Artificial sweeteners like sucralose and stevia, promoted as healthier alternatives to sugar, may alter gene expression and potentially increase the risk of diabetes in future generations, a new study warns.
A growing body of research suggests the negative effects of artificial sweeteners may be passed down to offspring due to their impact on gene activity.
These sweeteners are often found in the diet version of fizzy drinks as alternatives to sugar that taste sweet but contain no calories.
The new study showed the offspring of mice that ate sucralose or stevia had altered expression of genes linked to inflammation and metabolism, making them more vulnerable to conditions such as diabetes, the very problem such sweeteners were made to solve.
“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,” said Francisca Concha Celume, lead author of the study published in Frontiers in Nutrition.
The findings indicate that artificial sweeteners influence metabolism in ways that we do not yet fully understand.
The study split 47 male and female mice into three groups, each of which received either plain water or water containing a dose of sucralose or stevia, comparable to the amount a human might consume as part of a normal diet. The mice were bred for two consecutive generations, both of which received only plain water.
All the rodents were then tested for insulin resistance, a warning sign for diabetes.
The scientists also assessed faecal samples of the mice to look for changes in their gut microbiome.
Previous studies suggested that artificial sweeteners could compromise the function of the gut microbiome and ultimately alter gene expression.
The researchers specifically looked at the activity of five genes involved with inflammation, gut barrier function, and metabolism in the liver and intestines to provide a snapshot of potential influences on the gut.
Artificial sweeteners were found to produce different effects, which changed over time.
Only the male offspring of sucralose-consuming mice showed signs of impaired glucose tolerance, scientists found.
But in the next generation, elevated fasting blood sugar was detected in the male descendants of sucralose-consuming mice and the female descendants of stevia-consuming mice.
In both stevia and sucralose-consuming mice, gut bacteria were found producing fewer beneficial compounds.
The succeeding generations of the mice also had lower concentrations of beneficial gut bacteria compounds.
Mice that consumed sucralose were more seriously and more persistently affected by changes to their gut.
These mice had more disease-causing species and fewer beneficial bacteria in their faeces, the study found.
“The animals did not develop diabetes. Instead, what we observed were subtle changes in how the body regulates glucose and in the activity of genes associated with inflammation and metabolic regulation,” Dr Concha said.
“It is possible that such changes could increase susceptibility to metabolic disturbances under certain conditions, such as a high-fat diet.”
Overall, the study found that the effects linked to sucralose were more consistent and persistent across generations.
The scientists emphasised that while the study indicated a link between health status changes and artificial sweeteners, it didn’t establish causation.
“The goal of this research is not to create alarm, but to highlight the need for further investigation,” Dr Concha said.
“It may be reasonable to consider moderation in the consumption of these additives and to continue studying their long-term biological effects.”
Scientists not involved in the study noted that the findings could not directly apply to people just yet, but added that there was reason to be cautious.
“It is important to note that while mice share many biological similarities with humans, we cannot directly apply these results to people just yet,” Alyce Martin, head of the Gut Hormones in Health and Disease Lab at Flinders University, said.
“However, this study adds weight to recent global health warnings suggesting we should be more cautious.”
“This is a mouse study conducted under controlled laboratory conditions, very different from the complex dietary landscape of humans,” clinical associate professor Alex Polyakov from the University of Melbourne said, but added that “broader possible implications are important”.