Sex differences in the association between alcohol consumption and cognitive performance

Heavy alcohol drinking is associated with cognitive impairment, but little is known concerning the cognitive effect of moderate alcohol consumption. The Epidemiology of Vascular Aging (EVA) Study is a longitudinal study of cognitive and Vascular aging. Between June 1991 and June 1993, 1,389 subjects aged 59-71 years (574 men and 815 women) who had been recruited from the electoral rolls of Nantes, France, were examined. Trained psychologists administered a battery of 10 neuropsychological tests assessing most areas of cognitive functioning. Detailed information on alcohol intake was collected during a structured interview. A multiple linear regression model was used to examine the relations between test scores and alcohol consumption at baseline in men and women separately, controlling for age, education, income, depressive symptoms, and smoking status. Odds ratios for being a high cognitive performer (i.e., being in the top 10% of the distribution of summary scores from the neuropsychological battery) were calculated. Among men, neuropsychological test scores were not associated with alcohol consumption in either univariate or multivariate analysis; nor did the proportion of high cognitive performers vary by alcohol consumption. In contrast, among women, significant positive associations between alcohol consumption and cognitive performance were observed for most tests in multivariate analysis. For example, for the Mini-Mental State Examination, the adjusted mean score for female nondrinkers was 27.5 and that for the heaviest drinkers 28.2 (p < 0.001). The odds ratio for being a high cognitive performer was 2.5 (95% confidence interval 1.1-5.7) for women who usually consumed two or more drinks per day in comparison with nondrinkers. These findings suggest that, among women, moderate alcohol consumption may have a beneficial effect on cognitive function.