Prospective study of alcohol consumption and risk of dementia in older adults

Context  Alcohol consumption has been associated with complex changes in cerebral vasculature and structure in older adults. How alcohol consumption affects the incidence of dementia is less clear. Objective  To determine the prospective relationship of alcohol consumption and risk of dementia among older adults. Design, Setting, and Participants  Nested case-control study of 373 cases with incident dementia and 373 controls who were among 5888 adults aged 65 years and older who participated in the Cardiovascular Health Study, a prospective, population-based cohort study in 4 US communities. The controls were frequency-matched on age, death before 1999, and their attendance of a 1998-1999 clinic. Participants in this study underwent magnetic resonance imaging (MRI) of the brain and cognitive testing between 1992 and 1994 and were followed up until 1999. Main Outcome Measures  Odds of incident dementia, ascertained by detailed neurological and neuropsychological examinations according to average alcohol consumption, assessed by self-reported intake of beer, wine, and liquor at 2 visits prior to the date of the MRI. Results  Compared with abstention, the adjusted odds for dementia among those whose weekly alcohol consumption was less than 1 drink were 0.65 (95% confidence interval [CI], 0.41-1.02); 1 to 6 drinks, 0.46 (95% CI, 0.27-0.77); 7 to 13 drinks, 0.69 (95% CI, 0.37-1.31); and 14 or more drinks, 1.22 (95% CI, 0.60-2.49; P for quadratic term = .001). A trend toward greater odds of dementia associated with heavier alcohol consumption was most apparent among men and participants with an apolipoprotein E 4 allele. We found generally similar relationships of alcohol use with Alzheimer disease and vascular dementia. Conclusions  Compared with abstention, consumption of 1 to 6 drinks weekly is associated with a lower risk of incident dementia among older adults.