Which type of social activities may reduce cognitive decline in the elderly?: a longitudinal population-based study

BACKGROUND: Previous studies have found that social activities are beneficial for the reduction of cognitive decline (CD) in the elderly. However, knowledge regarding the types of social activities that reduce CD in later life is limited. The aim of this study is to examine which type of social activities reduce CD 4 years later among young-old (Y-O) and old-old (O-O) adults. METHODS: We conducted a secondary analysis using data from cognitively intact adults 65 years of age or older who participated in the Korean Longitudinal Study of Aging (KLoSA). Cognitive function was assessed using the Korean version of the Mini-Mental State Examination (MMSE). We computed CD between 2008 and 2012 by subtracting the Wave 4 MMSE score from the Wave 2 MMSE score. Multivariate linear regression analysis was conducted regarding the effects of social activities on CD after adjusting for age, sex, education, income, marital status, activities of daily living (ADL), instrumental activities of daily living (IADL), chronic diseases, quality of life, depressive symptom, change in depressive symptom, and cognitive functioning at baseline. RESULTS: Subjects who participated in senior citizen clubs or senior centers at baseline had a lower risk of CD 4 years later than those who did not in Y-O adults. Frequent contact with offspring by phone or letters was associated with reduced CD in O-O adults. Frequent face-to-face contact with offspring was positively associated with CD in O-O adults. Participating in two or more formal social activities was associated with reduced CD compared with nonparticipation in O-O adults. CONCLUSION: Encouraging older adults to participate in senior citizen clubs or to have frequent contacts with adult children by phone or letters may help reduce CD in later life among older adults. Participation in a variety of formal social activities may also have a beneficial effect on preventing CD in older adults. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12877-016-0343-x) contains supplementary material, which is available to authorized users.