Energy drinks: an emerging public health hazard for youth

Review of the energy drink literature from 2013: findings continue to support most risk from mixing with alcohol

PURPOSE OF REVIEW

In the field of caffeine research, interest in and concern for energy drink consumption have grown. Most caffeine-related research studies published in 2013 focused on energy drink consumption. This article reviews this literature.

RECENT FINDINGS

Prevalence of energy drink consumption varies by measure and age group. Lack of a standardized definition of use inhibits comparison across studies. Studies reviewed show that energy drink consumption is generally low, but the minority who drink the most may be consuming at unsafe levels. Energy drinks are popular among adolescents and young adults. They boost energy and alertness in some conditions, but may have adverse hemodynamic effects. Harmful consequences, including involvement in risky driving, riding with an intoxicated driver and being taken advantage of sexually, were reported significantly more often by adolescents and young adults who combined energy drinks with alcohol compared with those who did not.

SUMMARY

This review of recent literature focused on prevalence, motivation, and consequences of energy drink use. Clear findings emerged only on the dangers of mixing alcohol and energy drinks. The lack of a standardized measure made the comparison across studies difficult. Future research should extend and clarify these findings using standardized measures of use.

Daytime Sleepiness, Circadian Preference, Caffeine Consumption and Use of Other Stimulants among Thai College Students

We conducted this study to evaluate the prevalence of daytime sleepiness and evening chronotype, and to assess the extent to which both are associated with the use of caffeinated stimulants among 3,000 Thai college students. Demographic and behavioral characteristics were collected using a self-administered questionnaire. The Epworth Sleepiness Scale and the Horne and Ostberg Morningness-Eveningness Questionnaire were used to evaluate prevalence of daytime sleepiness and circadian preference. Multivariable logistic regression models were used to evaluate the association between sleep disorders and consumption of caffeinated beverages. Overall, the prevalence of daytime sleepiness was 27.9 % (95% CI: 26.2-29.5%) while the prevalence of evening chronotype was 13% (95% CI: 11.8-14.2%). Students who use energy drinks were more likely to be evening types. For instance, the use of M100/M150 energy drinks was associated with a more than 3-fold increased odds of evening chronotype (OR 3.50; 95% CI 1.90-6.44), while Red Bull users were more than twice as likely to have evening chronotype (OR 2.39; 95% CI 1.02-5.58). Additionally, those who consumed any energy drinks were more likely to be daytime sleepers. For example, Red Bull (OR 1.72; 95% CI 1.08-2.75) or M100/M150 (OR 1.52; 95% CI 1.10-2.11) consumption was associated with increased odds of daytime sleepiness. Our findings emphasize the importance of implementing educational and prevention programs targeted toward improving sleep hygiene and reducing the consumption of energy drinks among young adults.

Energy drink usage among university students in a Caribbean country: Patterns of use and adverse effects

Objective: There has been little inquiry addressing whether or not concerns about adverse effects of energy drink usage are relevant in the Caribbean. This survey investigated energy drink usage and adverse consequences among tertiary level students in Trinidad and Tobago.

Methods: A cross-sectional survey of 1994 students from eight institutions was conducted using a de novo questionnaire based on findings from a focus group of students. Chi-squared analyses and logistic regression were used to assess relationships between energy drink usage, adverse effects and other factors affecting energy drink use, and to verify predictors of energy drink use.

Results: Prevalence of use was 86%; 38% were current users. Males were more likely to use, used more frequently and at an earlier age. Energy drinks were used most commonly to increase energy (50%), combat sleepiness (45%) and enhance academic performance (40%), and occurred during sports (23%) and mixed with alcohol (22.2%). The majority (79.6%) consumed one energy drink per sitting; 62.2% experienced adverse effects, most commonly restlessness (22%), jolt and crash (17.1%) and tachycardia (16.6%). Awareness of adverse effects was associated with no use (p = 0.004), but adverse effects were not a deterrent to continued use.

Conclusion: Energy drink usage is prevalent among students. The use is not excessive, but associated with high rates of adverse effects and occurs in potentially dangerous situations like during exercise and with alcohol. There is a need to educate students about the potential adverse effects of energy drinks.

Energy drink consumption among young Australian adults: associations with alcohol and illicit drug use

BACKGROUND

Energy drinks are becoming increasingly popular among young people. The purpose of this study was to determine the prevalence of energy drink consumption and its associations with socio-demographic characteristics, alcohol, cigarette and illicit drug use in a population-based sample of young adults participating in the Western Australian Pregnancy Cohort (Raine) Study.

