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 epsilon4 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.