Do energy drinks contain active components other than caffeine?

Acute effects of energy drink consumption on microvascular reactivity in young male volunteers at rest: a randomized trial

Energy drinks are nonalcoholic beverages whose main ingredients are sugar, taurine, and caffeine. The consumption of energy drinks is increasing worldwide, but only a few conflicting studies have investigated the vascular effects of energy drinks in young adults. The aim of this study was to evaluate microvascular reactivity before and after energy drinks consumption in young healthy male volunteers. This was a cross-sectional prospective study. Microvascular reactivity signals were evaluated in the skin of the forearm using laser speckle contrast imaging with acetylcholine (ACh) iontophoresis before and 90 and 180 min after the randomized consumption of one ED or the same volume of water (control), followed by a postocclusive reactive hyperemia (PORH) test. Thirty-two volunteers were evaluated (age: 25.4±4.3 years). Energy drink consumption prevented the rest-induced reduction in cutaneous vascular conductance over time that was observed in the control group. In the control group, there were significant reductions in microvascular vasodilation at 90 and 180 min compared to baseline (P=0.004), but this was not the case in the energy drink group (P=0.76). Our results demonstrated that the reduction in microvascular conductance associated with prolonged immobility can be prevented by the consumption of one energy drink, highlighting the vasodilator effects of this beverage in young individuals at rest. The between-study variability in terms of the brand of energy drinks and the ingested volume, as well as the method of vascular evaluation and the inclusion criteria, may explain the discrepancies among previous studies on the vascular effects of energy drinks.

B Vitamins, Glucoronolactone and the Immune System: Bioavailability, Doses and Efficiency

The present review deals with two main ingredients of energy/power drinks: B vitamins and glucuronolactone and their possible effect on the immune system. There is a strong relationship between the recommended daily dose of selected B vitamins and a functional immune system. Regarding specific B vitamins: (1) Riboflavin is necessary for the optimization of reactive oxygen species (ROS) in the fight against bacterial infections caused by Staphylococcus aureus and Listeria monocytogenes. (2) Niacin administered within normal doses to obese rats can change the phenotype of skeletal fibers, and thereby affect muscle metabolism. This metabolic phenotype induced by niacin treatment is also confirmed by stimulation of the expression of genes involved in the metabolism of free fatty acids (FFAs) and oxidative phosphorylation at this level. (3) Vitamin B5 effects depend primarily on the dose, thus large doses can cause diarrhea or functional disorders of the digestive tract whereas normal levels are effective in wound healing, liver detoxification, and joint health support. (4) High vitamin B6 concentrations (>2000 mg per day) have been shown to exert a significant negative impact on the dorsal root ganglia. Whereas, at doses of approximately 70 ng/mL, sensory symptoms were reported in 80% of cases. (5) Chronic increases in vitamin B12 have been associated with the increased incidence of solid cancers. Additionally, glucuronolactone, whose effects are not well known, represents a controversial compound. (6) Supplementing with D-glucarates, such as glucuronolactone, may help the body's natural defense system function better to inhibit different tumor promoters and carcinogens and their consequences. Cumulatively, the present review aims to evaluate the relationship between the selected B vitamins group, glucuronolactone, and the immune system and their associations to bioavailability, doses, and efficiency.

Knowledge, attitude, and perception of energy drinks consumption among university students in Jordan

Energy drinks gained popularity after the launch of Red Bull in 1997. Different brands are now available and young adults mainly consume these drinks. This study assesses the knowledge, attitude, and perception of energy drink consumption among university students in Jordan. A validated online survey was used to collect the required data, extracted from Google Forms into an Excel spreadsheet and statistically analysed using Statistical Package for Social Sciences version 24.0. A nationally representative sample of university students with a mean age of 22⋅2 ± 3⋅9 years (n 749) was obtained. The participating students demonstrated a neutral level of knowledge about energy drinks, as the mean score of knowledge = 7⋅1 ± 2⋅2 (out of 12), with 66 % (n 498) of them having consumed energy drinks and experienced their effects. Generally, the study's participants demonstrated a neutral attitude towards energy drinks and 70⋅5 % (n 528) acknowledged that energy drinks increase activity, but more than 70 % of them believed that energy drinks have harmful side effects. It was found that there is a significant (P-value <0⋅5) positive correlation between knowledge score and female gender, studying a medical major, and monthly income. The main reasons for consuming energy drinks were reported to be: to stay awake for longer, help study, and become more energetic. There is a need for more structured awareness campaigns to warn students about the possible side effects of these products in order to reduce the consumption and popularity of these drinks among students.

Caffeinated non-alcoholic beverages on the postpartum mental health related to the COVID-19 pandemic by a cross-sectional study in Argentina

Purpose

This work aimed to study postpartum mental outcomes and determinants of the intake of caffeinated beverages during the pandemic in women from Argentina.

Methods

This cross-sectional study recruited 619 women who responded to online self-report questionnaires during the first and second waves of COVID-19, including validated instruments (Insomnia Severity Index, Perceived Stress Scale, Postpartum Depression Screening Scale, Memory Complaint Scale, and Breastfeeding Self-Efficacy Scale), and general data. Intake frequency and amount of caffeinated beverages were estimated. Multivariate regression and structural equation models identified associations and effects (p < 0.05).

Results

Women were under social restrictions for 60.39 days, with home and essential activities increasing caffeinated intake. They ingested (mL/d): yerba mate (1457.71), coffee (66.85), tea (67.61), and soft drinks (50.95), which provided 646.20 mg/d of caffeine. Intakes of coffee and yerba mate were higher than pre-pandemic ones. Coffee was positively associated with stress and insomnia, and indirectly linked to higher levels of depression and memory complaints, and lower breastfeeding self-efficacy. Tea showed a similar but weaker association. Yerba mate correlated inversely with depression (through direct pathways), insomnia, and memory complaints (through indirect pathways), promoting breastfeeding self-efficacy. Soft drinks and caffeine did not present significant associations.

Conclusion

Although findings do not imply causation, results suggest that beverages would exhibit caffeine-independent affective and cognitive roles, which might be anxiogenic in the case of coffee and tea (to a lesser extent). Yerba mate showed antidepressant potential. Given that breastfeeding might be compromised during the pandemic, yerba mate intake is promissory to protect postpartum mental health.

Awake and Alert: Examining the Portrayal of Energy Drinks on TikTok

PURPOSE

Energy drinks (EDs) are not recommended for minors' consumption due to a myriad of health risks, but marketing initiatives persist. This study explored the promotion of EDs on TikTok, a platform frequented by children and adolescents.

METHODS

197 highly viewed videos from the four top ED-related hashtags on TikTok were coded for engagement variables, user information, sponsorship status, video content, and sentiment toward EDs.

