The interactive effect of physical activity and APOE-Ɛ4 on cognitive function in older adults

The purpose of this study was to examine the relationship between physical activity (PA) and the APOE-Ɛ4 on cognitive functioning in cognitively normal older adults. Two hundred participants (mean age = 64.35 years old, male N = 61, female N = 139) estimated their average PA, underwent genetic testing, and completed a battery of neurocognitive tests assessing executive functioning, long-term memory, learning, and working memory. A cross-sectional between subjects 2 (APOE-Ɛ4 carrier status: carrier, non-carrier) x 2 (Physical activity: low, high) ANCOVA (age as covariate) was run for each cognitive test. Results revealed no significant main effects or significant interactions between PA and APOE-Ɛ4 carrier status across any cognitive domains. These results were contrary to the hypotheses. It was concluded that the protective effect of PA, and the risk effect of APOE-Ɛ4 that is present in cases of dementia may not have an effect on non-pathological cognitive decline. Future large-scale research is required to determine whether this is a true effect, or due to methodological limitations. Future research may benefit from the use of an objective measure of PA, inclusion of a measure of global cognitive functioning, and the use of a PA intervention or longitudinal design