The sweet and sour truth about sugar substitutes

While artificial sweeteners may be low in calories, there is an emerging downside that could make consumers reconsider the sugar substitutes. 

Researchers at the Royal Adelaide Hospital (RAH) are uncovering how artificial sweeteners affect blood sugar and their risk of contributing to diabetes. 

The rise of low-calorie sweeteners 

While sugar consumption has declined in recent decades, there has been a large shift towards low-calorie sweeteners, with people enticed by the promise of sweetness without the calories. 

Professor Chris Rayner, principal investigator and consultant gastroenterologist at the RAH said recent research has shown people who regularly drink beverages with artificial sweeteners have a higher risk of type 2 diabetes, even if they have a normal body weight.  

“Several large studies involving thousands of people suggest that regular consumption of low-calorie sweeteners could be as bad as sugar, or worse. The fact this applies even to healthy weight individuals suggests it’s not just due to people already at high risk who are choosing a sugar-free alternative.”

Investigating the effects of different artificial sweeteners

Not all artificial sweeteners are the same, so RAH researchers have launched the ’SWEET n SOUR’ study to determine how different types affect blood sugar control, and gut health.  

Associate Professor Tongzhi Wu, co-investigator at the Adelaide Medical School, The University of Adelaide said the study will look into the half a dozen sweeteners that are commonly used in the food and beverage industry. 

“Most studies have treated them as all the same, but the body handles them quite differently. It is very likely that some increase diabetes risk while others do not.” 

Over four weeks, participants will take one of five commonly consumed artificial sweeteners or a placebo and the researchers will measure differences in how their bodies regulate blood sugar, as well as how the healthy bacteria in the gut are functioning.  

How could artificial sweeteners increase the risk of diabetes?

Artificial sweeteners taste sweet because they bind to sweet taste receptors on the tongue. 

The same kind of receptors also exist in the small intestine and this may provide a pathway for artificial sweeteners to accelerate the absorption of sugar from the gut into the bloodstream.  

Over time, our cells can become less able to deal with these spikes in blood sugar, leading to type 2 diabetes. 

“This is just one of several potential ways that sweeteners could affect our health,” said A/Prof Wu.

“What we learn from this study will help the public to make better dietary choices for their health and will inform policy to safeguard public health.”

Get involved

To learn more about the “SWEET n SOUR” study and to participate, contact Michelle or Jacqui by email: or phone: 8313 6676. 

This research is supported by a grant from the National Health and Medical Research Council of Australia