Drinking energy drinks with spirits could make you more likely to end up getting in a fight, new research has found.
Scientists in the UK and Brazil tested what taurine and caffeine-heavy drinks like Red Bull do to fish when they're mixed with the likes of vodka - and the results weren't pretty.
Fish loaded up on alcohol and taurine were more likely to take on predators and less likely to socialise with other fish than those who were sober or merely drunk.
"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 study co-author Matt Parker of the University of Portsmouth.
"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."
The researchers used zebrafish for the study, because they have "similar biological and behavioural responses to alcohol" as humans "and are a highly social species".
Dr Parker said people should think twice about mixing vodka and Red Bull.
"Mixing alcohol and taurine might be a factor in increasing some of the negative effects of alcohol. People should be aware that drinking energy drinks in combination with alcohol may impair their judgement, and should do so with caution."
The findings were published in the Journal of Psychiatric Research.