Alcohol mixed with energy drinks: consumption patterns and motivations for use in U.S. college students

Energy drink usage by students attending an online university

Objective: This study determined the frequency, reasons for, and side effects of energy drinks (ED) consumption among online students. Participants: Students attending an online university. Methods: Participants were recruited by email and completed a 59-question survey about their prior months ED practices using a combination of validated surveys previously published examining similar constructs in on-campus students. Results: 307 students (age = 32.4 ± 6.5yrs) completed the survey, and 88% reported consuming EDs. Students' reasons for consuming ED included school (p < .001), work (p < .001), an event/competition (p < .001), pick me up (p < .001), lack of rest (p < .001), more energy (p < .001), and staying awake while driving (p < .001). Only individuals who consumed >10 ED/month reported side effects of headaches (p = .01) and speeding (p = .01). Conclusions: In our sample, a majority of the participants reported consuming ED for various daily activities. Only frequent consumers reported side effects suggesting they had become habituated to caffeine since they drank EDs despite experiencing side effects.

Escalating caffeine dose-dependently increases alcohol consumption in adult male, but not female, C57BL/6J mice

Although previous research has illustrated the effects of the consumption of alcohol and caffeine individually, less research has focused on the popular combination of the two drugs. The increase in alcohol consumption when combined with caffeine has led to the idea that the stimulant effects of caffeine may mask the depressant effects of alcohol, and this may contribute to increased binge drinking as the individual feels more awake and stimulated. Preclinical research has shown various effects of combined alcohol and caffeine where several studies show decreased alcohol consumption and others show increased alcohol consumption and even binge-like drinking. Results from a previous study in our lab indicate that intermittent access (IA) to steady levels of low (0.015 %) but not moderate (0.03 %) caffeine increased alcohol consumption in male C57BL/6J mice. The current studies further investigated the sex and dose differences in adult mice receiving varying concentrations of caffeine on combined alcohol intake. In Experiment 1, adult mice (n = 50, 25 males and 25 females) had IA to one of the following experimental bottles throughout the 4 week period: water, alcohol (10 % v/v), caffeine (0.015 % w/v), or 10 % alcohol +0.015 % caffeine. In Experiment 2, adult mice (n = 70, 35 males and 35 females) were given IA to one of the following experimental bottles: water, alcohol (10 % v/v; steady, maintained throughout the 4 weeks), caffeine (increasing 0.01 % to 0.015 % to 0.02 % to 0.03 % weekly), or 10 % alcohol+increasing caffeine (at the previously mentioned concentrations). When both caffeine and alcohol concentrations remained steady throughout the 4 weeks, there was no change in alcohol consumption. Chronic exposure to IA caffeine led to increased locomotor activity and decreased freezing episodes when tested in the open field test approximately 6 h after removal of the bottles. In Experiment 2, caffeine dose-dependently increased alcohol co-consumption in male mice whereas female mice consumed less alcohol when it was presented in conjunction with caffeine. The results in males are in line with clinical literature suggesting that the combination of alcohol and caffeine may lead to increased stimulation and alcohol drinking. Additionally, these studies provide evidence that the escalation of caffeine is crucial when investigating alcohol and caffeine co-consumption using the IA paradigm.

Prevalence of energy drink consumption world-wide: A systematic review and meta-analysis

BACKGROUND AND AIMS

The increasing market for energy drinks (EDs) in recent years, as well as the health risks caused by their consumption, prompt calls to estimate the prevalence of ED use among different countries. This systematic review and meta-analysis aimed to synthesize the prevalence of ED use in different continents and age groups.

METHOD

We searched two databases (i.e. PubMed and PsycInfo) on 31 March 2023 to identify studies reporting the prevalence of ED use. A total of 192 studies (196 distinct samples; n = 1 120 613; 53.37% males) from the United States, Europe, Asia, Oceania and Africa were included in the analysis. A random-effects model was applied to estimate the overall pooled prevalence at several time-periods. Subgroup analyses were performed to provide prevalence based on continent and age group. The quality of articles was assessed using Joana Brigg's Institute (JBI) critical appraisal checklist. Measurements included prevalence of ED use (i.e. life-time, past 12 months, past 30 days, past 7 days and daily use), continent and age group (i.e. children, adolescents, young adults and adults).

RESULTS

The life-time ED use world-wide-pooled prevalence was estimated to be 54.7% [95% confidence interval (CI) = 48.8-60.6; I2  = 99.80], 43.4% (95% CI = 36.1-50.6; I2  = 99.92) in the past 12 months, 32.3% (95% CI = 28.8-35.8; I2  = 99.82) in the past 30 days, 21.6% (95% CI = 18.7-24.5; I2  = 99.95) in the past 7 days and 8.82% (95% CI = 6.3-11.4; I2  = 99.95) daily ED use. Subgroups analyses showed significant differences in ED life-time use within age groups (P = 0.002) and continents (P = 0.035).

CONCLUSIONS

The world-wide prevalence of energy drink use appears to be high, particularly among adolescents and young adults.

Alcohol Versus Combined Alcohol and Energy Drinks Consumption: risk behaviours and consumption patterns among European students

INTRODUCTION

Recent research found that mixing energy drinks with alcohol (AmED) could be more risky than drinking alcohol alone. Our aim was to compare rates of risk behaviours in consumers AmED versus exclusive alcohol drinkers, matching them based on their drinking frequency.

METHODS

Data about sixteen-year-old students who reported the number occasions on which they had drunk AmED or alcohol only in the preceding 12 months (n = 32,848) were drawn from the 2019 ESPAD study. After matching for consumption frequency, the sample consisted of 22,370 students (11,185 AmED consumers and 11,185 exclusive alcohol drinkers). Key predictors comprised substance use, other individual risk behaviours and family characteristics (parental regulation, monitoring and caring).

RESULTS

The multivariate analysis showed significantly higher odds of being AmED consumers compared to exclusive alcohol drinkers in the majority of the investigated risk behaviours, including: daily tobacco smoking, illicit drug use, heavy episodic drinking, truancy at school, engaging in physical fights and serious arguments, having troubles with the police and having unprotected sexual intercourse. Instead, lower odds were found for reporting high parents' educational level, medium and low family economic status, perceived possibility to freely talk about problems to family members, spending free time reading books or other hobbies.

CONCLUSIONS

Our study shows that, given the same consumption frequency in the past year, AmED consumers typically reported higher associations with risk-taking behaviours compared to exclusive alcohol drinkers. These findings advance past research that failed to control for the frequency of AmED use versus exclusive alcohol consumption.

