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

Concomitant caffeine increases voluntary alcohol consumption in male, but not female, adolescent C57BL/6J mice

BACKGROUND

The notion that stimulating qualities of energy drinks reduce overall depressant effects of alcohol has resulted in an increase in the popularity of combining energy drinks with alcohol among young adults and teenagers. Alcohol misuse often emerges during or shortly after vulnerable adolescent years. Even though energy drinks are frequently advertised to and enjoyed by adolescents, there are limited investigations on the neurobehavioral effects of combining caffeine with alcohol during adolescence. This study sought to examine the impact of exposing C57BL/6J adolescent mice to concurrent alcohol and caffeine.

METHODS

In the current study, adolescent (n = 98, 50 males and 48 females) C57BL/6J mice were given access to two bottles using an intermittent access (IA) two-bottle choice drinking paradigm for a total of 4 weeks. The experimental bottle contained either caffeine (0.015% w/v), alcohol (10% v/v), or a combination of alcohol + caffeine at the aforementioned concentrations. Adolescent male and female mice were given free access to the substance(s) for 24 h, after which the experimental bottle was taken away for another 24 h.

RESULTS

Male adolescent mice consumed significantly more alcohol when combined with caffeine compared to male adolescent mice that had access to alcohol alone. Further, this trend was shown only in male adolescent mice and not in female adolescent mice, as females did not show any differences in alcohol consumption regardless of whether there was caffeine in the mixture. Ten days following the final removal of alcohol and/or caffeine bottles, mice were given a secondary bottle containing alcohol (10%) for 24 h. Male mice previously exposed to alcohol + caffeine consumed a significantly higher quantity of alcohol during the 24-h challenge period.

CONCLUSIONS

These data suggest that adolescent males may be more vulnerable to consuming higher amounts of alcohol when combined with caffeinated beverages.

Simultaneous use of alcohol, cannabis, and energy drinks predicts increased daily alcohol consumption and alcohol consequences

Simultaneous alcohol and cannabis (SAM) use and alcohol mixed with energy drinks (AmED) days are associated with heavier drinking and negative consequences compared to alcohol-only days. However, it remains unclear if SAM and AmED days differ from one another in terms of consumption and negative consequences. It also remains unclear how often days characterized by both SAM + AmED occur and if these days are associated with incremental risk for heavier drinking and negative consequences. College students who engage in SAM use and AmED completed a 30-day timeline followback interview. Day-level data on drinking days were curated to test whether days characterized by alcohol only, SAM use only, AmED use only, or SAM + AmED were associated with increased drinking quantity, negative alcohol consequences, and positive alcohol consequences. Twenty-one percent of drinking days were AmED days, 19% were SAM days, and 15.4% were SAM + AmED days. SAM-only, AmED-only, and SAM + AmED days were associated with increased drinking and negative consequences compared to alcohol-only days. However, SAM-only and SAM + AmED (but not AmED-only) days were associated with more positive consequences than alcohol-only days. SAM-only and AmED-only days did not differ in drinking quantity or consequences, whereas SAM + AmED days were associated with increased drinking and negative (but not positive) consequences compared to both SAM-only and AmED-only days. Combined SAM + AmED days are common and associated with increased risk for negative outcomes. Prevention efforts should consider how to reduce the occurrence of SAM + AmED use and how to reduce risk on days when it does occur. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Attitudes and consumption habits of energy drinks among adolescents and young adults in a Spanish population

Nowadays, the consumption of energy drinks (ED) is increasing exponentially in Western society. This has been widely associated with physical (arrhythmias, headaches, etc.), psychological (anxiety, depression, etc.), and social issues (risky behaviors such as excessive alcohol consumption, etc.). The present study aimed to investigate the consumption habits of energy drinks (ED) among adolescents and young adults in the Spanish population and their attitudes toward these drinks, as well as the factors influencing their consumption. A cross-sectional descriptive study based on a voluntary online questionnaire was conducted with a sample of 387 participants. Amongst participants, 38.8% consumed ED, and the youngest (14-18 years old) in this group were the most likely to mix them with alcohol and the least likely to consider them harmful (32.1%, p < 0.001; and 8.9%, p < 0.002, respectively). Male respondents and people who vaped were more likely to consume ED (OR = 2.94, CI = 1.76-4.93, p < 0.001; and OR = 3.18, CI = 1.91-8.00, p < 0.001, respectively). Social and healthcare policies should be proposed in order to reduce the consumption of ED, particularly among young people, provided that it is associated with other risky behaviors and the occurrence of adverse events.