RESULTS

Of the 197 videos analyzed (combined 70 + million views), 29% disclosed sponsorship and 22% featured a child/adolescent. ED consumption appeared in 46% of videos, with 15% depicting hazardous consumption. Most videos (67%) had a positive sentiment toward EDs.

DISCUSSION

ED-related TikTok videos are positively framed, have high engagement, and are not restricted for viewing by minors. As the platform's underage user-base grows, such videos may encourage heightened consumption. Given the known health risks, effective age-gated content restrictions are needed to reduce minors' exposure.

Formulations of selected Energy beverages promote pro-oxidant effects of ascorbic acid and long-term stability of hydrogen peroxide

Recently, autoxidation mediated by ascorbic acid (AA) and other ingredients, has been implicated in generation of hydrogen peroxide (H₂O₂) in so-called Energy beverages. Here, we report the use of cyclic voltammetry and the FOX assay to monitor at short and long incubation times, respectively, the production and stability of H₂O₂ generated by AA and redox-active ingredients. Levels of H₂O₂ in Energy drinks (36.5 ± 4.0 µM at 4 °C and 64.2 ± 7.6 µM at 20 °C) were found to be stable or increased (p < 0.05) upon vessel opening. A predictive model for the production of H₂O₂ as a function of AA concentration, temperature and incubation time, and depending on ingredients present, indicated that H₂O₂ peaked at 91-726 µM after 1 day and declined to ∼ 42-60 µM (4 °C) or zero after ∼10 days. The research supports that levels of H₂O₂ in beverages containing anti-oxidant mixtures and dissolved oxygen should be monitored and formulations modified to avoid AA autoxidation.

Habits of Energy Drink Consumption among Teens in Slovenia - Focus Group Findings

Introduction

Teachers in Slovenia have been noticing the increased consumption of energy drinks among pupils. Therefore, the purpose of this study was to investigate habits that contribute to the frequency of energy drink consumption.

Method

36 teens participated in the study: elementary school pupils (6th and 8th grades), general upper secondary school pupils, and secondary technical school pupils (1st and 3rd year). In the course of the study 6 group interviews were held to help investigate young people’s habits and their reasons for energy drink purchase and consumption. Moreover, we investigated the influence of age on the consumption and knowledge about energy drink ingredients, as well as their influence on the body.

Results

Interview analysis showed that energy drink consumers are predominantly secondary school pupils. Their choice most frequently depends on the price, their taste, or the brand. What influences elementary school pupils’ purchasing decisions are price, packaging, and advertisements, while secondary school pupils choose their drinks according to the lack of energy and how tired they feel. The predominant factors preventing energy drink consumption are health problems among family members and friends. Secondary school pupils know more about energy drink ingredients than elementary school pupils.

Conclusion

On the basis of these findings, we will design a survey questionnaire for Slovenian teenagers and teachers, didactic material, and suggestions for improving educational programmes.

Effects of Caffeine and Caffeinated Beverages in Children, Adolescents and Young Adults: Short Review

The prevalence of ED consumption has increased over the past 10–15 years. Studies describing the effects of caffeine and caffeinated beverages show confusing results, so it seems important to regularly summarize the available facts, and in more detail. By a thorough analysis of more than 156 scientific papers, the authors describe the molecular background of absorption, as well as the positive and negative effects of different dosages of caffeine, just like its effects in physical activity and performance. ED and EDwA consumption is a regular habit of not only adults, but nowadays even of children and adolescents. There are no safe dosages described of caffeine or ED consumption for children. There are no positive short- or long-term effects of these compounds/products concerning developing brain functions, psycho-motor functions, or social development. Instead, there are many unpleasant side effects, and symptoms of regular or higher-dose ED consumption, especially at younger ages. This mini review describes many details of these unpleasant side effects, their severity, and motivations for consuming these compounds/products. In a quantitative research in Hungary (10–26 years, mean age: 15.6 ± 3.8 y, 1459 subjects, randomly chosen population), a survey based on a questionnaire asking people about their ED consumption habits was conducted. According to the data, 81.8% of the participants consumed EDs at least once, and 63.3% tried several products of the kind. A positive correlation was found between age and consumption (p < 0.001). The results show that a high proportion of this group often consumed EDwA, in many cases leading to harmful side-effects of caffeine overdose. In a sample of Hungarian high school and college students (17–26 years), ED consumption matched the international data, and only 19.7% of respondents did not use EDs at all (had never tasted an ED in their life).

Consumption Patterns of Energy Drinks in Adolescents and Their Effects on Behavior and Mental Health: A Systematic Review

The aim of the current review was to analyze primary studies about energy drink consumption patterns in adolescents and their relationship with mental health. PubMed, PLOS ONE, PsycINFO, and ScienceDirect databases were searched to identify articles related to adverse effects of energy drinks in adolescents and young adults aged 11 to 18 years. Psychological and behavioral measures were based on validated screening tools used in various contexts, and bias was detected in energy drink consumption patterns. In regard to sex, boys consumed more energy drinks than girls, and a strong, positive association was reported between consumption and probability of risky behaviors; tendency for anxiety, depression, and impulsivity; poor academic performance; and sleep disturbances. A progressive increase in consumption was also noted of 25% to 75% within 5 years. Findings suggest that standardized consumption pattern assessment be included in evaluations of mental health to determine potential causal relationships. [Journal of Psychosocial Nursing and Mental Health Services, xx(x), xx-xx.].

Effect of caffeine on alcohol drinking in mice

Mixing alcohol (ethanol) with caffeinated beverages continues to be a common and risky practice. Energy drinks are one type of caffeinated beverage that may be especially problematic when used as mixers, due to their relatively high caffeine content in combination with their highly sweetened flavor profile. The present study used a mouse model of limited-access drinking and lickometer circuitry to examine the effects of an energy drink anid its caffeine content on ethanol consumption. Predictably, the highly sweetened energy drink significantly increased ethanol intake compared to a plain ethanol solution (6.34 ± 0.2 vs. 5.01 ± 0.3 g/kg; Cohen's d = 1.79). Interestingly, adulterating a plain ethanol solution with the same concentration of caffeine (without sweetener) found in the energy drink also increased ethanol intake (5.47 ± 0.3 vs. 4.11 ± 0.3 g/kg; Cohen's d = 1.4). A lower concentration of caffeine was without effect on ethanol drinking. Interestingly, plain caffeine solutions at both tested concentrations provoked high numbers of bottle contacts, indicating that the mice found the solution palatable. These findings suggest that altering the bitterness profile of an ethanol solution with the addition of caffeine can increase intake in a similar manner as sweetening the solution. Further, the findings underscore the importance of taste in motivating ethanol consumption and the potential role that caffeine can have in this process.