Alcohol Mixed with Energy Drinks (AmED) Use among University Students: A Systematic Review and Meta-Analysis

In the last decades, there has been a huge increase in the consumption of both Energy Drinks (EDs) and alcohol and, concurrently, these two trends generated the additional practice of mixing ED with alcohol, known as Alcohol mixed with Energy Drink (AmED). One of the most important group of AmED consumers is represented by young. Indeed, the study population of the researches in this field are mainly represented by college students and the results evidence a great range of negative consequences for health. The purpose of the systematic review was to explore the prevalence of AmED consumption among undergraduate students, together with motivations to their use, adverse effects and health-related behaviors associated to AmEDs use. The review was conducted according to the PRISMA Statement and PubMed, Scopus and Web of Science were interrogated. 42 articles, published from 2008 to 2021, were included in the review. An overall prevalence rate of 37% was estimated for AmEDs use in undergraduates, with geographical differences. Although a decrease in consumption was observed throughout the studied period, a continuous monitoring on this phenomenon is needed for identifying those risk groups that could develop risky behaviors related to AmEDs consumption and provide them targeted educational interventions.

Alcohol mixed energy drink usage and risk-taking among college students in Western New York State

Alcohol mixed energy drinks (AmED) may promote excessive alcohol intake and risk-taking among college students. Objective: To understand the relationship between AmED use and risky behavior as well as attitudes and motivations for AmED use. Participants: Undergraduate college students N = 422 (Study 1), N = 37 (Study 2). Methods: Using a mixed-methods approach, we first surveyed undergraduate students about their AmED and alcohol consumption and a series of risk behaviors, self-efficacy, and beliefs (Study 1). We then conducted focus groups within the same population to better understand attitudes, knowledge, and motivations for using AmED (Study 2). Results: Recent AmED use was significantly associated with an increased number of reported binge drinking occasions and self-reported driving while intoxicated events. Our qualitative data analyses revealed two major themes associated with AmED consumption: factors encouraging AmED use and decisions about driving while under the influence of alcohol. Conclusions: These findings add to the literature of beliefs and motivations for AmED use among college students.

Energy drink expectancies among college students

ObjectiveSince the late '90 s, energy drink consumption has increased. The purpose of this investigation was to examine energy drink expectancies of college students. Participants: The university registrar randomly selected fifty university classes to be surveyed. Methods: A cross-sectional research design was used to assess the prevalence of energy drink consumption and energy drink expectancies. Binary logistic regression analyses were conducted to ascertain which expectancies explained energy drink consumption. Results: The expectancy factors of 1,246 participants accounted for 25.8% of the variance in past 30-day energy drink consumption. Energy enhancement, anxiety/negative physical effects, withdrawal, and appetite suppression were each found to be significantly related to energy drink consumption. Conclusions: Energy enhancement and anxiety/negative effects were the strongest predictors of energy drink consumption among college students. The results from this study can be used to design interventions to challenge erroneous expectancies and reinforce others that promote moderation or abstinence.

Prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among active duty United States military personnel

BACKGROUND

Although representative data on caffeine intake in Americans are available, these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among United States active duty military service members (SMs).

METHODS

A stratified random sample of SMs were asked to complete an on-line questionnaire on their personal characteristics and consumption of caffeinated products (exclusive of dietary supplements). Eighteen percent (n = 26,680) of successfully contacted SMs (n = 146,365) completed the questionnaire.

RESULTS

Overall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218 ± 2 and 167 ± 3 mg/day for men and women, respectively. Caffeine consumers ingested 243 ± 2 mg/day (251 ± 2 mg/day men, 195 ± 3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p = 0.12). Among individual caffeinated products, coffee had the highest use (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with caffeine use (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank.

CONCLUSION

Compared to National Health and Nutrition Examination Survey data, daily caffeine consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.

Ethanol combined with energy drinks: Two decades of research in rodents

Many studies raised concerns on alcoholic beverages consumption mixed with energy drinks (AmED), which can induce higher rates of binge drinking and earlier development of alcohol use disorders. After 20 years of research, few studies with laboratory animals have focused on the effects of this mixture and the neurobiological and pharmacological mechanisms underlying them. We found 16 articles on AmED administration to rodents evaluating its effects on voluntary consumption, locomotion, anxiety-like behavior, memory, influence on the onset time of seizures, biochemical and neurochemical measures. Some of these studies indicated energy drinks (ED) can alter the pattern of use and motivation to consume ethanol (EtOH); increase the expression of sensitization to EtOH stimulant effect and the proportion of sensitized mice; decrease the aversiveness of high concentrations of EtOH, among other effects. In addition AmED hastens the loss of righting reflex and its effects on memory are controversial. After acute administration no difference was found in blood ethanol concentration (BEC) of rodents which received EtOH with or without ED, but after 60 days of treatment, AmED group had lower BEC levels than EtOH group. Data on biochemical and neurochemical parameters after AmED are not consistent. Although the AmED group presented higher glucose levels than the EtOH group when drugs were administered by gavage, this was not observed in a self-administration protocol. AmED may induce higher kidney damage, higher levels of plasma urea, uric acid and creatinine when compared to EtOH. Chronic consumption of AmED causes an inflammatory response and oxidative stress, which may induce cell death in the cortex and hypothalamus of adult rats. These controversial results show that AmED diverse effects depend on sex, age and lineage of the animals, duration of the treatment and route of administration. Further research is necessary to evaluate the mechanisms underlying AmED biological effects.

Energy Drink Consumption among Adolescents Attending Schools in Lubumbashi, Democratic Republic of Congo

BACKGROUND

The consumption of energy drinks (EDs) is increasing in the general population, but little is known about the consumption of EDs among pupils in Africa. This study was designed to assess the consumption of EDs among pupils between 10 and 17 years of age and to assess average caffeine concentrations contained in EDs sold in Lubumbashi.

METHODS

We conducted a cross-sectional survey in five schools using a standardised questionnaire taken face-to-face. Samples of locally purchased EDs were analysed by High Performance Liquid Chromatography with Ultra-Violet spectrometry (HPLC-UV).

RESULTS

Of 338 pupils (54% girls), 63% reported having consumed at least one ED in the last week and 34% drank at least one ED a day. The cheapest ED was the most widely consumed. Among pupils having consumed at least one ED in the last week, 79% reported consuming it for refreshment and 15% to get energy. For those who reported not consuming EDs, 40% reported that their parents or teachers forbade them to drink EDs. Some (14%) teenagers, mainly boys, mixed ED with alcohol. The concentrations of caffeine measured in twelve brands of EDs ranged from 7.6 to 29.4 mg/100 mL (median 23.3), giving caffeine contents of 37.5 to 160 mg (median 90 mg) per can or bottle. The estimated daily intake of caffeine through EDs was between 51.3 mg and 441.3 mg among those consuming EDs regularly.

CONCLUSION

Our study convincingly demonstrates that caffeine-containing EDs are not only consumed by youngsters living in affluent societies. We documented widespread regular consumption of EDs among (pre-)adolescent schoolchildren living in Lubumbashi, a large city of the Democratic Republic of Congo (DRC). In view of the global market expansion of caffeinated EDs, it is reasonable to suspect that similar surveys in other urban areas of sub-Saharan Africa would yield similar findings. Pricing and advertising regulations and education on EDs are necessary to limit the regular consumption of EDs among adolescents.