Acute Cardiovascular Effects of Simultaneous Energy Drink and Alcohol Consumption in Young Adults: A Review of Case Reports

(1) Background: The aim of this review was to identify and summarize adverse cardiovascular health events associated with the simultaneous consumption of energy drinks (ED) and alcohol. Potential prevention strategies and the implementation of research toward the underlying mechanisms for these pathologies were highlighted to emphasize the need for further investigation and to encourage more attention to this field. (2) Methods: The PubMed database was searched for case reports linked with adverse cardiovascular events after simultaneous ED and alcohol consumption. Inclusion criteria were: the reported age of the patient is between 16 and 35 years and confirmed co-consumption of EDs and alcohol. All relevant articles that met the inclusion criteria were fully read and all relevant data was extracted. The extracted data was summarized and presented in this review of cases. (3) Results: In total, 10 cases were identified. The analysis showed that mainly young adults (median age = 24.5 years), in particular men (80%) were affected. The three parts of the cardiovascular system affected were heart rhythm (42%), myocardial function (33%), and coronary arteries (25%). In 3 cases the outcome was fatal. Moreover, preexisting health conditions and/or potential trigger factors were present in 60% of selected cases. (4) Conclusions: This review of case reports suggests that the simultaneous consumption of EDs and alcohol can lead to adverse cardiovascular health events and even incidents with fatal outcomes were reported. Potential trigger factors and preexisting health conditions seem to increase the probability of adverse cardiovascular health events. Consumers should be informed about the potential risks and follow responsible consumption behavior to prevent future health events. More systematic studies are needed to determine the acute effects on the cardiovascular system in young adults.

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 and energy drinks: individual contribution of common ingredients on ethanol-induced behaviour

Since energy drinks (EDs) were sold to the general public as soft drinks and recreational beverages, mixing EDs with ethanol has grown in popularity, particularly among younger people. Given the research that links these drinks with higher risk behaviors and increased ethanol intake, ethanol combined with EDs (AmEDs) is a particularly worrying combination. EDs generally commonly include a variety of ingredients. Sugar, caffeine, taurine, and B-group vitamins are almost always present. Studies on the combined effect of ethanol and sugar and caffeine on ethanol-induced behaviors are extensive. Not so much in regards to taurine and vitamins. This review briefly summarises available information from research on the isolated compounds on EtOH-induced behaviors first, and secondly, the combination of AmEDs on EtOH effects. The conclusion is that additional research is needed to fully comprehend the characteristics and consequences of AmEDs on EtOH-induced behaviors.

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.

Effect of intermittent access to alcohol mixed in energy drink during adolescence on alcohol self-administration, anxiety, and memory during adulthood in rats

BACKGROUND

Mixing alcohol with caffeinated energy drinks is a common practice among young people. Consumption of alcohol mixed in energy drink is associated with increased risk of binge drinking and alcohol dependence. The purpose of this study was to determine whether voluntary intermittent access to alcohol mixed in energy drink in adolescent rats alters adult self-administration of alcohol, anxiety, and memory.

METHODS

For 10 weeks in the home-cage, two groups of adolescent female Sprague-Dawley rats had intermittent access to energy drink (ED) or 10% alcohol mixed in energy drink (AmED) with water concurrently available. Other rat groups had daily continuous access to ED or AmED. Anxiety was measured with an open field test and memory was assessed with a novel place recognition test. For self-administration, rats pressed levers for 10% alcohol alone on a fixed ratio (FR1) and on a progressive ratio (PR).

