Does coffee really wake you up when you are drunk?

According to foreign media reports, caffeine can eliminate the effects of excessive alcohol, which is an attractive point of view. Unfortunately, research shows that things are not that simple.

Us officials are investigating the safety of caffeine in snacks and energy drinks. More and more foods are adding irritants, and they are worried about the "cumulative effect" of stimulants. Is it our tea and coffee that drives society to over-rely on the world's most popular drugs?

A few years ago, I went to the local theater to see a show with some friends. My husband was late and a little excited because he spent most of the afternoon drinking at Christmas lunch in his office. Fortunately, it was a comedy, but his laughter still made the audience and even the actors look at him strangely.

In the interval before the second act, I bought him a cup of coffee to help him wake up. He became a little quieter before the end of the play, but can I think it was coffee that worked?

A lot of alcohol does have a calming effect. For the first hour and a half, when the blood alcohol concentration is very high, people will become more awake. Drowsiness increases two to six hours after drinking. Caffeine, by contrast, can wake people up. This leads to the idea that a cup of coffee can counteract the effect of a pint of beer.

Unfortunately, things are not that simple. Previous studies on the effects of caffeine on the driving ability of drunken people (experiments were conducted in the laboratory, not on the road) yielded conflicting results. Some people have found that caffeine can alleviate the slow response caused by alcohol, while others do not.

A recent study aimed at combing in more detail the effects of the combination of alcohol and caffeine was published in 2009. Mice were given the equivalent of eight cups of coffee in humans after drinking alcohol. After that, they seem to have sobered up a lot, but they are still much worse than awake mice when walking the maze.

So caffeine can counteract fatigue caused by alcohol, which explains why in many places, people like to have a cup of coffee after a meal. But caffeine does not eliminate the sense of chaos caused by drunkenness and alcohol. The reason is that we have to eliminate its effects through metabolism. The body will deal with it in several ways. The most important thing is that the liver secretes two enzymes, ethanol dehydrogenase and aldehyde dehydrogenase, to break down alcohol. After several steps, alcohol is eventually excreted as water and carbon dioxide.

For a unit of alcohol, it takes the body about an hour to metabolize. Some people go faster and some people slow down, depending on their genetic makeup and how often they eat and drink. Caffeine does not speed up the metabolism. But its impact depends on how you look at it. For example, a study shows that large amounts of caffeine can eliminate the negative effects of alcohol on memory, but the feeling of dizziness is still there.

There are also some ideas that caffeine will make the situation worse. If you feel tired, you will probably realize that you must be drunk, but if caffeine eliminates some fatigue, you may feel that you are awake, but in fact you are not. This may also explain the findings of a 2008 study of American college students. Those who choose drinks that contain both alcohol and caffeine, such as vodka and Red Bull, are twice as likely to be injured in accidents. They are more than twice as likely to accept a ride with a speeding driver. This is the independent effect of drinking. In an early study, students chose their own drinks and reported how drunk they were. But it also shows that caffeine can make people mistakenly think that they are awake, so it also has potentially disastrous consequences.

So if I still go to the theatre on the day of my husband's office party this year, I will know that only time will sober up. Then I would wish it was a play with three acts.