Abstract
Background/Aims: Isomaltulose (α-D-glucosylpyranosyl-1,6-D-fructofuranose) is a natural disaccharide used in human nutrition. It is structurally related to sucrose, but more slowly hydrolyzed and absorbed. Because this sugar’s metabolic effects are poorly characterized, we compared the effects of chronic ad libitum access to high-isomaltulose and high-sucrose diets on glucose metabolism in rats. Methods: Adult male rats were offered 62% isomaltulose, sucrose or starch diets ad libitum for 26 (trial 1) or 56 (trial 2) days. After 2- to 3-week adaptation, plasma glucose, fructose and insulin were measured after test meals of the adaptation diet. Results: The main finding was that both plasma glucose and plasma insulin concentrations were transiently but markedly increased after sucrose test meals compared to isomaltulose or starch meals. These differences were not associated with consistent differences in food intake, body weight gain or adiposity. Conclusions: Chronic isomaltulose feeding has beneficial effects on postprandial glucose metabolism in comparison to sucrose feeding in rats, although the effects are modest. Further work is warranted to determine whether substitution of isomaltulose for sucrose or other sweet carbohydrates might be therapeutically useful in patients with, or at risk for, insulin resistance or type 2 diabetes mellitus.