Status: 30.08.2022

Alcohol is one of the most important risk factors for cancer. Therefore: less is always better! But how much is too much? Does red wine really have a health-promoting effect? And what happens in the body when I drink too much alcohol? Prof. Dr. Heiner Wedemeyer, Director of the Clinical Department of Gastroenterology, Hepatology and Endocrinology at Hannover Medical School (MHH), answers these questions for us.

Alcohol is harmful if consumed in unhealthy quantities. But what is too much?

One standard drink a day, for example a glass of wine (about 125 ml) or beer (about 300 ml) is fine, but it should not be more than one. And that's the level at which most people don't harm themselves if they don't have any other illnesses. I always tell my patients that they should not do one thing: Drinking larger quantities, i.e. more than two drinks a day, and quite a lot at once, i.e. the big "binges".

Red wine in particular is often said to have a positive and health-promoting effect. What is the truth of this?

There are biological effects in the ingredients of red wine that have positive effects. This has been shown experimentally. A small glass of red wine a day in a healthy person is not harmful, but that does not mean that parts of this positive effect may not be due to other reasons, such as diet. Studies show, for example, that people who drink red wine tend to eat differently than people who mainly drink beer. Red wine also tends to be consumed in moderation.

How does alcohol consumption lead to cancer?

On the one hand, excessive alcohol consumption can lead to fat deposits. In medicine, we also speak of metabolic syndrome. Metabolic syndrome develops as a result of a hypercaloric diet and a lack of physical activity. An obvious example that probably everyone knows is the beer belly. These fat deposits can lead to latent chronic inflammation, which is ultimately present throughout the body. Chronic inflammation can be a contributing factor to cancer development in all organs via messenger substances or inflammatory mediators.

In addition, alcohol can lead to scarring processes in all organs. An example of this is liver cirrhosis - an expression of the fact that there is a lot of scar tissue in the liver. The same also applies to the pancreas, lungs or heart... As part of these scarring processes, the body tries to regenerate and new cells are created. Excessive regeneration can then also lead to cancer. This is a second mechanism, so to speak, which takes place independently of the actual inflammation.

Alcohol can also cause cell damage in higher doses. This means that cells break down because the alcohol or alcohol breakdown products in the cell are too strong and toxic. This impairs the energy supply in the cell, for example. Furthermore, protective signaling pathways, whose task it is to protect the cell from cancer, can also be impaired.

Another factor that should not be underestimated is that alcohol changes the microbiome, i.e. the entirety of all microorganisms in the gut. People who drink a lot of alcohol have a different microbiome in their stool than people who drink little or no alcohol. Conversely, this means that the microbiome can be influenced by diet. We know from various regulatory cycles that the gut microbiome also plays a major role in the development of cancer. These regulatory cycles are influenced by alcohol, mostly due to changes in the gut microbiome, and can contribute to the development of cancer.

Can I balance my alcohol consumption with a healthy lifestyle, for example through a healthy diet and exercise?

In the end, everything is connected. With sport and a "healthy" diet, and by that I mean a balanced diet, I can turn many screws and of course also do something good for my health. This also has a positive effect on the points just mentioned, such as the risk of chronic inflammation, metabolic diseases or the intestinal microbiome, which are negatively affected by increased alcohol consumption. As a general rule, alcohol should not be consumed in excess. If alcohol, then in moderation.

The interview was conducted by Maike Isfort, CCC Hannover (Claudia von Schilling Center) of the MHH

Note: Alcohol can be addictive and requires responsible consumption. Information and tips on health-conscious alcohol consumption can be found on the information page of the Federal Center for Health Education.