caffeine related disorders including caffeine intoxication, dependence, and withdrawal. The combined use of caffeine and alcohol is increasing sharply, and studies suggest that such combined use may increase the rate of alcohol-related injury. Several studies suggest that energy drinks may serve as a gateway to other forms of drug dependence. Regulatory implications concerning labeling and advertising, and the clinical implications for children and adolescents are discussed. PMID:18809264

  4. Effects of caffeine on sleep and cognition

    NARCIS (Netherlands)

    Snel, Jan; Lorist, Monicque M.; van Dongen, H.P.A.; Kerkhof, G.A.

    2011-01-01

    Caffeine can be used effectively to manipulate our mental state. It is beneficial in restoring low levels of wakefulness and in counteracting degraded cognitive task performance due to sleep deprivation. However, caffeine may produce detrimental effects on subsequent sleep, resulting in daytime

  5. Coffee, caffeine, and risk of completed suicide: results from three prospective cohorts of American adults.

    Science.gov (United States)

    Lucas, Michel; O'Reilly, Eilis J; Pan, An; Mirzaei, Fariba; Willett, Walter C; Okereke, Olivia I; Ascherio, Alberto

    2014-07-01

    To evaluate the association between coffee and caffeine consumption and suicide risk in three large-scale cohorts of US men and women. We accessed data of 43,599 men enrolled in the Health Professionals Follow-up Study (HPFS, 1988-2008), 73,820 women in the Nurses' Health Study (NHS, 1992-2008), and 91,005 women in the NHS II (1993-2007). Consumption of caffeine, coffee, and decaffeinated coffee, was assessed every 4 years by validated food-frequency questionnaires. Deaths from suicide were determined by physician review of death certificates. Multivariate adjusted relative risks (RRs) were estimated with Cox proportional hazard models. Cohort specific RRs were pooled using random-effect models. We documented 277 deaths from suicide. Compared to those consuming ≤ 1 cup/week of caffeinated coffee (coffee and 0.77 (0.63-0.93) for each increment of 300 mg/day of caffeine. These results from three large cohorts support an association between caffeine consumption and lower risk of suicide.

  6. EFFECT OF SHORT-TERM CAFFEINE SUPPLEMENTATION ON STRESS RESPONSE AND IMMUNE SYSTEM OF MALE ATHLETES

    Directory of Open Access Journals (Sweden)

    Asghar Tofighi

    2014-03-01

    Full Text Available Vigorous exercise stress might be leading cause of immune system disorders and appearance of acute and chronic inflammation in human body. Caffeine supplementation prior to exercise can be effective on body immune response. This study aimed to evaluate the effect of short-term caffeine supplementation on immune response and stress index in male athletes after an exhaustive aerobic exercise. Materials and methods : In a double-blind study 24 male athletes (endurance runner and triathlon randomly divided in Caffeine supplementation (CAF and Placebo (CON groups. One hour prior to main exhaustive treadmill test (Bruce test CAF group consumed caffeine (6 Mg/BW and CON group received placebo. Blood samples were collected before and immediately after exercise test from anticubital vein. After supplying serum; Cortisol, leukocyte and serum Heat shock protein 72 (Hsp72 concentrations were determined using ELISA method. Paired and independent t student test was used for analysis of inter and intra group differences respectively. Results: serum cortisol and Hsp72 concentrations in CON group was significantly higher than CAF group (P0.05. In addition Mean of variation in CON group was significantly higher than CAF group (P<0.05. Conclusions: Based on study results caffeine supplementation prior to short-term exhaustive aerobic exercise has positive effect on innate immunity and body defensive system.

