Re: Energy drinks and alcohol: research supported by industry may be downplaying harms
The author of "Energy drinks and alcohol: Research supported by industry may be downplaying the harms" (1) is to be commended for their recognition of the primary gap in the literature regarding the consumption trend of mixing alcohol with energy drinks (AmED). The lack of research administering higher doses or adopting more complex dosing procotols to assess the dose-dependent interactive effects of alcohol and energy drinks (EDs) restricts inferences regarding the intoxication experience of consumers in the night-time economy (2). We cannot conclusively make any statements regarding the pharmacological interactive effects of these two constituents until this situation is rectified.
However, we would further argue that such research should not be restricted to only assessing the pharmacological effects of co-ingestion. Psychological factors, such as consumer expectancies of AmED effects, could contribute to the intoxication experience. Research has demonstrated that AmED consumers report specific expectations for their intoxication experience. A study of US college athletes showed that consumers reported anticipating increased alertness and aggression and expected to sober up faster after AmED compared to when they consume alcohol without EDs (3). However, to date there has been no research assessing the contribution of AmED versus alcohol expectancies to potential differences in perceived intoxication. There is preliminary research in this area looking at the interactive effect of alcohol with caffeine, the primary psychoactive ED ingredient, on subjective intoxication. A recently published study (4) has shown that co-administration of caffeine (mean dose=220mg) with alcohol reduced subjective ratings of intoxication relative to when alcohol was ingested without caffeine. This effect occurred independent of whether participants were expecting to receive caffeine. However, the authors note that this study may have limited generalizability to AmED consumption. The study assessed a caffeine dose equivalent to a higher ED volume (approximately 2.75 standard 250mL EDs) than that administered in past AmED research (typically 1 standard 250mL ED). However, research involving administration of the whole beverage is required in order to account for the role of: (i) other ED ingredients which may contribute to performance outcomes (e.g., 5), and (ii) ED-specific expectancies (versus general caffeine expectancies).
The need for this research is heightened when we examine the typical characteristics of AmED consumers relative to alcohol consumers, with the former generally displaying higher risk-taking propensity (6). This predisposition towards risky behaviour coupled with specific expectancies regarding the AmED intoxication experience could create a situation of heightened risk for both the consumer and others in the drinking environment. Determining the relative role of pharmacological and psychological factors in the AmED intoxication experience is important from a harm minimisation perspective: at present we do not have a solid evidence-base upon which to base our response to this consumption practice. Undertaking such research could inform policy response regarding ED marketing and sales with alcohol, and indicate the potential efficacy of public health campaigns targeted at ensuring consumers are accurately informed regarding the AmED intoxication experience.
Author email: Amy.Peacock@utas.edu.au
1. Miller, P. (2013). Energy drinks and alcohol: Research supported by industry may be downplaying harms. British Medical Journal, 2013, 347, f5345
2. Peacock, A., Bruno, R., Martin, F. H., & Carr, A. (2013). The impact of alcohol and energy drink consumption on intoxication and risk-taking behavior. Alcoholism: Clinical and Experimental Research, 37, 1234-1242.
3. Woolsey, C., Waigandt, A., & Beck, N. C. (2010). Athletes and energy drinks: Reporting risk-taking and consequences from the combined use of alcohol and energy drinks. Journal of Applied Sport Psychology, 22, 65-71.
4. Heinz, A. J., de Wit, H., Lilje, T. C., & Kassel, J. D. (2013). The combined effects of alcohol, caffeine, and expectancies on subjective experience, impulsivity, and risk-taking. Experimental and Clinical Psychopharmacology, 21, 22-234.
5. Peacock, A., Martin, F. H., & Carr, A. (2013). Energy drink ingredients. Contribution of caffeine and taurine to performance outcomes. Appetite, 64, 1-4.
6. Brache, K., & Stockwell, T. (2011). Drinking patterns and risk behaviors associated with combined alcohol and energy drink consumption in college drinkers. Addictive Behaviors, 36, 1133-1140.
Competing interests: Peacock and Bruno have received placebo samples from Red Bull GmbH for an experimental study in 2011-2012. This organisation had no role in study design, data analysis, or manuscript preparation, or in subsequent experimental research.