Effects of Energy Drink Consumption on Physical Performance and Potential Danger of Inordinate Usage

The rise in energy drink (ED) intake in the general population and athletes has been achieved with smart and effective marketing strategies. There is a robust base of evidence showing that adolescents are the main consumers of EDs. The prevalence of ED usage in this group ranges from 52% to 68%, whilst in adults is estimated at 32%. The compositions of EDs vary widely. Caffeine content can range from 75 to 240 mg, whereas the average taurine quantity is 342.28 mg/100 mL. Unfortunately, exact amounts of the other ED elements are often not disclosed by manufacturers. Caffeine and taurine in doses 3–6 mg/kg and 1–6 g, respectively, appear to be the main ergogenic elements. However, additive or synergic properties between them seem to be implausible. Because of non-unified protocol design, presented studies show inconsistency between ED ingestion and improved physical performance. Potential side effects caused by abusive consumption or missed contraindications are the aspects that are the most often overlooked by consumers and not fully elucidated by ED producers. In this review, the authors aimed to present the latest scientific information on ED components and their possible impact on improving physical performance as well as to bring emphasis to the danger of inordinate consumption.

The Effects of Direct Red Bull Administration to Isolated Hearts of Trained and Untrained Rats Who Regularly Consumed or Did Not Consume Energy Drink: Focus on Cardiodynamics and Oxidative Stress

Energy drinks (EDs) contain caffeine and other active ingredients which affect cardiovascular system. The aims of this study were to examine direct effects of Red Bull (RB) on cardiodynamics and oxidative stress in isolated hearts of rats. The rats were divided into four groups: untrained rats who never consumed ED (dEDUT); untrained rats who consumed ED 5 days a week during 4 weeks (ch+dED-UT); rats trained 5 times a week for 4 weeks, but did not consume ED (dED-T); rats trained and consumed ED 5 times a week for 4 weeks (ch+dED-T). After sacrificing, hearts were isolated and perfused according to Langendorff technique. Through the isolated heart of all rats in each group, RB was administered. The parameters of cardiac function were recorded, and the levels of prooxidants were measured in the coronary effluent during coronary autoregulation. Rats in ch+dED-UT group had significantly lower rates of myocardial contraction and relaxation compared to rats in dED-UT group. The same effect was recorded in the dED-T group compared to dED-UT group. The levels of hydrogen peroxide were significantly higher in trained rats. Rats in ch+dED-T group also had significantly higher levels of superoxide anion radical and index of lipid peroxidation, as well as lower levels of nitrites when compared to ch+dED-UT group, while opposite effect was recorded in rats in dED-T group compared to dEDUT group. The RB could have a potentially negative inotropic effect in chronic consumers. Prooxidative effect of RB was most pronounced in trained chronic consumers.

Knowledge and prevalence of energy drinks consumption in Shanghai, China: a cross-sectional survey of adolescents

Background

In recent years, energy drinks (EDs) have been widely used among young people around the world. The extensive use of EDs also affects the sleep and exercise of adolescents.

Aims

This study aimed to investigate the consumption of EDs, the knowledge, attitude towards EDs and associated factors of EDs consumption among adolescents in Shanghai, China.

Methods

A total of 4608 adolescents completed a self-administered questionnaire assessing EDs use history, knowledge and attitude towards EDs. Adolescent Self-rating Life Events Checklist (ASLEC) was used to assess their life events. All participants were divided into two groups based on whether they used them or not. t-test and χ² test were used to compare the differences between the two groups, and binary logistic regression analysis was used to investigate the related factors for EDs consumption.

Results

70.5% of the participants reported having ever used EDs. The main avenues to getting information on EDs were from advertisements. 67.56% of them believed that EDs had adverse effects on health. 22.09% of the participants and 31.55% of their parents took a negative attitude towards EDs. Compared with the non-consumption group, participants in the consumption group were likely to be male, with older age, identified EDs more correctly and did not believe EDs had adverse effects, with more positive attitude and higher ASLEC score. Logistic regression results showed that gender, age, attitude of parents and themselves, knowledge of EDs and ASLEC score significantly predicted EDs consumption.

Conclusion

EDs consumption was popular among adolescents in Shanghai, and the tailored intervention programmes need to be developed based on the characteristics of adolescents.

Energy Drink Doses of Caffeine and Taurine Have a Null or Negative Effect on Sprint Performance

Jeffries, O, Hill, J, Patterson, SD, and Waldron, M. Energy drink doses of caffeine and taurine have a null or negative effect on sprint performance. J Strength Cond Res 34(12): 3475-3481, 2020-This study investigated the effects of caffeine and taurine coingestion on repeat-sprint cycling performance and associated physiological and perceptual responses. In a double-blind, cross-over, repeated measures study, 11 male subjects (age 21 ± 2 years; stature 178 ± 7 cm; body mass 80 ± 13 kg) completed 10 × 6-second sprints on a cycle ergometer, each separated by 24 seconds, one hour after ingesting: caffeine (80 mg) and taurine (1 g), equivalent to the amount observed in popular commercial energy drinks, or placebo (maltodextrin ∼1 g) in a gelatine capsule. Performance was measured on a cycle ergometer, whereas blood lactate concentration (B[la]), rating of perceived exertion (RPE), and heart rate (HR) were measured at baseline (pre-exercise) and after sprints 5 and 10. Magnitude-based inferences revealed likely, trivial differences in peak power and unclear, trivial intersprint fatigue index after ingestion of the caffeine and taurine supplement. Intrasprint fatigue was greater in the caffeine and taurine condition at sprint 10 (likely, small) and possibly smaller in sprints 6-9. The caffeine and taurine supplement had a likely large effect on HR at baseline (effect size = 0.94) and increases in B[la] after sprints 5 (likely small) and 10 (possibly small). There was no effect of the supplement on RPE (unclear, trivial). Administration of caffeine and taurine at doses equivalent to commercial energy drinks did not improve repeat-sprint cycling performance and seemed to induce greater fatigue within selected sprints, particularly at the end of the trial. This undesirable performance effect occurs in parallel with increased HR and glycolytic metabolic bi-products.

