M. Yanina Pepino, PhD, and colleagues out of Washington University School of Medicine, St. Louis, began looking at non-nutritive sweeteners such as Splenda® (sucralose) and the metabolic response following its ingestion. Previous studies have indicated metabolic effects in animal models but the actual effects of these sweeteners in people still remain uncertain.
Generally, artificial sweeteners were thought to have no effect on our metabolism nor increase the calorie intake making them a perfect substitute for sugar in diet products. Added in small amounts to our food, these artificial sweeteners interact with receptors on the tongue to provide that same sweet sensation as sugar. However, it has been noted that in animals, these artificial sweeteners bind to similar receptors in the mouth as those found along the GI tract and in the pancreas leading to insulin release and glucose absorption.
To better understand the potential effects of non-nutritive sweeteners in humans, Pepino's research group studied the effects on hormones and glucose of sucralose use in 17 morbidly obese, insulin sensitive individuals who have no prior use of the food additive. Using a randomized crossover design, researchers conducted a 5-hour modified oral glucose tolerance test upon two separate occasions. Patients either consumed sucralose or water 10 minutes prior to the first glucose administration. Prior to the second glucose administration, each patient drank the opposite of what they had in the first test.
In consideration of the study population, Pepino said, "Most of the studies of artificial sweeteners have been conducted in healthy, lean individuals…We wanted to study this population because these sweeteners frequently are recommended to them as a way to make their diets healthier by limiting calorie intake."
The authors reported a greater effect on the body's hormones and glucose regulation with the ingestion of sucralose compared to water. They also reported a greater incremental increase in peak plasma glucose levels followed by an average of 20% greater insulin secretion in patients who ingested sucralose. Following ingestion of sucralose, an average of 7% decrease in insulin clearance and a 23% decrease in insulin sensitivity was noted compared to water. The authors did not detect any significant differences between the effects of sucralose or water on glucagon-like peptide 1, glucose-dependent insulinotropic polypeptide or glucagon incremental AUC.
The authors concluded, "Our results indicate that this artificial sweetener is not inert -- it does have an effect." In regards to the clinical importance of their findings, Pepino said, "What these all mean for daily life scenarios is still unknown, but our findings are stressing the need for more studies…Whether these acute effects of sucralose will influence how our bodies handle sugar in the long term is something we need to know."
M. Y. Pepino, C. D. Tiemann, B. W. Patterson, B. M. Wice, S. Klein. Sucralose Affects Glycemic and Hormonal Responses to an Oral Glucose Load. Diabetes Care, 2013; DOI: 10.2337/dc12-2221