RESULTS

Intermittent access to AmED generated greater intake during the initial 30 min of access (AmED 1.70 ± 0.04 g/kg vs. ED 1.01 ± 0.06 g/kg) and during the subsequent 24 h (AmED 7.04 ± 0.25 g/kg vs. ED 5.60 ± 0.29 g/kg). Intermittent AmED caused a significant but small decrease in anxiety while neither ED nor AmED altered memory. During alcohol self-administration, group differences emerged only during PR testing during which intermittent AmED rats responded more than all other groups.

CONCLUSIONS

These findings suggest that intermittent access to AmED generates binge-like consumption that supports human findings that AmED generates greater alcohol consumption. Furthermore, experience with AmED may alter the motivational properties of alcohol into adulthood without necessarily causing a major impact on anxiety or memory.

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.

Risky behaviors, substance use, and other lifestyle correlates of energy drink consumption in children and adolescents: a systematic review

Increasing concerns have been raised on the health-related risks connected with energy drink (ED) consumption in children and adolescents, with high acute or chronic consumers exceeding 10% in either age group in Europe in 2011. Preliminary evidence has suggested a common pattern of ED and substance use, especially alcohol. Additional evidence has been accumulating very fast; in addition, other lifestyle and risky behaviors may contribute to shed light on the complex interplay of factors involved in ED consumption. We have undertaken a comprehensive systematic review of the evidence on psychosocial correlates of ED consumption in 0-18 years subjects, as published up to April 1, 2021, in MEDLINE/PubMed, PsycINFO, and Cochrane Reviews and Central Register of Controlled Trials, which allowed to select 104 original articles. Only ~ 10% of the papers provided results based on longitudinal analyses. A common pattern of ED consumption and polysubstance use, including alcohol, tobacco, and soft and hard drugs, was still confirmed in adolescents; violent and risky behaviors were also related to a higher ED consumption. In addition, frequent ED consumers are more likely to have bad dietary habits, including consumption of sugar-sweetened beverages and junk foods. A generally inconclusive evidence was found for sport/physical activities, although sedentary behaviors were generally related to ED consumption.

CONCLUSIONS

Frequent ED consumption might be a screening indicator to identify students at risk of substance use or other risky/problem behaviors; enquiring about an adolescent's recent ED consumption could create opportunities for early intervention/prevention by informed pediatricians.

WHAT IS KNOWN

• Substances, especially alcohol, are associated with energy drinks in most cross-sectional studies.

WHAT IS NEW

• Violent behaviors are associated with energy drink consumption, in the absence of longitudinal studies; problematic use of internet/videogames deserves further investigation; unhealthy dietary patterns are related to energy drinks; evidence on physical activity is inconclusive, but sedentary behaviors are related to energy drinks.

An on-premise study to investigate the effects of mixing alcohol with caffeinated beverages

OBJECTIVE

The purpose of this on-premise study was to determine if mixing alcohol with caffeinated mixers had an impact on objective and subjective intoxication.

METHODS

The study was conducted across eight drinking occasions in the City of Bristol, UK. Participants (N = 1041) were recruited outside popular night-time entertainment venues and interviewed regarding their alcohol consumption for that particular evening, including whether or not they had consumed caffeinated beverages with alcohol. Subjective intoxication was rated on an 11-point scale and objective intoxication determined with a breath alcohol test. Depending on their consumption on the night of the interview, participants also reported whether they consumed alcohol mixed with caffeinated mixers or alcohol-only on other consumption occasions.

RESULTS

Between-subjects analyses found that alcohol-caffeine consumers consumed more alcohol and had higher objective and subjective intoxication than those who consumed alcohol-only. These results remained significant regardless of whether or not they mixed alcohol with caffeinated mixers or consumed alcohol-only on the night of the interview. Within-subject analyses revealed that alcohol-caffeine consumers drank the same or less alcohol on alcohol-caffeine occasions compared to alcohol-only occasions.

CONCLUSIONS

These findings provide support that alcohol-caffeine use does not increase overall alcohol consumption, and may be one manifestation of a high risk-taking personality.

