咖啡:醒酒的"灵丹妙药",还是"毒药"?
众所周知,咖啡具有提神的功效,因而有些人把它当成了醒酒的佳品.但最新一期的《行为系统神经科学》杂志的某篇报告显示,在酒后喝咖啡并不能起到醒酒的效果,反而提高一些潜在的风险.

This is SCIENCE FRIDAY from NPR News. I'm Ira Flatow.

Later in the hour, the psychology of product pricing and the mysteries you can solve with math. First, if you rang in the New Year with friends last night and had a champagne or two and then had a cup of coffee before driving home, hoping to sober up, well, you may want to change that kind of thinking because research published this month in the journal Behavioral Neuroscience found that, at least in mice, caffeine was no help in countering the affects of alcohol on decision making and may actually make the consequences worse.

Joining me now is one of the authors of that study, Thomas Gould. He is an associate professor of psychology in the Center for Substance Abuse Research. He is director of the brain behavior and cognition area of the psychology department at Temple University in Philadelphia, and he joins us by phone. Welcome to SCIENCE FRIDAY.

Professor THOMAS GOULD (Psychology, Temple University): Thank you, Ira.

FLATOW: We shouldn't think that drinking that cup of coffee is going to make us better?

Prof. GOULD: That's correct, actually, and I was quite surprised when this paper came out, the reaction to it, in that the number of people that think that coffee actually will sober you up and reversing the affects of alcohol. But our study clearly showed that that was not the case.

FLATOW: And what was the study? The study was not conducted on people, correct?

Prof. GOULD: No, the study was conducted on mice. And what we looked at was we looked at the ability of mice to learn in a maze, that one arm of the maze contains stimuli that they find aversive. Mice do not like brightly-lit areas, nor do they like loud noises. Those areas oftentimes set them up for predators, so they tend to avoid those areas.

When the mice enter one end of the maze, those stimuli were turned on and they would learn to avoid that. But the animals that were given alcohol did not learn to avoid that, in fact they kept returning to that arm. And then when we tested them 24 hours later, they showed no memory of that arm being aversive. We gave the animals caffeine and then we also gave animals caffeine and alcohol together and the caffeine didn't reverse that. And during the training they kept going back to the aversive arm or the arm that would be signaling danger.

So they showed no lack of preference for it, in fact they actually tended to go there. And then 24 hours later, they showed no memory that that was an aversive area. So, if you translate that into human behavior, what you could say is that with alcohol you see this behavior that may be risky type behavior, putting yourself in dangerous situation and no real memory of that and that caffeine doesn't reverse those behaviors.

FLATOW: So that, whereas if you had a drink or two and if you didn't have that cup of coffee, you might just go sleep on the sofa somewhere.

Prof. GOULD: Well, exactly. There's been other studies that have shown that, you know - well, we know that alcohol is a depressant and caffeine is a stimulant and that caffeine can reduce some of the aversive or sedative effects of alcohol, such that what you basically have is a wide awake drunk. And there is some concern actually by both the FDA and the many states on these alcohol-caffeine drinks, especially these high energy drinks mixed with alcohol that have been marketed because some studies suggest that both in animal studies and in humans that people with these caffeine-alcohol drinks will consume more alcohol, which could further put them in trouble.

FLATOW: So, you become a more dangerous drunk.

Prof. GOULD: Exactly. And that's, you know, what, you know, our study suggests and there was a study done by a scientist down in Wake Forest, Dr. Mary O'Brien(ph), where she called college students and interviewed them and found college students that drank just alcohol drinks versus were drinking the alcohol-energy, high energy mix. And she found that students who were drinking the alcohol-caffeine mix had twice as likely to report that they were taken advantage of sexually and over twice as likely to have been hurt compared to the ones who were just drinking alcohol.

Now, there may be several reasons that could account for this. One may be if they are drinking the caffeine-alcohol mix, they may be consuming more alcohol. Another may be that when they are drinking the caffeine-alcohol mix that they may not realize that they are as intoxicated and they may put themselves in dangerous situations where they're more likely to get hurt because they just don't have the same cognitive, you know, capacity as someone that wasn't consuming those drinks.

FLATOW: Is there any way to test this out on humans?

Prof. GOULD: Well, you can test - for example, there was a study that looked at simulated driving.

FLATOW: Yeah.

Prof. GOULD: And they looked at individuals that had alcohol or individuals that had alcohol and caffeine and they measured things such as reaction time and, you know, braking time and choice reaction time, where you had to make a decision between two possibilities. And what they found was, as expected, alcohol produced deficits in all the measures and caffeine did not completely ameliorate in the deficits. In fact, most of them had no effects on.

For braking time there was a slight amelioration, so they were slightly better on braking time but compared to control subjects there still was a nine percent slowing of braking time. And what the authors calculated this is - to translate it to, if you were driving, say, 60 miles an hour, there would about an extra 60 feet that you would travel before you actually hit the brake. So it doesn't actually improve as far driving goes. So, there has been some studies in humans indicating that indeed this may be the case.

FLATOW: Well, it's interesting. So don't think that having that cup of coffee is going to sober you up.

Prof. GOULD: Exactly.

FLATOW: Or more information about that - or having those high energy drinks mixed as a cocktail, so to speak, in with your alcohol is going to make you be more responsible.

Prof. GOULD: Exactly. The study suggests that again, that people that are consuming them are more likely to put themselves in harmful situations. The studies - from our studies that shows that there is no reversing the cognitive deficits with the caffeine associated with alcohol consumption, so, yes, exactly.

FLATOW: All right, thank you very much for taking time out of your holiday to talk with us today.

Prof. GOULD: My pleasure, Ira.

FLATOW: Thomas Gould, associate professor of psychology and director with the brain behavior and cognition area of the psychology department at Temple University in Philadelphia.