  7. Does caffeine modulate verbal working memory processes? An fMRI study.

    Science.gov (United States)

    Koppelstaetter, F; Poeppel, T D; Siedentopf, C M; Ischebeck, A; Verius, M; Haala, I; Mottaghy, F M; Rhomberg, P; Golaszewski, S; Gotwald, T; Lorenz, I H; Kolbitsch, C; Felber, S; Krause, B J

    2008-01-01

    To assess the effect of caffeine on the functional MRI signal during a 2-back verbal working memory task, we examined blood oxygenation level-dependent regional brain activity in 15 healthy right-handed males. The subjects, all moderate caffeine consumers, underwent two scanning sessions on a 1.5-T MR-Scanner separated by a 24- to 48-h interval. Each participant received either placebo or 100 mg caffeine 20 min prior to the performance of the working memory task in blinded crossover fashion. The study was implemented as a blocked-design. Analysis was performed using SPM2. In both conditions, the characteristic working memory network of frontoparietal cortical activation including the precuneus and the anterior cingulate could be shown. In comparison to placebo, caffeine caused an increased response in the bilateral medial frontopolar cortex (BA 10), extending to the right anterior cingulate cortex (BA 32). These results suggest that caffeine modulates neuronal activity as evidenced by fMRI signal changes in a network of brain areas associated with executive and attentional functions during working memory processes.

  8. EFFECT OF SHORT-TERM CAFFEINE SUPPLEMENTATION ON STRESS RESPONSE AND IMMUNE SYSTEM OF MALE ATHLETES

    Directory of Open Access Journals (Sweden)

    Asghar Tofighi

    2014-04-01

    Full Text Available Vigorous exercise stress might be leading cause of immune system disorders and appearance of acute and chronic inflammation in human body. Caffeine supplementation prior to exercise can be effective on body immune response. This study aimed to evaluate the effect of short-term caffeine supplementation on immune response and stress index in male athletes after an exhaustive aerobic exercise. Materials and methods : In a double-blind study 24 male athletes (endurance runner and triathlon randomly divided in Caffeine supplementation (CAF and Placebo (CON groups. One hour prior to main exhaustive treadmill test (Bruce test CAF group consumed caffeine (6 Mg/BW and CON group received placebo. Blood samples were collected before and immediately after exercise test from anticubital vein. After supplying serum; Cortisol, leukocyte and serum Heat shock protein 72 (Hsp72 concentrations were determined using ELISA method. Paired and independent t student test was used for analysis of inter and intra group differences respectively. Results: serum cortisol and Hsp72 concentrations in CON group was significantly higher than CAF group (P0.05. In addition Mean of variation in CON group was significantly higher than CAF group (P<0.05. Conclusions: Based on study results caffeine supplementation prior to short-term exhaustive aerobic exercise has positive effect on innate immunity and body defensive system.

  9. A case-control field study on the relationships among type 2 diabetes, sleepiness and habitual caffeine intake.

    Science.gov (United States)

    Urry, Emily; Jetter, Alexander; Holst, Sebastian C; Berger, Wolfgang; Spinas, Giatgen A; Langhans, Wolfgang; Landolt, Hans-Peter

    2017-02-01

    The purpose of this study was to examine the possible links between type 2 diabetes, daytime sleepiness, sleep quality and caffeine consumption. In this case-control field study, comparing type 2 diabetic ( n=134) and non-type 2 diabetic ( n=230) participants, subjects completed detailed and validated questionnaires to assess demographic status, health, daytime sleepiness, sleep quality and timing, diurnal preference, mistimed circadian rhythms and habitual caffeine intake. All participants gave saliva under standardised conditions for CYP1A2 genotyping and quantification of caffeine concentration. Hierarchical linear regression analyses examined whether type 2 diabetes status was associated with caffeine consumption. Type 2 diabetic participants reported greater daytime sleepiness ( p=0.001), a higher prevalence of sleep apnoea ( p=0.005) and napping ( p=0.008), and greater habitual caffeine intake ( pcaffeine concentration at bedtime ( p=0.01). Multiple regression analyses revealed that type 2 diabetes status was associated with higher self-reported caffeine consumption ( pcaffeine ( pcaffeine intake. Subjective sleep and circadian estimates were similar between case and control groups. Type 2 diabetic patients may self-medicate with caffeine to alleviate daytime sleepiness. High caffeine intake reflects a lifestyle factor that may be considered when promoting type 2 diabetes management.

