A UK Biobank study found a statistical difference in brain size and gray matter, which tended to be smaller, in people drinking even one glass of alcohol a day compared to non-drinkers.

“This claim is well-supported by a large-scale study published in Nature Communications in March 2022. Researchers analyzed data from over 36,000 adults from the UK Biobank and found negative associations between alcohol intake and brain volume. The study specifically noted that these negative associations, affecting both gray and white matter, were detectable in individuals consuming an average of just one to two alcohol units per day. Context: The study found that the link between drinking and reduced brain volume grew stronger with higher levels of alcohol consumption. For example, in 50-year-olds, increasing from one to two alcohol units per day was associated with brain changes equivalent to aging two years.”