Gut reaction: Zero-calorie sweeteners produce same response as water
The study, published in Diabetes Care, analysed the effects of sucralose, acesulfame potassium (AceK) or a combination of the two on the release of a hormone known as glucagon-like peptide-1 (GLP-1) - which is known to slow gastric emptying, and reduce appetite.
Led by Dr Tongzhi Wu from the University of Adelaide, the team behind the research noted that their findings were contrary to some other studies in humans and in laboratory-based research, and as such added further to the debate on how the human body responds to sweeteners.
"This is a controversial area because there's a lot of conflicting research into artificial sweeteners," commented senior author Chris Rayner.
"The scientific debate centres on whether artificial sweeteners have a negative impact on our bodies, such as leading to the storage of fat. There are also questions about whether they have a beneficial impact, such as producing responses that signal fullness to the brain, or if they are inert and produce no impact."
The new study found that the gut's response to artificially sweetened drinks was neutral, and was no different to drinking a glass of water, he added.
To test the effects of the sweeteners, Wu and his colleagues recruited 10 healthy males who were studied on four occasions each, separated by at least 3 days, in single-blinded randomised fashion.
The trial consisted of an overnight fast, after which each subject consumed either 240 mL water alone or equivalently sweetened with 1) 52 mg sucralose, 2) 200 mg AceK, or 3) 46 mg sucralose plus 26 mg AceK.
Ten minutes later, each drank 75 g of glucose, made up to 300 mL with water, and containing 150 mg 13C-acetate. Blood glucose (glucometer), plasma insulin (ELISA), total GLP-1 (radioimmunoassay), and gastric emptying (breath test) were evaluated over 240 min, the team reported.
"Blood glucose, plasma insulin, and total GLP-1 concentrations did not change after either water or sweetened drinks, prior to glucose ingestion, but all increased after oral glucose (P ," said the team.
"In conclusion, sucralose and AceK, either alone or in combination, have no acute effect on gastric emptying, GLP-1, or glycemic responses after oral glucose in healthy humans," they added.
Short vs Long-term
Study co-author Dr Richard Young commented that population-level studies have yet to agree on the effects of long-term artificial sweetener intake in humans - noting that a recent study suggested an increased risk of developing type 2 diabetes in regular and high consumers of artificially sweetened drinks.
"Those studies indicate that artificial sweeteners may interact with the gut in the longer term, but so far no-one's managed to determine the actual mechanisms through which these sweeteners act," he said.
"So far it appears that artificial sweeteners have limited impact in the short term, but in people in a pre-diabetic or diabetic state, who are more likely to be regularly high users of artificial sweeteners, it might be a different story altogether," Young commented. "This is why more research is needed."
Source: Diabetes Care
Volume 36, Number 12, Pages e202-e203, doi: 10.2337/dc13-0958
"Artificial Sweeteners Have No Effect on Gastric Emptying, Glucagon-Like Peptide-1, or Glycemia After Oral Glucose in Healthy Humans"
Authors: Tongzhi Wu, Michelle J. Bound, et al