Study participants included more than 39,000 men and 157,000 women. They were asked about their diet and lifestyle habits as well as any pre-existing diseases. The researchers found that participants who ate five or more servings of white rice per week had a 17 percent increased risk of developing Type 2 diabetes. In contrast, those who ate two or more servings of brown rice per week had an 11 percent reduced risk.

Brown rice is the naturally occurring form of the grain. Refining it involves removing the outer layers, including the husk, bran and germ, leaving the inner white kernel. The end product is then often enriched, to replace a portion of the nutrients lost during the refining process. However, white rice is essentially a starch.

Sun explains that the loss of the fiber-rich outer layer allows starch to be absorbed more quickly into the body.

"The outer layers will slow down the penetration of digestive enzyme into the starch part so that the release of the sugar into the bloodstream will be slow for brown rice in comparison with white rice."

While the exact reasons are unknown, a diet of foods that quickly release sugar into the bloodstream is associated with a greater risk of Type 2 diabetes. This makes the selection of food such as brown rice important in preventing this disease.

In addition to this major benefit, Sun points out that less refined grains tend to have more nutritional benefits than their refined counterparts. In fact, he says replacing rice with whole grains such as whole wheat and barley could result in a 36 percent lower chance of developing Type 2 diabetes.