No Safe Level of Alcohol for the Brain

There is no safe amount of alcohol consumption for the brain; even moderate drinking adversely affects brain structure and function, according a British study of more 25,000 adults.

The study was published online May 12.

Using the UK Biobank, the researchers evaluated brain health on the basis of structural and functional brain MRI measures in 25,378 adults. Participants provided detailed information on their alcohol intake. The cohort included 691 never-drinkers, 617 former drinkers, and 24,069 current drinkers.

Median alcohol intake was 13.5 units (102 g) weekly. Almost half of the sample (48.2%) were drinking above current UK low-risk guidelines (14 units, 112 g weekly), but few were heavy drinkers (>50 units, 400 g weekly).

After adjusting for all known potential confounders and multiple comparisons, a higher volume of alcohol consumed per week was associated with lower gray matter in "almost all areas of the brain.

Widespread negative associations were also found between drinking alcohol and all the measures of white matter integrity that were assessed. There was a significant positive association between alcohol consumption and resting-state functional connectivity.

Higher blood pressure and body mass index "steepened" the negative associations between alcohol and brain health, and binge drinking had additive negative effects on brain structure beyond the absolute volume consumed.

There was no evidence that the risk for alcohol-related brain harm differs according to the type of alcohol consumed (wine, beer, or spirits).