Artificial sweeteners found to have neutral effect on gut

New research from the University of Adelaide has shown that artificial sweeteners have no negative effect on the gut.

PhD student Dr Tonghzhi Wu found that the gut’s response to artificially sweetened drinks was neutral - it was no different to drinking a glass of water.

The results of the study, conducted by researchers in the University’s School of Medicine and the Nerve-Gut Research Laboratory, were published in the December issue of Diabetes Care journal.

Ten healthy males consumed 240 mL of water alone or sweetened with sucralose, acesulfame potassium (AceK) or a combination of both. The researchers found that blood glucose, plasma insulin and total glucagon-like peptide-1 (GLP-1) did not change after consuming either water or the sweetened drinks.

“In conclusion, sucralose and AceK, either alone or in combination, have no acute effect on gastric emptying, GLP-1 or glycaemic responses after oral glucose in healthy humans,” the authors wrote.

However, the researchers warn that their results don’t necessarily mean that artificial sweeteners have no negative effect on the body.

“This is a controversial area because there’s a lot of conflicting research into artificial sweeteners,” said senior author Associate Professor 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 fact is, the human studies have been unclear as to whether artificial sweeteners have a positive or negative effect, and this is why we’re keen to better understand what's happening in our bodies.”

Co-author Dr Richard Young, Senior Postdoctoral Researcher at the Nerve-Gut Research Laboratory, says population-level studies have yet to agree on the effects of long-term artificial sweetener intake in humans. He points out, however, that a recent study has shown that those who consume large quantities of artificially sweetened drinks on a regular basis face an increased risk of developing type 2 diabetes.

“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,” Dr Young said.

“It’s a complicated area because the way in which the sweet taste receptors in our gut detect and act on sweetness is very complex.

“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. This is why more research is needed.”

The study was funded by the National Health and Medical Research Council (NHMRC). The study is available here.