The glycemic index (GI) describes how quickly a carbohydrate raises blood glucose (sugar) levels after it is eaten. Blood glucose is measured after consuming a specific carbohydrate and compared with the response produced by an equal amount of glucose or white bread. Because glucose enters the bloodstream faster than any other carbohydrate, it is assigned a value of 100, and other foods are rated relative to that standard. Foods with a low glycemic index raise blood sugar more slowly, produce a smaller insulin response, and lead to more gradual glucose release into the bloodstream than high-GI foods.
Research published in the American Journal of Clinical Nutrition (2010; 92(3):634–643) examined the relationship between dietary glycemic index and death from inflammatory disease. The study followed 1,245 men and 1,490 postmenopausal women, with an average age of 49. Diets with a high glycemic index—typically high in refined sugars and starches—were associated with a significantly higher risk. Participants whose diets fell into the highest tertile of glycemic index had a 2.9-fold greater risk of death from inflammatory disease compared with those consuming diets with a lower glycemic index.
