Journal of Applied Gerontology, Ahead of Print.
Current evidence concerning the effect of physical activity and social engagement on cognitive functioning in older adults with mild cognitive impairment (MCI) is underdeveloped. Drawing upon cognitive reserve theory, we used linear mixed models to investigate the impact of physical activity and social engagement on cognitive functioning in older adults living with MCI utilizing 16 years of data from the Health and Retirement Study (n = 1462). The average cognitive score (sum of immediate and delayed word recall, serial seven subtraction test, counting backwards, range: 0–27) at baseline was 9.6, with the average score decreasing by 0.14 points each year. Controlling for covariates, each unit increase in physical activity and social engagement, respectively, reduced the effect of time on cognitive functioning by 0.01 (β = 0.007, p < .0001) and 0.03 (β = 0.029, p = .04) points, small effects that accumulate over time. Findings suggest that greater physical activity and social engagement offer cognitive protection among older adults experiencing MCI.