Caffeinated energy drinks--a growing problem

Association between energy drink consumption, depression and suicide ideation in Korean adolescents

BACKGROUND

Suicide is the leading cause of death among adolescents in South Korea. Negative influences of the abuse of energy drinks on mental health problems have emerged.

AIMS

This study aimed to analyze the relationship between energy drink consumption, depression and suicide ideation.

METHODS

We analyzed the data of 26,346 boys and 26,966 girls who participated in the 2015 Korean Youth Risk Behavior Web-Based Survey. The independent variable was the frequency of energy drink consumption per week. Experience of depression and suicide ideation were considered as the dependent variables. Multiple logistic regression was performed.

RESULTS

An association was found between energy drink intake per week and depressive mood. Moreover, the most frequent energy drink intake (three times or more per week) group showed the highest association with depressive mood (odds ratios (ORs); boys: ORs = 1.40, 95% confidence interval (CI): 1.25-1.56; girls: ORs = 1.61, 95% CI: 1.44-1.79) and suicide ideation (boys: ORs = 1.46, 95% CI: 1.27-1.69; girls: ORs = 1.36, 95% CI: 1.20-1.55).

CONCLUSION

We observed that consumption of excessive amounts of energy drinks is associated with depression and suicide ideation. Therefore, appropriate regulation or education is needed to prevent adolescents from experiencing adverse outcomes.

Energy drink consumption, psychological distress, and suicidality among middle and high school students

BACKGROUND

Previous research has found links between energy drink consumption and mental health outcomes in youth. However, little is known about the factors that could moderate these relationships. The present study examined the associations between energy drink consumption and psychological distress, suicidal thoughts, and suicide attempts among adolescents, and tested whether sex and school type (i.e. middle vs. high school) would moderate these associations.

METHODS

Data on students in grades 7 through 12 was obtained from the 2017 Ontario Student Drug Use and Health Survey (N  =  5,538). Multivariable Poisson regression analyses were used to examine associations between energy drink consumption and mental health outcomes. Analyses were weighted and adjusted for the complex survey design.

RESULTS

Energy drink consumption was associated with greater risk of moderate to serious (adjusted incidence rate ratio (IRR) 1.19, 95% confidence interval (CI) 1.03-1.37) and serious (IRR: 1.45, 95% CI: 1.13-1.86) levels of psychological distress, suicidal thoughts (IRR: 1.98, 95% CI: 1.62-2.42), and suicide attempts (IRR: 3.67, 95% CI: 2.26-5.95). The association between energy drink consumption and mental health outcomes was much stronger among boys and middle school students.

LIMITATIONS

The cross-sectional nature of the data precludes causal inferences and there is possibility of bias related to self-reports.

CONCLUSIONS

Energy drink consumption among adolescents is strongly and differentially associated with mental health problems among male and female middle and high school students. Future research is necessary to replicate and disentangle the observed differences in more detail to inform the development of tailored interventions.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusion

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

Energy Drink Consumption and Substance Use Among Middle and High School Students

This study examined the association between energy drink consumption and substance use among adolescents and tested whether sex and/or grade level (i.e., middle vs. high school) moderate the association. Data were derived from the 2017 Ontario Student Drug Use and Health Survey, a representative survey of students in 7th to 12th grade. Analyses included 10,662 students who self-reported information on energy drink consumption and substance use. Poisson regression models were used with adjustments for important covariates. Energy drink consumption was associated with tobacco cigarette smoking (incidence rate ratio (IRR): 3.74; 95% confidence interval (CI): 3.22-4.35), cannabis use (IRR: 2.90; 95% CI: 2.53-3.32), binge drinking (IRR: 2.46; 95% CI: 2.05-2.96), opioid use (IRR: 2.23; 95% CI: 1.85-2.68), and alcohol use (IRR: 1.31; 95% CI: 1.26-1.36). The associations of energy drink consumption with tobacco cigarette smoking, cannabis use, and alcohol consumption were modified by grade level (two-way interaction terms p < 0.05). The association between energy drink consumption and substance use was generally much stronger among middle school students compared with high school students. The findings suggest that middle school students may be more vulnerable to the negative effects of energy drinks in relation with substance use.

What Should We Do About Habitual Caffeine Use in Athletes?

Caffeine is a well-established ergogenic aid, demonstrated to enhance performance across a wide range of capacities through a variety of mechanisms. As such, it is frequently used by both athletes and non-athletes alike. As a result, caffeine ingestion is ubiquitous in modern society, with athletes typically being exposed to regular non-supplemental caffeine through a variety of sources. Previously, it has been suggested that regular caffeine use may lead to habituation and subsequently a reduction in the expected ergogenic effects, thereby blunting caffeine’s performance-enhancing impact during critical training and performance events. In order to mitigate this expected performance loss, some practitioners recommended a pre-competition withdrawal period to restore the optimal performance benefits of caffeine supplementation. However, at present the evidence base exploring both caffeine habituation and withdrawal strategies in athletes is surprisingly small. Accordingly, despite the prevalence of caffeine use within athletic populations, formulating evidence-led guidelines is difficult. Here, we review the available research regarding habitual caffeine use in athletes and seek to derive rational interpretations of what is currently known—and what else we need to know—regarding habitual caffeine use in athletes, and how athletes and performance staff may pragmatically approach these important, complex, and yet under-explored phenomena.

