It is widely known that heavy drinking harms the brain, but even drinking as little as a few beers or glasses of wine per week will reduce brain volume, according to a new study of 36,000 adults. Researchers led by a University of Pennsylvania team reported in Nature Communications that alcohol consumption even at modest levels may carry risks to the brain, shrinking it in ways similar to the aging process. The study was conducted using the UK Biobank, a dataset from 500,000 British middle-aged and older adults that includes genetic and medical information, including white and gray matter volume in different regions of the brain.

The researchers found that the more alcohol people consumed on average, the greater the brain damage. Going from zero to a daily average of one alcohol unit (half a beer or half a glass of wine) is linked with the equivalent of a half a year of aging in 50-year-olds. Drinking an
average of two units a day (a pint of beer or glass of wine) produces changes in the brain equivalent to aging two years. The difference between zero and four units (two beers or glasses of wine) was equal to more than 10 years of aging. “It’s not linear,” says study co-author Remi Daviet. “It gets worse the more you drink. There is some evidence that the effect of drinking on the brain is exponential. That means that cutting back on that final drink of the night might have a big effect in terms of brain aging.”