Energy Drinks and Sports Performance, Cardiovascular Risk, and Genetic Associations; Future Prospects

The consumption of energy drinks (e.g., containing caffeine and taurine) has increased over the last decade among adolescents and athletes to enhance their cognitive level and improve intellectual and athletic performance. Numerous studies have shown that drinking moderate doses of such drinks produces beneficial effects, as they considerably boost the sporting performance of elite athletes in various sports, including both endurance and explosive events. However, apart from their ergogenic effects, the regular consumption of energy drinks also increases blood pressure and consequently incites problems such as hypertension, tachycardia, and nervousness, all of which can lead to cardiovascular disorders. A potential positive correlation between genetics and the moderate consumption of energy drinks and athletic performance has recently been reported; notwithstanding, a better understanding of the genetic variants involved in metabolism is a key area for future research to optimize the dose of energy drink consumed and obtain the maximal ergogenic effect in elite sports. The aim of this literature review, therefore, is to present the results of recent studies, classifying them according to the differences in the associations between energy drinks and: (i) Athletic performance; (ii) cardiovascular risk factors while practicing sports; and (iii) genetic associations and future prospects between the consumption of energy drinks and performance.

Deep Eutectic Solvents Based on Natural Ascorbic Acid Analogues and Choline Chloride

Deep eutectic solvents (DES) are one of the most promising green technologies to emerge in recent years given their combination of environmentally friendly credentials and useful functionalities. Considering the continued search for new DES - especially those that exemplify the aforementioned characteristics, we report the preparation of DES based on natural analogues of l-ascorbic acid for the first time. The onset of eutectic melting occurred at temperatures far below the melting point of the individual components and resulted in the generation of glass forming fluids with glass transition temperatures, viscosities and flow behavior that are comparable to similar systems. This work expands the current array of DES that can be produced using naturally occurring components, which given their potential to be bio-derived, interesting physicochemical properties (e. g. propensity to supercool and vitrify) and apparent antibacterial nature, may provide utility within a range of applications.

Energy drinks consumption and perceptions among University Students in Beirut, Lebanon: A mixed methods approach

Background

Energy drinks (ED) are caffeine- and sugar-rich beverages with other ingredients that are marketed for their energy-boosting and performance-enhancing effects. The consumption of these drinks, with and without alcohol, is dramatically increasing worldwide, despite the reported side effects and potential harms to consumers. Few studies, to date, have explored the perceptions and experiences of young adults towards these beverages.

Objective

The present study aimed to explore the consumption patterns and correlates of ED consumption, as well as the perceptions and experiences of university students in Lebanon towards these beverages.

Methods

A sequential explanatory mixed-methods approach was adopted. Data collection was conducted in two private universities in Beirut, Lebanon. A self-administered 36-item quantitative survey was first used to explore the prevalence and correlates of ED consumption among a convenience sample of university students (n = 226). The survey included questions related to socio-demographic characteristics, anthropometric measurements, and other lifestyle behaviors, including physical activity of university students. The subsequent qualitative phase consisted of focus group discussions (FGD) conducted to further examine the perceptions and experiences of university students towards ED. Descriptive statistics and logistic regression analyses were conducted using survey data, whereas the transcribed FGD were analyzed thematically.

Results

A total of 226 university students completed the survey. Results showed that 45% of survey respondents consumed ED at least once in their life (ever consumers), among which 30% reported consumption of ED mixed with alcohol (AmED). Adjusting for socio-demographic and anthropometric characteristics, coffee and sports drinks consumption were significantly associated with ED (OR = 2.45, 95% CI = 1.20, 5.00, and OR = 4.88, 95%CI = 2.41, 9.88, respectively). In addition, physically active participants were 1.89 times (95%CI = 1.01, 3.51) more likely to consume ED compared to their inactive counterparts. During the qualitative phase, a total of six FGD were conducted with 29 university students, who reported consuming ED at least once per month. Three main themes were derived reflecting individual-, interpersonal/social- and environmental-level factors affecting ED consumption among university students. These themes were further supported by eight subthemes, including: perceived benefits of ED, experienced side effects, misinformation about content of ED, peer pressure and social image, as well as affordability and accessibility of ED.

Conclusion

Findings highlight the need for public health policies and programs to curb the growing public health phenomenon of ED consumption amongst university students. Such programs should consider the multi-level factors affecting ED consumption at the individual, interpersonal/social, and environmental levels, including educational campaigns on ED potential harms, regulating ED content and labeling, as well as restricting sales and marketing of these beverages, especially among young consumers.

Supplemental taurine during adolescence and early adulthood has sex-specific effects on cognition, behavior and neurotransmitter levels in C57BL/6J mice dependent on exposure window

The mammalian brain goes through final maturation during late adolescence and early adulthood with sex differences in timing. The key cellular processes, including changes in neurotransmitter receptor density and synaptic pruning, make this age uniquely vulnerable to neurotoxic insults. Teenagers and young adults are the major consumers of energy drinks, which contain high levels of taurine and caffeine. Taurine is one of the most abundant amino acids in the central nervous system, but the effects of supplemental taurine consumption during adolescence has not been well studied. We conducted an initial short-term exposure study with 0.12% taurine in drinking water and a long-term exposure dose-response study using 0.06 and 0.12% taurine in male and female C57BL/6J mice. We examined a broad range of cognitive functions and behaviors and measured neurotransmitter levels. We found no significant differences in anxiety, open field locomotor activity, or sensorimotor gating. However, we found impairments in novel object recognition and sex differences in Morris water maze. When taurine treatment stopped before behavioral experiments began, male mice had significant impairments in spatial learning and memory. In the dose-response study when taurine treatment continued throughout behavioral experiments, females had significant impairments. We also found sex differences in neurotransmitter levels with females having higher levels of glutamate, DOPAC and 5-HIAA. We conclude that both females and males are at risk from excess taurine consumption during final brain maturation.

Assessment of Antioxidant Properties of Classic Energy Drinks in Comparison with Fruit Energy Drinks

Energy drinks (EDs) contain sugar, caffeine, and other bioactive compounds. Recently, new types of EDs, enriched with fruit juices, natural pigments, and plant extracts, have been launched in the market. The objective of this study was to investigate the composition and antioxidant properties of the most popular classic and fruit EDs. The study was carried out including 24 of the most popular energy drinks (classic and fruit EDs). The composition of EDs, especially caffeine and sugar, and antioxidant properties (antioxidant capacity, total polyphenols, total anthocyanins, vitamin C) were analyzed. Energy drinks with added fruit juice or natural pigments had a significantly higher (p ≤ 0.05) antioxidant capacity compared to classic energy drinks. Fruit EDs had a higher concentration of polyphenols and vitamin C. In some fruit EDs, slight amounts of anthocyanins were found. Generally, EDs are not a rich source of polyphenols and are not distinguished by high antioxidant capacity. However, fruit energy drinks and/or ones with added natural pigments have much better antioxidant properties than classic EDs. Both classic and fruit EDs contain a large amount of caffeine and sugar, therefore, it would be advisable not to drink large amounts of EDs for possible related health issues.

Why are caffeinated alcoholic beverages especially risky?

