Adherence to high-quality diet confers benefits for diabetes risk in Asians
Adherence to several predetermined dietary patterns derived from Western populations—such as the alternate Mediterranean diet (aMED) and Dietary Approaches to Stop Hypertension (DASH) diet—appears to reduce the risk of type 2 diabetes (T2D) in Asians, according to data from the Singapore Chinese Health study.
The study included 45,411 middle-aged and older individuals free of T2D, cancer or cardiovascular disease at baseline. All participants completed a validated food frequency questionnaire, with scores calculated for aMED, alternative Healthy Eating Index (AHEI)-2010, DASH diet, an overall plant-based diet index (PDI) and a healthful plant-based diet index (hPDI).
A total of 5,207 individuals developed T2D during a median follow-up of 11.2 years. Adjusted Cox proportional hazards analysis showed all five dietary pattern scores to be significantly associated with a lower risk of T2D.
Compared with the lowest score quintile, the highest quintile reduced T2D risk by 16 percent for aMED (adjusted hazard ratio [HR], 0.84; 95 percent CI, 0.77–0.92), 21 percent for AHEI-2010 (adjusted HR, 0.79; 0.73–0.87), 29 percent for DASH (adjusted HR, 0.71; 0.65–0.79), 17 percent for PDI (adjusted HR, 0.83; 0.76–0.92) and 19 percent for hPDI (adjusted HR, 0.81; 0.75–0.89; p<0.001 for all). [Am J Epidemiol 2018;doi:10.1093/aje/kwy183]
“These associations did not vary substantially by baseline age, sex, body mass index or hypertension status, but were limited to nonsmokers (p<0.001 for aMED; p=0.03 for AHEI-2010),” the investigators noted.
When components of the examined dietary patterns were analysed, higher consumption levels of whole grains and coffee and lower consumption levels of sugary beverages and red and processed meat were significantly protective against T2D risk, as the investigators pointed out.
The findings of an association between lower T2D risk and high-quality dietary patterns and of a detrimental impact of red meat, processed meat and sugar-sweetened beverages on T2D risk are consistent with those reported in previous studies. [Diabetes Care 2018;41:723-730; Int J Epidemiol 2017;46:1410-1420; Eur J Epidemiol 2017;32:363-375]
“The DASH index has been the strongest predictor of T2D risk among dietary pattern indices assessed in our study,” the investigators said. “[A]s compared with other indices, [DASH was] more strongly associated with certain compositions (whole grain and red and processed meat) shown to be significantly associated with T2D risk.”
“Therefore, the difference in strength of the associations may be explained, at least in part, by the diverse distributions of the dietary constituents making up these indices. A similar explanation may apply to account for the stronger associations observed in nonsmokers as compared with smokers,” they added.
The study has several limitations. Among those cited by the investigators were the use of a single dietary assessment at baseline, omission of the trans-fat component in the original AHEI-2010, use of total dairy as an alternative of low-fat dairy for the DASH index and self-report of incident diabetes.
“Finally, our findings may be most generalizable to East Asian populations, and should be confirmed for other ethnic groups,” they said.