Consumption and effects of caffeinated energy drinks in young people: an overview of systematic reviews and secondary analysis of UK data to inform policy

BACKGROUND

This overview and analysis of UK datasets was commissioned by the UK government to address concerns about children's consumption of caffeinated energy drinks and their effects on health and behaviour.

METHODS

We searched nine databases for systematic reviews, published between 2013 and July 2021, in English, assessing caffeinated energy drink consumption by people under 18 years old (children). Two reviewers rated or checked risk of bias using AMSTAR2, and extracted and synthesised findings. We searched the UK Data Service for country-representative datasets, reporting children's energy-drink consumption, and conducted bivariate or latent class analyses.

RESULTS

For the overview, we included 15 systematic reviews; six reported drinking prevalence and 14 reported associations between drinking and health or behaviour. AMSTAR2 ratings were low or critically low. Worldwide, across reviews, from 13% to 67% of children had consumed energy drinks in the past year. Only two of the 74 studies in the reviews were UK-based. For the dataset analysis, we identified and included five UK cross-sectional datasets, and found that 3% to 32% of children, across UK countries, consumed energy drinks weekly, with no difference by ethnicity. Frequent drinking (5 or more days per week) was associated with low psychological, physical, educational and overall well-being. Evidence from reviews and datasets suggested that boys drank more than girls, and drinking was associated with more headaches, sleep problems, alcohol use, smoking, irritability, and school exclusion. GRADE (Grading of Recommendations, Assessment, Development and Evaluation) assessment suggests that the evidence is weak.

CONCLUSIONS

Weak evidence suggests that up to a third of children in the UK consume caffeinated energy drinks weekly; and drinking 5 or more days per week is associated with some health and behaviour problems. Most of the evidence is from surveys, making it impossible to distinguish cause from effect. Randomised controlled trials are unlikely to be ethical; longitudinal studies could provide stronger evidence.

PROSPERO REGISTRATIONS

CRD42018096292 - no deviations. CRD42018110498 - one deviation - a latent class analysis was conducted.

A Comparison Between Ecological Momentary Assessment and the Adapted-Quick Drinking Screen: Alcohol Mixed With Energy Drinks

Aims

To compare alcohol consumption and risk-taking behaviours on alcohol mixed with energy drink (AMED) and alcohol-only (AO) drinking occasions collected via ecological momentary assessment (EMA) versus retrospective survey methods (adapted-Quick Drinking Screen: a-QDS).

Methods

Completing participants were 52 university students who reported AMED consumption during the 30-day data collection period. Alcohol consumption and risk-taking behaviours were captured for recreational AMED and AO consumption occasions using a smartphone-based app across 30 days. Data were aggregated for comparison with the a-QDS conducted at the end of data collection.

Results

Irrespective of data collection method, alcohol was consumed more frequently and at higher quantities on the heaviest drinking occasions when consumed alone compared with when it was mixed with energy drinks. Consistent with this finding, more risk-taking behaviours were experienced on AO occasions compared with AMED occasions. Compared with the a-QDS, the quantity of alcohol consumed on the average and heaviest drinking occasion was significantly higher when reported via EMA. This was consistent across both AO and AMED drinking occasions.

Conclusion

EMA provides a more valid measure of consumption quantity compared with retrospective recall, which was susceptible to under-reporting, although this was not differentially affected across consumption occasions. In line with previous research, this study demonstrated that mixing alcohol with energy drinks does not increase alcohol consumption or risk-taking behaviours.

Interaction of Energy Drinks with Prescription Medication and Drugs of Abuse

In recent years, the consumption of energy drinks (EDs) has become increasingly popular, especially among adolescents. Caffeine, a psychostimulant, is the main compound of EDs which also contain other substances with pharmacological effects. This review aims to compile current evidence concerning the potential interactions between EDs, medicines, and drugs of abuse as they are frequently consumed in combination. The substances involved are mainly substrates, inductors or inhibitors of CYP1A2, psychostimulants, alcohol and other depressant drugs. Furthermore, intoxications reported with EDs and other substances have also been screened to describe acute toxicity. The results of our review show that the consumption of both EDs alone and in combination is not as safe as previously thought. Health professionals and consumers need to be aware of the potential interactions of these drinks as well as the absence of long-term safety data.