  10. Consumer's risk in the EMA and FDA regulatory approaches for bioequivalence in highly variable drugs.

    Science.gov (United States)

    Muñoz, Joel; Alcaide, Daniel; Ocaña, Jordi

    2016-05-30

    The 2010 US Food and Drug Administration and European Medicines Agency regulatory approaches to establish bioequivalence in highly variable drugs are both based on linearly scaling the bioequivalence limits, both take a 'scaled average bioequivalence' approach. The present paper corroborates previous work suggesting that none of them adequately controls type I error or consumer's risk, so they result in invalid test procedures in the neighbourhood of a within-subject coefficient of variation osf 30% for the reference (R) formulation. The problem is particularly serious in the US Food and Drug Administration regulation, but it is also appreciable in the European Medicines Agency one. For the partially replicated TRR/RTR/RRT and the replicated TRTR/RTRT crossover designs, we quantify these type I error problems by means of a simulation study, discuss their possible causes and propose straightforward improvements on both regulatory procedures that improve their type I error control while maintaining an adequate power. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Current situation of energy conservation in high energy-consuming industries in Taiwan

    International Nuclear Information System (INIS)

    Chan, D.Y.-L.; Yang, K.-H.; Hsu, C.-H.; Chien, M.-H.; Hong, G.-B.

    2007-01-01

    Growing concern in Taiwan has arisen about energy consumption and its adverse environmental impact. The current situation of energy conservation in high energy-consuming industries in Taiwan, including the iron and steel, chemical, cement, pulp and paper, textiles and electric/electrical industries has been presented. Since the energy consumption of the top 100 energy users (T100) comprised over 50% of total industry energy consumption, focusing energy consumption reduction efforts on T100 energy users can achieve significant results. This study conducted on-site energy audits of 314 firms in Taiwan during 2000-2004, and identified potential electricity savings of 1,022,656 MWH, fuel oil savings of 174,643 kiloliters (KL), steam coal savings of 98,620 ton, and natural gas (NG) savings of 10,430 kilo cubic meters. The total potential energy saving thus was 489,505 KL of crude oil equivalent (KLOE), representing a reduction of 1,447,841 ton in the carbon dioxide emissions, equivalent to the annual carbon dioxide absorption capacity of a 39,131-ha plantation forest

  12. Corporate Sustainability Strategies: A Case Study in Brazil Focused on High Consumers of Electricity

    Directory of Open Access Journals (Sweden)

    Fabricio Casarejos

    2016-08-01

    Full Text Available The decline of socio-ecological resilience has emerged as an unprecedented truth with high risks to local and global economies, thereby increasing the vulnerability of businesses and markets while potentially threatening the wellbeing of civil society as a whole. From a business perspective, corporate strategies towards sustainability are crucial to strengthen the social and economic foundations that foster sustainable development. In order to assist enterprises pursuing leading market positions, this work proposes a set of strategic actions towards sustainability and an evaluation scheme to assess the effectiveness of their implementation process. This proposed global strategy encompasses five key sustainability indices—commitment, investment, difficulty, proactivity and vulnerability—focusing the investigation on a sample of enterprises representing the highest consumers of electricity in the state of Rio de Janeiro, Brazil. Addressing the energy consumption, this study also discusses the concerning level of GHG emissions that are associated with the generation of electricity. Although 85% of the enterprises participating in this survey recognized the relevance of the actions proposed, the current degree of proactivity and vulnerability associated with these enterprises indicate that very few of them have effectively implemented and invested in corporate sustainability programs, certainly a symptom of their institutional vulnerability.

  13. Caffeine reduces dipyridamole-induced myocardial ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T. (Univ. of Nijmegen (Netherlands))

    1989-10-01

    The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole-{sup 201}Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging.