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

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

Mineral Composition Evaluation in Energy Drinks Using ICP OES and Chemometric Tools

This study reports the simultaneous determination of the total concentrations of Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, and Zn in 17  samples of commercial energy drinks through inductively coupled plasma optical emission spectrometry and multivariate methods, such as Pearson correlation and principal component analysis (PCA), in order to conduct a more thorough evaluation of the original data. The samples studied were stored in two types of containers (polyethylene terephthalate bottles and aluminum cans) and purchased in the city of Belém (State of Pará, Brazil). The results showed high Na content in energy drinks, followed by K, Ca, and Mg. The accuracy of the optimized method was evaluated with the certified reference materials to assess trace elements in water (NIST 1643e); the resultant recoveries varied from 83 to 105%. Energy drinks stored in cans presented higher levels of aluminum and magnesium, while those bottled in polyethylene terephthalate bottles had a higher K content. There were significant differences between the observed Na concentrations and the values dictated on the drink package. Furthermore, PCA explained 70.38% of the total variance, allowing for an evaluation of the degree of similarity between the energy drinks studied and showing that the main contributions to the formation of groups are related to Fe, Na, Mg, and Zn contents. These results will be used to better understand the distribution of inorganic elements contained in energy drinks.

Internet-delivered attentional bias modification training (iABMT) for the management of chronic musculoskeletal pain: a protocol for a randomised controlled trial

INTRODUCTION

Chronic musculoskeletal pain is a complex medical condition that can significantly impact quality of life. Patients with chronic pain demonstrate attentional biases towards pain-related information. The therapeutic benefits of modifying attentional biases by implicitly training attention away from pain-related information towards neutral information have been supported in a small number of published studies. Limited research however has explored the efficacy of modifying pain-related biases via the internet. This protocol describes a randomised, double-blind, internet-delivered attentional bias modification intervention, aimed to evaluate the efficacy of the intervention on reducing pain interference. Secondary outcomes are pain intensity, state and trait anxiety, depression, pain-related fear, and sleep impairment. This study will also explore the effects of training intensity on these outcomes, along with participants' perceptions about the therapy.

METHODS AND ANALYSIS

The study is a double-blind, randomised controlled trial with four arms exploring the efficacy of online attentional bias modification training versus placebo training theorised to offer no specific therapeutic benefit. Participants with chronic musculoskeletal pain will be randomised to one of four groups: (1) 10-session attentional modification group; (2) 10-session placebo training group; (3) 18-session attentional modification group; or (4) 18-session placebo training group. In the attentional modification groups, the probe-classification version of the visual-probe task will be used to implicitly train attention away from threatening information towards neutral information. Following the intervention, participants will complete a short interview exploring their perceptions about the online training. In addition, a subgroup analysis for participants aged 16-24 and 25-60 will be undertaken.

ETHICS AND DISSEMINATION

This study has been approved by the University of Southampton Research Ethics Committee. Results will be published in peer-reviewed journals, academic conferences, and in lay reports for pain charities and patient support groups.

TRIAL REGISTRATION NUMBER

NCT02232100; Pre-results.

Acute Effects of Red Bull Energy Drinks on Atrial Electromechanical Function in Healthy Young Adults

Energy drinks (EDs) are widely consumed by adolescents and young adults. Almost all kinds of arrhythmias have been reported following EDs consumption, most of which is atrial fibrillation (AF). Atrial conduction time prolongation and heterogeneous sinusal impulses propagation to the atriums are the key electrophysiological mechanisms leading AF. We aimed to evaluate the acute effects of Red Bull ED ingestion on atrial electromechanical conduction times in healthy young adults. After a 12-hour fasting, 54 healthy young adults consumed 330 mL of Red Bull ED. Atrial electromechanical coupling (PA), intra-atrial electromechanical delay (intra-AEMD), and interatrial electromechanical delay (inter-AEMD) were measured at baseline and 2-hour after Red Bull ED ingestion by echocardiographic tissue-Doppler imaging (TDI) method. PA-lateral (49.7 ± 11.2 vs 54.1 ± 11.0 msn, p = 0.001) and PA-septal (40.8 ± 9.1 vs 43.7 ± 10.5 msn, p = 0.032) times were statistically significantly prolonged after Red Bull ED ingestion. There was also a statistically significant increase in the duration of inter-AEMD (14.4 ± 10.6 vs 18.1 ± 8.5 msn, p = 0.010) after ED ingestion. It was showed that even a single can of ED can acutely increase atrial electromechanical conduction times in young adults. These findings may be the cause of ED-associated AF.

Association of energy drink consumption with substance-use initiation among adolescents: A 12-month longitudinal study

BACKGROUND

Aggressive marketing has resulted in exponential growth of energy drink sales in recent years. Despite growing concerns about the negative health effects of energy drinks, they are increasingly popular among young people. Little is known about temporal associations between energy drink consumption and other drug use, though some researchers have suggested that energy drink consumption reflects an entry into a drug-using lifestyle.

AIMS

The purpose of this study was to evaluate whether energy drink use among adolescents who have never tried substances is associated with a risk of initiating tobacco (i.e. cigarettes, e-cigarettes, and hookah) and alcohol use.

METHODS

A school-based longitudinal study of 3071 adolescents ages 9-17 years was conducted in six federal states of Germany. Data analyses involved two assessment waves that took place approximately 12 months apart: baseline (fall-winter of school year 2016-2017), and 12-month follow-up (fall-winter of school year 2017-2018).

RESULTS

Multilevel models revealed that energy drink use at baseline was associated with cigarette (odds ratio for energy drink ever use, 3.15 (95% confidence interval, 2.07-4.78 )), e-cigarette (odds ratio, 4.32 (95% confidence interval, 2.87-6.51)), hookah smoking (odds ratio, 3.15 (95% confidence interval, 2.06-4.82)), and alcohol use (odds ratio, 2.26 (95% confidence interval, 1.75-2.93)) initiation within 12 months.