Effects of Mixing Energy Drinks With Alcohol on Driving-Related Skills

BACKGROUND

Energy drinks (EDs) reduce sleepiness and fatigue and improve driving performance whereas alcohol does just the opposite. Although it is a trendy combination among young people, the effects of alcohol mixed with EDs on driving performance have been poorly studied. The aim was to assess if there is an interaction between the effects of both drinks on driving-related skills as well as perceptions about driving ability.

METHODS

We conducted a randomized, double-blind, and placebo-controlled 4-way crossover clinical trial. Participants were 16 healthy volunteers. Interventions of 60 g of ethanol and 750 mL of Red Bull (RB) were administered in 2 separated doses. Conditions were alcohol + RB placebo, alcohol + RB, alcohol placebo + RB, and both placebos. Objective performance was assessed using a tracking test and simple reaction time, N-Back, and movement estimation tasks. Additionally, willingness to drive, other subjective effects, and ethanol and caffeine blood concentrations were also measured.

RESULTS

Alcohol increased the time outside the road in the tracking test and increased simple reaction time, but the addition of RB had no main or interaction effects on performance. Nonetheless, driving-related skills after alcohol + RB were better than after alcohol alone. Willingness to drive increased with the combination of drinks. RB also reduced alcohol-induced sedation whereas drunkenness did not change. These effects were seen even though alcohol + RB increased alcohol (14.8%) and caffeine plasma concentrations (17.6%).

CONCLUSIONS

Mixing EDs with alcohol predisposes consumers to drive under alcohol influence, perhaps in part because EDs counteract its detrimental effects on driving-related skills. Clinicaltrials.gov: NCT02771587.

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.

A Cross-Cultural Comparison of the Effects of Alcohol Mixed with Energy Drink (AMED) Consumption on Overall Alcohol Consumption and Related Consequences

There is a growing body of scientific literature examining the effects of alcohol mixed with energy drink (AMED) on alcohol consumption and related negative consequences, such as risky behavior or negative health effects. It is unknown whether differences in cultural context may influence these AMED effects. The current cross-cultural study compared the data of N = 6881 students from The Netherlands (N = 4424), UK (N = 1594), and Australia (N = 863). Demographics, alcohol consumption, its consequences, and motives for AMED consumption were assessed. Analyses included (a) between-groups comparison of AMED and alcohol only (AO) consumers, (b) within-subjects comparison of AMED and AO occasions among AMED consumers only, and (c) comparisons between the three countries. The between-groups analysis revealed that AMED consumers drink more alcohol than AO consumers (p < 0.001). AMED consumers differed from AO consumers in many other aspects. For example, AMED consumers were significantly more often a smoker and had higher risk-taking scores. Within subject analysis among AMED consumers showed that significantly less alcohol was consumed on AMED, compared to AO occasions (p < 0.001). These findings were observed for both typical drinking occasions and the past month's heaviest drinking occasion, and were consistent across the three countries. Comparisons between countries revealed that on both AMED and AO occasions, the UK sample consumed significantly more alcohol than the Australian and Dutch samples. Across countries, neutral motives such as 'I like the taste' and 'I wanted to drink something else' were the most frequently reported motives for consuming AMED. The most notable difference between the countries was the finding that consuming AMED 'To get drunk' was endorsed significantly more often among the UK sample (45.6%) than the Australian (31.2%) and Dutch (8.0%) samples. Negative alcohol-related consequences were significantly less frequently reported for AMED occasions compared to AO occasions. Some country-specific consequences of AMED consumption were observed, but these were more likely related to characteristics of the country and their drinking culture (e.g., the Australian sample reported more often driving a car after AMED consumption compared to the other countries, and this pattern of results was also found for AO occasions). In conclusion, there were limited differences between countries with regard to demographics of consumers and motives for AMED consumption, but the UK sample consumed significantly more alcohol and reported the highest frequency of negative alcohol related consequences. Consistent across countries was the observation that AMED consumers consume significantly less alcohol on their past month heaviest AMED drinking occasion, compared to their past month heaviest AO drinking occasion.