  14. Caffeine reduces dipyridamole-induced myocardial ischemia

    International Nuclear Information System (INIS)

    Smits, P.; Aengevaeren, W.R.; Corstens, F.H.; Thien, T.

    1989-01-01

    The mechanism of action of coronary vasodilation after dipyridamole may be based on inhibition of cellular uptake of circulating endogenous adenosine. Since caffeine has been reported to be a competitive antagonist of adenosine we studied the effect of caffeine on the outcome of dipiridamole- 201 Tl cardiac imaging in one patient. During caffeine abstinence dipyridamole induced myocardial ischemia with down-slope ST depressions on the ECG, and reversible perfusion defects on the scintigrams. When the test was repeated 1 wk later on similar conditions, but now shortly after infusion of caffeine (4 mg/kg), the ECG showed nodepressions, and the scintigrams only slight signs of ischemia. We conclude that when caffeine abstinence is not sufficient, the widespread use of coffee and related products may be responsible for false-negative findings in dipyridamole-201Tl cardiac imaging

  15. Effects of two doses of glucose and a caffeine-glucose combination on cognitive performance and mood during multi-tasking.

    Science.gov (United States)

    Scholey, Andrew; Savage, Karen; O'Neill, Barry V; Owen, Lauren; Stough, Con; Priestley, Caroline; Wetherell, Mark

    2014-09-01

    This study assessed the effects of two doses of glucose and a caffeine-glucose combination on mood and performance of an ecologically valid, computerised multi-tasking platform. Following a double-blind, placebo-controlled, randomised, parallel-groups design, 150 healthy adults (mean age 34.78 years) consumed drinks containing placebo, 25 g glucose, 60 g glucose or 60 g glucose with 40 mg caffeine. They completed a multi-tasking framework at baseline and then 30 min following drink consumption with mood assessments immediately before and after the multi-tasking framework. Blood glucose and salivary caffeine were co-monitored. The caffeine-glucose group had significantly better total multi-tasking scores than the placebo or 60 g glucose groups and were significantly faster at mental arithmetic tasks than either glucose drink group. There were no significant treatment effects on mood. Caffeine and glucose levels confirmed compliance with overnight abstinence/fasting, respectively, and followed the predicted post-drink patterns. These data suggest that co-administration of glucose and caffeine allows greater allocation of attentional resources than placebo or glucose alone. At present, we cannot rule out the possibility that the effects are due to caffeine alone Future studies should aim at disentangling caffeine and glucose effects. © 2014 The Authors. Human Psychopharmacology: Clinical and Experimental published by John Wiley & Sons, Ltd.

  16. Studies of action of heavy metals on caffeine degradation by ...

    African Journals Online (AJOL)

    Caffeine is an important naturally occurring compound that can be degraded by bacteria. Excessive caffeine consumption is known to have some adverse problems. Previously, Leifsonia sp. strain SIU capable of degrading caffeine was isolated from agricultural soil. The bacterium was tested for its ability to degrade caffeine ...

  17. Consumer Behavior

    NARCIS (Netherlands)

    Hoyer, W.D.; MacInnis, D.J.; Pieters, R.

    2013-01-01

    CONSUMER BEHAVIOR combines a foundation in key concepts from marketing, psychology, sociology, and anthropology with a highly practical focus on real-world applications for today's business environment. The new edition of this popular, pioneering text incorporates the latest cutting-edge research

  18. Review of methodologies and polices for evaluation of energy efficiency in high energy-consuming industry

    International Nuclear Information System (INIS)

