Objectives: To examine the cognitively protective effect of leisure and physical activities while accounting for prior cognitive ability, a rarely considered confounder of the previously reported associations between activity and cognitive aging.
Design: Longitudinal cohort study.
Setting: Glostrup, Denmark.
Participants: Community-dwelling sample of adults recruited into the Glostrup 1914 Cohort (baseline N = 802). All were born in 1914 and were assessed at ages 50, 60, 70, and 80. New participants were recruited during the study to counter attrition.
Measurements: On each occasion, cognitive ability was assessed using four tests, which defined a general cognitive ability score. Self-reported participation in leisure and physical activities was also collected. In general, physical activity was summarized on a 3- or 4-point scale, and leisure activity as none versus some (ages 50 and 60) or according to participation in a list of common activities (age 70). The effect of activity-leisure and physical-on the level of cognitive ability and cognitive change over time from age 60 to 80 was examined in growth curve models.
Results: Greater activity (leisure or physical) was consistently associated with a higher level of cognitive ability. Adjusting for baseline cognitive ability (age 50) attenuated these associations, suggesting that associations between activity and cognition reported in old age are largely a consequence of preserved differentiation. A small but significant association remained between greater physical activity at age 60 or 70 and less cognitive decline.
Conclusion: The association between more-frequent leisure activity and less cognitive decline mainly reflects the positive cross-sectional association between activity and cognition, although the link that remains between greater physical activity and a more-successful cognitive aging trajectory is of particular relevance to those who are developing interventions.
© 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.