Prospective study of alcohol consumption and risk of dementia in older adults
Mukamal KJ, Kuller LH, Fitzpatrick AL, Longstreth WT, Mittelman MA and Siscovick DS;
Commented by , 26 May 2003
Aim of the study
To determine the prospective relationship of alcohol consumption and risk of dementia in older adults.
Method
Nested case-control study of 373 cases with incipient dementia and 373 controlswho were among 5888 adults age 65 and older who participated in the Cardiovascular Health Survey, a prospective, population-based cohort study in four US communities. The controls were frequency-matched on age, death before 1999, and 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 followed up until 1999.
The main outcome measures were odds of incipient dementia according to average alcohol consumption, assessed by self-report intake of beer, wine, and liquor at 2 visits prior to the date of the MRI. Dementia was diagnosed by a detailed neurological assessment using DSM-IV criteria.
Results
Compared with abstention from alcohol, the adjusted odds for dementia among those whose weekly alcohol consumption was less than 1 drink were 0.65 (95% confidence intervals <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); 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 E4 allele. Similar relationships of alcohol use were found with Alzheimer’s disease and vascular dementia.
Discussion
This study is important to clarify the potential benefits of ‘moderate’ consumption of alcohol in preventing dementia. One potential explanation is the observation that moderate alcohol consumption is associated with a lower risk of cardiovascular disease in the elderly. Mixed findings on brain MRI have been reported from the Cardiovascular Health Study cohort: moderate alcohol consumption was associated with greater brain atrophy but fewer silent infarcts and less white matter disease.
A large cohort study in Bordeaux has found a strong inverse association between wine consumption (up to 4 glasses a day) and the risk of dementia. The Rotterdam study found a U-shaped association between alcohol use and the risk of dementia, with the lowest risk between 1 to 3 drinks per day.
The current study suggests a higher risk with consumption higher than 2 drinks per day. It thus looks like for persons who enjoy a social drink, ‘mild’ amounts (1 or 2 drinks a day) and not moderate amounts (more than 2 drinks a day) could be considered as a healthy habit in old age.