Even moderate alcohol consumption is associated with brain shrinkage
Drinking alcohol is one of the neurotoxins. Its consumption seems to be associated with reduced brain volume.
Even discreet alcohol consumption, which is common among many people, is associated with shrinkage and premature aging of the brain. This is the conclusion of researchers led by Reagan Wetherill of the University of Pennsylvania. The team reports on this in the journal Nature Communications.
The scientists analyzed medical data from more than 36,000 adults. For this purpose, they accessed the "UK Biobank" database, which contains health-related information on several hundred thousand British citizens. In addition to basic information such as age, height, gender and socioeconomic status, the database also contains brain scans - magnetic resonance imaging data that allow conclusions to be drawn about brain volume. In addition, all the people studied had given information on their drinking behavior during the previous year in questionnaires.
Accelerated aging
The evaluation of this information showed that the more alcohol a person consumes, the more clearly his or her brain volume is reduced. The shrinkage is tantamount to premature aging, because brain mass also shrinks with years of life. Even amounts of alcohol that are widely considered harmless are therefore associated with measurable effects. For example, 50-year-olds who consume a bottle of beer or a glass of wine daily exhibit brain loss equivalent to two additional years of life - measured against the average volume one would expect for that age. The shrinkage affects the entire organ, but especially the frontal and parietal lobes and the insular cortex. These brain regions participate in the control of movements as well as the processing of sensory impressions; the frontal lobe is also considered the seat of individual personality and social behavior. Drinking alcohol is one of the neurotoxins.
However, the researchers emphasize that the observed effect is a statistical correlation that becomes apparent in retrospective data analysis. Causal statements cannot be derived from this without further ado. To obtain these, for example, longitudinal studies are necessary, whose participants are repeatedly examined over time.
The connection between alcohol consumption and brain shrinkage does not seem to be linear, the scientists write. While a small glass of beer a day equates to just half an extra year of life, four glasses a day adds ten years. "It gets worse the more you drink," says Remi Daviet of the University of Wisconsin-Madison, one of the researchers involved. Some evidence suggests that the effect of alcohol may grow exponentially as the amount increases, he says. But that would also mean that those who drink the most would benefit the most from limiting their consumption.
The threshold values above which the health risk for adults is proven to increase are usually 12 grams of alcohol per day for women and 24 grams per day for men. These figures are given, for example, by the German Centre for Addiction Issues. Since alcoholic beverages differ greatly in their percentage content, an attempt is made to make them comparable among themselves by converting them into "standard drinks." A standard drink contains about 10 grams of pure alcohol, although this amount is defined differently from country to country.
According to the World Health Organization (WHO), around two and a half billion people consume alcohol worldwide. These consume an average of 33 grams a day, which is equivalent to around three standard drinks - and, according to the new study, is associated with significant brain changes. According to the WHO, three million people die each year as a result of alcohol consumption.
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