Fructose-free sweets: New study suggests taste receptor role in regulating metabolism

28 May 2024 --- The newly published research by scientists at the Monell Chemical Senses Center in Philadelphia, US, reveals that the stimulation and inhibition of the sweet taste receptor TAS1R2-TAS1R3 can regulate glucose metabolism in the human body.

Paul Breslin, Ph.D. researcher at Monell and professor of nutritional science at Rutgers University, US, discusses what this means for managing metabolic disorders and developing fructose-free consumer products. 

“The basic question we asked was, do taste receptors help regulate or modulate metabolism, the utilization of glucose or the handling of glucose,” Breslin tells Nutrition Insight. “If you stimulate sweet taste in the absence of sugar or calories, like if you have a diet soda, it probably doesn’t change your blood glucose or blood insulin.”

“The novelty of our findings is that the receptor we studied in this experiment impacts blood glucose and insulin during a glucose meal differently, depending on whether it is stimulated or inhibited,” he says. 

The new findings provide evidence that taste receptors play a role in regulating metabolism and nutrient handling. Breslin calls for policymakers, health care providers and industry to take note of the research findings.

Glucose in the body 
For the study, published in PLoS One, the research team conducted oral glucose tolerance tests on healthy humans, as well as the plasma glucose, insulin and glucagon before, during and after the tests and up to 120 minutes after a meal. 

The taste receptor studied in this experiment impacts blood glucose and insulin during a glucose-rich meal differently.“We asked if the presence of glucose in the body, acting on the taste receptors, either hyper exciting them or inhibiting them, would have an impact on what you did with that glucose,” he details. 

He explains that his team did a couple of things different from others who have explored the aforementioned question, namely exploring the taste receptor itself. “We either excited it very strongly, or we completely shut it down and inhibited it.” Additionally, the team evaluated people’s sensitivity to sucralose, a high-potency non-caloric sweetener.

“People vary in how sensitive they are to that. For any given concentration, some people might say, it’s very sweet. Some people might say it’s not so sweet. When we strongly excited the receptor, the effect was larger in those who were more sensitive to the sweetness and less strong in those who were less sensitive to the sweetness. And the same was true for the inhibitor.”

The research team argues that, in general, the modern diet including the excessive intake of food and beverages high in sucrose, high fructose corn syrup and high-potency sweeteners might be hyperstimulating TAS1R2-TAS1R3, leading to the improper regulation of glucose in the blood.

“For people who are more sensitive to the inhibitor it slows the onset of blood glucose and insulin. Generally speaking, that is not a good thing for healthy people because you want to be able to anticipate blood sugar coming in. The ideal is to not have your blood glucose go very high with as little insulin as possible.”

“We were asking if we can provide the push-pull evidence that the taste receptors are modulating. The answer is most certainly yes.”

Industry implications
Breslin states that the study’s findings can present an opportunity for the development of F&B products that are “tasty, desirable, rewarding, profitable for the company and that are better for health.”

“A public health initiative should be not only for people to reduce the amount of sugar that they consume overall, but to have sweetener systems that have calories and can deliver pleasure and joy to people just like sugary sweet things do, while being less damaging by taking fructose away or reducing it.”

He points out that eating fructose can potentially hyperstimulate sweet taste receptors. “That can do something like we showed in this study; it can alter the way you handle the glucose. If you’re eating a lot of fructose, it’s simultaneously a burden on your liver.”

The development of sweet foods without fructose may be of interest to consumers, industry, health practitioners and policymakers.“There are very few things on the market that are like that right now. We have things that have less sugar in them. We have diet versions, but we don’t really have foods that are sweet, that don’t have fructose in them. I think that’s doable, and it’s a place where we can all go that would be a global public health initiative.”

“When the consumers learn of this, they will get a hint that this is an awesome product that is better for them, and you can imagine that it is more profitable for the company. So companies will want to do this and be profitable. It doesn’t make sense to tell a company that it can’t be profitable anymore.”

Public health action 
He further argues that governments “that want to take care of their people” should be interested in this discussion as well. “And then there are trade organizations, doctors’ organizations, dentists, neuroscientists and other groups that can come together and participate. All these people should have a seat at the table.”

“We can all come up with common goals. We actually want to reduce sugar intake — the people, the government, scientists and industry. Everybody wants that. The trick is, how do we get everyone to agree on how to achieve this without introducing too many regulations that interfere with people’s lives and freedoms or with companies’ ability to operate independently.”

He asserts that reducing sugar intake, ensuring people consume foods that are nutritionally richer and reducing fructose in the diet “are things that we can all agree on.”  

“Even entities who we think of as selling sugar for a living — like the big soft drink companies — most certainly don’t want to hurt anyone. They want to be able to move products, give pleasure and make a profit. If we can all figure out a way to help them do that, it’s a win-win for everybody. I think that’s possible.”

By Milana Nikolova