What are the benefits of red wine

For the first time, he had more red wine supplies than socks and underpants, announced the journalist Harald Martenstein some time ago. After all, he is regularly given red wine, but sales are dwindling. As a rule, he puts the bottles in front of dear guests, wrote Martenstein in his column in the time. That worked quite well in the past, "because people have not yet been so moderate". But now? "Nowadays most guests only drink one or two glasses because they are totally aware."

The publicist may owe this restriction in the drinking behavior of his friends to a series of studies that have warned against high alcohol consumption since the 1980s, but recommend moderate consumption. In the meantime, the appeal has even turned into a real commandment: "Drink a glass of red wine every day to protect yourself from heart attacks and strokes," is the credo.

Indeed, there seem to be some arguments in favor of the health benefits of the red drop. "Is it time for a toast to the red wine again?" Asks the trade magazine Science on the occasion of a study. It is about the ingredient resveratrol, which is contained in red wine and, in contrast to white wine, is supposed to give it a particularly health-promoting effect. Scientists at Harvard Medical School in Boston used cell experiments to test the circumstances under which resveratrol can activate a protein called sirtuin. This is considered to be one of the key enzymes in the field of cancer and heart attack prophylaxis and is supposed to be responsible for longevity.

Could the study read like a plea for a glass of red wine every day? As is so often the case in nutritional science, things are not as simple as expected. Certainly, many epidemiological studies over the last 30 years suggest that moderate consumption of red wine reduces the risk of developing heart disease, stroke or diabetes; this also reduces mortality. In a meta-analysis of 84 studies in 2011, William Ghali from the University of Calgary showed that people with light to moderate alcohol consumption suffer from cardiovascular diseases a quarter less than abstainers.

The possible mechanisms of heart protection are also described in detail: Alcohol increases the good HDL cholesterol and thins the blood so that clots are less likely to form. "This suggests that the epidemiological findings are correct," says Ulrich Keil from the University of Münster. The epidemiologist suspects that the hearts of people with moderate alcohol consumption are actually healthier because of the alcohol and not, conversely, that people with healthy hearts drink more alcohol than sick people. An interpretation that not all researchers agree with.

According to the World Health Organization (WHO) and various other professional societies, ten grams of alcohol per day are considered moderate for women - twice as much for men. Ten grams of alcohol are contained in four centiliters of schnapps, a quarter of a liter of beer or an eighth of a liter of wine. Ulrich Keil believes, however, that these values ​​are due to the emotionality of the discussion: "If you look at the studies, 20 grams for women and 30 grams for men are optimal for the heart," says the doctor, who recently worked with the International Forum on Alcohol Research accused the WHO of wrongly demonizing alcohol.

How the wine industry gets involved in research

Whether the alcohol is drunk with food or consumed without solid food seems to be irrelevant, at least for heart protection. For the heart it is also irrelevant whether the weekly ration is consumed regularly over seven days or whether alcohol-free days are included. And finally, it does not matter in what form the alcohol is consumed. The beneficial effects apply not only to red wine, but also to beer and schnapps, which are often outlawed by health-conscious laypeople.

Also the Science- The study does not change anything about these findings from epidemiology: "Experiments with individual substances in the culture dish do not say much," says Ulrich Keil. His colleague Kailash Prasad from the University of Saskatchewan in Canada summed up in a review article a year ago: "Resveratrol can prevent vascular calcification in animal experiments and in-vitro studies, but there is a lack of robust clinical studies that prove any preventive effect in humans."

The fact that the myth of red wine as the healthiest alcoholic drink persists is above all to blame the efforts of the wine industry. It financed the first studies on the health potential of wine. Even today, a noticeable amount of research is being carried out in California, South Africa, Italy or France, celebrating resveratrol as a miracle substance because the substance from the skin of red grapes is antioxidant and anti-inflammatory and also prevents obesity.

Such study results are then disseminated in industry brochures which find an amazing readership. So it is Statutory Health Insurance Physician - one of the highest-circulation papers in the health sector - regularly a free issue with the name Vinomed at. This leaflet discusses the latest studies on the health potential of Merlot, Chianti wines or Riesling, but only the positive ones. The publisher is the German Wine Academy, which is supported, among other things, by the Viticulture Association.

Breweries have less access to research

It is true that the breweries have been trying to get access to the university laboratories for some time - after all, there are also numerous healthy substances in beer such as xanthumol, which can be used to kill cancer cells, at least in the Petri dish. But it will probably take years to counter the image of healthy red wine.

However, the message that alcohol in moderation is generally beneficial to health is not without controversy. While the Münster researcher Keil considers it to be sufficiently proven, Helmut Karl Seitz from the Alcohol Research Center of Heidelberg University does not derive any reliable evidence from the facts available. In the studies, the health status of alcohol consumers is compared with that of abstainers, complains Seitz: "But abstainers are often ex-drinkers or sick people." In addition, people with moderate drinking behavior are otherwise more health-conscious.