A recent study suggests that drinking coffee will not improve the impaired reflexes and judgment of a person who's been drinking alcohol. In fact, because it makes people less sleepy, caffeine may make matters worse, causing people to feel alert when they actually aren't. It can give people more energy to do all the incredibly stupid things they think of doing while drunk, but usually don't do because they feel too tired or incapable.
Such as driving home on New Year's Eve after some festive drinking.
'Caffeine doesn't change blood alcohol levels and it doesn't change things as far as being able to make proper choices, and those can lead to very dire consequences.'
The study tested the effects of alcohol and caffeine—both separately and together—on laboratory mice. When given separately, alcohol impaired the learning ability of mice and their judgment and also made them less anxious, while caffeine made the mice more anxious. When given together, alcohol blocked caffeine's ability to increase anxiety, but caffeine didn't reverse alcohol's impairment of learning and judgment. The result was a laid−back mouse prone to taking risks and not aware that it was taking them.
Thomas J. Gould, Ph.D., is an associate professor of psychology and director of Brain and Cognitive Sciences at Temple University in Philadelphia and co−author of the study. Gould feels that the study has definite implications for humans: "The myth about coffee's sobering powers is particularly important to debunk because the co−use of caffeine and alcohol could actually lead to poor decisions with disastrous outcomes. Caffeine doesn't change blood alcohol levels and it doesn't change things as far as being able to make proper choices, and those can lead to very dire consequences."
In other words, caffeine and alcohol are not a good mix.
Because caffeine can make an individual less likely to realize that they are drunk, the researchers express concern over the 30 or so beverages on the market that contain both caffeine and alcohol. These beverages have become increasingly popular with younger people; an FDA newsletter estimates that up to 26% of college students consume them. In November, the FDA sent letters to 30 manufacturers of these beverages, asking for evidence that the beverages are safe and that their continued sale should be permitted.
In the study, mice were trained in a four−armed maze. They were specifically trained to avoid one arm of the maze, where a bright light would flash and an 85 decibel noise would sound upon entry. After training, the mice were tested in the same maze, but no light or noise would sound when the mice entered the "danger" arm—the mice had already learned that this arm was not a safe place to be. Varying amounts of alcohol and/or caffeine were administered to the mice during both the training and testing sessions; saline was administered to one group of mice as a placebo. The overall movements of the mice were tracked, with movement into the "danger" arm taken as an indication of learning impairment or poor judgment.
But whether you’re a man or a mouse, the only proven way to sober up is to wait until your body can metabolize the alcohol.
The results of the study were published in the December 2009 issue of the journal Behavioral Neuroscience.