CONCLUSIONS

These results raise the possibility that energy drinks may potentially act as a gateway drug to other substances. However, inferences regarding whether this association is or is not causal cannot yet be made.

Energy drinks

Purpose

This research aimed to study patterns of energy drinks (ED) consumption among university students and to identify the determinants for their preferences.

Design/methodology/approach

This cross-sectional study was conducted among 400 students from various departments of Jashore University of Science and Technology, Bangladesh, by convenience sampling. A self-administered, structured questionnaire was used to collect data.

Findings

About 52.3 per cent of the students were between 21 and 23 years of age, and half of them were male. More than half (53 per cent) of the students had consumed ED at least once in their lifetime. Only 22.1 per cent of these consumers had any knowledge of the ingredients in ED, and 4.3 per cent did not know the possible negative impacts. Bivariate analysis was performed to identify the variables significantly associated with ED consumption among students. The risks of ED consumption were found to be: male gender (Odds Ratio (OR) = 4.04; 95 per cent Confidence Interval (CI) = 2.36–6.92), father educated up to SSC (OR = 18.47; 95 per cent CI = 2.30–148.90) or college and above (OR = 17.01; 95 per cent CI = 2.31–135.60), smoker (OR = 3.87; 95 per cent CI = 1.61–9.35) and doing irregular physical activity (OR = 2.43; 95 per cent CI = 1.23–4.78).

Originality/value

ED consumption among university students is high, but their perception regarding the ingredients and potential health hazards is opaque. Therefore, it is imperative that at both community and individual levels, interventions should focus on educating and empowering individuals to make firm and positive decisions concerning their dietary habits and health.

[Prevalence and associated factors to energy drinks consumption among teenagers in the province of Barcelona (Spain)]

OBJECTIVE

To analyse the prevalence of energy drinks consumption among 4th year high school students in the province of Barcelona (Spain), and its association to sociodemographic characteristics and health related habits.

METHOD

Cross-sectional study including 8078 students from randomly selected high schools in 41 municipalities. Sociodemographic and health characteristics were collected from the Questionnaire on health related habits. Studied variables: energy drinks consumption, sociodemographic characteristics, health related habits and risk behaviours. Descriptive and bivariate analyses were performed. To analyse the factors associated with energy drinks consumption, logistic regression models were used, adjusting by sex and age and considering significance at p-value <0.05.

RESULTS

30.9% of the sample consumed energy drinks during the last week. According to the model, consumption was higher among men (odds ratio [OR]: 3.29; 95% confidence interval [95%CI]: 2.82-3.83), first generation migrants (OR: 2.46; 95%CI: 2.01-3.03), and children of parents without studies (OR: 3.15; 95%CI: 2.08-4.77). Not having breakfast (OR: 1.53; 95%CI: 1.17-2.00), practising sport (OR: 1.40; 95%CI: 1.11-1.75), regular alcohol (OR: 1.51; 95%CI: 1.19-1.91) and tobacco (OR: 1.79; 95%CI: 1.33-2.41) consumption, and a worse school performance (OR: 2.21; 95%CI: 1.47-3.32), were also risk factors for energy drinks use.

CONCLUSIONS

Energy drinks consumption is a prevalent habit among adolescents. Its pattern varies depending on sociodemographic characteristics, with gender playing a relevant role. Health related habits and risk behaviours have been associated too to energy drinks use. Further evidence regarding consumption and its risk factors will allow the development of effective preventive strategies.

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.

The Structural Equation Model of Intention to Discontinue Drinking Highly Caffeinated Beverage of Undergraduate Students

Purpose

The purpose of this study was to test a model for intention to discontinuation drinking high caffeinated beverages among undergraduate students. This model was based on the Ajzen’s theory of planned behavior and Becker’s health belief model.

Methods

Participants consisted of 201 undergraduate students. Data were collected by questionnaires from March 11 to May 24, 2019. Collected data were analyzed using SPSS/WIN 22.0, AMOS 22.0 program.

Results

The assessment of the model indicated an acceptable fit (normed χ²=1.65, goodness-of-fit index [GFI]=.83, adjusted GFI=.79, comparative fit index [CFI]=.92, standardized root mean square residual [SRMR]=.05, Tucker-Lewis index [TLI]=.91, normed fit index [NFI]=.87, root mean square error of approximation [RMSEA]=.07). Perceived behavior control, subjective norm, the subjective attitude was found to have a significant direct effect on the intention to discontinuation of drinking a high caffeinated beverage. The variances of this model explained 45.3% of the variance in intention to discontinuation of drinking a high caffeinated beverage.

Conclusion

These results suggest that a need to increase awareness of adverse effects and potential risks of high caffeinated beverage consumption in undergraduate students. Besides, the university and government should provide education and campaigns to prevent excessive high-caffeinated beverage consumption.

Energy drinks and population health: consumption pattern and adverse effects among Saudi population

BACKGROUND

Caffeine containing energy drinks (EDs) are heavily consumed, particularly among young adults. The number of reports of caffeine intoxication from caffeinated EDs and problems related to caffeine dependence and withdrawal is increasing. The objective was to assess the knowledge and perceived beneficial effects of EDs consumers, to assess consumption patterns and determine the adverse effects experienced by different EDs consumer groups residing in Saudi Arabia.