PURPOSE

Evidence suggests that people drink more alcohol and experience more adverse alcohol-related consequences (ARCs) on occasions when they also consume caffeine. The current study examined whether this increase in risk is a result of caffeine attenuating the subjective effects of alcohol intoxication (i.e., the masking hypothesis).

METHODS

Undergraduate students (n = 148) reported their drinking patterns using a modified Timeline Followback approach. For each recalled drinking occasion, alcohol consumption, caffeine consumption, perceived blood alcohol concentration, and ARCs were assessed. Generalized linear mixed models were used to examine the influence that alcohol and caffeine consumption had on perceived intoxication and the experience of ARCs.

RESULTS

At the occasion level, greater caffeine consumption was associated with increased consumption of alcohol and increased ARCs. There was also a significant curvilinear relationship between the amount of alcohol consumed and perceived intoxication, such that the more alcohol was consumed on each occasion the less each additional drink increased perceived intoxication. Increased caffeine consumption weakened the association between alcohol consumption and perceived intoxication and it also weakened the association between alcohol consumption and ARCs. Specifically, the weakest relationship between ARCs and alcohol consumption existed at the highest level of caffeine consumption (240+ mg). Caffeine increased subjective intoxication.

CONCLUSIONS

These findings do not support the masking hypothesis. Caffeine was strongly associated with ARCs when consumed at high doses and this effect does not appear to be the result of drinking more alcohol or underestimating one's blood alcohol content. Efforts to reduce caffeinated alcohol beverage use are greatly needed.

Relationships between use of dietary supplements, caffeine and sensation seeking among college students

Objective: Caffeine and dietary supplement (DS) use by college students is not well-documented. Given reported associations between energy drink consumption and sensation seeking, we used the Sensation Seeking Scale Form V (SSS-V) to assess relationships between sensation-seeking, caffeine, and DS use. Participants: Data from 1,248 college students from five US institutions were collected from 2009 to 2011. Methods: Linear regression was used to examine relationships between scores on the SSS-V and caffeine and DS use, demographic, and lifestyle characteristics. Results: Male sex, nonHispanic race-ethnicity, higher family income, tobacco use, consuming caffeinated beverages, more than 400 mg caffeine per day, and energy drinks with alcohol at least 50% of the time, were significantly associated with higher total SSS-V scores (P < 0.001). Those using protein DSs had higher total, disinhibition, and boredom susceptibility SSS-V scores (Ps < 0.001). Conclusions: Results demonstrate a positive correlation between sensation-seeking attitudes and habitual caffeine, energy drink, and DS consumption.

Risk assessment of energy drinks with focus on cardiovascular parameters and energy drink consumption in Europe

To assess the possible cardiovascular risks associated with energy drink (ED) consumption in Europe, a comprehensive literature research was performed in regard to (i) possible ED-induced dose-dependent cardiovascular outcomes, (ii) ED consumption patterns in Europe and (iii) the risks of EDs in combination with alcohol. The identified intervention studies primarily investigated acute ED effects in young healthy adults. Moderate consumption of EDs corresponding to an acute caffeine intake of up to 200 mg did not result in clinically relevant cardiovascular changes in young healthy adults. However, high intake of EDs (about 1 L) was associated with moderate to severe adverse effects in some participants (i.a. prolonged QTc interval, palpitations). Studies have indicated that on some occasions, a substantial proportion of ED consuming children and adolescents (12% in 16 EU Member States) drink EDs in high quantities (≥1 L). This could pose a possible health risk to this group since adverse effects by such high ED consumption have been observed already in young healthy adults. Among further measures that might be considered to minimize this identified risk, policy makers could develop information and educational programs with the aim of raising public awareness.

Hacking the Brain: Dimensions of Cognitive Enhancement

In an increasingly complex information society, demands for cognitive functioning are growing steadily. In recent years, numerous strategies to augment brain function have been proposed. Evidence for their efficacy (or lack thereof) and side effects has prompted discussions about ethical, societal, and medical implications. In the public debate, cognitive enhancement is often seen as a monolithic phenomenon. On a closer look, however, cognitive enhancement turns out to be a multifaceted concept: There is not one cognitive enhancer that augments brain function per se, but a great variety of interventions that can be clustered into biochemical, physical, and behavioral enhancement strategies. These cognitive enhancers differ in their mode of action, the cognitive domain they target, the time scale they work on, their availability and side effects, and how they differentially affect different groups of subjects. Here we disentangle the dimensions of cognitive enhancement, review prominent examples of cognitive enhancers that differ across these dimensions, and thereby provide a framework for both theoretical discussions and empirical research.

Differential Effects of Caffeine on Motor and Cognitive Outcomes of Penetrating Ballistic-Like Brain Injury

This study assessed the effect of caffeine on neurobehavioral recovery in the WRAIR penetrating ballistic-like brain injury (PBBI) model. Unilateral frontal PBBI was produced in the right hemisphere of anesthetized rats at moderate (7%-PBBI) or severe (10%-PBBI) injury levels. Animals were randomly assigned to pretreatment groups: acute caffeine (25 mg/kg CAF gavage, 1 h prior to PBBI), or chronic caffeine (0.25 g/L CAF drinking water, 30 days prior to PBBI). Motor function was evaluated on the rotarod at fixed-speed increments of 10, 15, and 20 RPM. Cognitive performance was evaluated on the Morris water maze. Acute caffeine showed no significant treatment effect on motor or cognitive outcome. Acute caffeine exposure prior to 10%-PBBI resulted in a significantly higher thigmotaxic response compared to vehicle-PBBI groups, which may indicate caffeine exacerbates post-injury anxiety/attention decrements. Results of the chronic caffeine study revealed a significant improvement in motor outcome at 7 and 10 days post-injury in the 7%-PBBI group. However, chronic caffeine exposure significantly increased the latency to locate the platform in the Morris water maze task at all injury levels. Results indicate that chronic caffeine consumption prior to a penetrating TBI may provide moderate beneficial effects to motor recovery, but may worsen the neurocognitive outcome.

