Location: Obesity and Metabolism ResearchTitle: Metabolic responses to prolonged consumption of glucose- and fructose-sweetened beverages are not associated with postprandial or 24-hour glucose and insulin excursions) Author
Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2011
Publication Date: 7/1/2011
Publication URL: www.ajcn.org/content/94/1/112.long
Citation: Stanhope, K., Griffin, S.C., Bremer, A.A., Schaefer, E., Natkajima, K., Schwarz, J.M., Beysen, C., Berglund, L., Keim, N.L., Havel, P.J. 2011. METABOLIC RESPONSES TO PROLONGED CONSUMPTION OF GLUCOSE- AND FRUCTOSE-SWEETENED BEVERAGES ARE NOT ASSOCIATED WITH POSTPRANDIAL OR 24-HOUR GLUCOSE AND INSULIN EXCURSIONS. American Journal of Clinical Nutrition. 94:112-119. Interpretive Summary: When a food or beverage is consumed, blood sugar levels increase, particularly if the foodstuff contains sugars or other carbohydrates. The glycemic index is a characteristic of an individual food or beverage that projects how high blood sugar levels will rise in the first two hours following ingestion of the food/beverage. In this study we compared blood sugar and insulin responses to consumption of beverages sweetened with glucose, a simple sugar with a glycemic index of 83, to beverages sweetened with fructose, a simple sugar with a glycemic index of 38, and related these responses to other measures of sugar metabolism thought to indicators of poor handling of sugars in the body. We found that despite the higher levels of blood sugar associated with ingesting the glucose-sweetened beverage compared to the fructose-sweetened beverage, there were no clinically significant changes in the sugar metabolism markers with glucose-beverage ingestion. However, the fructose-beverage led to increases of several disease-risk factors, even though circulating levels of blood glucose remained lower with this sugar. These results suggest that ingesting fructose in the form of a beverage is an exception to the glycemic index concept that use of foods or beverages with a high glycemic index increases risk of chronic disease.
Technical Abstract: It has been proposed that the adverse metabolic effects of chronic consumption of sugar-sweetened beverages which contain both glucose and fructose are a consequence of increased circulating glucose and insulin excursions, i.e dietary glycemic index (GI). Objective: We determined if the greater adverse effects of fructose, compared with glucose consumption, were associated with glucose and insulin exposure. Research Design and Methods: Subjects were studied in a metabolic facility (CCRC) and consumed an energy-balanced diet containing 55% of energy as complex carbohydrate for 2 weeks (GI = 64). Subjects then consumed 25% of energy requirements as fructose- or glucose-sweetened beverages along with their usual ad libitum diets for 8 weeks at home, and then as part of an energy-balanced diet for 2 weeks at the CCRC (Fructose GI = 38, Glucose GI = 83). 24-h glucose and insulin profiles, and fasting plasma glycated albumin and fructosamine concentrations were measured before and after 2, 8, and 10 weeks of beverage consumption. Results: Consumption of fructose-sweetened beverages lowered glucose and insulin post-meal peaks and 23-h area under the curve, while consumption of glucose-sweetened beverages increased these parameters. Plasma glycated albumin concentrations were slightly (~3%) lower after 10 weeks fructose consumption, whereas fructosamine concentrations did not differ between groups. Conclusions: The adverse effects of fructose consumption are not mediated by increased glucose and insulin excursions. These results suggest that the specific effects of fructose, and not glucose and insulin excursions (GI), contribute to the adverse effects of consuming sugar-sweetened beverages on lipids and insulin sensitivity.