The sweet taste receptor could be much more than just a flavor sensor. According to a recent study conducted by researchers at the Monell Chemical Senses Center (I link it here), this receptor, known as TAS1R2-TAS1R3, plays a key role in the regulation of glucose metabolism in humans.
A discovery that opens new perspectives for the management of metabolic disorders such as diabetes and which invites us to rethink the link between taste and health.
A receptor with many faces
TAS1R2-TAS1R3 is not just any receptor. Discovered in 2001 by a team of scientists including those from the Monell Center, it is responsible for the perception of sweet taste. What we feel on the tip of our tongue, so to speak. But its functions are not limited to that area. This receptor is in fact expressed throughout the mouth, or rather: throughout the body. And also in some intestinal cells, where it could facilitate the absorption and assimilation of glucose. It would be part of a real "metabolic surveillance system" for sugars.
Our objective was to determine whether TAS1R2-TAS1R3 influences glucose metabolism in two directions.
Paul Breslin, senior author of the study and professor of nutritional sciences at Rutgers University.
To test this hypothesis, the researchers gave a group of volunteers a meal containing glucose, along with an agonist (sucralose, a zero-calorie sweetener) or an antagonist (lactisol, a sodium salt that inhibits the sweet taste) of the receptor. TAS1R2-TAS1R3.
The results? Surprising
I'll make it short: stimulating or inhibiting the receptor altered the participants' glucose tolerance in different ways.
Specifically, sensitivity to sucralose was related to an early increase in blood glucose and insulin levels, while sensitivity to lactisol-induced sweet taste inhibition was associated with a decrease in glucose levels.
The novelty of our results is that the receptor we studied in this experiment influences glucose and insulin in the blood during a carbohydrate meal differently, depending on whether it is stimulated or inhibited.
Paul Breslin
An elegant and pervasive system
According to the researchers, this mechanism of regulating metabolism through the sweet taste receptor is “elegant in its simplicity”. TAS1R2-TAS1R3 is in fact expressed, as mentioned, throughout the body. Mouth, gastrointestinal tract, pancreas, liver and fat cells. The latter three are major metabolic regulatory tissues, all part of the body's 24-hour metabolic surveillance system.
What can it mean?
Lots of things. First of all: current eating habits, characterized by excessive consumption of foods and drinks rich in sucrose and sweeteners, could hyperstimulate TAS1R2-TAS1R3, contributing to improper regulation of blood glucose. This could be one of the causes, perhaps the main one, of metabolic syndrome, an important factor that increases the risk of heart disease, stroke and diabetes.
TAS1R2-TAS1R3 receptor, future perspectives: from the laboratory to the clinic
The results of this study open new perspectives for the management of metabolic disorders. The researchers suggest that future studies should examine the effects of stimulating and inhibiting TAS1R2-TAS1R3 in people at risk for metabolic syndrome, to determine the therapeutic potential of manipulating this receptor for improved metabolic control.
Studies like these show that the sweet taste receptor TAS1R2-TAS1R3 helps regulate glucose differently, depending on the sweetness of the food or drink.
Paul Breslin
The ultimate goal is to apply this knowledge to make what we eat and drink healthier. Because, as Breslin points out, “a small positive metabolic change can add a lot to the lives and health of humans when it accumulates over decades and millions of people.”
One receptor, many functions, a potentially enormous impact on our health. Research on sweet taste reminds us once again of the complexity and interconnection of biological systems, and invites us to look beyond appearances. Because sometimes, the key to better management of complex diseases like diabetes can be hidden right there, on the tip of our tongue.
