The glycemic index is a way of measuring how fast a particular food is digested and the effect that it has on your blood sugar levels. White bread is assigned a value of 100 and other foods are compared with that. White rice and brown rice have similar glycemic index levels, but other factors make brown rice a healthier choice for your menu.
Carbohydrates are an essential part of your daily nutrition. Carbohydrates give your body the nutrients it needs to support your body's functions and provide you with enough fuel for energy. Carbohydrates are found in many foods, in the form of starches, sugars and fibers. Grouped into two categories, carbohydrates include complex carbohydrates, which are starches and simple carbohydrates, which are sugars. The starches and sugars are digested and broken down into glucose, your body's primary fuel. Fibers, both soluble and insoluble, are not digestible and pass through your digestive system. Fiber is necessary for digestive health even though it does not supply nutrients.
All carbohydrates are not digested by your body at the same rate. A better way to measure the digestibility of carbohydrates is the glycemic index. This index measures the changes in blood sugar levels after you eat a particular food. Foods that cause large increases in blood sugar levels have a high glycemic index, while those that don't cause large increases have a low GI. Typically, foods that contain sugars rapidly boost blood sugar levels and so have a high GI. Starchy foods are digested more slowly and tend to have a lower GI.
Although the GI is a good guideline, it only measures the effect of a small amount of food, usually 50 g of carbohydrates, over a period of two hours. The glycemic load takes into account the GI of a particular food and also its portion size. The rationale is that a small amount of high-GI food would have the same effect on the body as a larger amount of low-GI food. The glycemic load is calculated by taking the GI of a food, multiplying it by the amount of carbohydrates in grams and dividing that number by 100. Understanding the glycemic load is useful for diabetics and others needing to monitor the quality and quantity of food that they eat.
White rice is the same plant as brown rice, but white rice is actually only the inner part of the rice grain. A milling process removes the indigestible outer hull and the bran, leaving only the starchy white endosperm. Because the milling process removes vitamins from the rice, in the U.S. most white rice has B vitamins added back into it. The glycemic index of white is 44 for converted rice, 56 for long-grain white rice and 72 for short-grain white rice.
Brown rice is less processed than white rice. The rice grains have the outer hull removed, but the underlying bran and germ layers are left on the grain. The bran layers are what make the rice brown. Brown rice is more nutritious than white rice because the bran contains vitamins, minerals and oils. It also has more fiber than white rice. Brown rice is sometimes called whole-grain rice. The glycemic index of brown rice is 55, putting it about equivalent to long-grain white rice. However, brown rice is a better food than white rice because of the additional fiber and nutrients it contains. Since a larger amount of fiber contributes to fullness, you may eat less and thus have a lower glycemic load from brown rice.
Eat to Stay Healthy
Substituting brown rice for white rice increases the amount of fiber and other nutrients in your diet and may be healthier for you. Researchers at the Harvard School of Public Health investigated the effect of consuming white rice or brown rice on the risk of developing type 2 diabetes. The study, led by Qi Sun, appeared in the June 14, 2010 issue of the "Archives of Internal Medicine" and used questionnaires about lifestyle and diet to follow 197,228 study participants. The study concluded that replacing white rice with brown rice would decrease an individual's risk for developing diabetes by 16 percent.