With the holiday season upon us, a familiar end-of-party ritual is coming under fire. It turns out that drinking coffee after an evening of imbibing your favorite holiday cocktails doesn't actually sober you up, new research finds. In fact, caffeine may make matters worse: it can give you a false sense of your sobriety and your ability to, say, drive a car -- even though you're still just as intoxicated.
"Caffeine will make you less sleepy and maybe you are less likely to fall asleep behind the wheel, but it won't make you any less drunk," says the study's co-author Thomas Gould, an associate professor of psychology at Temple University in Philadelphia. "If you need to stop quickly, you are not going to have the braking time you normally have when you're sober. You are not going to be able to quickly and properly make choices."
What the caffeine-booze combo actually results in is an "awake drunk," a state that can lead drinkers to take more risks than if they simply feel tired and intoxicated, says Gould. The finding that caffeine doesn't reverse the negative cognitive impact of alcohol has important implications, not just for post-party traditions, but also for those popular alcoholic drinks containing caffeine, he adds.
Debunking a Myth
Flavored beverages such as United Brands' Joose, which contains caffeine and an alcohol content of 9.9% (twice that of beer), have become all the rage among the college -- and younger -- crowd. Young adults are guzzling up drinks with names such as Wide Eye and 3 A.M. Vodka because, they say, the caffeine boost with the alcohol lets them drink all night long without getting tired.
But Gould wants to debunk the myth about coffee's sobering powers. "When people drink alcohol-energy drinks, they get a false sense of security that caffeine can reduce the negative effects of alcohol," says Gould. "But the cognitive impairment remains and that can lead to poor choices and the inability to react to key stimuli."
Last month, the U.S. Food and Drug Administration sent letters to 30 makers of caffeinated alcoholic beverages asking for clear evidence that the products are safe. If the companies are unable to provide such evidence, "the FDA will take appropriate action to ensure that the products are removed from the marketplace," the regulatory agency said in a statement.
Meantime, many alcohol-safety advocates are calling for these drinks to be pulled off store shelves no matter what. "Certain alcohol companies are marketing caffeinated alcoholic drinks to young people to enable them to drink all night long," says Chuck Hurley, CEO of MADD (Mothers Against Drunk Driving). "This magnifies the risks to kids because it makes wide-wake young drunks."
United Brands did not immediately respond to a request for comment.
A Learning Disability
While previous studies have examined caffeine's interaction with alcohol, Gould says his is perhaps the first to look at whether caffeine reduces alcohol-related problems in "learning," which includes the ability to avoid things we know cause us harm. Such harmful things may include getting behind the wheel of a car or having unprotected sex with a stranger while drunk.
For the research, Gould used groups of laboratory mice. In one experiment, the "control" group was given a saline solution, while the other group was given enough ethanol (pure alcohol) to create a blood-alcohol content level of 0.05 to 0.09 (0.08 or greater is considered legally drunk). This second group of mice was also given the equivalent of up to six cups' worth of coffee in caffeine.
Sure enough, the ethanol blocked the caffeine's ability to make the mice more anxious, but it didn't reverse the ethanol's negative effective on learning, meaning the animals were more relaxed but less able to avoid threats, the researchers say. In particular, animals on the caffeine-alcohol cocktail spent 40% of the time in a safe part of a maze and 40% in a "dangerous" part of the maze that had bright light and loud sound. By contrast, the teetotaler mice spent 60% of their time in the safe zone and only 20% in the "danger zone."
With the alcohol-caffeine mix, "you see a shift from preferring the safe environment to no real preference for one or the other," says Gould. "Mice by nature are nocturnal animals and like dark, secluded areas. They won't venture into brightly lit areas as that's where birds and cats will see them."
Risking Life and Limb
Of course, if the combo leads mice to risk life and limb, then researchers speculate that people are likely to do the same. But are human brains, which weigh about 3 pounds, really going to respond the same way to such substances as mice brains, which weigh about 0.02 ounces? Gould says the two organs are actually remarkably similar, with the major difference being humans have much more cortex, the part of the brain that is responsible for higher-brain functions, such as sensation and memory.
"Drugs affect our system in the same way they affect rodent brains," says Gould. "That's why they're a viable model."
With news that our brains respond very similarly to those of our smaller, furrier friends, MADD's Hurley says it's important to cast aside once and for all the fantasy that coffee -- or other forms of caffeine -- can reverse the effects of drinking. For folks looking to tie one on over the holidays, "there is a process by which the human body gets rid of alcohol," says Hurley. "It's generally one drink an hour and you can't speed it up."
So basically, when it comes to sobering up fast, nobody has built a better mousetrap.
Major buzzkill: Study finds caffeine won't sober you up