Alcohol Consumption and Behavioral Consequences in Romanian Medical University Students

Alcohol consumption is a major public health problem facing universities. The objectives of the present study were to investigate alcohol consumption and the behaviors associated with it among Romanian university medical students, with particular reference to sex differences, behavioral consequences, and lifestyle patterns. We performed a cross-sectional study on 722 medical students (60.4% females; 39.6% males); the participants filled out a validated questionnaire containing the following items co-occurring with alcohol consumption: smoking, illicit drug use, energy drink consumption, and other behavioral drinking consequences. Physical activity was estimated using the IPAQ questionnaire. We statistically analyzed the interrelation between alcohol consumption and target factors. The present study showed a high percentage of at-risk drinkers among male (15.0%) and female medical students (14.9%) in the studied group. Male students reported higher illicit drug use and physical activity than female students, but the at-risk female drinkers' group consumed more drugs than the low-risk female drinkers. Both male and female drinkers engaged in other risky behaviors correlated with drinking (e.g., smoking, low academic performance, and driving a car after drinking). Public health policies, strategies, and interventions should be initiated to reduce alcohol consumption and associated behaviors in medical students.

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.

The Energy to Smoke: Examining the Longitudinal Association between Beverage Consumption and Smoking and Vaping Behaviours among Youth in the COMPASS Study

This study examined the longitudinal association between changes in sugar-sweetened and/or caffeinated beverage consumption and smoking/vaping behaviour among Canadian adolescents. Using longitudinal data from the COMPASS study (2015/16 to 2017/18), four models were developed to investigate whether beverage consumption explained variability in smoking and vaping behaviour in adolescence: (1) smoking initiation, (2) vaping initiation, (3) current smoking status, and (4) current vaping status. Models were adjusted for demographic factors. Multinomial logit models were used for model 1, 2, and 3. A binary logistic regression model was used for model 4. An association between change in frequency of beverage consumption and smoking/vaping behaviour was identified in all models. A one-day increase in beverage consumption was associated with smoking initiation (OR = 1.38, 95% CI: 1.25, 1.51), vaping initiation (OR = 1.23, 95% CI: 1.14, 1.32), identifying as a current smoker (OR = 1.17, 95% CI: 1.01, 1.35), and currently vaping (OR = 1.08, 95% CI: 1.04, 1.11). Change in high-energy drink consumption was the best predictor of smoking behaviours and vaping initiation but not current vaping status. Given the health consequences of smoking and vaping and their association with high-energy drink and coffee consumption, policy initiatives to prevent smoking/vaping initiation, and to limit youth access to these beverages, warrant consideration.

Caffeine increases alcohol self-administration, an effect that is independent of dopamine D2 receptor function

The rising popularity of alcohol mixed with energy drinks (AmEDs) has become a significant public health concern, with AmED users reporting higher levels of alcohol intake than non-AmED users. One mechanism proposed to explain this heightened level of alcohol intake in AmED users is that the high levels of caffeine found in energy drinks may increase the positive reinforcing properties of alcohol, an effect that may be dependent on interactions between adenosine receptor signaling pathways and the dopamine D₂ receptor. Therefore, the purpose of the current study was to confirm whether caffeine does increase the positive reinforcing effects of alcohol using both fixed ratio (FR) and progressive ratio (PR) designs, and to investigate a potential role of the dopamine D₂ receptor to caffeine-induced increases in alcohol self-administration. Male Long-Evans rats were trained to self-administer a sweetened alcohol solution (10% v/v alcohol + 2% w/v sucrose) on an FR2 schedule of reinforcement, and the effects of caffeine (0, 5, 10, and 20 mg/kg, i. p. [intraperitoneally]) on the maintenance of alcohol self-administration and alcohol break point were examined. Parallel experiments in rats trained to self-administer sucrose (0.8% w/v) were conducted to determine whether caffeine's reinforcement-enhancing effects extended to a non-drug reinforcer. Caffeine pretreatment (5-10 mg/kg) significantly increased sweetened alcohol self-administration and motivation for a sweetened alcohol reinforcer. However, similar increases in self-administration of a non-drug reinforcer were not observed. Contrary to our hypothesis, the D₂ receptor antagonist eticlopride did not block a caffeine-induced increase in sweetened alcohol self-administration, nor did it alter caffeine-induced increases in motivation for a sweetened alcohol reinforcer. Taken together, these results support the hypothesis that caffeine increases the positive reinforcing effects of alcohol, which may explain caffeine-induced increases in alcohol intake. However, the reinforcement-enhancing effects of caffeine appear to be independent of D₂ receptor function.

Effects of caffeine on ethanol-elicited place preference, place aversion and ERK phosphorylation in CD-1 mice

BACKGROUND

Epidemiological studies indicate a rise in the combined consumption of caffeinated and alcoholic beverages, which can lead to increased risk of alcoholic-beverage overconsumption. However, the effects of the combination of caffeine and ethanol in animal models related to aspects of drug addiction are still underexplored.

AIMS

To characterize the pharmacological interaction between caffeine and ethanol and establish if caffeine can affect the ability of ethanol (2 g/kg) to elicit conditioned place preference and conditioned place aversion, we administered caffeine (3 or 15 mg/kg) to male CD-1 mice before saline or ethanol. Moreover, we determined if these doses of caffeine could affect ethanol (2 g/kg) elicited extracellular signal-regulated kinase phosphorylation in brain areas, nucleus accumbens, bed nucleus of stria terminalis, central nucleus of the amygdala, and basolateral amygdala, previously associated with this type of associative learning.

RESULTS

In the place-conditioning paradigm, caffeine did not have an effect on its own, whereas ethanol elicited significant conditioned-place preference and conditioned-place aversion. Caffeine (15 mg/kg) significantly prevented the acquisition of ethanol-elicited conditioned-place preference and, at both doses, also prevented the acquisition of ethanol-elicited conditioned-place aversion. Moreover, both doses of caffeine also prevented ethanol-elicited extracellular signal-regulated kinase phosphorylation expression in all brain areas examined.

CONCLUSIONS

The present data indicate a functional antagonistic action of caffeine and ethanol on associative learning and extracellular signal-regulated kinase phosphorylation after an acute interaction. These results could provide exciting grounds for further studies, also in a translational perspective, of their pharmacological interaction modulating other processes involved in drug consumption and addiction.

Alcohol mixed with energy drinks: Expectancies of use and alcohol-related negative consequences among a young adult sample

OBJECTIVE

Energy drinks are a popular mixer with alcohol among college-aged young adults. Few studies to date have examined the relationships between expectancies of alcohol mixed with energy drink (AmED) use, AmED use and AmED-related negative consequences.

METHODS

Eighty college-aged young adults were surveyed regarding their alcohol and AmED use, related negative consequences and AmED expectancies. Associations were assessed using chi-square tests and Cramér's V. A simple mediational model also was used to explore the potential relationships between AmED expectancies, AmED use and AmED-related negative consequences.

