Diet Quality Indices and Risk of Type 2 Diabetes Mellitus: The Singapore Chinese Health Study

We aimed to test whether predefined dietary patterns that are inversely related to risk of type 2 diabetes (T2D) in Western populations were similarly associated with lower T2D risk in an Asian population. We included 45,411 middle-aged and older participants (ages 45-74 years) in the Singapore Chinese Health Study who were free of diabetes, cancer, and cardiovascular disease at baseline (1993-1998). Participants were followed up for T2D diagnosis through 2010. Dietary information was collected using a validated food frequency questionnaire. Dietary pattern scores were calculated for the alternate Mediterranean diet (aMED), Alternate Healthy Eating Index 2010 (AHEI-2010), the Dietary Approaches to Stop Hypertension (DASH) diet, an overall plant-based diet index, and a healthful plant-based diet index. During a median of 11.1 years of follow-up, 5,207 incident cases of T2D occurred. After adjustment for multiple potential confounders, the 5 dietary pattern scores were significantly associated with 16% (for aMED) to 29% (for DASH) lower risks of T2D when comparing the highest score quintiles with the lowest (all P-for-trend values < 0.001). These associations did not vary substantially by baseline age, sex, body mass index, or hypertension status but were limited to nonsmokers (aMED: P for interaction < 0.001; AHEI-2010: P for interaction = 0.03). Adherence to a high-quality diet, as reflected by several predefined diet quality indices derived in Western populations, was significantly associated with lower T2D risk in an Asian population.