Mixing energy drinks, alcohol could up risky behaviour

Mixing alcohol with energy drinks could be exacerbate the negative effects of binge drinking, such as impairing judgement and increasing risky behaviour, a study has found.

Many people mix energy drinks with alcohol to counteract the sedative nature of alcohol, tricking users into feeling more awake and less drunk than they really are.

Researchers from the University of Portsmouth in the UK and the Federal University of Santa Maria in Brazil tested the effects of taurine, a key ingredient of many energy drinks, and alcohol on social and fear responses in zebrafish.

They found that taurine seemed to increase the fear-reducing properties of alcohol, but also affected social communication.

"This study is the first to show that the two together may be exacerbating some of the negative effects of binge drinking; that is reduction of fear and problems in social communication while intoxicated, which collectively increase the risk of fighting, violence and participation in risky behaviours," said Matt Parker, from the University of Portsmouth.

In the study, published in the Journal of Psychiatric Research, the researchers tested how taurine and alcohol (at volumes reflecting levels that would induce moderate human intoxication) affected the behaviour of 192 zebrafish.

The fish were divided into shoals (with four fish per shoal) and were exposed to either just water, taurine and alcohol separately or taurine and alcohol for one hour.

Their shoaling behaviours were then analysed at different time intervals at 0-5 minutes, 30-35 minutes and 55-60 minutes. The fish were also tested for their fear-like responses to a predator by dividing the tank into four areas, with the furthest area used to mimic a predator fish.

The fish that were exposed to both alcohol and taurine had fewer interactions with other fish in the shoal compared to those exposed to water alone or just alcohol.

These fish also showed more 'risky' behaviour, spending more time in the predator zone than other groups.

Alcohol reduces our inhibitions, and in low doses can cause relaxation and euphoria. However, in higher doses this low inhibition can cause problems with fighting or risky behaviour.

Zebrafish have similar biological and behavioural responses to alcohol, and are a highly social species, making them ideal for studying the effects of alcohol on behaviour.

People should be aware that drinking energy drinks in combination with alcohol may impair their judgement, and should do so with caution, researchers said.