RESULTS

AmED use was associated with more types of related negative consequences than heavy alcohol use alone, and where AmED use and heavy alcohol use were mutually associated with a related negative consequence, the strength of association was stronger for AmED use. While several AmED-related negative consequences were associated with AmED expectancies, unwanted sexual contact and getting into a verbal argument were associated with the greatest number of expectancies. The mediational model identified a statistically significant indirect effect of AmED expectancies on AmED-related negative consequences mediated by AmED use.

CONCLUSIONS

The study results contribute to the evidence that AmED use may confer additional risk for related negative consequences beyond heavy alcohol use and suggest that AmED expectancies may have a role in AmED use, which, in turn, is associated with AmED-related negative consequences. AmED expectancies may be targets for intervention to reduce AmED use considering the possible subsequent related negative consequences, especially those involving negative interpersonal experiences.

Coffee and cigarettes: Examining the association between caffeinated beverage consumption and smoking behaviour among youth in the COMPASS study

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Caffeinated beverage consumption is associated with smoking behaviours in youth.

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High energy drink consumption is most strongly associated with smoking behaviours.

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Caffeinated beverages and smoking behaviour demonstrate a dose–response association.

In adults, coffee, sugar-sweetened beverage (SSB) and high energy drink consumption have been related to increases in risky behaviour, including smoking. However, these associations are not well understood during adolescence. The purpose of this study was to examine the association between beverage consumption and smoking behaviour among Canadian adolescents. Using data from the COMPASS study (2016–2017; n = 46,957), four models were developed to investigate whether beverage consumption explained variability in smoking behaviour in adolescence (age = 15.7 ± 1.2 yrs); 1) smoking status; 2) e-cigarette use status; 3) days smoking cigarettes per month; and 4) days using an e-cigarette per month. Models were adjusted for demographic factors. Logistic (models 1 and 2) and ordinal logistic (models 3 and 4) were used for analysis. An association between the frequency of SSBs, coffee/tea or high energy drinks consumption and smoking behaviour was identified in all models. Greater beverage consumption was associated with being a current smoker (OR = 2.46 (2.02, 2.99)), former smoker, (OR = 2.50 (1.53, 4.08)), and currently using an e-cigarette (OR = 4.66 (3.40, 6.40)). Higher beverage consumption was also associated with more days smoking/using an e-cigarette per month (OR = 2.67 (1.92, 3.70) and 3.45 (2.32, 5.12), respectively). High energy drink consumption on 4 or 5 days of the school week was the best predictor of smoking behaviour in all models. Given the health consequences of smoking and e-cigarette use and their association with SSB, high energy drinks and coffee consumption, policy initiatives to prevent smoking initiation and limit access to these beverages needs ongoing attention and implementation.

Sub-chronic taurine administration induces behavioral sensitization but does not influence ethanol-induced dopamine release in the nucleus accumbens

Preclinical studies have shown that the amino acid taurine is of importance for the dopamine elevating properties of ethanol. Taurine intake has escalated over the last decade due to increased consumption of taurine-containing energy drinks and dietary supplements. Whether long-term intake of large amounts of taurine induces adaptations affecting ethanol-induced dopamine elevation is not clear. Thus the aim of the present studies was to explore the impact of repeated administration of large amounts of taurine on ethanol-induced behavior and dopamine neurotransmission. Repeated daily systemic administration of taurine increased taurine-induced locomotor activity and rearing. Acute administration of taurine and ethanol in naïve animals produced an additive effect on extracellular taurine but no alteration of the ethanol-induced dopamine elevation, as measured by in vivo microdialysis. Sub-chronic administration of taurine did not modify the taurine- or dopamine-elevating properties of ethanol. Daily taurine treatment also failed to change the mRNA expression of the taurine transporter and GABA_A- and glycine-receptor subunits, as measured by qPCR in nucleus accumbens tissue. We conclude that systemic administration of taurine may have long lasting central effects, here displayed as behavioral sensitization. However, repeated daily exposure to taurine does not appear to influence the dopamine elevating properties of ethanol.

Energy drink constituents (caffeine and taurine) selectively potentiate ethanol-induced locomotion in mice

Mixing alcohol with energy drinks has emerged as a popular trend over the last decade. However, epidemiological studies have found this consumption to be associated with increased hazards, such as binge drinking, increased alcohol-related harm and risk of developing alcohol use disorder. The mechanisms underlying these effects are not clear, but much attention has been attributed to caffeine. However, taurine, another common ingredient in energy drinks, has also been associated with the dopamine elevating properties of ethanol, and may in this respect contribute to the increased liability associated with the mixture of alcohol and energy drinks. In the present study we measured locomotor activity, a phenomenon previously linked to the dopamine activating and reinforcing properties of the drug, following acute systemic administration with caffeine (1, 5, 15, 30 mg/kg), taurine (30, 60, 300, 600 mg/kg) and ethanol (1.75, 2.5, 3.25 g/kg), alone or in combination. We found that ethanol and caffeine, but not taurine, increased locomotion compared to vehicle. In addition, when combined with ethanol, caffeine, but not taurine, increased the locomotor stimulatory effect of ethanol. Furthermore, the combination of caffeine and taurine were able to further enhance the ethanol-induced locomotor response. Eleven days of intermittent caffeine exposure produced a sensitized response to the caffeine-induced locomotion, but did not alter the additive effect produced by the combination of caffeine and taurine on ethanol-induced locomotion. Based on the present study we suggest that the combination of caffeine and taurine, at a specific dose range, enhances the locomotor stimulatory properties of ethanol, a phenomenon previously linked to the reinforcing properties of the drug.

The association between caffeinated alcoholic beverages and the perpetration of intimate partner violence

Background: Problematic alcohol use is a recognized risk factor for intimate partner violence (IPV) perpetration.Objective: The use of caffeinated alcoholic beverages (CAB) appears to be associated with high-risk drinking behavior but the relationship between CAB use and IPV has yet to be explored.Methods: Sixty male and 40 female married or dating participants responded to an online survey including measures of past-year alcohol use and partner violence.Results: Logistic regression analyses revealed that CAB users were significantly more likely to perpetrate physical assault and partner injury after controlling for age, sex, ethnicity, income, and heavy alcohol use. The relationship between CAB use and perpetration of sexual coercion was better accounted for by heavy alcohol use.Conclusion: Results from the current study suggest that there exists an independent link between CAB use and partner violence perpetration.

