Eating too much red meat and poultry may increase risk of developing diabetes, a large Asian study suggests.

The study, published in the American Journal of Epidemiology, partially attributes the risk to the higher content of heme iron in these meats.The results suggest that eating fish/shellfish is not associated with risk of diabetes.These findings come from the Singapore Chinese Health Study, which recruited 63,257 adults aged 45-74 years between 1993 and 1998, and then followed them up for an average of about 11 years. In their analysis, Professor Koh Woon Puay from Duke-NUS Medical School in Singapore and her team found a positive association between intakes of red meat and poultry and risk of developing diabetes. Specifically, compared to those in the lowest quartile intake, those in the highest quartile intake of red meat and poultry had a 23 per cent and 15 per cent increase in the risk of diabetes, respectively.

The increase in risk associated with red meat/poultry was reduced by substituting them with fish/shellfish, the study showed. In trying to understand the underlying mechanism for the role of red meat and poultry in the development of diabetes, the study also investigated the association between dietary heme-iron content from all meats and the risk of diabetes, and found a dose-dependent positive association. After adjusting for heme-iron content in the diet, the red-meat and diabetes association was still present, suggesting that other chemicals present in red meat could be accountable for the increase in risk of diabetes. Conversely, the association between poultry intake and diabetes risk became null, suggesting that this risk was attributable to the heme-iron content in poultry.The study suggests that chicken parts with lower heme-iron contents such as breast meat, compared to thighs, could be healthier.