The relationship between stress, physical activity and cognitive decline with age
Date
2017-08-29
Authors
Vendittelli, Rebecca
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Cognitive decline is often associated with increasing age. However, there is growing support that modifiable lifestyle factors such as exercise and stress influence outcomes. That is, physical activity (PA) seems to be protective, while stress engenders decline. Moreover, there is evidence to suggest that these variables interact such that being active positively moderates the negative effects of stress on cognitive decline. The present study examines the effects of both average PA and stress on cognitive decline (i.e., between-person effects), the coupled association between PA and cognition and stress and cognition (i.e., within-person, or occasion specific effects), and the possible interaction between PA and stress on cognitive outcomes. Coordinated analyses of The Memory and Aging Project (MAP; N = 1,853, mean age = 79) and Longitudinal Aging Study Amsterdam (LASA; N = 4,109, mean age = 68) were conducted. A series of multilevel models (MLM) were fit to the data, evaluating differences in baseline and linear change in perceptual speed, episodic memory, and MMSE scores in both data sets. Average PA was associated with the intercept of perceptual speed and episodic memory, and decline in all 3 outcomes in MAP only. There was a significant coupled association between PA and all cognitive outcomes in MAP, and with perceptual speed in LASA. Average stress was not associated with baseline scores or rates of change in any of the cognitive outcomes in either study. However, occasion specific stress was associated with perceptual speed and episodic memory in the unexpected direction in LASA. Lastly, there was a significant positive interaction between occasion specific stress and occasion specific activity on MMSE and perceptual speed scores in LASA. That is, on occasions when participants reported more stress than usual, if they also reported more exercise than usual, they tended to score better on these outcomes. Findings support the beneficial effects of both average and occasion specific activity on cognitive abilities, however failed to demonstrate the adverse effects of stress, and only partially supported an interaction between activity and stress. Limitations and future directions are discussed.
Description
Keywords
physical activity, exercise, stress, aging