METHODS

An observational cross-sectional study with data from a randomly selected Saudi population was conducted during the period of January 15th, 2015, to April 15th, 2015, using a pre-tested 43-item questionnaire. The data were obtained and collected using interview questionnaires. Sociodemographic characteristics and data on EDs consumption patterns, the level of awareness among study subjects, and the purported benefits and reported adverse effects of EDs were collected. Frequency, percentage, and arithmetic means were calculated using Chi-square and ANOVA tests, and data with p < 0.05 were considered significant.

RESULTS

Of the 816 individuals invited to participate in the study, 783 participants responded and completed interviews, response rate was 96%. Consumers attributed the popularity of EDs to massive advertising media (46.7%) and their stimulating and invigorating effects (37.5%). EDs are consumed by subjects for their effects on fatigue reduction (64.6%), increased alertness and focus (75.8%), and assistance during long driving trips (75.7%). Study subjects reported suffering from adverse effects, including mainly diuresis (53.7%), palpitations (50.7%), insomnia (50.7%). Importantly, an inverse association was identified between knowledge of EDs and consumption rate, and a proportional association was identified between experienced adverse effects and consumption frequency. Lower knowledge scores were identified in daily consumers than in 1-3 times monthly consumers; higher adverse events were experienced by daily consumers than by 1-3 times monthly consumers. The majority of consumers (84.6%) recommended that authorities should regulate EDs consumption.

CONCLUSIONS

Excessive EDs consumption is associated with an increased risk of experiencing several adverse events, which is commensurate with published studies. Increasing knowledge about EDs and their possible risks could decrease their consumption by the general public.

Serum miRNAs are differentially altered by ethanol and caffeine consumption in rats

Alcoholism is a multifactorial disease with high risk for dependence determined by genetic background, environmental factors and neuroadaptations. The excessive consumption of this substance is related to psychiatric problems, epilepsy, cardiovascular disease, cirrhosis and cancers. Caffeine is one of the most popular psychostimulants currently consumed in the world. The combination of ethanol and caffeine ingested by consuming "energy drinks" is becoming increasingly popular among young people. We analyzed the effect of simultaneous consumption of ethanol and caffeine on the serum profile of miRNAs differentially expressed in the ethanol-drinking rat model (UChB strain). Adult rats were divided into three groups (n = 5 per group): UChB group (rats fed with 1 : 10 (v/v) ethanol ad libitum); UChB + caffeine group (rats fed with 1 : 10 (v/v) ethanol ad libitum + 3 g L-1 of caffeine); control group (rats drinking water used as the control for UChB). The treatment with caffeine occurred from day 95 to 150 days old, totalizing 55 days of ethanol + caffeine ingestion. The expressions of microRNAs (miR) -9-3p, -15b-5p, -16-5p, -21-5p, -200a-3p and -222-3p were detected by Real Time-PCR (RT-PCR). The expressions of miR-9-3p, -15b-5p, -16-5p and -222-3p were upregulated in the UChB group. Conversely, simultaneous ingestion of ethanol and caffeine significantly reversed these expressions to similar levels to control animals, thus emphasizing that caffeine had a protective effect in the presence of ethanol. In addition, miR-21-5p was downregulated with ethanol consumption whereas miR-222-3p was unchanged. Ethanol and caffeine consumption was capable of altering serum miRNAs, which are potential biomarkers for the systemic effects of these addictive substances.

Rewarding and aversive doses of caffeine alter activity but not conditioned place preference induced by ethanol in DBA/2J mice

Increases in the consumption of ethanol and caffeine have been attributed to increased subjective feelings of intoxication and pleasure from the combination. Previous studies have shown that caffeine can be rewarding at low doses and aversive at high doses, although these findings are at times inconsistent between studies using comparable doses. Similarly, studies investigating the rewarding effects of ethanol and caffeine combinations have yielded mixed results. To address this issue, the present experiments were designed to investigate the rewarding effects of caffeine, as well as of caffeine + ethanol combinations. Male DBA/2J mice were exposed to an unbiased conditioned place preference (CPP) procedure with various doses of caffeine (1, 3, 10, 30 mg/kg) and ethanol (1, 2 g/kg), as well as various conditioning trial durations (5, 30, 60 min). Caffeine dose-dependently increased locomotor activity during conditioning, and produced a biphasic effect on place conditioning. Specifically, a low dose of caffeine (3 mg/kg) produced place preference, while a high dose (30 mg/kg) produced place aversion. When combined with alcohol, caffeine dose-dependently increased ethanol's stimulatory effect. However, the addition of caffeine had no effect on ethanol place preference, as there were no differences in the strength of place preference between mice conditioned with ethanol alone, and mice conditioned with any combination of ethanol and caffeine. These studies add evidence for caffeine's biphasic effects while also emphasizing the importance of considering temporal and methodological parameters when using Pavlovian conditioning procedures to study drug combinations.