    Li, Ming-Jia; Tao, Wen-Quan

    2017-01-01

    Highlights: • The classification of the industrial energy efficiency index has been summarized. • The factors of energy efficiency and their implement in industries are discussed. • Four main evaluation methodologies of energy efficiency in industries are concluded. • Utilization of the methodologies in energy efficiency evaluations are illustrated. • Related polices and suggestions based on energy efficiency evaluations are provided. - Abstract: Energy efficiency of high energy-consuming industries plays a significant role in social sustainability, economic performance and environmental protection of any nation. In order to evaluate the energy efficiency and guide the sustainability development, various methodologies have been proposed for energy demand management and to measure the energy efficiency performance accurately in the past decades. A systematical review of these methodologies are conducted in the present paper. First, the classification of the industrial energy efficiency index has been summarized to track the previous application studies. The single measurement indicator and the composite index benchmarking are highly recognized as the modeling tools for power industries and policy-making in worldwide countries. They are the pivotal figures to convey the fundamental information in energy systems for improving the performance in fields such as economy, environment and technology. Second, the six factors that influence the energy efficiency in industry are discussed. Third, four major evaluation methodologies of energy efficiency are explained in detail, including stochastic frontier analysis, data envelopment analysis, exergy analysis and benchmarking comparison. The basic models and the developments of these methodologies are introduced. The recent utilization of these methodologies in the energy efficiency evaluations are illustrated. Some drawbacks of these methodologies are also discussed. Other related methods or influential indicators

  19. Monkey liver cytochrome P450 2C9 is involved in caffeine 7-N-demethylation to form theophylline.

    Science.gov (United States)

    Utoh, Masahiro; Murayama, Norie; Uno, Yasuhiro; Onose, Yui; Hosaka, Shinya; Fujino, Hideki; Shimizu, Makiko; Iwasaki, Kazuhide; Yamazaki, Hiroshi

    2013-12-01

    Caffeine (1,3,7-trimethylxanthine) is a phenotyping substrate for human cytochrome P450 1A2. 3-N-Demethylation of caffeine is the main human metabolic pathway, whereas monkeys extensively mediate the 7-N-demethylation of caffeine to form pharmacological active theophylline. Roles of monkey P450 enzymes in theophylline formation from caffeine were investigated using individual monkey liver microsomes and 14 recombinantly expressed monkey P450 enzymes, and the results were compared with those for human P450 enzymes. Caffeine 7-N-demethylation activity in microsomes from 20 monkey livers was not strongly inhibited by α-naphthoflavone, quinidine or ketoconazole, and was roughly correlated with diclofenac 4'-hydroxylation activities. Monkey P450 2C9 had the highest activity for caffeine 7-N-demethylation. Kinetic analysis revealed that monkey P450 2C9 had a high Vmax/Km value for caffeine 7-N-demethylation, comparable to low Km value for monkey liver microsomes. Caffeine could dock favorably with monkey P450 2C9 modeled for 7-N-demethylation and with human P450 1A2 for 3-N-demethylation. The primary metabolite theophylline was oxidized to 8-hydroxytheophylline in similar ways by liver microsomes and by recombinant P450s in both humans and monkeys. These results collectively suggest a high activity for monkey liver P450 2C9 toward caffeine 7-N-demethylation, whereas, in humans, P450 1A2-mediated caffeine 3-N-demethylation is dominant.

  20. Caffeine Citrate Dosing Adjustments to Assure Stable Caffeine Concentrations in Preterm Neonates.

    Science.gov (United States)

    Koch, Gilbert; Datta, Alexandre N; Jost, Kerstin; Schulzke, Sven M; van den Anker, John; Pfister, Marc