Food Choices of Young Adults in the United States of America: A Scoping Review

Understanding food choice is critical to developing effective health promotion efforts to counter the leading causes of morbidity and mortality in the United States. Although physiologic, environmental, and social factors influence the development of health conditions, routine decisions, such as food choice, also contribute substantially over time. Behavioral scientists believe that these routine decisions represent a key opportunity to improve population health. We conducted a scoping review of both health and business literature to identify themes in the food choices of young adults aged 19-24 y in the United States. Informed by the Joanna Briggs Institute processes for scoping reviews, we conducted a structured search of 8 health and business databases on 18 April 2017. The databases were PubMed, Business Source Complete, PsycInfo, Cochrane Library, CINAHL, Web of Science, SCOPUS, and ABI/Inform Collection. Eligible literature captured real-world dietary choices of the general population of young adults between 1 January, 2007 and 31 December, 2017. Records were screened in Covidence. Data was extracted into Excel and key findings thematically analyzed. The search returned 9085 records. Ninety-nine records met the eligibility criteria. Themes identified in the foods chosen by young adults include inadequate fruit and vegetable consumption, choosing international flavors and food formats, convenience foods, frequent snacking, the selection of healthy foods based on perceptions of what is healthy rather than the nutrient or calorie content of foods, an interest in sustainable production methods, the desire to customize/tailor foods, foods young people find interesting, and regional foods. This research identified common food choices that can help inform the tailoring of health promotion efforts; however, more research is needed to understand the underlying mechanisms and principles shaping these choices.

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.

Using Placebo Beverages in Group Alcohol Studies

BACKGROUND

Placebo beverage conditions remain a key element in the methodological toolkit for alcohol researchers interested in evaluating pharmacological and nonpharmacological factors influencing the effects of alcohol consumption. While interest in experimentally examining alcohol in social context is on the rise, there has been little research examining the effectiveness of placebo manipulations in group settings, when just 1 suspicious participant could potentially jeopardize the effect of the placebo on group members. Moreover, research has rarely considered the association between individual difference factors (e.g., gender) and placebo manipulation effectiveness. The present study, using an uncommonly large sample of placebo-consuming participants, was well suited to investigate fundamental questions regarding placebo efficacy that have not been assessed previously. Specifically, we aimed to examine placebo efficacy and general processes of placebo functioning in a group context. We also assessed potential associations between a variety of individual difference factors and placebo response.

METHODS

A total of 240 participants (50% male) consumed placebo beverages during a triadic drinking period (across 80 three-person groups). Participants reported their subjective intoxication, stimulation, and sedation 8 minutes following drink consumption and estimated the alcohol content of their drink at the end of the study.

RESULTS

Participants consuming placebo beverages in groups were nearly universal in reporting that they had consumed alcohol (>99%) and had experienced an increase in feelings of intoxication [t(239) = 22.03, p < 0.001] and stimulation [t(239) = 5.53, p < 0.001], levels that were similar to those observed in prior studies conducted with participants drinking placebos in isolation. Further, participants' placebo responses were independent of their 2 group members and were largely unaffected by a variety of individual difference factors.

CONCLUSIONS

Placebo response generally operated independently of group-member influences, suggesting that researchers can successfully conduct placebo beverage studies utilizing group drinking designs.

Correlates of Alcohol Mixed with Energy Drink Use Among First Year College Students: Clinical and Research Implications

Background: Alcohol mixed with energy drink (AmED) use among college students is associated with specific adverse effects (e.g., sexual assault, driving while intoxicated). This study offered the opportunity to evaluate correlates of past year AmED use in a large sample of college students. Methods: In autumn 2010, emails were sent to all first year students (n = 29,536) at 11 colleges and universities in North Carolina and Virginia, inviting them to participate in a brief web-based survey to be used to establish a cohort for the parent tobacco use study; 10,340 (35%) students responded to the web-based survey, which elicited items on demographics, past year use of AmED, and other health behaviors. Results: Past year of AmED was reported by 29.4% of students. Logistic regression analysis revealed that female gender (adjusted odds ratios [AOR] = 1.28, 95% confidence interval [CI] = 1.16-1.42); ever use of smokeless tobacco (AOR = 3.51, 95% CI = 3.00-4.10); current smoking (AOR = 4.97, 95% CI = 4.34-5.69); 2 or fewer days of physical activity per week (AOR = 1.16, 95% CI = 1.04-1.28); and 7 or 8 hours of sleep per day (AOR = 1.12, 95% CI = 1.02-1.24) predicted risk of past year use of AmED. Conclusions: Nearly a third of first year college students reported past year use of AmED. Our finding of increased past year use of AmED use among women is new and might reflect the changing epidemiology of female college alcohol use. Of additional concern, such use might also reflect targeted marketing to women by the energy drink industry. Findings can guide future research as well as substance counseling to college students.

Caffeinated energy drink use by U.S. adolescents aged 13-17: A national profile

The present study examined the national prevalence and distribution of adolescent use of caffeinated energy drinks, assessing variations in sociodemographic characteristics, personality traits, lifestyles, and patterns of alcohol and caffeine use. A cross-sectional survey was conducted in May 2014, using a nationally representative sample of 1,032 U.S. early (aged 13-15; n = 602) and middle adolescents (aged 16-17; n = 430). Nearly two thirds of teens reported ever using energy drinks; 41% had done so recently, that is, in the past 3 months. Middle adolescents reported higher prevalences of both lifetime and recent use of energy drinks than early adolescents. Common situational contexts for use (e.g., compensating for lack of sleep or playing sports) differed by both gender and age cohort. In hierarchical logistic regression analyses, gender and geographic region significantly predicted both lifetime and recent use for early adolescents only, whereas age and race were significant predictors only for middle adolescents. For both age cohorts, odds of both lifetime and recent use increased with sensation-seeking score, lifetime alcohol use, and recent caffeinated soft drink use. Among early adolescents, grade point average predicted lifetime use only, whereas coffee and caffeine pill use predicted recent use only. Among middle adolescents, impulsivity and past sports participation predicted lifetime but not recent use. Our findings show that adolescent energy drink use is widespread and varies as a function of demographic, psychosocial, lifestyle, and substance use characteristics. Future research is needed to assess whether differences between early and middle adolescent use patterns are primarily developmental or cohort effects. (PsycINFO Database Record

The multiplicative effect of combining alcohol with energy drinks on adolescent gambling

PURPOSE

There has been increased concern about the negative effects of adolescents consuming a combination of alcohol mixed with energy drinks (AmED). To date, few studies have focused on AmED use and gambling. The present study analyzed the multiplicative effect of AmED consumption, compared to alcohol alone, on the likelihood of at-risk or problem gambling during adolescence.

METHODS

Data from the ESPAD®Italia 2015 study, a cross-sectional survey conducted in a nationally representative sample of students (ages 15 to 19years) were used to examine the association between self-reported AmED use (≥6 times,≥10 times, and ≥20 times during the last month) and self-reported gambling severity. Multivariate models were used to calculate adjusted prevalence ratios to evaluate the association between alcohol use, AmED use, and gambling among a representative sample of adolescents who reported gambling in the last year and completed a gambling severity scale (n=4495).

RESULTS

Among the 19% students classed as at-risk and problem gamblers, 43.9% were classed as AmED consumers, while 23.6% were classed as alcohol consumers (i.e. did not mix alcohol with energy drinks). In multivariate analyses that controlled for covariates, AmED consumers were three times more likely to be at-risk and problem gamblers (OR=3.05) compared to non-consuming adolescents, while the effect became less pronounced with considering those who consumed alcohol without the addition of energy drinks (OR=1.37).

