Meat, Dietary Heme Iron, and Risk of Type 2 Diabetes Mellitus: The Singapore Chinese Health Study

Abstract

We evaluated the relationships of red meat, poultry, fish, and shellfish intakes, as well as heme iron intake, with the risk of type 2 diabetes mellitus (T2D).The Singapore Chinese Health Study is a population-based cohort study that recruited 63,257 Chinese adults aged 45-74 years from 1993 to 1998. Usual diet was evaluated using a validated 165-item semiquantitative food frequency questionnaire at recruitment. Physician-diagnosed T2D was self-reported during 2 follow-up interviews in 1999-2004 and 2006-2010. During a mean follow-up of 10.9 years, 5,207 incident cases of T2D were reported. When comparing persons in the highest intake quartiles with those in the lowest, the multivariate-adjusted hazard ratio for T2D was 1.23 (95% confidence interval (CI): 1.14, 1.33) for red meat intake (P for trend < 0.001), 1.15 (95% CI: 1.06, 1.24) for poultry intake (P for trend = 0.004), and 1.07 (95% CI: 0.99, 1.16) for fish/shellfish intake (P for trend = 0.12). After additional adjustment for heme iron, only red meat intake remained significantly associated with T2D risk (multivariate-adjusted hazard ratio = 1.13, 95% CI: 1.01, 1.25; P for trend = 0.02). Heme iron was associated with a higher risk of T2D even after additional adjustment for red meat intake (multivariate-adjusted hazard ratio = 1.14, 95% CI: 1.02, 1.28; P for trend = 0.03). In conclusion, red meat and poultry intakes were associated with a higher risk of T2D. These associations were mediated completely for poultry and partially for red meat by heme iron intake.

Keywords: fish; heme iron; poultry; prospective studies; red meat; type 2 diabetes.

Figure 1.

Estimated change in hazard ratio for the associations of the substitution of 1 serving of red meat, poultry, or fish with risk of developing type 2 diabetes, the Singapore Chinese Health Study, 1993–2010. The model was adjusted for age, sex, dialect, year of interview, educational level, body mass index, physical activity level, smoking status, alcohol use, baseline history of self-reported hypertension, adherence to the vegetable-, fruit-, and soy-rich dietary pattern, and total energy intake.

Figure 2.

Dose-response relationship between heme iron intake and the risk of type 2 diabetes in men (A) and women (B) using restricted cubic analysis, the Singapore Chinese Health Study, 1993–2010 (P for interaction = 0.001). The model was adjusted for age, sex, dialect, year of interview, educational level, body mass index, physical activity level, smoking status, alcohol use, baseline history of self-reported hypertension, a diet with a high consumption of meat and dim sum dishes, vegetable-, fruit-, and soy-rich dietary pattern, and total energy intake.