The Association of Alcohol Consumption with the Risk of Dementia

While previous research has related alcohol intake to the risk of dementia, this study importantly focuses on elderly people participating in a randomized trial of Gingko biloba that had a null result (N=3021, median age 78 years, 46% female), evaluating the association of alcohol consumption with mild cognitive impairment (MCI) and dementia. There were 512 new cases of dementia diagnosed over a 6-year follow up; diagnoses were validated by cognitive evaluations, MRI, and an expert panel of clinicians. At least some alcohol consumption was self-reported at baseline by 58% of participants. Researchers adjusted results for potential confounders, including body weight, smoking, diabetes, cardiovascular and other diseases, depression, race, ethnicity, clinic site, educational level, social activity, medication use, and genotype for APOE e4, which is associated with Alzheimer’s disease.

• Among participants without MCI at baseline (n=2548), alcohol consumption was not significantly associated with lower risk of dementia (compared with <1 drink per week); the hazard ratio (HR) for dementia with abstinence was consistent with a slightly higher but non-significant risk (HR 1.17 (95% Confidence Interval [CI], 0.84-1.62).
• Participants with MCI at baseline (n=473) consuming >14 drinks/week had a non-significantly increased risk for dementia (HR, 1.72 [95% CI, 0.87-3.40]).
• Daily consumption of 1 drink was associated with a lower dementia risk than less-than-daily consumption of ≥2 drinks (HR, 0.45 [95% CI, 0.23-0.89]).

Comments: An important strength of this study was the extensive evaluation for cognitive impairment and dementia in these older adults. Overall, these data are not inconsistent with most previous studies that show a J-shaped association for the relation of alcohol consumption to the risk of dementia, with abstinence associated with higher risk, and regular but not excessive drinking associated with higher risk (though not statistically significant in this study).

R. Curtis Ellison, MD

Reference: Koch M, Fitzpatrick AL, Rapp SR, et al. Alcohol consumption and risk of dementia and cognitive decline among older adults with or without mild cognitive impairment. JAMA Netw Open. 2019:2(9):e1910319.