Low but not moderate amounts of caffeine increase co-consumption of ethanol in C57BL/6J mice

The increasingly popular combination of "energy drinks" containing high amounts of caffeine and alcohol has been shown to induce a stimulated, rather than sedated, state which may result in increased binge drinking and increased risk for alcohol-attributable accidents. We sought to examine consumption patterns of and withdrawal from alcohol and caffeine using a voluntary co-consumption animal model. Male and female adult C57BL/6J mice were given access to increasing doses of caffeine (0.01-0.05%) and/or alcohol (3-20%) in a two-bottle choice, intermittent access voluntary paradigm with fluid consumption recorded daily. Anxiety-like behavior during withdrawal was assessed via elevated plus maze or open field test in experiment 2. Increasing both alcohol and caffeine simultaneously in Experiment 1 resulted in no significant changes in co-consumption compared to mice given access to only alcohol or caffeine. Experiment 2 held caffeine concentration steady while slowly increasing alcohol content and resulted in mice consuming more alcohol when it was consumed in tandem with low dose caffeine. Both male and female mice consumed more caffeine when it was paired with alcohol; however, no significant differences were observed during withdrawal behavior. These results suggest that caffeine may dose-dependently positively influence alcohol consumption in mice and echo clinical literature suggesting that caffeine and alcohol together may result in a heightened state of stimulation and lead to further binge drinking. The intermittent access paradigm affords increased translational validity regarding investigations of alcohol and caffeine co-consumption and may be useful in identifying the neurobiological mechanisms concerning co-consumption of such substances.

Risk-Taking Behavior and the Consumption of Alcohol Mixed with Energy Drink among Australian, Dutch and UK Students

The relationship between risk-taking behavior, alcohol consumption and negative alcohol-related consequences is well known. The current analyses were conducted to investigate whether alcohol mixed with energy drink (AMED) is related to risk-taking behavior and if there is a relationship between the amount of energy drink mixed with alcohol consumed, risk-taking behavior and negative alcohol-related consequences. Data from N = 1276 AMED consuming students from the Netherlands, UK and Australia who completed the same survey were evaluated. The analysis revealed that, compared to AMED occasions, on alcohol only (AO) occasions significantly more alcohol was consumed and significantly more negative alcohol-related consequences were reported. On both AO and AMED occasions, there was a strong and positive relationship between amount of alcohol consumed, level of risk-taking behavior and number of reported negative alcohol-related consequences. In contrast, the level of risk-taking behavior was not clearly related to energy drink consumption. Across risk-taking levels, differences in the amount of energy drink consumed on AMED occasions did not exceed one 250 mL serving of energy drink. When correcting for the amount of alcohol consumed, there were no statistically significant differences in the number of energy drinks consumed on AMED occasions between the risk-taking groups. In conclusion, alcohol consumption is clearly related to risk-taking behavior and experiencing negative alcohol-related consequences. In contrast, energy drink intake was not related to level of risk-taking behavior and only weakly related to the number of experienced negative alcohol-related consequences.

The Relationship Between Energy Drink Consumption, Caffeine Content, and Nutritional Knowledge Among College Students

We sought to determine which demographic characteristics influence energy drink consumption habits and to examine whether caffeine content and knowledge of human nutrition affect college students' decisions to consume these beverages. We used an online survey to ask 265 college students, who did not participate in a varsity sport, to complete a survey consisting of demographic questions, the General Knowledge Questionnaire for adults, and questions about energy drink consumption habits. We found, overall, that 23.1% of our sample used energy drinks. When compared to non-consumers (76.9%), users had a significantly lower GPA, were older, and preferred drinks with a higher caffeine content. Users reported that they consumed these drinks because they wanted to feel more alert and they enjoyed the taste, even though they reported adverse effects such as trouble sleeping, shaking and tremors, and stomachaches. Knowledge of human nutrition did not affect users' choice to consume these drinks. Although the majority of college students do not consume energy drinks, room for improvement remains to curb the use of these caffeinated beverages amongst college students.

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.