Attentional and working memory performance following alcohol and energy drink: A randomised, double-blind, placebo-controlled, factorial design laboratory study

Alcohol mixed with energy drinks (AMED) studies have typically not shown antagonism of acute alcohol effects by energy drink (ED), particularly over relatively short time frames. This study investigated the effects of alcohol, ED, and AMED on attentional and working memory processes over a 3 h period. Twenty-four young adults took part in a randomised, double-blind, placebo-controlled, factorial, 4-arm study. They were administered 0.6g/kg alcohol and 250 ml ED (containing 80 mg caffeine), and matching placebos alone and in combination. A battery of attentional and working memory measures was completed at baseline then 45, 90 and 180 min post-treatment. Alcohol produced a characteristic shift in speed/accuracy trade-off, having little effect on reaction times while increasing errors on all attentional measures (4-choice Reaction Time, Number Pairs and Visual Search), as well as a composite Attentional error score and one working memory task (Serial Sevens). ED alone improved two working memory measures (Memory Scanning accuracy and Digit-Symbol reaction times) and improved speed of responding on a composite Working Memory score. There was no consistent pattern of AMED vs. alcohol effects; AMED produced more errors than alcohol alone on one attentional measure (Visual Search errors) at 45 min only whereas AMED resulted in fewer errors on the Serial Sevens task at 90 min and better Digit-Symbol accuracy and reaction time at 45 min. Alcohol consumption increases error rate across several attentional and working memory processes. Mutual antagonism between alcohol and ED showed no consistent pattern and likely reflects a complex interaction between caffeine and alcohol levels, phase of the blood alcohol limb, task domain and cognitive load.

The Impact of Coffee and Caffeine on Multiple Sclerosis Compared to Other Neurodegenerative Diseases

Background: The literature concerning the effect of coffee and caffeine on Multiple Sclerosis (MS) with focus on fatigue is investigated in this review. Potentially clinically relevant effects were also assessed in studies concerning comparable neurodegenerative diseases, such as Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). Since the existing studies obtained very inconclusive results, we systematically reviewed these studies to summarize the evidence on the possible effects of coffee and caffeine on those disease entities. Previous studies suggested that coffee and caffeine intake is associated with a reduced risk of developing MS and other neurological diseases.

Methods: The PubMed database was searched using the keywords “coffee” OR “caffeine” in combination with keywords for each of the different diseases. Besides the keyword search, we included studies by reference list search. Studies on the effects of coffee and caffeine on the single neurological diseases were included for this review. A total of 51 articles met our inclusion criteria. The reviewed articles assessed the impact of coffee and caffeine on the susceptibility for neurological diseases, as well as the effect of coffee and caffeine on disease progression and possible symptomatic effects like on performance enhancement.

Results: Higher intake of coffee and caffeine was associated with a lower risk of developing PD. In some of the MS studies there, is evidence for a similar effect and experimental studies confirmed the positive impact. Interestingly in MS coffee and caffeine may have a stronger impact on disease course compared to effects on disease susceptibility. In ALS no such beneficial effect could be observed in the clinical and experimental studies.

Conclusion: This literature assessment revealed that coffee and especially caffeine could have a preventative role in the development of several neurodegenerative diseases if provided in comparatively high doses. The systematic assessment indicates that coffee and caffeine intake must not be considered as a health risk. Additional clinical studies are needed to fully understand how far coffee and caffeine intake should be considered as a potential therapeutic approach for certain disease entities and conditions.

Biomarkers for In Vivo Assessment of Transporter Function

Drug-drug interactions are a major concern not only during clinical practice, but also in drug development. Due to limitations of in vitro-in vivo predictions of transporter-mediated drug-drug interactions, multiple clinical Phase I drug-drug interaction studies may become necessary for a new molecular entity to assess potential drug interaction liabilities. This is a resource-intensive process and exposes study participants, who frequently are healthy volunteers without benefit from study treatment, to the potential risks of a new drug in development. Therefore, there is currently a major interest in new approaches for better prediction of transporter-mediated drug-drug interactions. In particular, researchers in the field attempt to identify endogenous compounds as biomarkers for transporter function, such as hexadecanedioate, tetradecanedioate, coproporphyrins I and III, or glycochenodeoxycholate sulfate for hepatic uptake via organic anion transporting polypeptide 1B or N¹-methylnicotinamide for multidrug and toxin extrusion protein-mediated renal secretion. We summarize in this review the currently proposed biomarkers and potential limitations of the substances identified to date. Moreover, we suggest criteria based on current experiences, which may be used to assess the suitability of a biomarker for transporter function. Finally, further alternatives and supplemental approaches to classic drug-drug interaction studies are discussed.

Caffeine in the Diet: Country-Level Consumption and Guidelines

Coffee, tea, caffeinated soda, and energy drinks are important sources of caffeine in the diet but each present with other unique nutritional properties. We review how our increased knowledge and concern with regard to caffeine in the diet and its impact on human health has been translated into food-based dietary guidelines (FBDG). Using the Food and Agriculture Organization list of 90 countries with FBDG as a starting point, we found reference to caffeine or caffeine-containing beverages (CCB) in 81 FBDG and CCB consumption data (volume sales) for 56 of these countries. Tea and soda are the leading CCB sold in African and Asian/Pacific countries while coffee and soda are preferred in Europe, North America, Latin America, and the Caribbean. Key themes observed across FBDG include (i) caffeine-intake upper limits to avoid risks, (ii) CCB as replacements for plain water, (iii) CCB as added-sugar sources, and (iv) health benefits of CCB consumption. In summary, FBDG provide an unfavorable view of CCB by noting their potential adverse/unknown effects on special populations and their high sugar content, as well as their diuretic, psycho-stimulating, and nutrient inhibitory properties. Few FBDG balanced these messages with recent data supporting potential benefits of specific beverage types.

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

BACKGROUND & AIMS

Caffeine intake in a convenience sample of U.S. college students (N = 1248) was surveyed at five geographically-dispersed United States (U.S.) universities.

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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.

Energy drink and ginseng consumption by Italian university students: a cross-sectional study

INTRODUCTION

The consumption of energy drinks (ED) and ginseng by young people to enhance their mental and physical performance has become widespread. Reported side-effects of ED have raised doubts regarding their safety. This cross-sectional study investigates the phenomenon.

METHODS

An anonymous questionnaire was administered to a representative sample of Verona university students. The resulting data were analyzed with Excel 2013, STATA 13 software.

RESULTS

ED and ginseng consumption was reported by 38.6% and 37.4% of the students, respectively. More than 70% of ED and ginseng users were 18 to 22 years old. Excluding non-responders, ED consumers were mostly males (51.8% vs 33.0%), contrary to ginseng consumers (females 40.4% vs 30.9%). Being a working student was significantly positively associated both to EDs (OR 1.5) and ginseng use (OR 1.4). The most frequently reported academic and other reasons for ED use were: "to study longer" (47.5%), and "to socialize" (29.1%). The most often used combinations were ED containing alcohol (65.6%) and ginseng-coffee beverages (71.8%).

CONCLUSIONS

The diffusion of ED and ginseng consumption warrants prevention and monitoring measures, and deserves further analysis.

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

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.