Caffeine Exacerbates Postictal Hypoxia

A stroke-like event follows seizures which may be responsible for the postictal state and a contributing factor to the development of seizure-induced brain abnormalities and behavioral dysfunction associated with epilepsy. Caffeine is the world's most popular drug with ∼85% of people in the USA consuming it daily. Thus, persons with epilepsy are likely to have caffeine in their body and brain during seizures. This preclinical study investigated the effects of acute caffeine on local hippocampal tissue oxygenation pre and post seizure. We continuously measured local oxygen levels in the CA1 region of the hippocampus and utilized the electrical kindling model in rats. Rats were acutely administered either caffeine, or one of its metabolites, or agonists and antagonists at adenosine sub-receptor types or ryanodine receptors prior to the elicitation of seizures. Acute caffeine administration caused a significant drop in pre-seizure hippocampal pO₂. Following a seizure, caffeine, as well as two of its metabolites paraxanthine, and theophylline, increased the time below the severe hypoxic threshold (10 mmHg). Likewise, the specific A_2A receptor antagonist, SCH-58261, mimicked caffeine by causing a significant drop in pre-seizure pO₂ and the area and time below the severe hypoxic threshold. Moreover, the A_2A receptor agonist, CGS-21680 was able to prevent the effect of both caffeine and SCH-58261 adding further evidence that caffeine is likely acting through the A_2A receptor. Clinical tracking and investigations are needed to determine the effect of caffeine on postictal symptomology and blood flow in persons with epilepsy.

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

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

Intravenous and oral caffeine self-administration in rats

Caffeine is widely consumed for its psychoactive effects worldwide. No pre-clinical study has established reliable caffeine self-administration, but we found that caffeine can enhance the reinforcing effects of non-drug rewards. The goal of the present studies was to determine if this effect of caffeine could result in reliable caffeine self-administration. In 2 experiments rats could make an operant response for caffeine delivered in conjunction with an oral 'vehicle' including saccharin (0.2% w/v) as a primary reinforcer. In Experiment 1, intravenous (IV) caffeine infusions were delivered in conjunction with oral saccharin for meeting the schedule of reinforcement. In control conditions, oral saccharin alone or presentations of IV caffeine alone served as the reinforcer. In Experiment 2, access to caffeine was provided in an oral vehicle containing water, decaffeinated instant coffee (0.5% w/v), or decaffeinated coffee and saccharin (0.2%). The concentration of oral caffeine was then manipulated across testing sessions. Oral and IV caffeine robustly increased responding for saccharin in a manner that was repeatable, reliable, and systematically related to unit IV dose. However, the relationship between oral caffeine dose and operant behavior was less systematic; the rats appeared to titrate their caffeine intake by reducing the consummatory response (drinking) rather than the appetitive response (lever pressing). These studies establish reliable volitional caffeine self-administration in rats. The reinforcement enhancing effects of caffeine may help to explain widespread caffeine use by humans, who ingest caffeine in complex vehicles with reinforcing properties.

European Cardiac Arrhythmia Society Statement on the cardiovascular events associated with the use or abuse of energy drinks

Energy drinks are increasingly used by young people and young athletes in order to improve their performance alone or in association of other substances, particularly alcohol. In recent years, a number of reports of reports have raised attention on the side-effects associated with the use or abuse of energy drinks particularly serious cardiovascular events. The European Cardiac Arrhythmia Society (ECAS) has undertaken a systematic and critical review of reported data on cardiovascular events including life-threatening arrhythmias with or without cardiac arrest and other cardiovascular events, and discussed in this review the possible causal effect of caffeine and other ingredients contained in energy drinks and the reported events. Twenty-two cardiovascular events were reported in association with the use or abuse of energy drinks. The European Cardiac Arrhythmia Society would like to draw attention on the possible cardiovascular complications that may occur with the consumption of these beverages and to emphasize the prevention measures to be taken particularly in the young population. Well-designed prospective studies are needed to clarify the possible role of energy drinks in inducing the cardiovascular events reported.

A Case of Psychosis and Renal Failure Associated with Excessive Energy Drink Consumption

Energy drinks are nonalcoholic beverages that are widely consumed in the general population, and worldwide usage is increasing. The main stimulant component of energy drinks is typically caffeine. Few case reports exist that link energy drink consumption to psychosis, and similarly few reports exist that associate energy drink consumption with acute renal failure. We present a patient who simultaneously developed psychosis and acute renal failure associated with excessive energy drink consumption. The patient required haemodialysis, and his psychosis resolved on cessation of energy drinks and a brief course of antipsychotic medication. We perform a review of similar cases where excessive caffeinated energy drink consumption has been linked to psychosis or acute renal failure. To our knowledge, this is the first case report describing both renal failure and psychosis occurring simultaneously in a patient. Recognising the spectrum of disorders associated with excessive energy drink consumption is vital for both physicians and psychiatrists, as this has important implications for both prognosis and treatment.

Impact of Energy Drinks on Health and Well-being

PURPOSE OF REVIEW

Energy drinks and energy shots are functional supplements with higher caffeine content marketed toward adolescents and young adults with the intention of boosting energy. Parallel to its rising popularity, there are safety concerns with the consumption of these beverages. Herein, we reviewed the impact these supplements produce on health and well-being.

RECENT FINDINGS

Most of the promoted benefits of the beverages can be attributed to caffeine. The physiologic effects, if any, of other ingredients such as vitamins and herbal extracts are unclear. The presence of a higher caffeine content as compared to soft drinks may predispose to caffeine intoxication in susceptible individuals. Also, the practice of co-ingestion of these beverages with alcohol is still prevalent and associated with serious consequences. Strict regulations (restriction of sales, clear warning labels, capping caffeine levels) and public education may help prevent the adverse outcomes from these beverages.

Caffeinated energy drink consumption and predictors of use among secondary school students over time in the COMPASS cohort study

Consumption of caffeinated energy drinks (CED) by youth is a public health priority, given the lack of regulation and evidence for both short and long-term health effects of CED use. Considering the potential risks associated with excessive caffeine consumption, this paper examined CED consumption and predictors of CED use over time in a large sample of Canadian secondary school students participating in the COMPASS study.