Alcohol mixed with energy drinks: what about taurine?

RATIONALE

Since energy drinks (EDs) were marketed to the general public as recreational and soft drinks, mixing these with alcohol has become a popular practice, especially in the younger population. Alcohol mixed with EDs (AmEDs) is a particularly alarming combination, given the evidence that consistently associate these drinks with increased risk behaviours and greater alcohol consumption. Caffeine and taurine are commonly found in EDs. In contrast to caffeine, the studies on taurine psychoactive properties and how this amino acid influences ethanol intake alone or in combination with caffeine are not so numerous.

OBJECTIVES

We summarised relevant and available data on the studies focusing on taurine as a psychoactive agent and its influence on ethanol (EtOH)-induced behaviours. Given the increased risk that represents mixing alcohol with energy drinks, we put emphasis on the research exploring the impact of these combinations on motivated behaviour towards EtOH consumption.

RESULTS

The research on taurine properties on motivated behaviour towards EtOH consumption is limited, and mostly all done in combination with caffeine or other molecules. This makes it difficult to elucidate the effect of this amino acid when combined with alcohol.

CONCLUSIONS

Incomplete understanding of the properties and effects of AmEDs is unavoidable until more studies are performed on the influence of taurine on motivation to consume alcohol. Taurine should be further explored, particularly in regard to its potential beneficial applications, motivational properties and synergies with other psychoactive ingredients (i.e. caffeine).

Energy Drinks and Their Adverse Health Effects: A Systematic Review and Meta-analysis

CONTEXT

Energy drinks are the fastest growing product in the beverage industry. However, there is concern regarding potential for adverse effects with use.

OBJECTIVE

To evaluate the reported adverse effects of energy drink consumption.

DATA SOURCES

The electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies from inception to November 2019, and pertinent data were abstracted.

STUDY SELECTION

Only clinical studies reporting adverse events after energy drink consumption were included.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Data regarding sample size characteristics, energy drink characteristics, comparators, and all adverse events were extracted in duplicate and recorded.

RESULTS

A total of 32 studies and 96,549 individuals were included. Frequently reported adverse events in the pediatric population were insomnia (35.4%), stress (35.4%), and depressive mood (23.1%). Frequently reported adverse events in the adult population were insomnia (24.7%), jitteriness/restlessness/shaking hands (29.8%), and gastrointestinal upset (21.6%). Alcohol mixed with energy drinks significantly reduced the likelihood of sedation effects but increased the likelihood of stimulatory effects. Energy drink consumption significantly increased the odds of insomnia (OR, 5.02; 95% CI, 1.72-14.63) and jitteriness/activeness (OR, 3.52; 95% CI, 1.28-9.67) compared with the control group.

CONCLUSION

The authors recommend that individuals avoid frequent energy drink consumption (5-7 energy drinks/week) and avoid co-consumption with alcohol; increased regulatory standards should be placed in the sale of energy drinks, particularly with regard to the pediatric population.

Consumption Patterns of Alcohol and Alcohol mixed with Energy Drinks in Australian Students and Non-Students

Studies assessing alcohol mixed with energy drink (AMED) use and drinking behaviors have been largely restricted to student-only cohorts. Thus, it is not known whether evidence from these studies is applicable to non-student populations. This study examined alcohol consumption and involvement in negative alcohol-related consequences among AMED and alcohol-only (AO) users, with the aim of determining whether drinking behaviors differ according to student status. An online survey was conducted in Australia to assess alcohol consumption and alcohol-related consequences following AMED and AO consumption, according to student status. The final sample consisted of 1369 participants. Between-subjects analyses comparing AMED and AO users, confirmed previous findings in that, compared with AO users, AMED users consumed significantly more alcohol, consumed alcohol more frequently and were involved in a greater number of alcohol-related consequences. Within-subjects analyses of AMED users comparing AMED and AO drinking occasions revealed that significantly less alcohol was consumed and involvement in negative alcohol-related consequences was lower during AMED compared with AO drinking occasions. Regardless of drink type, compared with students, non-students consumed more alcohol, consumed alcohol more frequently and were involved in a greater number of negative alcohol-related consequences. These findings provide further evidence that AMED use is one manifestation of a risk-taking personality and suggest that non-students drink more alcohol, drink more frequently and are involved in a greater number of negative alcohol-related consequences than students.

