Researchers followed 63,257 Chinese adults aged 45–74 for an average of 10.9 years and found that eating red meat was associated with increased risk for developing diabetes. The authors suggest that it may be the iron in meat that could cause diabetes (American Journal of Epidemiology, May 23, 2017). Another recent article showed that women who ate a lot of meat prior to pregnancy are the ones most likely to become diabetic during pregnancy (Eur J Nutr, Mar 11, 2017). Many other studies have associated eating meat with increased risk for diabetes (JAMA Intern Med, Jul 22, 2013;173(14):1328-35) and for gestational diabetes (Adv Nutr, July 1, 2013;4(4):403-11).
How Iron in Meat Could Cause Diabetes
Hereditary diseases that cause high iron levels, such as hemochromatosis and thalassemia, are also associated with a very high incidence of diabetes. High iron levels can cause both Type I and Type II diabetes. Excess iron is a potent oxidant that can destroy the pancreatic beta cells that make insulin so a person may lose his ability to make insulin (Type I diabetes), and high levels of iron damage the cell membranes so they cannot respond to insulin, leading to Type II diabetes (Cell Metab, Mar 5, 2013;17(3):329–341). High tissue levels of iron can cause many of the abnormalities associated with diabetes, such as lack of insulin, mitochondrial dysfunction and liver damage (Science, 2005;307:384–387). Meat contains heme iron while plants contain non-heme iron, and you absorb 35 percent of heme iron but only 2 to 15 percent of non-heme iron. The human body gets rid of excess iron primarily through bleeding such as menstruation or blood donation. However, most meat eaters do not suffer from excess iron because you also get rid of excess iron through sweating and the normal loss of skin, intestinal and lung cells.
Meat Appears to Increase Insulin Resistance
Most cases of diabetes are caused by a person's cells not being able to respond to insulin. Just four weeks on a high-meat diet increased risk for people not being able to respond to insulin (Metabolism, March 2017;68:173–183) as did four weeks on a high dairy diet (American Journal of Clinical Nutrition, Dec 17, 2015). Epidemiological studies show that vegetarians have a significantly lower incidence of diabetes than people who eat meat (Diabetes Spectrum, May 2017;30(2): 82-88) and that eating animal protein increases diabetes risk (Am J Epidemiol,(2016) 183 (8): 715-728).
Neu5Gc in Meat May be Linked to Diabetes
In 1982, Ajit Varki discovered Neu5Gc, a sugar-protein that is found in all mammals except humans. Your immunity protects you from foreign bodies such as germs by noticing that they have different sugar-proteins on the surface of their cells than you do, so your immunity attacks and destroys the germs. When you eat meat from mammals, you absorb Neu5Gc into your bloodstream and then into your cells. Your immunity recognizes that Neu5Gc is a foreign sugar-protein and tries to kill it just as it would attack an invading germ. This process is called inflammation. Your immunity then stays active and starts attacking the Neu5Gc in your cells to damage them and prevent them from responding to insulin. Then when your blood sugar rises, your pancreas releases insulin, but your cells cannot respond to insulin and blood sugar levels rise too high can lead to diabetes. This theory is not yet accepted by the scientific community and certainly all people who eat meat do not become diabetic.
The diet I recommend is not necessarily a strict vegetarian diet, but it is very high in plants and low in animal products. Many studies show that a vegetarian diet helps to lower high blood sugar levels and treat diabetes (Diabetes Spectrum, May 2017;30(2): 82-88), and epidemiological studies show that vegetarians are less likely to develop diabetes. A vegetarian diet keeps iron intake low and reduces other factors that increase diabetes risk such as weight gain and lack of dietary fiber. High blood sugar levels can also be reduced by:
• losing excess weight
• restricting refined carbohydrates such as foods made from flour, sugar added foods and all drinks with sugar in them
• restricting fried foods
• eating lots of vegetables, beans, nuts and other seeds