Caffeine Merely Masks Alcohol's Effect
An animal study in the journal Behavioral Neuroscience finds that coffee after alcohol consumption might merely make the drinker feel more capable, which could lead to bad decision making. Steve Mirsky reports

Cup of coffee after a night on the town to sober up? Well, a mouse study finds that caffeine does not counter the intoxicating effects of alcohol. It merely masks the inebriation, which could lead to poor decisions. Because drinkers might think they’ve sobered up, whereas they could just be more wired. The study is in the journal Behavioral Neuroscience.

Researchers gave mice doses, separately and together, of caffeine and alcohol. Tests then gauged how well the mice learned how to avoid part of a maze that appeared dangerous because of bright lights or loud sounds. And mouse anxiety was tested, through their willingness to be in an open area.

No surprise, drunk animals were more relaxed and had less anxiety, and had trouble learning to avoid possible danger. Then the mice got alcohol and caffeine together. And the caffeine did not improve a drunk animal’s ability to learn. So the mouse is more relaxed but less able to avoid threats—if it had a tiny car available it probably would have thought it was “fine, I’m fine enough to drive it.”

—Steve Mirsky