A new study published in Frontiers in Nutrition reports on Apr. 10 that the popular non-nutritive sweeteners sucralose and stevia may have negative effects on metabolic health, which could be passed down to subsequent generations—at least in mice.
The findings come as health organizations are increasingly concerned about the potential long-term impacts of artificial sweeteners, which are commonly used as sugar substitutes in diet drinks and other foods. The study raises questions about whether these additives might influence metabolism beyond their intended use for reducing calorie intake.
Dr Francisca Concha Celume of the Universidad de Chile, lead author of the study, said, "We found it intriguing that despite the growing consumption of these additives, the prevalence of obesity and metabolic disorders such as insulin resistance has not declined. This does not mean that sweeteners are responsible for these trends, but it raises the question of whether they influence metabolism in ways we do not yet fully understand."
Researchers divided 47 male and female mice into three groups: one received plain water; others were given water with doses of either sucralose or stevia similar to human consumption levels. After breeding two consecutive generations who only drank plain water, scientists tested each generation for glucose tolerance—a measure linked to diabetes risk—and analyzed changes in gut microbiome composition and gene expression related to inflammation and metabolism.
Results showed that different sweeteners had distinct effects over time. In particular, male offspring from sucralose-consuming mice displayed impaired glucose tolerance in the first generation; by the second generation, both male descendants exposed to sucralose and female descendants exposed to stevia showed elevated fasting blood sugar levels. Both groups also had more diverse gut bacteria but produced fewer beneficial short-chain fatty acids across generations.
"When we compared generations, these effects were generally strongest in the first generation and tended to decrease in the second generation," Concha said. She added: "Overall, the effects linked to sucralose were more consistent and persistent across generations." Changes included increased expression of genes tied to inflammation and reduced activity of genes involved with metabolism after exposure to sucralose for two generations; stevia's impact was less pronounced.
Concha explained: "The changes we observed in glucose tolerance and gene expression could be interpreted as early biological signals related to metabolic or inflammatory processes... It is possible that such changes could increase susceptibility to metabolic disturbances under certain conditions." However, she cautioned against drawing direct conclusions about human health from this research: "The goal of this research is not to create alarm, but to highlight the need for further investigation... It may be reasonable to consider moderation in the consumption of these additives and continue studying their long-term biological effects."
