Relationship between alcohol consumption and dementia with Mendelian randomization approaches among older adults in the United States

Background In observational studies, the association between alcohol consumption and dementia is mixed. Methods We performed two-sample Mendelian randomization (MR) using summary statistics from genome-wide association studies of weekly alcohol consumption and late-onset Alzheimer’s disease and one-sample MR in the Health and Retirement Study (HRS), wave 2012. Inverse variance weighted two-stage regression provided odds ratios of association between alcohol exposure and dementia or cognitively impaired, non-dementia relative to cognitively normal. Results Alcohol consumption was not associated with late-onset Alzheimer’s disease using two-sample MR (OR=1.15, 95% confidence interval (CI):[0.78, 1.72]). In HRS, doubling weekly alcohol consumption was not associated with dementia (African ancestries, n=1,322, OR=1.00, 95% CI [0.45, 2.25]; European ancestries, n=7,160, OR=1.37, 95% CI [0.53, 3.51]) or cognitively impaired, non-dementia (African ancestries, n=1,322, OR=1.17, 95% CI [0.69, 1.98]; European ancestries, n=7,160, OR=0.75, 95% CI [0.47, 1.22]). Conclusion Alcohol consumption was not associated with cognitively impaired, non-dementia or dementia status.