Cognitive Effects of Moderate Alcohol Consumption
Several
studies suggest that moderate drinking may reduce the risk of cognitive
decline associated with aging and dementia, including Alzheimer
disease. To assess the effect of alcohol on cognitive dysfunction
(defined as scoring in the lowest quintile on tests of cognitive
functioning), researchers evaluated approximately 11 years of follow-up
data on 6033 men and women (aged 35–55 years at baseline
and 46–68 when cognition was assessed) in the United Kingdom. Results
from analyses adjusted for potential confounders (e.g., age, smoking,
socioeconomic status, cholesterol and blood pressure levels) include
the following:
- On most measures (tests of verbal and mathematical
reasoning, verbal fluency, and verbal meaning), men
who consumed >241 g of alcohol per week (over 3 standard
drinks per day), compared with men who consumed <1
g per week, experienced significantly lower odds (odds
ratios, ORs, from 0.5 to 0.6) of cognitive dysfunction
(with borderline significant findings on the test of
memory). - Female drinkers experienced significantly lower odds
of dysfunction on tests of verbal meaning (ORs from
0.3 to 0.6 at amounts <=160 g per week) and on one
measure of verbal fluency (OR 0.5 at 49–80 g per
week). - More frequent drinkers usually had the lowest odds
of cognitive dysfunction on most measures. Lifetime
abstaining men and women (compared with occasional and
moderate drinkers) generally had higher odds.
Comments:
This
study is consistent with prior studies showing the possible
benefits of moderate drinking on cognition in middle-aged
adults. The mechanisms of protection against cognitive
dysfunction are unknown, but may relate to decreased cerebral
vascular disease and/or increased cerebral blood flow associated
with moderate alcohol consumption.
R. Curtis Ellison, MD
Reference:
Britton
A, Singh-Manoux A, Marmot M. Alcohol consumption
and cognitive function in the Whitehall II Study. Am
J Epidemiol. 2004;160(3):240–247.
(view
abstract)