How does stevia taste so extremely sweet and how does the sweetner keep our blood sugar levels under control? Researchers at KU Leuven (University of Leuven, Belgium) have discovered that stevia stimulates a protein that is essential for our perception of taste and is involved in the release of insulin after a meal. These results create new possibilities for the treatment of diabetes.
Stevia is very popular as a non-caloric substitute for sugar. The plant based sweetner also has positive effect on blood sugar levels although the science behind it was no known. Koenraad Philippaert and Rudi Vennekens from the KU Leuven Department of Cellular and Molecular Medicine have now revealed the underlying mechanism. They collaborated with other KU Leuven scientists and with researchers from Université catholique de Louvain and University of Oxford.
Experiments showed that the active components of stevia extract, stevioside and steviol stimulate TRPM5 ion channel. The proteins known as ion channels are kind of microscopic pathway through which minuscule charged particles enter and leave the cell. These channels are behind many processes in the body.
Reason unleashed:
“TRPM5 is first and foremost essential for the taste perception of sweet, bitter, and umami on the tongue,” Philippaert continues. “The taste sensation is made even stronger by the stevia component steviol, which stimulates TRPM5. This explains the extremely sweet flavour of stevia as well as its bitter aftertaste.”
TRPM5 is also responsible for the release of insulin from the pancreas after a meal. Thus, it prevents abnormally high blood sugar levels and development of Type 2 Diabetes.
“If mice consume a high-fat diet for a long period of time they eventually develop diabetes,” Professor Vennekens explains. “But this is less the case for mice that also receive a daily dose of stevioside: they are protected against diabetes. Stevia did not have this protective effect on mice without TRPM5. This indicates that the protection against abnormally high blood sugar levels and diabetes is due to the stimulation of TRPM5 with stevia components.”
This opens new perspective treatments to control or even prevent diabetes.
“But we must not get ahead of ourselves,” warns Philippaert. “This is fundamental research, and there is still a long way to go before we can think of new treatments for diabetes. For one thing, the dosages that the mice received are much higher than the amount of stevioside found in beverages and other products for human consumption. Further research is necessary to show if our findings readily apply to humans. All this means that new treatments for diabetes will not be for the very near future.”