Mar 4, 2022 - Health

A drink a day could be associated with brain changes, study finds

Illustration of a martini glass with a brain on a skewer instead of an olive.

Illustration: Shoshana Gordon/Axios

Having even one drink a day could reduce one's overall brain size over time, according to a study published today in the journal Nature Communications.

Why it matters: The study found the greatest risks with heavy drinking, but alcohol consumption was linked to reduced brain volume among far more moderate drinkers. The findings could throw cold water on other studies suggesting that lighter alcohol consumption has no impact on, or may even benefit, the brain.

The analysis by University of Wisconsin and University of Pennsylvania researchers looked at data from 36,000 people who were part of the UK Biobank, a dataset with genetic and medical information from half a million British middle-aged and older adults.

  • The researchers factored such variables as age, height, gender, smoking status and socioeconomic status and corrected for overall head size.
  • Those who drank the most had changes in brain size and function that are associated with cognitive impairments from aging. But the linkage also was evident with moderate drinkers.

What they're saying: "These findings contrast with scientific and governmental guidelines on safe drinking limits," said Henry Kranzler, who directs the Penn Center for Studies of Addiction, in a statement.

  • For example, he pointed out, the National Institute on Alcohol Abuse and Alcoholism recommends women consume an average of no more than one drink per day and men consume no more than two drinks daily on average.
  • "That exceeds the consumption level associated in the study with decreased brain volume," Kranzler said.

The bottom line: This study looked at correlation, not causation. But the size of the data set and the strength of the association should at least give drinkers pause before they call for another round, the researchers said.

Go deeper