The relationship between alcohol use and dementia in adults aged more than 60 years: a combined analysis of prospective, individual-participant data from 15 international studies.
Level 3 - non-randomized controlled study
Individual participant data meta-analysis of prospective non-randomized cohort studies
PubMed 35993434 · doi:10.1111/add.16035
What was done
An individual participant data meta-analysis evaluated 15 prospective epidemiological cohort studies across six continents. The analysis included 24,478 community-dwelling adults aged over 60 years (mean age 71.8 years, 58.3% female, 54.2% current drinkers) who were dementia-free at baseline and had at least one follow-up assessment. Cox regression models evaluated the association between alcohol consumption and incident all-cause dementia (diagnosed by clinical interview) over 151,636 person-years of follow-up.
What was found
A total of 2,124 incident dementia cases occurred (14.0 per 1,000 person-years). Compared with abstainers, dementia risk was lower in occasional drinkers (HR = 0.78; 95% CI: 0.68–0.89), light-moderate drinkers (HR = 0.78; 95% CI: 0.70–0.87), and moderate-heavy drinkers (HR = 0.62; 95% CI: 0.51–0.77). No significant difference was found between lifetime abstainers and former drinkers (HR = 0.98; 95% CI: 0.81–1.18). Moderate drinking up to 40 g/day was associated with lower risk versus lifetime abstaining, but among current drinkers, risk did not differ consistently by amount consumed. Findings were consistent across sexes, but showed substantial heterogeneity by continent.
Why it matters
By harmonizing individual-level data across diverse global cohorts and separating lifetime abstainers from former drinkers, this study shows that alcohol consumption in older adults is associated with lower dementia risk than abstinence, with no clear dose-response gradient among active drinkers.
Limits
The observational prospective design cannot establish causality or eliminate residual confounding and healthy survivor bias. Alcohol intake was based on self-report, and considerable heterogeneity was observed across geographic regions.
Cited by
- context Some studies suggest light to moderate drinking is associated with a 26% to 28% risk reduction for dementia and Alzheimer's disease.
- supports A pooled analysis of over 15 international studies of adults over 60 found that occasional and light-to-moderate drinkers had a 22% lower dementia risk, and moderate-to-heavy drinkers had a 30% lower dementia risk, compared to abstainers.