Aims: To identify variables that explain the association between alcohol abstention and cognitive performance. We hypothesized that demographic and personality variables would be important for explaining the association in all age cohorts, but that health variables would be more important in the older age-cohorts.
Design: Three age cohorts (20-24, 40-44, 60-64 years) were sampled randomly, yielding a total of 7485 participants, with data from 602 alcohol abstainers and 4158 light or moderate drinkers used in this study. Setting The sample was drawn from the cities of Canberra and Queanbeyan, Australia.
Measurements: Scales measuring demographic, health and personality variables and cognitive and physical tests were administered. Participants drinking at hazardous or harmful levels were excluded from the analysis.
Findings: A range of demographic and physical function measures were found to explain partially the finding of abstainers having lower cognitive test scores. The effects of independent variables were largest in the 60-64-year-old age group with a trend for physical variables such as lung function and grip strength to become more important in the older age groups. In the 20-24-year-olds, the majority of the effect remained unexplained.
Conclusion: There is evidence that poorer cognitive test performance by abstainers reflects in part selection effects and poorer physical functioning, but does not appear to be due to mental or physical health conditions or personality.