Weizmann Institute of Science study find that artificial sweeteners alter the balance of microbes in certain people and make them more susceptible to metabolic diseases such as diabetes
Researchers admit more work must be performed before reaching definitive conclusions.
Using artificial sweeteners may set the stage for diabetes in some people by hampering the way their bodies handle sugar, suggests a preliminary study done mostly in mice at Israel’s Weizmann Institute of Science.
The study was released Wednesday by the journal Nature.
In work that raises questions over whether artificial sweeteners — widely seen as “healthier” substitutes for sugars — should be reassessed, the researchers said the substances altered the balance of microbes in the gut linked to susceptibility to metabolic diseases like diabetes.
“In our studies we found that artificial sweeteners may drive, or contribute to … an exaggerated elevation in blood glucose levels — the very same condition that we often aim to prevent by consuming them,” said Dr. Eran Elinav of the Immunology Department, who led the work with Prof. Eran Segal from the Computer Science and Applied Mathematics Department.
Elinav’s team conducted a series of experiments in both mice and humans, repeating them several times to check their results.
Researchers began by testing three widely used sweeteners: saccharin (used in Sweet’N Low); sucralose (Splenda), and aspartame (NutraSweet), in 20 mice. Some animals received one of those substances in their water, and others received sugar water or plain water.
After 11 weeks, researchers gave all the mice a dose of sugar and monitored the response in their blood sugar levels. Mice that initially received sugar water or plain water showed about the same response. But mice that received any of the sweeteners showed markedly higher blood sugar levels, indicating impairment in handling of the sugar dose. Further mouse experiments linked that outcome to an effect on gut bacteria.
To gain some preliminary information on people, the researchers turned to 381 non-diabetic volunteers who filled out a questionnaire that estimated their consumption of artificial sweeteners. The 40 participants who used the most sweeteners had higher blood sugar than 236 non-users.
In another preliminary test, researchers gave saccharin for a week to seven healthy volunteers who normally do not use sweeteners. Four showed a decline in their ability to handle sugar over the course of the week. The makeup of their gut bacteria changed markedly over the week, while that of the other three changed little.
Some experts who didn’t participate in the work urged caution in interpreting the results.
Nutrition and metabolism experts who were not involved in Elinav’s studies said the results were intriguing, but were mainly focused on mice, were very preliminary and should not trigger changes in recommendations on so-called non-caloric artificial sweeteners.
“This research raises caution that artificial sweeteners may not represent the ‘innocent magic bullet’ they were intended to be to help with the obesity and diabetes epidemics, but it does not yet provide sufficient evidence to alter public health and clinical practice,” said Nita Forouhi, program leader at the Medical Research Council’s epidemiology unit at Cambridge University.
Rates of obesity and diabetes are reaching epidemic proportions worldwide, and advice to cut down on sugar intake as part of a more healthy diet is often accompanied by recommendations to replace sugary drinks with “diet” or “light” versions that use artificial sweeteners instead.
James Hill, an obesity expert at the University of Colorado, called the work good science. Still, overall, “I do not think there is enough data yet to lead to a definitive conclusion about artificial sweeteners and the body’s handling of sugar,” he wrote in an email.
“I certainly do not think there is sufficient evidence to conclude that they are harmful.”
But Yanina Pepino of Washington University in Saint Louis said the results make a convincing case that sweeteners hamper the body’s handling of sugar by altering gut bacteria. The results add to her belief that sweeteners and sugar should be used in moderation, especially by children, she said.
“It’s really providing strong data suggesting we need to do more research,” she said.
The authors said they are not recommending any changes in how people use artificial sweeteners based on their study. The researchers, like outside experts, said more study is needed, while industry groups called the research limited and said other evidence shows sweeteners are safe and useful for weight control.
Overall, the results suggest that some people may be affected by artificial sweeteners, said Elinav.
Christopher Gardner, a nutrition expert at Stanford University who did not participate in the study, said the saccharin doses given the volunteers were within federal dietary guidelines, but still much higher than a typical person would consume — the equivalent of 42 12-ounce sodas a day for a person weighing 150 pounds.
In a statement, the Food and Drug Administration said the sweeteners “have been thoroughly studied and have a reasonable certainty of no harm to consumers.”
The Calorie Control Council, an industry group that represents the manufacturers of sweeteners and the products in which they are used, said the study has limitations that diminish its applicability to people.
View original Israel Hayom publication at: http://www.israelhayom.com/site/newsletter_article.php?id=20201