Smoking and cognitive ability for non-dementia older adults

Research findings on the relationships between smoking and cognitive functions in later adulthood were inconsistent. In many studies, cognitive function in early life was not controlled. Socioeconomic status was often measured poorly. In the current study, using a large panel sample of non-dementia older adults, we analyzed the influences of smoking experiences on cognitive changes between adolescence and later adulthood. The analytical sample was men and women from the Wisconsin Longitudinal Study, a 50-year study of 10,317 Wisconsin high school seniors of class 1957. Multivariate regression was employed. The dependent variables were cognitive functions collected at age 54 in 1993 (the Weschler Adult Intelligence Scale: WAIS) and at age 65 in 2004 (WAIS, cognition fluency, word recall, and digit ordering). The explanatory variables included current smoking, ever smoking, and years of smoking. The cognitive ability in adolescence was measured by the Henmon-Nelson test at freshman and junior years in high school. Current socioeconomic status (education, occupational status, and income), drinking behaviors, major chronic diseases, and other demographic characteristics were also controlled. The preliminary analysis showed differences in adult cognitive function between smokers and non-smokers at age 50s controlling for adolescent cognitive ability. A closer examination on the influences of smoking tenure on cognitive function in later adulthood and smoking cessation on short-term cognitive changes between age 50s and 60s will be followed next.