A man sleeps in a pub in front of an almost empty beer mug. Anyone who drinks a few more glasses on carnival days might notice an uninvited guest: the hangover after the rush. Photo: dpa
Beer on wine, leave it alone? Only wimps cat? There is a lot of wisdom about the consequences of alcohol intoxication. Not all stand up to scientific scrutiny.
Stuttgart/Berlin – If you drink a few extra glasses on Carnival days, you might notice an uninvited guest: the Nachdurst, also called Brand, which is often accompanied by a severe hangover (the medical term is veisalgia) with nausea, vomiting and dizziness. But how does the thirst-quenching effect of alcohol come about??
Scientists have extensively studied the consequences of alcohol consumption. An overview:
In which order you drink, the tomcat does not care
"Beer on wine, let it be. Wine on beer, that's my advice."Researchers at the University of Witten/Herdecke have exposed the prominent advice on hangover avoidance as a myth with a humid experiment. Their insight: for the hangover, it does not matter in which order you have poured beer and wine into yourself.
Participants in the study, published in the American Journal of Clinical Nutrition, initially drank only wine or beer on two different evenings and switched to the other drink at 0.5 per mille of alcohol in the blood. It made no difference to the morning after.
"We have clearly shown: The saying is not true – at least for white wine and lager," says Kai Hensel, a medical doctor who led the experiment in Witten, Germany.
If you're hungover, you must be a wimp
Waking up with a hangover after a night of drinking is not a sign of weakness. This is the conclusion of a survey of Dutch students conducted by scientists at the University of Utrecht. There were no differences in well-being or other resilience between those who were prone to hangovers and those who suffered less from the effects of drinking.
"At the end of the day, however, the hangover sensation is of course subjective, because it is, after all, a form of pain," says scientist Hensel in this regard.
Tired, thirsty, unable to concentrate
Utrecht alcohol researchers also asked Dutch students how their hangover manifests itself. It came out: fatigue, thirst and concentration problems are the symptoms mentioned by more than 95 percent of respondents suffering from hangovers. Also very common were headaches and nausea. A good one in five respondents reported experiencing anxiety.
It depends on what is in it
An experiment by U.S. researchers showed bourbon causes a more severe hangover than vodka. The scientists attribute this to the fact that bourbon has a 37-fold higher proportion of so-called congeners – chemical substances that are formed during the production of alcohol.
Ginseng helps to break down alcohol
Korean researchers gave a group of 25-year-old men first 100 milliliters of whiskey and then a water solution containing red ginseng. A control group was given only an ineffective placebo after the whiskey. In the ginseng group, the alcohol content in the blood decreased significantly faster – and with it the risk of a bad hangover.
The thirst after intoxication
Researchers at the University of Texas Southwestern Medical Center in Dallas (U.S. state of Texas) have explored the question of post-drinking in a study. In the experiment with mice, the scientists found that alcohol in the liver boosts the production of the hormone FGF21. This messenger is also responsible for the appetite for sweets, as researchers from the University of Copenhagen found in 2017.
The experts studied normal and genetically modified rodents that could not produce the liver neurotransmitter. In normal diet all animals drank the same amount of water. But when the mice were fed food that has a similar effect on nutrient balance in the body as alcohol, a striking difference emerged. While the normal mice drank more, the fluid intake of the genetically modified mice did not change.
Thirst center in the brain is stimulated
For the researchers, it is clear that the release of FGF21 stimulates the thirst center in the hypothalamus, the section of the diencephalon that functions as the most important control center of the autonomic nervous system. This prevents the threat of a lack of fluids, which is caused by the diuretic effect of alcohol. At the same time, the desire to continue drinking alcohol is suppressed.
Thirst is nothing more than an unmistakable signal from the body that fluid balance is at risk of becoming unbalanced. This agonizing feeling motivates to drink and in this way ensures that the organism remains functional.
Only water helps with a hangover
Special sensors in the thirst center of the brain analyze whether and how much fluid the body needs and what kind of fluid it is. While alcohol increases the feeling of thirst and pure juice has no effect at all, water quenches thirst permanently.
The Texas researchers' findings not only help hungover Wasen visitors, but could also have therapeutic benefits. "Perhaps FGF21 could one day be used as a drug to prevent excessive alcohol consumption and its consequences," says Dallas University biochemist David Mangelsdorf.