CONCLUSIONS

The present study clearly established that consuming AmED might pose a significantly greater risk of experiencing gambling-related problems among adolescents.

Development and initial psychometric validation of the Brief-Caffeine Expectancy Questionnaire (B-CaffEQ)

Caffeine is the most widely available and consumed psychoactive substance in the United States. Extant work indicates that across substances, use expectancies play a marked role in the development and maintenance of consumption patterns. Despite a burgeoning line of etiological and intervention-oriented research focused on expectancies (e.g., alcohol), there is a limited literature regarding caffeine use effect expectancies, specifically. To facilitate this work, the Caffeine Expectancy Questionnaire (CaffEQ) was developed and psychometrically validated; however, the length of the CaffEQ (i.e., 47 items) may hinder widespread adoption of this tool. As such, the current study provides an initial psychometric validation of a brief, 20-item version-the Brief-Caffeine Expectancy Questionnaire (B-CaffEQ)-in a multiethnic sample of undergraduate students (N = 975). Results showed that the B-CaffEQ replicated the 7-factor structure of the original CaffEQ using both constrained (confirmatory factor analysis) and less constrained (exploratory structural equation modeling) structural models and evidenced good internal consistency across subscales. The B-CaffEQ also demonstrated concurrent validity with caffeine use frequency indices, replicated and extended convergent validity between caffeine expectancy subscales and related behavioral and psychological constructs, and demonstrated discriminant validity with other related, but notably distinct, stimulant use metrics (e.g., cocaine, Ritalin). Lastly, the B-CaffEQ appears to provide an invariant measure of expectancies across types of caffeine users. These findings indicate that the B-CaffEQ is a reliable assessment of caffeine use effect expectancies, with acceptable-to-good psychometric properties-comparable in length to other substance use expectancies measures-that may be more readily incorporated into research and clinical settings. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Driving under the influence behaviours among high school students who mix alcohol with energy drinks

Alcohol and energy drinks are commonly used substances by youth in Canada, and are often mixed (AmED). While several studies have shown that AmED can have dangerous effects, less well understood is how AmED is associated with driving under the influence of either alcohol or drugs. This study sought to determine whether youth who use AmED were more likely to engage in driving, or being a passenger of a driver, under the influence of alcohol or cannabis compared to youth who use either alcohol or energy drinks alone. This study used data from grade 10-12 students who took part in the 2014/2015 Canadian Student Tobacco, Alcohol and Drugs Survey (N=17,450). The association of past-year AmED use with past-30day: driving under the influence of alcohol or cannabis, and riding with an alcohol- or cannabis-influenced driver, was assessed using logistic regression. One in four youth had consumed AmED in the previous 12months. AmED users were more likely to engage in all risk behaviours except riding with a drinking driver, relative to youth who only consumed alcohol. No association was observed for youth who consumed alcohol and energy drinks on separate occasions. Youth who use AmED demonstrate a higher risk profile for driving under the influence of alcohol or cannabis, than youth who use alcohol alone. Future research should explore the biopsychosocial pathways that may explain why using energy drinks enhances the already heightened risk posed by alcohol on other health-related behaviours such as driving under the influence.

Daily conformity drinking motivations are associated with increased odds of consuming alcohol mixed with energy drinks

Recent research indicates that individuals drank more heavily and experienced more harms on days they consumed alcohol mixed with energy drinks (AmEDs). Limited research, thus far, has examined predictors of AmED use on a daily level. Drinking motives, or reasons for drinking, are shown to discern AmED users from non-users, but the extent to which daily drinking motives covary with AmED use has not been tested. The current study used a daily diary design to determine how motives differ between AmED and other drinking occasions. Participants included 122 college students (73.8% women) with a mean age of 20.39years. Participants completed up to 14 daily surveys, resulting in 389 drinking days (40days involved AmED use). Participants reported on their drinking motives at baseline as well as on each drinking day. Multilevel models revealed that, after controlling for other motives, AmED use was more likely on days where conformity motives were higher than usual and was less likely when enhancement motives were higher. Daily social and coping motives as well as all motives measured at baseline were unassociated with AmED use. Our findings suggest that conformity motives, or drinking to fit in with others, are the most salient drinking motive predicting AmED use on a drinking day. Given that conformity motives are often less associated with alcohol use outcomes in general, these findings highlight AmEDs as a unique alcoholic beverage. Clinicians and interventionists working with frequent AmED users should consider the unique conditions under which AmEDs are consumed.

Alcohol mixed with energy drink (AMED): A critical review and meta-analysis

The purpose of this systematic review and meta-analysis was to critically review the (1) prevalence of alcohol mixed with energy drink (AMED) consumption, (2) motives for AMED consumption, (3) correlates of AMED consumption, and (4) whether AMED consumption has an impact on (a) alcohol consumption, (b) subjective intoxication, and (c) risk-taking behavior. Overall a minority of the population consumes AMED, typically infrequently. Motives for AMED consumption are predominantly hedonistic and social. Meta-analyses revealed that AMED consumers drink significantly more alcohol than alcohol-only (AO) consumers. Within-subject comparisons restricted to AMED consumers revealed that alcohol consumption does not significantly differ between typical AMED and AO occasions. On past month heaviest drinking occasions, AMED users consume significantly less alcohol on AMED occasions when compared to AO occasions. AMED consumers experience significantly fewer negative consequences and risk-taking behavior on AMED occasions compared with AO occasions. Meta-analyses of subjective intoxication studies suggest that AMED consumption does not differentially affect subjective intoxication when compared to AO consumption. In conclusion, when compared to AO consumption, mixing alcohol with energy drink does not affect subjective intoxication and seems unlikely to increase total alcohol consumption, associated risk-taking behavior, nor other negative alcohol-related consequences. Further research may be necessary to fully reveal the effects of AMED.

Behavioral effects of the combined use of alcohol and energy drinks on alcohol hangover in an experimental mice model

In last few years it has been a significant increase in the consumption of alcohol combined with energy drink. The aim of this work was to study the effect of this mixture in motor and affective behaviors during an alcohol hangover episode. Male Swiss mice received one of the following treatments: saline + sucrose; saline + energy drink; ethanol + sucrose; ethanol + energy drink. Ethanol dose was 3.8 g/kg BW (i.p.) and energy drink dose was 18 ml/kg BW (gavage) at ZT1 (8 am) (ZT: Zeitgeber time; ZT0: 7 am; lights on). The behavioral tests used were tight rope test to determine motor coordination; hanging wire test to study muscular strength; elevated plus maze and open field tests to evaluate anxiety like-behavior and locomotor activity. Tests were carried out at basal point that matched with lights onset and every 6 h up to 18 h after treatments. Hangover onset was established at ZT7 when blood alcohol concentration (BAC) was almost zero. Our results showed that the mixture of alcohol and energy drink altered significantly motor skills. Specifically, a significant decrease was observed in the performance of the animals in the tightrope and hanging wire tests in groups treated with the mixture of alcohol and energy drink. A significant impairment in the anxiety-like behavior was observed mainly at the beginning of alcohol hangover. These findings suggest that energy drink added to alcohol extends motor disabilities observed during an alcohol hangover episode in comparison with animals that received alcohol alone.

