Self-reported alcohol intake and cognition in aging twins

Objective: To determine the relationship between long-term alcohol intake and cognitive functioning in aging Caucasian men. Method: A retrospective cohort and co-twin-control study of self-reported alcohol intake and cognitive testing using the National Academy of Sciences-National Research Council (NAS-NRC) Twin Panel of U.S. veterans (born between 1917 and 1927). The study included 4,739 twins with two self-reported drinking histories (1970s and 1980s) and a telephone mental status interview (1990 and 1991) that also included 145 individuals with a diagnosis of alcoholism. Results. Age and education adjusted cognitive scores were lower (p < .05) in diagnosed alcoholics than in the remainder of the subjects. To compare age and education adjusted cognitive scores to alcohol intake, the 4,739 twins were divided, based upon questionnaire data, into nondrinkers and 5 quintiles of drinkers by average reported drinks of alcohol weekly (<1.0, 1-3.3, 3.4-8.1, 8.2-16.0, > 16.0). Past drinkers had scores lower (p < .05) than nondrinkers and all but quintiles 1 and 5 of the drinkers. The light drinkers in quintile 1 and the heavy drinkers in quintile 5 scored lower (p <.05) than the moderate drinkers in quintile 4. Monozygotic twins in quintile 4 scored higher (p < .05) than their co-twins in quintiles 1-3. Conclusions: No evidence was found to indicate an association between moderate long-term alcohol intake and lower cognitive scores in aging individuals. There was a suggestion of a small protective effect of past moderate alcohol intake on cognitive function with aging.