by Joel Fuhrman, M.D. and Deana Ferreri, Ph.D.
Usually, when we think about foods that increase diabetes risk, we think of white flour-based processed foods, sugary sodas, and desserts, since these foods are known to produce dangerous increases in blood glucose. Also, many diabetics are under the impression that that they should avoid carbohydrate-containing foods, and eat higher levels of protein to keep their blood glucose levels in check. However, dietary factors associated with diabetes are not a simple question of carbohydrate vs. protein. Whole food sources of carbohydrate, like fruit and whole grains, are protective.1 On the other hand, several studies have now confirmed that high intake of meat, which contains no carbohydrate, increases the risk of diabetes.
A meta-analysis of 12 prospective cohort studies has revealed that high total meat intake increased type 2 diabetes risk 17% above low intake, high red meat intake increased risk 21%, and high processed meat intake increased risk 41%.2
All the reasons behind these associations are not yet clear. One possibility is the pro-oxidant properties of heme iron (found only in animal products), the primary source of which is red meat. High dietary intake of heme iron and also high body stores of iron have been previously associated with increased diabetes risk in multiple studies3,4, whereas dietary nonheme iron (found only in plant foods) was protective. Heme iron from fish and poultry was also associated with diabetes risk. Oxidative stress, which may be brought on by excessive iron, plays an important role in the production of advanced glycation end products (AGEs), which contribute to both insulin resistance and diabetes complications.5 Also meat is a concentrated source of calories, it has a high caloric density and people can get a good blast of fat and protein, easily exceeding the body's requirements for macronutrients. Meat eating is also associated with weight gain and of course, excess body weight is the most important risk factor for diabetes. Like most other chronic diseases that plague Americans, diabetes is a consequence of a high-calorie, low-nutrient diet-style that is deficient in protective unrefined plant foods.
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2. Aune D, Ursin G, Veierød MB. Meat consumption and the risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies. Diabetologia. 2009 Nov;52(11):2277-87.
3. Rajpathak SN, Crandall JP, Wylie-Rosett J, et al. The role of iron in type 2 diabetes in humans. Biochim Biophys Acta. 2009 Jul;1790(7):671-81.
Luan de C, Li H, Li SJ, et al. Body iron stores and dietary iron intake in relation to diabetes in adults in North China. Diabetes Care. 2008 Feb;31(2):285-6.
4. Rajpathak S, Ma J, Manson J, Willett WC, Hu FB. Iron intake and the risk of type 2 diabetes in women: a prospective cohort study. Diabetes Care. 2006
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