Consuming large amounts of sugar is harmful to health, which is why many people look for alternative sweeteners that taste similar and do not contribute to significant weight gain or cause other health problems. One of the available options is stevia, a sweetener derived from the leaves of the Stevia rebaudiana plant, native to Paraguay and Brazil, which many dietitians recommend as a sugar substitute, since it is very sweet, but has fewer calories and a minimal effect. on blood glucose levels.
While research suggests that the brain can distinguish between different sweet substances, the neural processes underlying this ability to distinguish sweeteners remain poorly understood. Therefore, a team of researchers from the Shanghai University of Science and Technology, the Chinese Academy of Sciences (CAS) and other institutes in China has carried out a study to better understand what happens in the brains of mice when they are given feed with different types of sweeteners. Their findings have been published in Neuroscience Research and indicate that the response of neurons to sucrose and stevia is similar, suggesting that stevia could be an equally pleasant, but healthier sugar substitute.
As the researchers explain in their article in the aforementioned journal, this study explores how the mouse brain distinguishes between different types of sweet flavors, focusing on a specific area of the brain called the anterior paraventricular nucleus of the thalamus (aPVT). To investigate, these scientists fed mice six different diets, all equally sweet but with different types of sweeteners, for six weeks. The diets included a normal diet, a high sucrose diet (common sugar), a high stevioside diet (derived from stevia), a high xylitol diet, a high glycyrrhizin diet, and a high mogroside diet.
The researchers’ goal was to find out how the neurons in the mice’s brain responded to constant consumption of these different sweeteners during the study period. Additionally, they were interested in determining whether any of the low-calorie sweeteners they examined elicited sugar-like brain responses.
Stevia faithfully reflects the perceived taste of sugar
They observed that the mice showed a notable preference for the high-sucrose and high-stevioside diets. When examining the brains of the animals after consuming these diets, they found that activity in the anterior paraventricular nucleus of the thalamus was significantly higher in the mice that consumed sucrose and stevioside compared to the other sweeteners. Furthermore, using advanced imaging techniques, they observed that this area of the brain was rapidly activated when consuming sucrose and stevioside, but not when consuming xylitol or simply water.
These results suggest that the anterior paraventricular nucleus of the thalamus plays a key role in mice’s preference for sweets, highlighting that stevioside is the only plant-based sweetener that elicits a response in the brain comparable to that of sucrose, common sugar, suggesting that stevia is the most “brain-friendly” among the most commonly used sugar alternatives and most closely reflects the perceived taste of sugar. This could help us better understand how sweet preferences develop in mammals, including humans, the authors said.
Stevioside is the only plant-based sweetener that elicits a response in the brain comparable to that of sucrose, the common sugar.
“We found that, given the abundance of food, compared with other types of sugar substitutes, the activity in the PVT brain region induced by stevia was more similar to that induced by sucrose,” explained Yingjie Zhu, co-author of the article. in statements to Medical Xpress. “This suggests that stevia could potentially be the most brain-friendly sugar substitute. Therefore, in the relevant food and beverage industries stevia should receive more attention.”
The study’s findings could serve as a basis for beverage manufacturers to incorporate stevia into their products in the future to reduce the amount of calories they provide. Additionally, it could inspire other neuroscientists to further examine the neural underpinnings of stevia consumption. Zhu has stated that they intend to use functional magnetic resonance imaging (fMRI) to investigate whether a similar phenomenon occurs in the human brain.