Using linked longitudinal data (n = 4949) from the first three years of the COMPASS study (2012/13 to 2014/15), three logistic Generalized Estimated Equation models were performed to examine predictors of weekday CED use, weekend CED use, and weekly CED use.

The prevalence of weekly CED use remained fairly consistent across the three years of follow-up; 12.5% in year-1, 11.3% in year-2, and 11.4% in year-3. Smokers and marijuana users at follow-up were all at greater odds of weekday or weekly CED use, regardless of baseline use. Binge drinkers at baseline were at greater odds for weekday or weekly CED use, but not if they started binge drinking after their baseline year. Marijuana users at follow-up were all at greater odds of weekend CED use, regardless of baseline marijuana use.

>1 in 10 youth reported consuming CEDs one or more times per week, where specific subpopulations of youth, such as marijuana users, appear to be more frequent CED users. Although CED use remained relatively constant over the three-year period examined, prevalence of CED use remains problematic among secondary school students.

Energy drinks in children and adolescents: demographic data and immediate effects

Energy drinks consumption has become increasingly common in the last few years, despite evidence associating these products with vast adverse health effects. This led us to explore the phenomenon of energy drinks consumption in adolescents in the Israeli Arab population of the Nazareth area (Northern Israel), examining their awareness of risks associated with consumption of energy drinks, investigating their immediate effects on the body. Our study revealed that the consumption of energy drinks is very common in adolescents of both sexes, though more common in boys. Of 375 students who filled out the questionnaire, 206 reported that they consumed energy drinks (55%), 91 were male (44.4%), and 115 were female (55.6%). In the experimental stage of this study, we found that energy drinks significantly increased systolic blood pressure in most participants within a brief period of time after drinking.Conclusion: Given the prevalence of energy drinks consumption and their side effects, it is important to increase awareness of the risks associated with their regular use and to combat this phenomenon through the education system in schools. What is Known: • Energy drinks consumption has become popular and frequent among adolescents across the world. • The immediate effects of energy drinks in children and adolescents are poorly described. What is New: • Religious and social norms are not a barrier to ED consumption among the varied investigated population. • Our study describes the immediate effect of energy drinks during the first 2 h after consumption, revealing systolic blood pressure to be significantly increased.

The Effects of High Peripubertal Caffeine Exposure on the Adrenal Gland in Immature Male and Female Rats

The consumption of high levels of dietary caffeine has increased in children and adolescents. Human and animal studies have shown that chronic intake of high doses of caffeine affects serum glucocorticoid levels. Given that glucocorticoids play a role in peripubertal organ growth and development, chronic high doses of caffeine during puberty might impair maturation of the adrenal glands. To evaluate any effects of caffeine exposure on growing adrenal glands, 22-day-old male (n = 30) and female Sprague Dawley rats (n = 30) were divided into three groups (n = 10/group); group 1 received tap water (control) and groups 2 and 3 received water containing 120 and 180 mg/kg/day caffeine, respectively, via gavage for 4 weeks. At the end of the experiment, adrenal glands were weighed and processed for histological analysis. Relative adrenal weights increased in both groups of caffeine-fed males and females, whereas absolute weights were decreased in the females. In the female caffeine-fed groups the adrenal cortical areas resembled irregularly arranged cords and the medullary area was significantly increased, whereas no such effects were seen in the male rats. Our results indicate that the harmful effects of caffeine on the adrenal glands of immature rats differ between females and males. Although female rats seemed to be more susceptible to damage based on the changes in the microarchitecture of the adrenal glands, caffeine affected corticosterone production in both female and male rats. In addition, increased basal adrenocorticotropic hormone levels in caffeine-fed groups may reflect decreased cortical function. Therefore, caffeine may induce an endocrine imbalance that disturbs the establishment of the hypothalamo–pituitary adrenal axis during puberty, thereby leading to abnormal stress responses.

Direct inhibitory effect of caffeine on viability, synthesis activity and gene expression in cultures of chondrocytes extracted from the articular cartilage of rats

ABSTRACT The aim of this study was to evaluate the effect of concentrations of caffeine on the viability, synthesis activity and gene expression in cultures of chondrocytes. Extracted articular cartilage from the femurs and tibias of 15 Wistar rats at three days old to isolate chondrocytes. Chondrocytes were cultured in chondrogenic medium (control) or supplemented with caffeine (0.5, 1.0, 2.0mM). Cell viability, alkaline phosphatase activity and collagen synthesis were assessed using colorimetric assays at 7, 14, 21 days. The chondrocyte cultures of all groups grown under coverslips were stained with hematoxylin-eosin to determine the percentage of cells/field and with PAS, safranin O, alcian blue to determine the percentage of matrix chondrogenic/field at 21 days. The expressions of gene transcripts for aggrecan, collagen-II, Sox-9, Runx-2 and alkaline phosphatase were also evaluated by RT-PCR at 21 days. The means were compared using Student-Newman-Keuls. Caffeine significantly reduced the conversion of MTT to formazan, percentage of cells/field, collagen synthesis, alkaline phosphatase activity, synthesis of PAS+, safranin O+ and alcian blue+ chondrogenic matrix, and the expression of aggrecan, Sox-9 and II collagen. It is concluded that caffeine at concentrations of 0.5, 1.0, 2.0mM has a direct inhibitory effect on chondrogenesis in cultures of chondrocytes from rats.

