As I sit here drinking my morning coffee, I’m reminded of one of most common myths about drunk driving: that coffee will sober a person up.
I’ve said it countless times. The only thing that will sober a person up is time. I repeat: Drinking coffee to sober up is a myth, a potentially very dangerous one.
Just because you drink coffee with caffeine, doesn’t mean you’ll have any less alcohol in your system. While a person my feel a little more awake, they will still be drunk whether they drink one cup of coffee or ten cups of coffee.
Okay you drink a cup of coffee (or several) and while you may be more awake, you have the same alcohol in your system. But what about drinking coffee to reduce the effects of intoxication and increase driving ability?
Sorry, that too is a myth.
Coffee is a stimulant which may serve to reduce lethargy and tiredness. This does not mean that the effects of the intoxication are reduced. In fact, the effects of coffee may serve to trick the brain into thinking that the intoxicating effects of alcohol have been reduced.
A 1983 study entitled “Interactions of Alcohol and Caffeine on Human Reaction Time,” found that “Caffeine has a synergistic interaction with alcohol…(It) has the effect of potentiating the detrimental effects already induced by alcohol…Motor skills which involve delicate muscular coordination and accurate timing have been found to be adversely affected by caffeine."
An earlier 2010 study on the effects of caffeine and alcohol found that “[people] whose motor skills, visual reaction times, and judgment are impaired by alcohol may not perceive that they are intoxicated as readily when they’re also ingesting a stimulant. Only the symptoms of drunkenness are reduced – but not the drunkenness. They can’t tell if they’re drunk; they can’t tell if someone else is drunk.”
If increasing the likelihood for a DUI weren’t enough, coffee can actually make the dreaded hangover even worse. Alcohol causes dehydration which is partly why people are hungover after a night of drinking. Caffeine is a diuretic which also causes dehydration, thus making the hangover even more miserable.
Forgo the coffee. It won’t help. And remember that the only thing that will sober a person up is time.