Energy drinks (EDs) increase driving performance while decreasing drowsiness and exhaustion, but alcohol has the reverse effect. Although it is a popular combination among young people, the consequences of combining alcohol and EDs on driving performance have received little attention. For a study, researchers sought to determine if there was any interaction between the effects of both beverages on driving-related abilities and perceptions of driving competence. They carried out a four-way crossover clinical experiment that was randomized, double-blind, and placebo-controlled. 16 healthy participants took part in the study. In two dosages, 60 g of ethanol and 750 mL of Red Bull (RB) were delivered. Alcohol + RB placebo, alcohol + RB, alcohol placebo + RB, and both placebos were used as conditions. A tracking test, as well as basic reaction time, N-Back, and movement estimating tasks were used to measure objective performance. In addition, readiness to drive, other subjective effects, and blood concentrations of ethanol and caffeine were also examined.

In the tracking test, alcohol increased the duration outside the road and increased simple response time, but the addition of RB had no main or interaction impact on performance. Nonetheless, driving-related abilities were better after alcohol + RB than after alcohol alone. The mix of beverages boosted my willingness to drive. RB also decreased alcohol-induced drowsiness, although it had no effect on intoxication. Despite the fact that alcohol + RB raised alcohol (14.8%) and caffeine plasma concentrations, these effects were seen (17.6% ). 

Mixing EDs with alcohol predisposed consumers to drive under the influence of alcohol, possibly because EDs counterbalance the adverse effects of alcohol on driving-related abilities.

Reference:academic.oup.com/ijnp/article/25/1/13/6335586

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