Alcohol Mixed with Energy Drinks (AmED) and Negative Alcohol-Related Consequences among South Korean College Students

Consumption of alcohol mixed with energy drinks (AmED) has been associated with various alcohol-related consequences among college students. However, more information is required to assess how this relationship is affected by sociodemographic and environmental factors. This paper investigates the association between AmED consumption and negative alcohol-related consequences while (1) stratifying AmED users by sex, (2) examining a range of outcomes specific to the college context (e.g., missing class), and (3) controlling for drinking frequency and amount. We surveyed and analyzed the data of 4592 students in a nationally representative sample of 82 colleges in South Korea. Multiple linear regression analysis was used to identify the association between AmED use and a number of alcohol-related consequences (ranging from a score of 0–12) while adjusting for covariates, including drinking frequency and intake per drinking session. Of our study population, 22.0% of alcohol-consuming men and 13.4% of alcohol-consuming women reported AmED consumption in the past 12 months. AmED users experienced a greater number of alcohol-related consequences (e.g., missing class, engaging in unplanned sexual activity) than non-AmED users (men β: 0.804, p ≤ 0.0001; women β: 0.522, p ≤ 0.0001). Male AmED users consuming alcohol once a month (β: 1.155, p ≤ 0.0001) and female users consuming less than once a month (β: 1.019, p ≤ 0.0001) experienced the greatest number of consequences compared to non-users, as did AmED users consuming 3–4 drinks per drinking session (men β: 1.012, p ≤ 0.0001; women β: 0.993, p ≤ 0.0001). Our findings reveal that both male and female college students who consume AmED experience a greater number of negative alcohol-related consequences than those who do not. Rather than high-risk drinkers, moderate drinkers who consume alcohol infrequently and/or in low amounts may experience more consequences when consumers of AmED.

Consumption of energy drinks among Turkish University students and its health hazards

Objective:

To determine the awareness, consumption patterns of energy drinks (ED) and health hazards among students at a Turkish University.

Methods:

This cross-sectional descriptive study was conducted by questionnaire method between in 2017 among Erciyes University students. Total 1257 students from the Faculties of Medicine, Communication and Physical Education and Sports College participated in the study. Pearson chi-square test, binary logistic regressions were used for statistical analysis. p <0.05 values were considered significant.

Results:

Students who tried at least once and consumed regularly ED were 52.5% and 15.7% respectively. Consuming regularly and trying ED were more common among students who were studying at Physical Education and Sports High school, male, smoking, alcohol consumer, doing regular physical activity. Mean age of students to start drinking ED was 15.1 years. Most common reason for ED consumption was; staying awake. Alcohol mixed energy drinks consumption rate was 37.6% among regular ED consumers. Most declared harmful effect was palpitation.

Conclusion:

ED consumption among Erciyes University students was widespread. Students should be informed about EDs’ hazards for health. Legal regulations regarding production, marketing and advertising of EDs must be reconsidered.

Investigating associations between caffeinated beverage consumption and later alcohol consumption among early adolescents

Previous research has demonstrated that caffeinated beverage consumption predicts alcohol consumption among early adolescents. This study aimed to investigate this association in two ways: (1) by examining if this association remained significant once other established risk factors for alcohol were adjusted for statistically; and (2) by considering three possible moderators of this association: gender, sensation-seeking, and parental monitoring. Data from the Camden Youth Development Study, a longitudinal, community-based study of middle-school students, were used. Youth were initially assessed in 6th and 7th grade and followed-up 16 months later. Self-reports of frequency of energy drink, coffee, and alcohol consumption, as well as sensation-seeking, perceived peer and best friend alcohol use, alcohol expectancies, and parental monitoring, were used. Results indicated that both energy drink and coffee consumption predicted later alcohol consumption, even after adjusting for other risk factors for alcohol consumption. Parental monitoring was a significant moderator of this link, such that youth who consumed energy drinks and reported low parental monitoring were particularly at risk for later alcohol consumption. These findings indicate that the link between earlier caffeine consumption and later alcohol consumption is not simply due to the co-occurrence of caffeine consumption with other risk factors for alcohol use. In addition, risk associated with early energy drink consumption appears to be particularly pronounced for youth in families characterized by low parental monitoring.

Energy Drinks Induce Acute Cardiovascular and Metabolic Changes Pointing to Potential Risks for Young Adults: A Randomized Controlled Trial

BACKGROUND

Case reports suggest a link between energy drinks (EDs) and adverse events, including deaths.

OBJECTIVES

We examined cardiovascular and metabolic effects of EDs and mixtures providing relevant ingredients of EDs compared to a similarly composed control product (CP) without these components.

METHODS

This randomized, crossover trial comprised 38 adults (19 women, mean BMI 23 kg/m2, mean age 22 y). We examined effects of a single administration of a commercial ED, the CP, and the CP supplemented with major ED-ingredients at the same concentrations as in the ED. The study products were administered at 2 volumes, 750 or 1000 mL.

RESULTS

Both volumes of the study products were acceptably tolerated with no dose-dependent effects on blood pressure (BP, primary outcome), heart rate, heart rate corrected duration of QT-segment in electrocardiography (QTc interval), and glucose metabolism. After ED consumption, 11% of the participants reported symptoms, in contrast to 0-3% caused by other study products. After 1 h, administration of an ED caused an increase in systolic BP (116.9 ± 10.4 to 120.7 ± 10.7 mmHg, mean ± SD, P < 0.01) and a QTc prolongation (393.3 ± 20.6 to 400.8 ± 24.1 ms, P < 0.01). Also caffeine, but not taurine or glucuronolactone, caused an increase in BP, but no QTc prolongation. The BP effects were most pronounced after 1 h and returned to normal after a few hours. All study products caused a decrease in serum glucose and an increase in insulin concentrations after 1 h compared to baseline values, corresponding to an elevation in the HOMA-IR (ED + 4.0, other products + 1.0-2.8, all P < 0.001).

