The authors investigated the relation between alcohol consumption and cognitive function in a United Kingdom cohort study (4,272 men, 1,761 women) with median follow-up of 11 years. Measures of alcohol consumption were obtained at baseline (1985-1988) and four subsequent phases of data collection. Cognitive function (memory test, AH4, Mill-Hill, phonemic and semantic fluency) was assessed at phase 5 (1997-1999), when participants were aged 46-68 years. Of people who reported drinking alcohol in the past year, those who consumed at least one drink in the past week, compared with those who did not, were significantly less likely to have poor cognitive function. The beneficial effect extended to those drinking more than 240 g per week (approximately 30 drinks). The effect was stronger for women than men and was not confined to those with evidence of vascular disease. Similar associations were found in cross-sectional and longitudinal analyses. The relations were not explained by confounding by smoking and by physical and mental health and, to a large extent, were not mediated by cholesterol or blood pressure. However, the relations were weakened when social position was added to the model. The authors concluded that for middle-aged subjects, increasing levels of alcohol consumption were associated with better function regarding some aspects of cognition. Nonetheless, it is not proposed that these findings be used to encourage increased alcohol consumption.