Results from animal studies that indicated sucralose could modify the absorption of glucose in the intestine were not observed when the sweetener was fed to humans, according to findings published in the British Journal of Nutrition.
Researchers from the University of Adelaide and the Royal Adelaide Hospital also report that consumption of the sweetener did not affect levels of a hormone linked to hunger - glucagon-like peptide-1 (GLP-1).
“Species differences are likely to account for the lack of effect of sucralose in human subjects,” wrote the researchers, led by Christopher Rayner.
“It has been reported that there is much lower duodenal expression of [the glucose transporter] GLUT2 in human subjects than in rats and mice, while expression of [sodium-dependent glucose transporter] SGLT1 is much greater in human subjects,” they added.
The controversy
Previous studies with animals have suggested that sweeteners may interact with glucose and enhance the absorption of glucose in the gut via GLUT2 expression.
Indeed, scientists from the National Institute of Diabetes, Digestive and Kidney Diseases (NIH) recently reported that a synergistic effect between sucralose and glucose may trigger the release of the appetite-suppressing hormone glucagon-like peptide-1 (GLP-1), and therefore promote a feeling of fullness (Diabetes Care, 2010, Vol. 32, pp. 2184-2186).
“This raises the question as to whether the combination of an artificial sweetener with a carbohydrate could have a synergistic effect on glucose absorption in human subjects,” explained Rayner and his co-workers.
“The notion that consuming artificial sweeteners together with carbohydrates could enhance glucose absorption and therefore elevate postprandial blood glucose concentrations is of fundamental clinical importance,” they added.
The human test
In order to study such links in humans, the Adelaide-based researchers recruited ten health subjects with an average age of 27 and an average BMI of 23.4 kg/m2 and randomly assigned them to receive either sucralose (provided by Tate & Lyle) or a saline solution in combination with a solution containing both glucose and “its non-metabolised analogue, 3-O-methylglucose (3-OMG)” via a catheter directly into the intestine.
Results showed no differences in levels of blood glucose, GLP-1, or 3-OMG between the sucralose and control groups.
“Sucralose does not appear to modify the rate of glucose absorption or the glycaemic or incretin response to intraduodenal glucose infusion when given acutely in healthy human subjects,” concluded the researchers.
Supporting science
The findings are inline with a review by NIH scientists, which failed to find a link between intakes of artificial sweeteners and metabolic changes in children (International Journal of Pediatric Obesity, doi: 10.3109/17477160903497027).
The overall safety of sucralose was re-assessed and supported by an expert panel, made up of scientists from Rutgers University, New York Medical College, Harvard School of Public Health, Columbia University, and Duke University.
Writing in Regulatory Toxicology and Pharmacology (2009, Vol. 55, pp. 6-12) the panel concluded: “The extensive safety data of sucralose and maltodextrin have been rigorously evaluated by experts around the world, and the available evidence demonstrates that Splenda, sucralose, and maltodextrin are safe for their intended uses.”
Sucralose is reportedly used as an ingredient in over 4,000 products worldwide, according to Tate & Lyle.
Source: British Journal of Nutrition
Published online ahead of print, doi:10.1017/S0007114510001327
"Effect of the artificial sweetener, sucralose, on small intestinal glucose absorption in healthy human subjects"
Authors: J. Ma, J. Chang, H.L. Checklin, R.L. Young, K.L. Jones, M. Horowitz, C.K. Rayner