METHODS

We used self-administered questionnaires to assess energy drink consumption patterns, alcohol intake, cigarette and illicit drug use at the 20-year cohort follow-up. Data was also collected on socio-demographics, physical activity, body mass index (BMI) and dietary intake. Our sample included 1234 participants (47% male, mean age 20 ± 0.5 years). We considered energy-drink consumption as a categorical (users versus non-users) variable.

RESULTS

Overall, 48% of participants consumed energy drinks at least once per month, with an average intake of 1.31 ± 0.75 cans per day amongst energy drink users. The most significant correlates of energy drink use were being in part-time or full-time employment, being male, being a cigarette smoker, having heavier alcoholic spirit consumption patterns and being an ecstasy user (all p<0.05). No significant associations were observed with BMI or dietary intake.

CONCLUSIONS

Australian energy drink users tend to have heavier alcohol consumption patterns be a cigarette smoker and use illicit drugs relative to non-users. More research is needed regarding the health risks associated with energy drink use in young adults, including their possible role in the development of substance abuse problems.

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

Current regulation of caffeine-containing products is incoherent, fails to protect consumers' interests, and should be modified in multiple ways. We make the case for one of the regulatory reforms that are needed: all consumable products containing added caffeine should be required by the Food and Drug Administration (FDA) to include caffeine quantity on their labels. Currently, no foods or beverages that contain caffeine are required to include caffeine content on their labels. Strengthening these lax labeling requirements could prevent direct caffeine-induced harm, protect those most vulnerable to caffeine-related side effects, and enhance consumer autonomy and effective caffeine use. Consumers have an interest in regulating their intake of caffeine and thus, ought to know how much caffeine their foods and beverages contain.

Adenosine inhibits the excitatory synaptic inputs to Basal forebrain cholinergic, GABAergic, and parvalbumin neurons in mice

Coffee and tea contain the stimulants caffeine and theophylline. These compounds act as antagonists of adenosine receptors. Adenosine promotes sleep and its extracellular concentration rises in association with prolonged wakefulness, particularly in the basal forebrain (BF) region involved in activating the cerebral cortex. However, the effect of adenosine on identified BF neurons, especially non-cholinergic neurons, is incompletely understood. Here we used whole-cell patch-clamp recordings in mouse brain slices prepared from two validated transgenic mouse lines with fluorescent proteins expressed in GABAergic or parvalbumin (PV) neurons to determine the effect of adenosine. Whole-cell recordings were made from BF cholinergic neurons and from BF GABAergic and PV neurons with the size (>20 μm) and intrinsic membrane properties (prominent H-currents) corresponding to cortically projecting neurons. A brief (2 min) bath application of adenosine (100 μM) decreased the frequency but not the amplitude of spontaneous excitatory postsynaptic currents (EPSCs) in all groups of BF cholinergic, GABAergic, and PV neurons we recorded. In addition, adenosine decreased the frequency of miniature EPSCs in BF cholinergic neurons. Adenosine had no effect on the frequency of spontaneous inhibitory postsynaptic currents in cholinergic neurons or GABAergic neurons with large H-currents but reduced them in a group of GABAergic neurons with smaller H-currents. All effects of adenosine were blocked by a selective, adenosine A1 receptor antagonist, cyclopentyltheophylline (CPT, 1 μM). Adenosine had no postsynaptic effects. Taken together, our work suggests that adenosine promotes sleep by an A1 receptor-mediated inhibition of glutamatergic inputs to cortically projecting cholinergic and GABA/PV neurons. Conversely, caffeine and theophylline promote attentive wakefulness by inhibiting these A1 receptors in BF thereby promoting the high-frequency oscillations in the cortex required for attention and cognition.

A comprehensive strategy to overhaul FDA authority for misleading food labels

The modern food environment is considered a primary driver of obesity and other nutrition-related chronic diseases. A significant contribution to this environment is the proliferation of claims on food packaging that provides a misleading picture of a product's healthfulness. The Food and Drug Administration (FDA) is the agency responsible for food labels but it lacks the regulatory authority and adequate resources to address the majority of questionable labeling practices. The FDA's current system of enforcement is thus essentially based on voluntary compliance and consumer- and manufacturer-initiated litigation has not successfully filled the regulatory gap. This manuscript reviews the current state of food labeling claims and the FDA's inadequate authority over misbranded food products. It analyzes competing views on regulatory compliance strategies and argues that a regulatory overhaul consistent with the best science and the First Amendment is necessary. With increased resources and authority, the FDA can meet current public health challenges and adequately ensure that labels are clear and consumers are properly informed and protected.