The Effects of Caffeine, Taurine, or Caffeine-Taurine Coingestion on Repeat-Sprint Cycling Performance and Physiological Responses

Purpose: To investigate the effects of caffeine (C), taurine (T), caffeine and taurine coingestion (C +T), or placebo (P) on repeated Wingate cycling performance and associated physiological responses. Methods: Seven male team-sport players participated in a randomized, single-blind, crossover study, where they completed 3 Wingate tests, each separated by 2 min, an hour after ingesting: C (5 mg/kg body mass [BM]), T (50 mg/kg BM), C +T (5 mg/kg BM + 50 mg/kg BM), or P (5 mg/kg BM) in a gelatin capsule. Performance was measured on an ergometer, and blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP), and rate pressure product (RPP) were measured at rest (presupplement), baseline (1 h postsupplement), and during and after exercise. Results: Magnitude-based inferences revealed that all of the supplements increased (small to moderate, likely to very likely) mean peak power (MPP), peak power (PP), and mean power (MP) compared to P, with greater MPP, PP, and MP in T compared to C (small, possible). Intrasprint fatigue index (%FIIntra) was greater in T compared to P and C (moderate, likely), and %FIInter was lower in T compared to C (small, possible). C and C +T increased HR, MAP, and RPP compared to P and T at baseline (moderate to very large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint. Conclusions: T elicited greater improvements in performance compared to P, C, or C +T while reducing the typical chronotropic and pressor effects of C.

Caffeinated energy drink consumption among adolescents and potential health consequences associated with their use: a significant public health hazard

Caffeinated energy drinks (EDs) are increasingly popular among adolescents despite growing evidence of their negative health effects. The consumption of EDs has seen a substantial increase during the past few decades, especially in the Western and Asian countries. EDs contain high levels of caffeine, sugar, and novel ingredients, and are often marketed through youth-oriented media and venues. The known and unknown pharmacology of the constituents of EDs poses a risk of caffeine toxicity and other ill effects when consumed by young people. Caffeine intoxication may result in tachycardia, vomiting, cardiac arrhythmias, seizures, and even death. Other health concerns related to consumption of EDs include obesity and dental enamel erosion resulting from the acidity of EDs. Coingestion of caffeine and ethanol has been associated with increased risk-taking behaviors in adolescent users, impaired driving, and increased use of other illicit substances. Several researchers have demonstrated that consuming alcohol mixed with energy drinks leads to altered subjective states including decreased perceived intoxication, enhanced stimulation, and increased desire to drink/increased drinking compared to consuming alcohol alone. 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. In conclusion: 1) health care providers should educate youth and their parents about the risks of caffeinated drinks; 2) emergency department clinicians should consider asking patients about ED and traditional caffeine usage and substance use when assessing patient symptoms; 3) policy makers should increase their attention on introducing regulatory policies on television food advertising to which youth are exposed; 4) failure to comply with standards for efficacious product labelling, and absence of broader education regarding guidelines, need to be addressed and 5) further studies must be done to improve our understanding of potential negative consequences of caffeinated energy drinks on health. (www.actabiomedica.it)

Arrhythmogenic effects of energy drinks

Energy drinks (ED) are increasingly popular, especially among adolescents and young adults. They are marketed as enhancers of energy, alertness, and physical performance. ED contain high doses of caffeine and other active ingredients. Their safety has come under question due to reports temporally linking ED consumption with serious cardiovascular events, including arrhythmias and sudden cardiac death. In this article, we report 2 cases of life-threatening ventricular arrhythmias in young patients after consuming ED. We also review the ingredients of ED, the physiologic effects on the cardiovascular system, and the available evidence suggesting arrhythmogenecity.

Randomized Controlled Trial of High-Volume Energy Drink Versus Caffeine Consumption on ECG and Hemodynamic Parameters

Background

Caffeine in doses <400 mg is typically not considered arrhythmogenic, but little is known about the additional ingredients in energy drinks. We evaluated the ECG and blood pressure (BP) effects of high‐volume energy drink consumption compared with caffeine alone.

Methods and Results

This was a randomized, double‐blind, controlled, crossover study in 18 young, healthy volunteers. Participants consumed either 946 mL (32 ounces) of energy drink or caffeinated control drink, both of which contained 320 mg of caffeine, separated by a 6‐day washout period. ECG, peripheral BP, and central BP measurements were obtained at baseline and 1, 2, 4, 6, and 24 hours post study drink consumption. The time‐matched, baseline‐adjusted changes were compared. The change in corrected QT interval from baseline in the energy drink arm was significantly higher than the caffeine arm at 2 hours (0.44±18.4 ms versus −10.4±14.8 ms, respectively; P=0.02). The QTc changes were not different at other time points. While both the energy drink and caffeine arms raised systolic BP in a similar fashion initially, the systolic BP was significantly higher at 6 hours when compared with the caffeine arm (4.72±4.67 mm Hg versus 0.83±6.09 mm Hg, respectively; P=0.01). Heart rate, diastolic BP, central systolic BP, and central diastolic BP showed no evidence of a difference between groups at any time point. Post energy drink, augmentation index was lower at 6 hours.

Conclusions

The corrected QT interval and systolic BP were significantly higher post high‐volume energy drink consumption when compared with caffeine alone. Larger clinical trials validating these findings and evaluation of noncaffeine ingredients within energy drinks are warranted.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02023723.

Association between energy drink intake, sleep, stress, and suicidality in Korean adolescents: energy drink use in isolation or in combination with junk food consumption

BACKGROUND

A considerable amount of research suggests that the frequent use of caffeinated energy drinks may be associated with undesirable effects, particularly so in children and adolescents. This study aimed to investigate the associations between energy drink intake and mental health problems, in isolation or in combination with junk food consumption, in a nationally representative sample of Korean adolescents.

METHODS

Data from the 2015 Korean Youth Risk Behavior Web-Based Survey, collected from 68,043 adolescents aged 12-18 years (mean age 15.09 ± 1.72 years), were analyzed. Questionnaires were administered to collect information related to dietary behavior including energy drink intake and junk food consumption. Single item measures of sleep dissatisfaction, stress, depression, suicidal ideation, suicide plan, and suicide attempt were also administered. Associations between energy drink intake and sleep dissatisfaction, perceived severe stress, persistent depressive mood, and suicidality were investigated, and a multivariate approach was taken so that additional variance from demographic and lifestyle factors could be controlled for statistically.

RESULTS

Energy drink intake was significantly associated with sleep dissatisfaction (adjusted odd ratios [AORs] = 1.64 and 1.25), severe stress (AORs = 2.23 and 1.38), depressive mood (AOR = 2.59 and 1.51), suicidal ideation (AORs = 3.14 and 1.43), suicide plan (AORs = 4.65 and 1.78), and suicide attempt (AORs = 6.79 and 1.91), with a higher risk for more frequent use of energy drinks (≥5 times/wk) than for less frequent use (1-4 times/wk). The detrimental effect of energy drinks on mental health was particularly prominent in frequent junk food consumers.

