Dietary patterns and risk of dementia in an elderly Japanese population: the Hisayama Study

To our knowledge, there are no previous reports that assessed the association between dietary patterns and risk of dementia in Asian populations.

We investigated dietary patterns and their potential association with risk of incident dementia in a general Japanese population.

A total of 1006 community-dwelling Japanese subjects without dementia, aged 60-79 y, were followed up for a median of 15 y. The reduced rank regression procedure was used to efficiently determine their dietary patterns. Estimated risk conferred by a particular dietary pattern on the development of dementia was computed by using a Cox proportional hazards model.

Seven dietary patterns were extracted; of these, dietary pattern 1 was correlated with high intakes of soybeans and soybean products, vegetables, algae, and milk and dairy products and a low intake of rice. During the follow-up, 271 subjects developed all-cause dementia. Of these individuals, 144 subjects had Alzheimer disease (AD), and 88 subjects had vascular dementia (VaD). After adjustment for potential confounders, risks of development of all-cause dementia, AD, and VaD were reduced by 0.66 (95% CI: 0.46, 0.95), 0.65 (95% CI: 0.40, 1.06), and 0.45 (95% CI: 0.22, 0.91), respectively, in subjects in the highest quartile of score for dietary pattern 1 compared with subjects in the lowest quartile.

Our findings suggest that a higher adherence to a dietary pattern characterized by a high intake of soybeans and soybean products, vegetables, algae, and milk and dairy products and a low intake of rice is associated with reduced risk of dementia in the general Japanese population.