Alcohol consumption and risk of dementia: a systematic review and meta-analysis.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational studies (assessed via Newcastle-Ottawa Scale)
PubMed 41376207 · doi:10.1111/imj.70288
What was done
Authors searched PubMed, Embase, Cochrane Library, and Web of Science through July 22, 2024, for studies evaluating alcohol intake and dementia risk. Quality of included original studies was assessed using the Newcastle-Ottawa Scale. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were computed, and subgroup analyses were performed by consumption level, geographic region, and age.
What was found
Overall alcohol exposure was not significantly associated with dementia risk: all-cause dementia (ACD) RR = 1.03 (95% CI: 0.84–1.27), Alzheimer disease (AD) RR = 0.97 (95% CI: 0.86–1.08), vascular dementia (VD) RR = 1.09 (95% CI: 0.95–1.26), and other dementia RR = 0.62 (95% CI: 0.33–1.15). In subgroup analyses by intake level, light-to-moderate drinking was linked to lower risk of ACD (RR = 0.88, 95% CI: 0.81–0.96) and AD (RR = 0.88, 95% CI: 0.79–0.97), with stronger protective associations in Europe and individuals aged 60–69 years. Conversely, heavy drinking significantly increased risk for ACD (RR = 1.18, 95% CI: 1.02–1.36), AD (RR = 1.29, 95% CI: 1.21–1.36), and VD (RR = 1.25, 95% CI: 1.11–1.40).
Why it matters
This meta-analysis clarifies a non-linear relationship where heavy alcohol consumption raises dementia risk across multiple subtypes, whereas light-to-moderate intake is associated with a modest risk reduction.
Limits
The abstract does not report the total number of included studies, overall participant sample size, or follow-up durations. As a synthesis of observational studies, the findings are susceptible to residual confounding, self-report misclassification of alcohol intake, and potential sick-quitter bias.
Cited by
- contradicts The World Alzheimer Report 2022 concluded that a protective effect against Alzheimer's disease exists only for red wine up to four glasses per day, but not for other alcohol types.