Influence of physical activity and the MIND diet on cognition

Background
Physical activity or the Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet as a neuroprotective diet is known to be beneficial for cognitive health among older adults, but little is known about the influence on cognition when both behaviors are combined. Therefore, this study was conducted to investigate whether engaging in both behaviors is associated with better cognitive health compared with either behavior alone or neither behavior.

Method
Data were from the Health and Retirement Study for this cross-sectional, observational study. A total of 3,463 non-demented participants with the mean age of 68.0 ± 10.0 years were included. Associations of physical activity (PA) and the MIND diet (MIND) with global cognition and odds of cognitive decline were explored using multivariate linear regression and binary logistic regression models with interaction terms between PA and MIND.

Result
Compared with neither behavior (PA−/MIND−), PA only (PA+/MIND−) was not associated with cognitive outcomes. Compared with PA−/MIND−, MIND only (PA−/MIND+) predicted higher global cognition (mean difference, d = 0.81; p < 0.001) and lower odds of cognitive decline (odds ratio, OR = 0.68; p < 0.01). Compared with PA−/MIND−, both behaviors (PA+/MIND+) predicted higher global cognition (d = 0.98; p < 0.001) and lower odds of cognitive decline (OR = 0.69; p < 0.01). Compared with PA+/MIND−, PA+/MIND+ predicted higher global cognition (d = 0.60; p < 0.001), but did not predict a risk of cognitive decline. Compared with PA−/MIND+, PA+/MIND+ did not predict cognitive outcomes.

Conclusion
Adherence to both physical activity and the MIND diet was associated with better cognitive outcomes than non-adherence to both or adherence to physical activity only. Encouraging both behaviors would be important for the cognitive health of older adults.