Monday, August 06, 2007

High glycemic index diets increase the risk of chronic degenerative disease

Long-term consumption of high-glycemic foods may increase oxidative stress and the risk of chronic degenerative diseases. Leading U.S. researchers recently concluded that a low-GI diet, not a low carbohydrate diet, appears to be beneficial in reducing the production of free radicals and oxidative stress.

Glycemic index (GI) is a measure of the rate that the carbohydrates in a food or meal are digested and appear in the blood as glucose (sugar). Glycemic load is a way of measuring the total carbohydrates in a meal or diet with a mathematical adjustment for GI. These measurements can be used to simultaneously describe the quality (glycemic index) and quantity of carbohydrate in a meal or diet.

Recent data suggest that the sudden rise in blood sugar associated with a high glycemic load may increase free radical production and the risk of oxidative damage. This increased production has been implicated in many disease processes including chronic heart disease, accelerated aging, and type 2 diabetes.

Investigators from several leading U.S. institutions recently investigated whether a diet with a high GI or GL is associated with greater oxidative stress by taking specific measurements in nearly 300 healthy adults. Participants with a higher GI and GL diet were found to exhibit increases in oxidative stress when compared to those eating a diet lower in glycemic index and load.

Researchers concluded that chronic consumption of high-GI foods may lead to chronically high oxidative stress, increasing the risk for several degenerative diseases. A low-GI diet, not a low carbohydrate diet, appears to be beneficial in reducing oxidative stress.

Source: Relations of glycemic index and glycemic load with plasma oxidative stress markers, Youqing Hu, Gladys Block, Edward P Norkus, Jason D Morrow, Marion Dietrich and Mark Hudes, American Journal of Clinical Nutrition, Vol. 84, No. 1, 70-76, July 2006.