While artificial sweeteners can help some people control their calorie intake, they could set the stage for the development of diabetes. That’s the disturbing finding of a preliminary study published Wednesday in the journal Nature, though outside nutritionists say it needs to be replicated before firm conclusions can be made from the study.
In several experiments involving mice and a small group of people, researchers from the Weizmann Institute of Science in Israel found that artificial sweeteners appear to disrupt the flora of bacteria residing in the intestines, which leads to a rise in blood sugar levels. Mice that were fed aspartame, saccharin, and sucralose experienced changes in their gut microbiome and also were at higher risk of developing glucose intolerance, a precursor to diabetes.
When the researchers transplanted the bacteria found in the mice’s feces into a different group of mice, this group also developed blood sugar changes even though the animals had never been fed artificial sweeteners.
“We demonstrated that the bacteria could cause changes that would cause disturbances in glucose levels,” said study coauthor Eran Elinav, an immunologist at the Weizmann Institute.
He and his colleagues also observed seven volunteers — who normally abstained from eating artificial sweeteners — and found that when they ate regular doses of saccharin for a week, four developed elevated blood sugar levels. They also studied gut bacteria in 400 people and found that those who used artificial sweeteners regularly had different gut bacteria than those who didn’t consume them.
“As scientists, we simply point to the immense body of experiments that we carried out in humans and mice and in none have we seen any beneficial effects” for consuming artificial sweeteners, said Eran Segal, a study coauthor and computational biologist at the Weizmann Institute. “We believe at the very least that this study and this result should prompt additional debate into what is currently a massive use of artificial sweeteners.”
Nutrition experts not involved in the study, however, urged caution concerning the new finding. “It would be a mistake to conclude that diet sodas are worse than drinks sweetened with sugar or high-fructose corn syrup, and no diet soda drinker should interpret the new study as license to switch to regular soda,” said a statement released by the nonprofit Center for Science in the Public Interest.