Abstract
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.
Publication types
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Randomized Controlled Trial
MeSH terms
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Adolescent
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Adult
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Alcoholic Beverages / adverse effects*
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Attention / drug effects*
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Caffeine / administration & dosage
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Caffeine / adverse effects
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Cross-Over Studies
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Double-Blind Method
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Drug Interactions
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Energy Drinks / adverse effects*
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Ethanol / administration & dosage
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Ethanol / adverse effects
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Ethanol / blood
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Female
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Humans
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Male
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Memory, Short-Term / drug effects*
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Reaction Time / drug effects
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Young Adult
Grants and funding
Red Bull GmB provided energy drinks and placebos for this study. The company had no input into the design, conduct or interpretation of the study nor this manuscript. SB has received research and travel funding from Red Bull GmB. BT owns shares in AstraZeneca. He is an employee of eResearch Technology Ltd (ERT), clinical research service provider, and owner, director and employee of Mobile Cognition Ltd, provider of cognitive testing solutions. ERT and Mobile Cognition provided support in the form of salary for author BT, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. AS has received research funding from the Australian Research Council, Biotechnology and Biological Sciences Research Council, European Commission Framework 5 Research and Innovation initiative, National Health and Medical Research Council; and funding travel costs and consultancy from the food, supplement and pharmaceutical industry (Abbott Nutrition, Arla Foods, Australian Wine Research Institute, Barilla, Bayer, Blackmores, Cognis, Cyvex, Dairy Health Innovation Consortium, Danone, DuPont, GlaxoSmithKline, Ginsana, Kemin Foods, Martek, Masterfoods, Naturex, Nestlé, Neurobrands, Novartis, Nutricia-Danone, Red Bull, Sanofi, Sen- Jam Pharmaceuticals, Verdure Sciences, Unilever, Wrigley Science Institute), and from Energy Drink manufacturers (Red Bull GmB and GlaxoSmithKline). The specific roles of these authors are articulated in the ‘author contributions’ section.