The importance of the glycemic index (GI) and fiber in diabetes mellitus (DM) nutrition therapy has been controversial. In this issue of the Archives, Jenkins et al1 compared a lower-GI (46%, glucose scale), high soluble fiber (fiber source primarily legumes; 37.6 g of fiber per day) diet with a higher-GI (58%, glucose scale), whole wheat fiber (26.8 g of fiber per day) diet. Both diets decreased hemoglobin A1c, −0.5% and −0.3%, respectively. Lipid values also improved from both diets, and systolic blood pressure decreased by −4.5 mm Hg on the lower-GI, high soluble fiber diet. Absolute coronary risk (10-year percentage) decreased from 10.7% to 9.6% and from 10.4% to 9.9%, respectively. Are the modest benefits from the dietary components, or are they a result of the reduced energy intake of approximately 200 kcal per day? The more important question might be whether people with DM can implement any of these often difficult interventions in the “real world” to the extent it will have an impact on their glycemic control or cardiovascular risk factors.
Franz MJ. Diabetes Mellitus Nutrition Therapy: Beyond the Glycemic IndexComment on “Effect of Legumes as Part of a Low Glycemic Index Diet on Glycemic Control and Cardiovascular Risk Factors in Type 2 Diabetes Mellitus”. Arch Intern Med. 2012;172(21):1660–1661. doi:10.1001/2013.jamainternmed.871