Acute impact of caffeinated alcoholic beverages on cognition: A systematic review.

Energy drinks are popular beverages that are supposed to counteract sleepiness, increase energy, maintain alertness and reduce symptoms of hangover. Cognitive enhancing seems to be related to many compounds such as caffeine, taurine and vitamins. Currently, users mostly combine psychostimulant effects of energy drinks to counteract sedative effects of alcohol. However, recent literature suggests that this combination conducts to feel less intoxicated but still impaired. The goal of the present article is to review cognitive impact and subjective awareness in case of caffeinated alcoholic beverage (CAB) intoxication.

PubMed (January 1960 to March 2016) database was searched using the following terms: cognitive impairments, alcohol, energy drinks; cognition, alcohol, caffeine.

99 papers were found but only 12 randomized controlled studies which explored cognitive disorders and subjective awareness associated with acute CAB or AED (alcohol associated with energy drinks) intoxication were included.

The present literature review confirmed that energy drinks might counteract some cognitive deficits and adverse effects of alcohol i.e. dry mouth, fatigue, headache, weakness, and perception of intoxication due to alcohol alone. This effect depends on alcohol limb but disappears when the complexity of the task increases, when driving for example. Moreover, studies clearly showed that CAB/AEDs increase impulsivity which conducts to an overconsumption of alcohol and enhanced motivation to drink compared to alcohol alone, potentiating the risk of developing addictive behaviors. This is a huge problem in adolescents with high impulsivity and immature decision making processes.

Although energy drinks counteract some cognitive deficits due to alcohol alone, their association promotes the risk of developing alcohol addiction. As a consequence, it is necessary to better understand the neurobiological mechanisms underlying these interactions in order to better prevent the development of alcohol dependence.