Background/objective: Dietary patterns in Western populations have been linked to type 2 diabetes, but the association of distinctive dietary patterns of Japanese population remains unclear. We prospectively investigated the association between dietary patterns and risk of developing type 2 diabetes among Japanese adults.
Subjects/methods: Participants were 27, 816 men and 36,889 women aged 45-74 years who participated in the second survey of the Japan Public Health Center-based prospective study and had no history of diabetes. Dietary patterns were derived by using principal component analysis of the consumption of 134 food and beverage items ascertained by a food frequency questionnaire. Odds ratios of self-reported physician-diagnosed type 2 diabetes over 5 year were estimated using logistic regression analysis.
Results: A total of 1194 new cases (692 men and 502 women) of type 2 diabetes were self-reported. We identified three dietary patterns: prudent, westernized and traditional Japanese patterns. Any dietary pattern was not significantly associated with type 2 diabetes risk after adjustment for covariates in both men and women. The multivariate-adjusted odds ratios (95% confidence interval) for type 2 diabetes for the highest versus lowest quartile of each dietary pattern score in men and women, respectively, were 0.93 (0.74-1.16) and 0.90 (0.69-1.16) for the prudent pattern, 1.15 (0.90-1.46) and 0.81 (0.61-1.08) for the westernized pattern, and 0.97 (0.74-1.27) and 0.87 (0.66-1.15) for the traditional pattern.
Conclusions: Although a small protective effect of the prudent dietary pattern cannot be excluded, dietary patterns may not be appreciably associated with type 2 diabetes risk in Japanese.