Researchers at Harvard Medical School report that replacing 50 grams of white rice daily with the same amount of brown rice lowers the risk of type 2 diabetes by 16 percent, and replacing the same amount of white rice with whole barley or wheat lowers diabetes risk by 36 percent (Archives of Internal Medicine, published online June 14, 2010). Those who ate five or more servings of white rice per week were 17 percent more likely to become diabetic than those who ate less than one serving per month. Those who ate two or more servings of brown rice per week were 11 percent less likely to develop type 2 diabetes than those eating less than one serving of brown rice per month.
White rice causes a much higher rise in blood sugar than brown rice does. The higher the rise in blood sugar, the more insulin is released by the pancreas. Excessive insulin production can eventually stop the pancreas from making insulin which increases risk for diabetes. A high rise in blood sugar also causes sugar to stick to the surface membranes of cells. Once stuck on a cell, sugar cannot get off and is eventually converted by a series of chemical reactions to sorbitol that destroys the cell to cause all the side effects of diabetes: heart attacks, strokes, blindness, deafness, kidney damage and so forth.
White rice is "refined" by removing the bran and germ portions of brown rice, which removes fiber, vitamins, magnesium and other minerals, lignans, phytoestrogens, and phytic acid. All of these nutrients may help to prevent diabetes.
All whole grains are seeds of grasses which have a thick outer capsule that requires extensive cooking to make them palatable. Removing the outer coating or grinding whole grains into flour makes the sugars readily available for rapid absorption and higher rises in blood sugar levels. More on whole grains