Functional decline in the elderly: evidence for direct and stress-buffering protective effects of social interactions and physical activity.

Advances in medical technology and improvements in health behavior have greatly increased the proportion of Americans who survive into old age. Consequently, identifying environmental and behavioral factors that enhance or protect the health and functional capacity of older adults is an important goal. This study investigated the extent to which social interactions and physical activity can protect older adults from the declines in functional ability that typically occur with age and the extent to which they buffer the negative effects of widowhood on physical functioning. Data were from the Longitudinal Study of Aging, a six-year follow-up of over 7,000 respondents in the 1984 National Health Interview Survey. Using individual growth curve models which examine the effects of predictor variables on change over time, this study investigated how physical activity, social interactions, and widowhood are related to the rate of change in functional health over a six-year period. Results suggested that physical activity and social interactions each exerted independent effects on functional decline. In addition, physical activity and social interactions buffered the effects of widowhood on functional decline, especially in men who died before the end of the study. Results suggest a need for health promotion programs to encourage both physical and social activities in the elderly.