Alcohol consumption in relation to cognitive dysfunction and dementia

Findings on alcohol and cognitive dysfunction and dementia have been inconsistent. A dose-response meta-analysis of cohort and case-control studies was conducted to evaluate the available evidence.
A systematic search was conducted on PubMed/MEDLINE, Scopus, Embase, and PsychInfo databases and Google Scholar up to April, 2023. Seventeen eligible studies comprising 80,680 total persons with 4929 cases for dementia and 13,530 total persons with 1,579 cases for cognitive dysfunction were included for dose-response analysis. When compared to the reference group of 0 g/day of alcohol intake, the dose-response meta-analysis revealed a significant non-linear (J-shaped) association between alcohol intake and the risk of each of cognitive dysfunction, (lower dose range: 1-30.5 g/day, RR: 0.97; 95 % CI 0.95-0.99; higher dose range: >30.5 g/day, RR: 1.07; 95 % CI 1.01-1.15) and dementia (lower dose range: 1-17.5 g/day, RR: 0.92; 95 % CI 0.88-0.96, higher dose range: >17.5 g/day, RR: 1.23; 95 % CI 1.09-1.35). The lowest risk was achieved at approximately 30 g/day of alcohol for cognitive dysfunction and 15 g/day for dementia. The J-shape association remained with subgroups defined by age (≤65; >65 years) or study duration (<10; ≥10 years) for dementia, and within age >65 and duration <10 years for cognitive dysfunction.
The researchers observed a J-shape association between alcohol consumption and both cognitive dysfunction and dementia, with light-to-moderate alcohol intake being associated with a reduced risk in adults. Further studies are needed to clarify more specifically the association between alcohol consumption and six domains of cognitive dysfunction based on diagnostic and statistical manual of mental disorders (DSM) criteria.
Source: Zarezadeh M, Mahmoudinezhad M, Faghfouri AH, Mohammadzadeh Honarvar N, Regestein QR, Papatheodorou SI, Mekary RA, Willett WC. Alcohol consumption in relation to cognitive dysfunction and dementia: A systematic review and dose-response meta-analysis of comparative longitudinal studies. Ageing Res Rev. 2024 Jul 20;100:102419.