Religious affiliation and the risk of dementia in Taiwanese elderly

Religious affiliations vary across ethnic groups because of different cultural backgrounds. Some studies have explored the association between religious affiliation and cognitive decline. Only a small portion of patients with cognitive decline progress to dementia. However, the association between religious affiliation and dementia risk remains unclear.

In this case-control study, we recruited 280 patients with Alzheimer's disease (AD) and 138 with vascular dementia (VaD) (both aged ≥60 years) from three teaching hospitals in northern Taiwan between 2007 and 2010. Age-matched healthy controls (n=466) were recruited from an elderly health checkup program and from volunteers visiting the hospital during the same period. Three religious affiliations-Taoism, Buddhism, and Christianity-were evaluated. The study also assessed the effect of important factors such as gender or leisure activities on the association of religious affiliation with dementia risk.

Participants with Christianity affiliation showed decreased AD risk (adjusted odds ratio [AOR]=0.46, 95% confidence interval [CI]=0.25-0.87) compared with those without any religious affiliation. Moreover, this effect was stronger in women (AOR=0.38, 95% CI=0.15-0.92) and in participants who exercised regularly (>3 times/week; AOR=0.33, 95% CI=0.14-0.77). No significant association was observed among participants with Taoism and Buddhism affiliations. Affiliation to none of the religions was associated with VaD risk.

Thus, Chinese participants having Christianity affiliation showed decreased AD risk. Moreover, the protective effect was more evident in women and in participants who exercised regularly.