More alcohol, smaller brains

In this cohort study of healthy middle-aged or older adults, decreases in brain volume were detected with as little as 1–2 drinks per day. The greater the alcohol intake, the greater the decrease in brain volume.

This Study Summary was published on June 28, 2022.

Background

Chronic alcohol consumption has been linked to brain atrophy, loss of neurons, and negative changes in brain structure. The negative effects of alcohol on the brain may also interact with the effects of aging,[1] potentially amplifying the negative effects of alcohol in the brain in older individuals.

Although the effects of chronic high-level alcohol consumption on the brain have been well studied in individuals with alcohol use disorder, the effects of alcohol on the brain in more casual alcohol consumers is not well understood. This study examined the associations between alcohol intake and brain structure.

The study

This cohort study analyzed alcohol intake data from 36,768 participants (ages 40–69) in the UK Biobank in conjunction with data on brain structure, as measured by multimodal imaging. The brain imaging for the study included resting and task-based functional magnetic resonance imaging and diffusion imaging.

The results

There were negative associations between alcohol intake and brain structure at both the microstructural and macrostructural levels. Alcohol intake was associated with decreases in global brain volume, regional gray matter volume, and microstructure of the white matter. The negative associations between alcohol intake and brain structure were detected in participants who consumed as little as 1–2 drinks per day but increased with increasing alcohol intake.

The authors suggested that consuming as little as one drink per day could be associated with changes in brain volume.

This Study Summary was published on June 28, 2022.