People with and those carrying extra weight often turn to sugar substitutes. They taste sweet but, unlike sugar, contain no calories. Health organizations around the world, however, are worried about the long-term effects of these .
Experts warn that can:
- disrupt energy metabolism
- increase the risk of developing diabetes
- cause digestive disorders
- disturb the gut microbiome
- stimulate appetite
- raise the likelihood of cardiovascular disease
Meanwhile, a new study from researchers at the University of Chile found that two popular sweeteners, sucralose and stevia, negatively affect the and gene expression, and therefore could potentially worsen metabolic health. The researchers emphasized that this impact can be passed from one generation to the next in a paper published by Frontiers in Nutrition.
“We were intrigued that despite widespread consumption of these additives, the prevalence of obesity and metabolic disorders like insulin resistance has not dropped.” Francesca Concha Selume, lead author of the study.
How researchers tested sugar substitutes across generations
The researchers divided 47 male and female mice into three groups. They gave the first group regular water, the second group water with sucralose, and the third group water with stevia (at doses comparable to human dietary intake).
The team then bred these groups of mice for two successive generations. The rodents in those new generations received only plain water.
Each generation underwent a glucose tolerance test that detects insulin resistance, an early warning sign of diabetes.
The researchers also collected fecal samples from the rodents to study changes in the gut microbiome and the concentrations of short-chain fatty acids. Scientists believe that sugar substitutes can affect short-chain fatty acids by altering the gut microbiome.
The team also examined the expression of five genes related to:
- intestinal barrier function
- inflammation
- intestinal and liver metabolism
Those genes helped the researchers understand how sweeteners might harm health. In the end, the team found that different sweeteners produced different effects, and those effects changed over time.
What the researchers found
- In the first generation of newborn mice, signs of impaired glucose tolerance appeared only in male offspring exposed to sucralose.
- In the second generation, fasting blood sugar was elevated in male descendants exposed to sucralose and in female descendants exposed to stevia.
- In both groups of rodents that consumed sugar substitutes, the researchers observed a more diverse microbiome but lower concentrations of short-chain fatty acids. This suggests the bacteria were producing fewer beneficial metabolites.
- In the mice given sucralose, changes in the fecal microbiota were more pronounced: the researchers found more pathogenic species and fewer beneficial ones.
The researchers reported that sucralose triggered the expression of inflammation-related genes and suppressed the expression of metabolism-related genes across two successive generations. The team also found that stevia affected gene expression, but its impact did not persist beyond a single generation.
Those effects were generally strongest in the first generation and tended to weaken in the second generation. Overall, the sucralose-related effects were more consistent and stable across generations, the researchers said.
The team added that the changes in glucose tolerance and gene expression can be interpreted as early biological warning signs tied to metabolic or inflammatory processes.
“The goal of this study is not to cause panic but to underscore the need for further research. People may want to use these additives in moderation while we continue to study their long-term biological effects,” Francesca Concha Selume summarized.
Photo: Unsplash