Are energy drinks unique mixers in terms of their effects on alcohol consumption and negative alcohol-related consequences?

Introduction

Previous research has suggested that consuming alcohol mixed with energy drinks (AMED) increases overall alcohol consumption. However, there is limited research examining whether energy drinks are unique in their effects when mixed with alcohol, when compared with alcohol mixed with other caffeinated mixers (AOCM). Therefore, the aim of this survey was to investigate alcohol consumption on AMED occasions, to that on other occasions when the same individuals consumed AOCM or alcohol only (AO).

Methods

A UK-wide online student survey collected data on the frequency of alcohol consumption and quantity consumed, as well as the number of negative alcohol-related consequences reported on AO, AMED and AOCM occasions (N=250).

Results

Within-subjects analysis revealed that there were no significant differences in the number of alcoholic drinks consumed on a standard and a heavy drinking session between AMED and AOCM drinking occasions. However, the number of standard mixers typically consumed was significantly lower on AMED occasions compared with AOCM occasions. In addition, when consuming AMED, students reported significantly fewer days consuming 5 or more alcohol drinks, fewer days mixing drinks, and fewer days being drunk, compared with when consuming AOCM. There were no significant differences in the number of reported negative alcohol-related consequences on AMED occasions to AOCM occasions. Of importance, alcohol consumption and negative alcohol-related consequences were significantly less on both AMED and AOCM occasions compared with AO occasions.

Conclusion

The findings that heavy alcohol consumption occurs significantly less often on AMED occasions compared with AOCM occasions is in opposition to some earlier claims implying that greatest alcohol consumption occurs with AMED. The overall greatest alcohol consumption and associated negative consequences were clearly associated with AO occasions. Negative consequences for AMED and AOCM drinking occasions were similar, suggesting that energy drink was comparable with AOCM in this regard.

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

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.

Children and young people's perceptions of energy drinks: A qualitative study

BACKGROUND

Consumption of soft drinks is declining in many countries, yet energy drink sales continue to increase, particularly amongst young consumers. Little is currently known about the drivers behind these trends. Energy drinks are high in sugar and caffeine, and evidence indicates that regular or heavy use by under 18s is likely to be detrimental to health. This study aimed to explore children and young people's attitudes and perceptions in relation to energy drinks in a UK context.

METHODS

Eight focus groups were conducted with pupils aged 10-11 years (n = 20) and 13-14 years (n = 17) from four schools in northern England. A sub-sample also took part in a mapping exercise to generate further insights. Data were analysed using the constant comparative approach.

RESULTS

Energy drinks were reportedly consumed in a variety of public and private places, generally linked to social activities, sports and computer gaming (particularly amongst boys). Participants demonstrated strong brand awareness and preferences that were linked to taste and perceived value for money. The relatively low price of energy drinks and their widespread availability were identified as key factors, along with gendered branding and marketing. Some participants demonstrated a critical approach to manufacturers' claims and many were keen to become better informed, often through school- or peer-based interventions. Other potential interventions included age restrictions, voluntary schemes involving retailers and improved labelling.

CONCLUSIONS

The lack of a single dominant factor in participants' consumption choices suggests that there is unlikely to be a 'silver bullet' in attempting to address this issue. However, the findings provide support for policy-level interventions that seek to change the behaviours of manufacturers and retailers as well as consumers, and actively involve children and young people where possible.

Effects of caffeinated alcoholic beverages with low alcohol and high caffeine content on cognitive and motor functions

OBJECTIVE

In Taiwan, caffeinated alcoholic beverages (CABs), with high caffeine but low alcohol concentrations compared to those sold in Western countries, are commonly consumed at work and have been associated with work-related injuries. However, the effects on cognitive and motor functions and self-perception have not been examined.

METHODS

Twenty-eight healthy male volunteers (mean age: 32.6 ± 2.7) participated in the study. Each participant visited our laboratory 4 times at intervals of at least 1 week and was assigned to one of 4 trials in a counterbalanced order at each visit: placebo, alcohol, caffeinated energy drink, and CAB. They completed the subjective perception ratings, go/no-go tasks, Stroop color-word tests, Purdue pegboard tests, and the standardized field sobriety test. We used analysis of variance to examine the intraindividual differences in the performance.

RESULTS

Consuming alcohol of 0.23 g/kg typically consumed by Taiwanese CAB drinkers caused significant impairments in fine and crude motor functions; caffeine (1.5 mg/kg) did not antagonize these effects but led to an improvement in response speed in the go/no-go task. The subjective perceptions produced by alcohol were not masked by caffeine.

CONCLUSIONS

CABs that contains a higher ratio of caffeine to alcohol did not counteract the motor function impairments induced by alcohol.

Energy drinks and alcohol-related risk among young adults

BACKGROUND

Energy drink consumption, with or without concurrent alcohol use, is common among young adults. This study sought to clarify risk for negative alcohol outcomes related to the timing of energy drink use.

METHODS

The authors interviewed a community sample of 481 young adults, aged 18-25, who drank alcohol in the last month. Past-30-day energy drink use was operationalized as no-use, use without concurrent alcohol, and concurrent use of energy drinks with alcohol ("within a couple of hours"). Negative alcohol outcomes included past-30-day binge drinking, past-30-day alcohol use disorder, and drinking-related consequences.

RESULTS

Just over half (50.5%) reported no use of energy drinks,18.3% reported using energy drinks without concurrent alcohol use, and 31.2% reported concurrent use of energy drinks and alcohol. Relative to those who reported concurrent use of energy drinks with alcohol, and controlling for background characteristics and frequency of alcohol consumption, those who didn't use energy drinks and those who used without concurrent alcohol use had significantly lower binge drinking, negative consequences, and rates of alcohol use disorder (P < .05 for all outcomes). There were no significant differences between the no-use and energy drink without concurrent alcohol groups on any alcohol-related measure (P > .10 for all outcomes).

CONCLUSIONS

Concurrent energy drink and alcohol use is associated with increased risk for negative alcohol consequences in young adults. Clinicians providing care to young adults could consider asking patients about concurrent energy drink and alcohol use as a way to begin a conversation about risky alcohol consumption while addressing 2 substances commonly used by this population.

The Safety of Ingested Caffeine: A Comprehensive Review

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.

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.

