The glycemic index concept is an extension of the fiber hypothesis, suggesting that fiber consumption reduces the rate of nutrient influx from the gut. The
glycemic index has particular relevance to those chronic Western diseases associated with central obesity and insulin resistance. Early studies showed that starchy carbohydrate foods have very different effects on postprandial blood glucose and insulin responses in healthy and diabetic subjects, depending on the rate of digestion. A range of factors associated with food consumption was later shown to alter the rate of glucose absorption and subsequent glycemia and insulinemia. At this stage, systematic documentation of the differences that exist among carbohydrate foods was considered essential. The resulting
glycemic indexclassification of foods provided a numeric physiologic classification of relevant carbohydrate foods in the prevention and treatment of diseases such as diabetes. Since then, low-
glycemic-
index diets have been shown to lower urinary C-peptide excretion in healthy subjects, improve
glycemic control in diabetic subjects, and reduce serum lipids in hyperlipidemic subjects. Furthermore, consumption of low-
glycemicindex diets has been associated with higher HDL-cholesterol concentrations and, in large cohort studies, with decreased risk of developing diabetes and cardiovascular disease. Case-control studies have also shown positive associations between dietary
glycemic index and the risk of colon and breast cancers. Despite inconsistencies in the data, sufficient, positive findings have emerged to suggest that the dietary
glycemic index is of potential importance in the treatment and prevention of chronic diseases.
David JA Jenkins, Cyril WC Kendall, Livia SA Augustin, Silvia Franceschi, Maryam Hamidi, Augustine Marchie, Alexandra L Jenkins, and Mette Axelsen
Glycemic index: overview of implications in health and disease
Am J Clin Nutr 2002 76: 1 266S-273S