Use of Alcohol Mixed with Energy Drinks Increases the Prevalence of Driving Violations among Brazilian Truck Drivers

Background: The use of alcohol mixed with energy drinks (AmED) has been reported to be associated with a variety of unsafe driving practices. Truck drivers are vulnerable to driving violations, particularly because of their engagement in drug use. The use of AmED among these professionals remains unknown. Aim: To estimate the prevalence of AmED use and its association with driving violations among truck drivers. Methods: 684 drivers were recruited in Sao Paulo, Brazil. The use of drugs was reported. Drivers were split into three groups: (a) alcohol abstainers (AA); (b) alcohol-only users (AO); and (c) users of AmED. Intergroup comparisons were performed by polynomial logistic regression (the reference category was AO). We also performed Poisson regression analysis to obtain the prevalence ratio; the significance level was stipulated at 5%. Results: The prevalence of drivers reporting the use of AmED was 16.8%. Users of AmED (a) were younger, (b) were less experienced drivers, (c) had a heavier pattern of alcohol use, (d) used illicit drugs more frequently, and (e) had poorer sleep quality than AO subjects. A higher prevalence of drivers who had arguments or fights while driving (PR = 1.71) and of drivers who drove unbelted (PR = 1.66) ingested AmED than of AO subjects. Conclusions/importance: The use of AmED increased the prevalence of driving violations beyond the risks commonly attributed to alcohol use. We suggest additional investments in preventative measures based on the beverage category and a revision of the work organization of truck drivers to reduce their health and social risks.

Age at first alcohol use predicts current alcohol use, binge drinking and mixing of alcohol with energy drinks among Ontario Grade 12 students in the COMPASS study

INTRODUCTION

This study investigates the influence of age at first use of alcohol on current alcohol use and associated behaviours in a large sample of Canadian youth.

METHODS

This descriptive-analytical study was conducted among Ontario Grade 12 students enrolled in the COMPASS Host Study between 2012 and 2017. We used generalized estimating equations (GEE) modelling to determine associations between age at first alcohol use and likelihood of current versus non-current alcohol use, binge drinking and mixing of alcohol with energy drinks among respondents.

RESULTS

Students reporting an age at first alcohol use between ages 13 and 14 years were more likely to report current alcohol use versus non-current use (OR = 2.80, 95% CI: 2.26-3.45) and current binge drinking versus non-current binge drinking (OR = 3.22, 95% CI: 2.45-4.25) compared to students reporting first alcohol use at age 18 years or older. Students who started drinking at 8 years of age or younger were more likely to report current versus non-current alcohol use (OR = 3.54, 95% CI: 2.83-4.43), binge drinking (OR = 3.99, 95% CI: 2.97-5.37), and mixing of alcohol with energy drinks (OR = 2.26, 95% CI: 1.23-4.14), compared to students who started drinking at 18 years or older.

CONCLUSION

Starting to drink alcohol in the early teen years predicted current alcohol use, current binge drinking and mixing of alcohol with energy drinks when students were in Grade 12. Findings indicate a need for development of novel alcohol prevention efforts.

Caffeinated Alcoholic Beverages and Intimate Partner Violence Victimization

Background: Caffeinated alcoholic beverage (CAB) use is associated with general victimization beyond the use of alcohol alone. Materials and Methods: No prior research has evaluated the association between CAB use and intimate partner violence (IPV) victimization. This study evaluated the CAB-IPV victimization relationship using the responses of 100 (40 female) respondents to an online survey. Results: Results of logistic regression analyses indicated that CAB use was associated with IPV physical and sexual victimization after adjusting for demographics and heavy alcohol use. Exploratory analyses detected little evidence of sex differences in the strength of the relationship between CAB use and IPV victimization. Conclusions: The current results provide initial evidence that CAB use may place males and females at greater risk of IPV victimization.

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.

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.

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.