    2017-12-01

    To identify dosing strategies that will assure stable caffeine concentrations in preterm neonates despite changing caffeine clearance during the first 8 weeks of life. A 3-step simulation approach was used to compute caffeine doses that would achieve stable caffeine concentrations in the first 8 weeks after birth: (1) a mathematical weight change model was developed based on published weight distribution data; (2) a pharmacokinetic model was developed based on published models that accounts for individual body weight, postnatal, and gestational age on caffeine clearance and volume of distribution; and (3) caffeine concentrations were simulated for different dosing regimens. A standard dosing regimen of caffeine citrate (using a 20 mg/kg loading dose and 5 mg/kg/day maintenance dose) is associated with a maximal trough caffeine concentration of 15 mg/L after 1 week of treatment. However, trough concentrations subsequently exhibit a clinically relevant decrease because of increasing clearance. Model-based simulations indicate that an adjusted maintenance dose of 6 mg/kg/day in the second week, 7 mg/kg/day in the third to fourth week and 8 mg/kg/day in the fifth to eighth week assures stable caffeine concentrations with a target trough concentration of 15 mg/L. To assure stable caffeine concentrations during the first 8 weeks of life, the caffeine citrate maintenance dose needs to be increased by 1 mg/kg every 1-2 weeks. These simple adjustments are expected to maintain exposure to stable caffeine concentrations throughout this important developmental period and might enhance both the short- and long-term beneficial effects of caffeine treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Caffeine and performance over consecutive days of simulated competition.

    Science.gov (United States)

    Stadheim, Hans Kristian; Spencer, Matthew; Olsen, Raymond; Jensen, Jørgen

    2014-09-01

    Performance improvements after caffeine (CAF) ingestion are well documented when using a 1-d protocol. In numerous competitions such as the Tour de France, Tour de Ski, world championships, and National College Athletic Association championships, athletes compete for several days in a row. To date, no studies have investigated the effects of CAF when competing for consecutive days in a row. This study aimed to investigate the effects of placebo (PLA) and two different CAF doses (3 and 4.5 mg·kg body mass) on performance in a 10-min all-out, cross-country, double poling ergometer test (C-PT) 2 d in a row. Eight highly trained male cross-country skiers (V˙O2max-run, 78.5 ± 1.6 mL·kg·min) participated in the study, which was a randomized, double-blind, PLA-controlled, crossover design. Performance was assessed as distance covered during a 10-min all-out C-PT. Oral ingestion of CAF or PLA was consumed 75 min before the all-out C-PT. Poling distance was improved after CAF ingestions compared with that after PLA on both days. The improvements on day 1 were 4.0% (90% confidence limits, ±3.3) and 4.0% ± 2.9% for both CAF doses, respectively (P performance was associated with increased HR, adrenaline concentration, blood lactate concentration, and V˙O2 consumption after CAF ingestion. Furthermore, performance was elevated despite higher creatine kinase concentration and muscular pain at arrival on day 2 for both CAF doses. Both CAF doses improved performance in the 10-min all-out C-PT compared with PLA over two consecutive days. Therefore, CAF seems useful for athletes competing over consecutive days despite higher muscle damage occurring after enhanced performance on the first day.

  2. [Severe caffeine poisoning with rhabdomyolysis].

    Science.gov (United States)

    Wolter, J; Grün, D; Otto, S

    2018-04-01

    We report the case of a young man who took a large amount of caffeine powder dissolved in water in a suicide attempt. He was found comatose. The initial diagnosis was difficult. In hospital he suffered from rhabdomyolysis with renal failure and sepsis rapidly developed. After renal replacement treatment with hemodialysis, long-term artificial ventilation with tracheotomy and a 3‑week stay in the intensive care unit, the patient could be discharged to a rehabilitation center.

  3. Caffeine and Cannabis Effects on Vital Neurotransmitters and Enzymes in the Brain Tissue of Juvenile Experimental Rats.

    Science.gov (United States)

    Owolabi, J O; Olatunji, S Y; Olanrewaju, A J

    2017-05-01

    Caffeine and cannabis are globally consumed and abused psychoactive substances. While caffeine is legally used in various forms, including in tea and coffee as beverages, it is also consumed in soda and energy drinks as additives. Cannabis, on the other hand, is considered illegal in most countries; albeit, it is being consumed globally particularly by adolescents. The adolescent stage marks a critical stage of brain development and maturation. Influences of agents on the brain at this stage may affect neuronal structural and functional attr