The safety of sugar substitutes is once again called into question.
Researchers led by the Cleveland Clinic have linked xylitol, a low-calorie sugar substitute, with an increased risk of myocardial infarction, stroke or deaths related to cardiovascular diseases, according to a study published this Thursday in the European Heart Journal.
Xylitol is a sugar alcohol found in small amounts in fruits and vegetables, and the human body also produces it. As an additive, it has the look and taste of sugar, but 40% fewer calories. It is used in concentrations much higher than those found in nature, in sugar-free chewing gum, candies, toothpastes and bakery products. It can also be found in products labeled “keto-friendly,” especially in Europe.
The same research team last year discovered a similar association with the popular sugar substitute erythritol. The use of sugar substitutes has increased significantly in the last decade as concern grows over rising obesity rates.
Dr. Stanley Hazen, lead author of the study and professor of cardiovascular and metabolic sciences at the Lerner Research Institute at the Cleveland Clinic, said, “We are introducing these products into our food pyramid, and the people most likely to consume them are the people who are most likely to consume them. who are at greater risk” of suffering a myocardial infarction or stroke, such as diabetics.
Many heart attacks and strokes occur in people who have no known risk factors, such as diabetes, hypertension, or high cholesterol levels. The team of researchers began studying sugar alcohols that occur naturally in the human body to see if these compounds could predict cardiovascular risk in these people.
In the study, researchers measured the level of natural xylitol in the blood of more than 3,000 participants after an overnight fast. They found that people whose xylitol levels placed them in the top 25% of the study group had approximately twice the risk of heart attack, stroke or death within three years than people in the bottom quarter. .
The researchers also wanted to understand the mechanism of action, so they fed xylitol to mice, added it to blood and plasma in a laboratory, and gave a drink containing xylitol to 10 healthy volunteers. In all of these cases, xylitol seemed to activate platelets, which are the blood component that controls clotting, Hazen explained. Blood clots are the leading cause of heart attack and stroke.
“It only takes xylitol interacting with platelets on its own for a very short period of time, a matter of minutes, for the platelet to become overloaded and much more prone to clotting,” Hazen explained.
The next question is what makes natural xylitol high in some people and how it can be reduced, said Dr. Sadiya Khan, a cardiologist at Northwestern Medicine's Bluhm Cardiovascular Institute and professor of cardiovascular epidemiology at Northwestern's Feinberg School of Medicine. who did not participate in the new study.
Much remains to be investigated, according to Hazen. In the meantime, she recommends patients avoid consuming xylitol and other sugar alcohols, whose spelling ends in “itol.” Instead, he recommends using moderate amounts of sugar, honey or fruit to sweeten foods, adding that toothpaste and chewing gum probably won't be a problem because you're ingesting very little xylitol.
The report had important limitations.
First, the study of xylitol naturally present in people's blood was observational and can only show an association between sugar alcohol and cardiac risk. It does not prove that xylitol caused the highest incidence of myocardial infarction, stroke or death.
However, given the totality of the evidence presented, “It is probably reasonable to limit your intake of artificial sweeteners,” Khan added. “Maybe the answer is not to replace sugar with artificial sweeteners, but to think about more complete, high-quality components, such as vegetables and fruits, as natural sugars.”
Artificial sweeteners shouldn't be difficult to avoid, added Joanne Slavin, PhD, RDN, professor of food science and nutrition at the University of Minnesota-Twin Cities. They appear on the ingredient list of packaged products.
“That they never took xylitol?” asked Slavin, who had no connection to the study. For some people struggling to reduce sugar in their diet, substitutes are a tool, and it all comes down to personal choice, he explained.
Although Slavin found the study interesting and cause for some concern, he noted that sugar alcohols are expensive and are often used in very small amounts in sugar-free gum and candies.
Another limitation of the study is that participants whose blood xylitol levels were measured were at high risk for heart disease or had documented heart disease, so the results may not be applicable to healthy individuals.
Still, many people in the general public share the characteristics of the study participants, Hazen said.
“In middle-aged and older Americans, it is common to have obesity and diabetes or high cholesterol and hypertension,” he mentioned.