CONCLUSIONS

Our data suggest that energy drink intake had detrimental effects related to stress, sleep dissatisfaction, mood, and suicidality, in isolation or in combination with junk food consumption, in Korean adolescents. However, the cross-sectional study design prevents our ability to assess causal relationships.

Adolescent intake of caffeinated energy drinks does not affect adult alcohol consumption in C57BL/6 and BALB/c mice

The rise in marketing and mass consumption of energy drink products by adolescents poses a largely unknown risk on adolescent development and drug reward. Yet, with increasing reports of acute health issues present in young adults who ingest large quantities of energy drinks alone or in combination with alcohol, the need to elucidate these potential risks is pressing. Energy drinks contain high levels of caffeine and sucrose; therefore, exposure to energy drinks may lead to changes in drug-related behaviors since caffeine and sucrose consumption activates similar brain pathways engaged by substances of abuse. With a recent study observing that adolescent caffeine consumption increased cocaine sensitivity, we sought to investigate how prolonged energy drink exposure in adolescence alters alcohol use and preference in adulthood. To do so, we utilized three different energy drink exposure paradigms and two strains of male mice (C57BL/6 and BALB/c) to monitor the effect of caffeine exposure via energy drinks in adolescence on adult alcohol intake. These paradigms included two models of volitional consumption of energy drinks or energy drink-like substances and one model of forced consumption of sucrose solutions with different caffeine concentrations. Following adolescent exposure to these solutions, alcohol intake was monitored in a limited-access, two-bottle choice between water and increasing concentrations of alcohol during adulthood. In none of the three models or two strains of mice did we observe that adolescent 'energy drink' consumption or exposure was correlated with changes in adult alcohol intake or preference. While our current preclinical results suggest that exposure to large amounts of caffeine does not alter future alcohol intake, differences in caffeine metabolism between mice and humans need to be considered before translating these results to humans.

Unique Behavioral and Neurochemical Effects Induced by Repeated Adolescent Consumption of Caffeine-Mixed Alcohol in C57BL/6 Mice

The number of highly caffeinated products has increased dramatically in the past few years. Among these products, highly caffeinated energy drinks are the most heavily advertised and purchased, which has resulted in increased incidences of co-consumption of energy drinks with alcohol. Despite the growing number of adolescents and young adults reporting caffeine-mixed alcohol use, knowledge of the potential consequences associated with co-consumption has been limited to survey-based results and in-laboratory human behavioral testing. Here, we investigate the effect of repeated adolescent (post-natal days P35-61) exposure to caffeine-mixed alcohol in C57BL/6 mice on common drug-related behaviors such as locomotor sensitivity, drug reward and cross-sensitivity, and natural reward. To determine changes in neurological activity resulting from adolescent exposure, we monitored changes in expression of the transcription factor ΔFosB in the dopaminergic reward pathway as a sign of long-term increases in neuronal activity. Repeated adolescent exposure to caffeine-mixed alcohol exposure induced significant locomotor sensitization, desensitized cocaine conditioned place preference, decreased cocaine locomotor cross-sensitivity, and increased natural reward consumption. We also observed increased accumulation of ΔFosB in the nucleus accumbens following repeated adolescent caffeine-mixed alcohol exposure compared to alcohol or caffeine alone. Using our exposure model, we found that repeated exposure to caffeine-mixed alcohol during adolescence causes unique behavioral and neurochemical effects not observed in mice exposed to caffeine or alcohol alone. Based on similar findings for different substances of abuse, it is possible that repeated exposure to caffeine-mixed alcohol during adolescence could potentially alter or escalate future substance abuse as means to compensate for these behavioral and neurochemical alterations.

A Review of Energy Drinks and Mental Health, with a Focus on Stress, Anxiety, and Depression

Background: Concerns have been expressed regarding the potential for caffeinated energy drinks to negatively affect mental health, and particularly so in young consumers at whom they are often targeted. The products are frequently marketed with declarations of increasing mental and physical energy, providing a short-term boost to mood and performance. Although a certain amount of evidence has accumulated to substantiate some of these claims, the chronic effects of energy drinks on mental health also need to be addressed.

Methods: To review the relevant literature, PubMed and PsycINFO were searched for all peer-reviewed articles published in English that addressed associations between energy drink use and mental health outcomes. Case reports were also considered, though empirical studies investigating acute mood effects were excluded as a review of such articles had recently been published. Fifty-six articles were retrieved: 20 of these (along with eight more identified through other means) were included in the current review, and, because the majority addressed aspects of stress, anxiety, and depression, particular focus was placed on these outcomes.

Results: Though a number of null findings (and one negative relationship) were observed, the majority of studies examined reported positive associations between energy drink consumption and symptoms of mental health problems.

Conclusions: Though the findings imply that energy drink use may increase the risk of undesirable mental health outcomes, the majority of research examined utilized cross-sectional designs. In most cases, it was therefore not possible to determine causation or direction of effect. For this reason, longitudinal and intervention studies are required to increase our understanding of the nature of the relationships observed.

Electrocardiographic and blood pressure effects of energy drinks and Panax ginseng in healthy volunteers: A randomized clinical trial

BACKGROUND

Energy drink usage has been linked to emergency room visits and deaths. The objective of the study is to assess the electrocardiographic and blood pressure effects of energy drinks, Panax ginseng and placebo in healthy individuals.

METHODS

This was a randomized, double blinded, placebo controlled, crossover study. Young healthy volunteers with no comorbid conditions consumed 32oz of an energy drink, control drink with 800mg of Panax ginseng or matching placebo-control drink over 45min. Primary endpoints were QTc interval and systolic blood pressure. Secondary endpoints included QT interval, PR interval, QRS duration, heart rate, and diastolic blood pressure. All endpoints were assessed at baseline, 1, 2, 3.5, and 5.5h.

RESULTS

A significant increase in QTc interval 2h post energy drink consumption was evident when compared to placebo (3.37±10.7ms and -3.19±11.8ms respectively; p=0.030). Similarly, systolic blood pressure 2h post energy drink consumption increased when compared to placebo (2.00±6.37mmHg and -2.67±5.83mmHg respectively; p=0.014). The PR interval significantly reduced over a 2h period post energy drink use in a clinically non-meaningful manner. Heart rate at 2h was not significantly higher in the energy drink group when compared to others. The QT interval, QRS interval and diastolic blood pressure were not impacted at any time point.

CONCLUSIONS

Certain energy drinks consumed at a high volume significantly increase the QTc interval and systolic blood pressure by over 6ms and 4mmHg respectively. Panax ginseng does not have a significant impact on ECG or blood pressure parameters.