CONCLUSION

A single high-volume intake of ED caused adverse changes in BP, QTc, and insulin sensitivity in young, healthy individuals. These effects of EDs cannot be easily attributed to the single components caffeine, taurine, or glucuronolactone. This trial was registered at clinicaltrials.gov as NCT01421979.

Gender Differences in Any-Source Caffeine and Energy Drink Use and Associated Adverse Health Behaviors

Background: The majority of college students report caffeine use with many using caffeine daily. Energy drink (ED) use, in particular, is common among college students, and numerous studies link these heavily caffeinated drinks to a variety of adverse consequences including substance use and risky behaviors. However, little is known about correlations between any-source caffeine use and other substance use and problems. The purpose of this study was to evaluate patterns of caffeine use and examine the relationships between caffeine, in general, and EDs specifically, and adverse health behaviors in college students. Methods: We used data from a longitudinal study of alcohol use and health-related outcomes to assess caffeine, alcohol, nonprescription drug, and tobacco use and symptoms of alcohol dependence in 1958 freshmen from a mid-Atlantic university during Fall 2012. We compared adverse health behaviors between caffeine users and nonusers and ED users and nonusers. Data were evaluated separately in men and women. Results: While women reported significantly more caffeine use than men, men reported more ED use. EDs, regardless of frequency of use, were associated with all adverse health behaviors, but only in female students. Similarly, daily any-source caffeine use was significantly associated with alcohol, nonprescription drug, and tobacco use in female students, but in men, the association was less robust. Conclusions: This research shows that caffeine use is prevalent among college students, and, in female students, is associated with alcohol, nonprescription drug, and tobacco use and alcohol dependence symptoms. Interventions aimed at promoting healthy behaviors may be especially useful in this population.

Health Related Nutritional Knowledge and Dietary Behavior Regarding Caffeine Intake among High School Students in Yongin Region

Objectives

We aimed to examine health-related nutritional knowledge and dietary behavior related to caffeine intake among high school students (n = 310) in the Yongin region of Korea.

Methods

Data were collected using a face-to-face survey, and analyzed using chi-square test, t- test, and logistic regression analysis.

Results

The level of caffeine intake in respondents was divided into low (< 30 mg/d; n = 208) and high caffeine intake groups (> 30 mg/d; n = 102). Total nutritional knowledge related to bone disease was higher in the low intake group (score 2.75) than the high intake group (score 2.39; p < 0.05). The high intake group had lower scores for nutritional knowledge (score 0.70; p < 0.05) related to how caffeinated beverages affect sleep and for dietary behavior (score 3.25; p < 0.001), based on “I avoid caffeinated foods before sleep,” than the low intake group (nutritional knowledge score, 0.80; dietary behavior score, 3.76).

Conclusion

In the overall analysis, the low caffeine intake group had better nutritional knowledge related to bone and sleep health, and healthier dietary behavior related to sleep health compared with the high intake group.

Acute caffeine supplementation in combat sports: a systematic review

Caffeine used as a supplement has been shown to improve physical and cognitive performance in several sport modalities due to its effects on the central nervous system. This review assesses the direct effects of caffeine supplementation on performance in combat sports. Using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, relevant studies were identified through the Medline, Scopus and SPORTDiscus databases. Of 1053 search results, only 9 articles fulfilled the inclusion criteria. Of these, three studies detected no ergogenic effect of caffeine supplementation, while six studies did observe a significant positive effect. Supplementation with 3-6 mg/kg of caffeine was found to increase the glycolytic contribution to energy metabolism during the execution of real or simulated combats, as indicated by elevated blood lactate concentrations. Caffeine intake was also noted to improve levels of strength, power and upper arm muscular endurance. These effects were not paralleled by an increase in the exertion perceived by the athlete.

Discriminating Between Fatigue and Sleepiness in the Naval Operational Environment

OBJECTIVE

To assess the similarities and differences between reported levels of fatigue and sleepiness as a consequence of working at sea.

PARTICIPANTS

767 crewmembers of a U.S. Navy ship.

METHODS

Retrospective analysis of a survey to include questions about demographics, caffeine consumption, sleep adequacy, the Epworth Sleepiness Scale (ESS), and the Fatigue Severity Scale (FSS).

RESULTS

ESS scores (8.41 ± 4.66) indicated that 32% of the participants had excessive daytime sleepiness (ESS score > 10), while approximately 7% had an ESS score of 16 or more. FSS scores (average FSS = 3.01 ± 1.37) indicated that 28% of the participants had elevated fatigue (FSS score ≥ 4). Even though ESS and FSS scores were correlated (r = 0.39), their association explained only 15% of the variability observed. In terms of behavioral and lifestyle patterns, crewmembers with elevated fatigue (FSS ≥ 4) reported getting less exercise than those reporting less fatigue. Individuals with excessive sleepiness (ESS > 10) reported higher caffeine consumption. Crewmembers with elevated fatigue and comorbid sleepiness (FSS ≥ 4 and ESS > 10) reported receiving less sleep than other crew members.

CONCLUSIONS

These results suggest that subjective fatigue and subjective sleepiness, as measured by the FSS and ESS scales, are distinct constructs and both are consequences of working at sea. The scores on the two scales correlate differentially with behavioral and lifestyle patterns of the crewmembers.