Participating in social activities helps preserve cognitive function: an analysis of a longitudinal, population-based study of the elderly.

BACKGROUND This study examines how changes in cognition over time are related to participation in social activities and the extent of social networks. METHODS Data are drawn from a population-based, longitudinal study that began in 1989 among elderly Taiwanese. An over-dispersed Poisson model is used to regress the number of failed cognitive tasks (0-5) in 1996, 1999, and 2000 on prior measures of cognitive impairment, social activities, social networks, health status, and sociodemographic characteristics. The analysis sample comprises 2387 individuals, who contribute a total of 4603 observations across three survey intervals (1993-96, 1996-99, 1999-2000). RESULTS After adjusting for prior cognitive impairment, baseline health status, and sociodemographic factors, respondents who participated in one or two social activities failed 13% fewer cognitive tasks (P < 0.01) than those with no social activities; those who engaged in three or more activities failed 33% fewer cognitive tasks (P < 0.001). In contrast, none of the social network measures was related to cognitive impairment. CONCLUSIONS Despite a social structure where elderly persons often live with their children and social interaction is likely to be more family-centered than in western countries, data from Taiwan suggest that participation in social activities outside the family may have a bigger impact on cognitive function than social contacts with family or non-relatives.