Atherosclerosis

Eating a diet high in refined carbohydrates (e.g., white rice) appears to increase the risk of coronary heart disease, and thus of heart attacks, especially in overweight women.

Cancer prevention and diet

Whole grains (such as brown rice) contain high amounts of insoluble fiber—the type of fiber some scientists believe may help protect against a variety of cancers. In an analysis of the data from many studies, people who eat relatively high amounts of whole grains were reported to have low risks of lymphomas and cancers of the pancreas, stomach, colon, rectum, breast, uterus, mouth, throat, liver, and thyroid.

Consuming a diet high in insoluble fiber is best achieved by switching from refined grains to whole grains (for example, switching from white rice to brown rice).

In the debate over whether dietary fat increases breast cancer risks, only one fact is indisputable: women in countries that consume high amounts of meat and dairy fat have a high risk of breast cancer, while women in countries that mostly consume rice, soy, vegetables, and fish (instead of dairy fat and meat) have a low risk of breast cancer. As a result, many doctors recommend a modified Asian diet to women wishing to lower their risk of breast cancer, even though they know the protective effect of such a diet might be for reasons unrelated to dietary fat intake.

Constipation

Fiber, particularly insoluble fiber, is linked with prevention of chronic constipation. Insoluble fiber from food acts like a sponge. Adding water to the “sponge” makes it soft and easy to push through the gastrointestinal tract. Insoluble fiber comes mostly from vegetables, beans, brown rice, whole wheat, rye, and other whole grains. Switching from refined grains to whole grains (e.g., from white rice to brown rice) often helps relieve constipation. It is important to drink lots of fluid along with the fiber—at least 16 ounces (480 ml) of water per serving of fiber. Otherwise, a “dry sponge” is now in the system, which can worsen the constipation.

Diabetes

Eating carbohydrate-containing foods, whether they are high in sugar or high in starch (such as rice), temporarily raises blood sugar and insulin levels. The blood sugar-raising effect of a food, called its “glycemic index,” depends on how rapidly its carbohydrate is absorbed. Many starchy foods have a glycemic index similar to sucrose (table sugar). People eating large amounts of foods with high glycemic indices (such as white rice), have been reported to be at increased risk of type 2 diabetes. On the other hand, eating a diet high in carbohydrate-rich foods that have lower glycemic indices (such as brown rice as opposed to white rice), is less likely to increase the risk of type 2 diabetes.

Heart attack

Eating a diet high in refined carbohydrates (e.g., white rice) appears to increase the risk of coronary heart disease, and thus of heart attacks, especially in overweight women.

Insulin resistance syndrome (IRS)

Some authorities recommend that people with IRS avoid high-carbohydrate diets, and some recommend a diet lower in carbohydrate than current public health guidelines suggest. The rationale is that high carbohydrate intake stimulates increased insulin levels, which can lead to high triglycerides, low HDL, and other adverse changes in the levels of blood fats that contribute to heart disease risk. Other authorities disagree, however, because they believe a lower carbohydrate diet will result in higher calorie intake from fat, leading to more difficulties with overweight, insulin resistance, and heart disease risk. A recent preliminary study suggested that a healthful, balanced diet low in fried foods and sausages, and high in vegetables, fruits, fish, and complex carbohydrates such as brown rice, was associated with protection from many aspects of IRS.

Irritable bowel syndrome (IBS)

Limited research has suggested that fiber might help people with IBS. However, most studies find that IBS sufferers do not benefit by adding wheat bran to their diets and some feel worse as a result of wheat bran supplementation. It has been suggested that the lack of positive response to wheat bran may result from a wheat sensitivity, which is one of the most common triggers for food sensitivity in people with IBS. Brown rice is a good source of fiber and is less likely to trigger food sensitivities than is wheat bran.