Energy drink enhances the behavioral effects of alcohol in adolescent mice

Mixing alcohol with energy drinks has become increasingly popular among teenagers and young adults due to the prevailing view that the stimulant properties of energy drinks decrease the depressant effects of alcohol. Surprisingly, in spite of energy drinks being heavily marketed to and consumed by adolescents, there is scarcely available preclinical data on the neurobehavioral effects of energy drinks mixed with alcohol during adolescence. Thus, here we examine the effects of the combined exposure to alcohol and energy drink on adolescent mice using a variety of behavioral tasks to assess locomotor activity, righting reflex and motor coordination. At postnatal day 40, male and female Swiss mice were assigned to the following experimental groups: alcohol diluted in energy drink (Ed+Etoh), alcohol diluted in water (Etoh) or controls (Ctrl: energy drink or water). Alcohol and energy drink (Red Bull) concentrations were 4g/kg and 8ml/kg, respectively, and all solutions were administered via oral gavage. When compared to Etoh mice, Ed+Etoh animals displayed greater locomotor activity and increased anxiety-like behaviors in the open-field, lost their righting reflexes sooner and displayed poorer motor coordination in the rotarod. Collectively, our findings indicate that alcohol-induced deficits in adolescent mice are worsened by energy drink and go against the view that the stimulant properties of energy drinks can antagonize the adverse effects of alcohol.

Intoxication-Related Alcohol Mixed with Energy Drink Expectancies Scale: Initial Development and Validation

BACKGROUND

Young adult use of alcohol mixed with energy drinks (AmEDs) has been linked with elevated risks of a constellation of problem behaviors. These risks may be conditioned by expectancies regarding the effects of caffeine in conjunction with alcohol consumption. The aim of this study was to describe the construction and psychometric evaluation of the Intoxication-Related AmED Expectancies Scale (AmED_EXPI), 15 self-report items measuring beliefs about how the experience of AmED intoxication differs from the experience of noncaffeinated alcohol (NCA) intoxication.

METHODS

Scale development and testing were conducted using data from a U.S. national sample of 3,105 adolescents and emerging adults aged 13 to 25. Exploratory and confirmatory factor analyses were conducted to evaluate the factor structure and establish factor invariance across gender, age, and prior experience with AmED use. Cross-sectional and longitudinal analyses examining correlates of AmED use were used to assess construct and predictive validity.

RESULTS

In confirmatory factor analyses, fit indices for the hypothesized 4-factor structure (i.e., Intoxication Management [IM], Alertness [AL], Sociability [SO], and Jitters [JT]) revealed a moderately good fit to the data. Together, these factors accounted for 75.3% of total variance. The factor structure was stable across male/female, teen/young adult, and AmED experience/no experience subgroups. The resultant unit-weighted subscales showed strong internal consistency and satisfactory convergent validity. Baseline scores on the IM, SO, and JT subscales predicted changes in AmED use over a subsequent 3-month period.

CONCLUSIONS

The AmED_EXPI appears to be a reliable and valid tool for measuring expectancies about the effects of caffeine during alcohol intoxication.

Alcohol Mixed with Energy Drinks: Daily Context of Use

BACKGROUND

The link between use of alcohol mixed with energy drinks (AmEDs) and alcohol-related harms is well established, but limited research has examined the context in which AmEDs are consumed. Identifying the social and environmental characteristics of use may illuminate whether AmEDs are used in settings that could increase the likelihood of engaging in risky behaviors or experiencing harms. This study used a 2-week daily diary assessment to compare days in which AmEDs were consumed ("AmED days") and days where other types of alcohol were used ("non-AmED days") on where, when, and with whom drinking occurred.

METHODS

Participants were 122 (90 women) heavy drinking college students who reported mixing caffeine with alcohol at least once in the past week. Data were collected across 389 drinking days; 40 of these days involved AmED use.

RESULTS

Multilevel modeling findings revealed that odds of drinking AmEDs were higher on days where individuals drank at a bar or club and drank at home relative to other locations. In addition, odds of pregaming were higher on AmED days as compared to non-AmED days. AmED use was linked with lower odds of drinking game behavior.

CONCLUSIONS

Overall, AmEDs appear to be consumed in potentially risky contexts. In combination with prior findings that AmED days are linked with heavier alcohol use and more harms experienced, these findings support the unique nature of AmED consumption in terms of the factors that may predict or maintain potentially hazardous drinking patterns.

Effects of caffeine on alcohol reinforcement: beverage choice, self-administration, and subjective ratings

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). The 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 that 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.

Consumption of energy drinks among Québec college students

OBJECTIVES

Consumption of energy drinks (ED) raises concerns because of adverse health effects possibly linked with high levels of caffeine and sugar intake. The study looks at the scope of ED consumption as well as some of the associated characteristics.

METHODS

Thirty-six public colleges in the Canadian province of Québec agreed to participate in a descriptive cross-sectional study (n = 36). In February 2013, participating colleges invited their students to answer an online questionnaire on consumption of ED, alcoholic ED (AED), and ED in combination with other psychotropic drugs. A descriptive and correlational analysis was carried out. Logistic regressions explored associations between ED consumption and associated characteristics.

RESULTS

Of the students who successfully completed the questionnaire and participated in the study (n = 10,283), a low proportion consumed ED (9.1%; n = 935) and/or AED (1.1%; n = 109) at least once a week in the previous month. Although low in proportion, a number of participants reported having used ED with other stimulant psychoactive substances (n = 247) and ≥3 ED/day (n = 193) or ≥3 AED/occasion (n = 167), which can pose a risk for serious adverse effects. Weekly ED consumption was associated with consumption of ≥20 cups of coffee/week, smoking, excessive use of alcohol and past use of cannabis, glues or solvents and amphetamines.

CONCLUSION

A majority of respondents are not heavy users of ED, AED, or ED with drugs. Yet, the profiles of ED consumption potentially harmful to health that characterize some participants indicate that the potential health consequences of such behaviour are of concern.

Faster self-paced rate of drinking for alcohol mixed with energy drinks versus alcohol alone

The consumption of alcohol mixed with energy drinks (AmED) has been associated with higher rates of binge drinking and impaired driving when compared with alcohol alone. However, it remains unclear why the risks of use of AmED are heightened compared with alcohol alone even when the doses of alcohol consumed are similar. Therefore, the purpose of this laboratory study was to investigate if the rate of self-paced beverage consumption was faster for a dose of AmED versus alcohol alone using a double-blind, within-subjects, placebo-controlled study design. Participants (n = 16) of equal gender who were social drinkers attended 4 separate test sessions that involved consumption of alcohol (1.97 ml/kg vodka) and energy drinks, alone and in combination. On each test day, the dose assigned was divided into 10 cups. Participants were informed that they would have a 2-h period to consume the 10 drinks. After the self-paced drinking period, participants completed a cued go/no-go reaction time (RT) task and subjective ratings of stimulation and sedation. The results indicated that participants consumed the AmED dose significantly faster (by ∼16 min) than the alcohol dose. For the performance task, participants' mean RTs were slower in the alcohol conditions and faster in the energy-drink conditions. In conclusion, alcohol consumers should be made aware that rapid drinking might occur for AmED beverages, thus heightening alcohol-related safety risks. The fast rate of drinking may be related to the generalized speeding of responses after energy-drink consumption. (PsycINFO Database Record