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Experts say there are a number of health concerns with artificial sweeteners. PatriciaEnciso/Getty Images
  • Xyltol is a sugar alcohol added to many products, ranging from sugar-free candy and gum to toothpaste.
  • Researchers say high levels of circulating xylitol are associated with an elevated three-year risk of cardiovascular events.
  • They noted their study had several limitations, including clinical observation studies demonstrate association and not causation.

Sugar substitutes may not be the healthiest thing for people, according to new research.

In a study published in the European Heart Journal, Cleveland Clinic researchers report that higher amounts of xylitol, a type of sugar alcohol, can increase the risk of heart attack, stroke, and other cardiovascular events.

The researchers said they found the associations in a large-scale patient analysis, a clinical intervention study, and preclinical research models.

Xylitol is a lower-calorie sugar substitute with a low glycemic index. Sugar alcohols are carbohydrates that don’t actually contain alcohol.

Xylitol occurs naturally in small amounts in fibrous fruits and vegetables, corn cobs, trees, and the human body. It’s used as a sugar substitute because its taste is comparable to sugar but has fewer calories.

Xylitol is found in many products, ranging from sugar-free candy and gum to toothpaste. People also use it as a sweetener and for baking.

The research team said over the past decade, sugar substitutes such as sugar alcohols and artificial sweeteners have significantly increased in processed foods promoted as healthy alternatives.

The Cleveland Clinic team found a similar link between another sugar alcohol, erythritol, and cardiovascular risk last year. They said in a statement that xylitol isn’t as common as erythritol in keto or sugar-free products in the United States, but they noted it is common in other countries.

“This study again shows the immediate need for investigating sugar alcohols and artificial sweeteners, especially as they continue to be recommended in combating conditions like obesity or diabetes,” said Dr. Stanley Hazen, the chairperson of Cardiovascular and Metabolic Sciences at Cleveland Clinic’s Lerner Research Institute as well as the co-section head of preventive cardiology in the Heart, Vascular and Thoracic Institute, in the statement.

“It does not mean throw out your toothpaste if it has xylitol in it, but we should be aware that consumption of a product containing high levels could increase the risk of blood clot related events,” Hazen added.

In an analysis of more than 3,000 subjects in the United States and Europe, the researchers reported that high levels of circulating xylitol were associated with an elevated three-year risk of cardiovascular events.

A third of subjects with the highest amount of xylitol in their plasma were found more likely to experience a cardiovascular event.

The team conducted pre-clinical testing to confirm the findings. They discovered xylitol caused clotting in platelets and heightened risk of thrombosis.

The researchers also tracked platelet activity from subjects who ingested a xylitol-sweetened drink versus a glucose-sweetened drink. They found every measure of clotting ability significantly increased immediately following ingestion of xylitol but not glucose.

The team said the study had several limitations, including that clinical observation studies demonstrate association and not causation. They said more studies are needed to assess the long-term cardiovascular safety of xylitol.

Dr. Cheng-Han Chen, an interventional cardiologist and medical director of the structural heart program at MemorialCare Saddleback Medical Center in California, told Medical News Today that people should avoid large amounts of xylitol until its effects are better understood.

“Based on this study, it is thought that xylitol affects the ‘stickiness’ of platelets in the bloodstream, potentially increasing the risk of forming a blood clot in the heart or in the brain,” said Chen, who was not involved in the research.

Dr. Rigved Tadwalkar, a consultative cardiologist at Providence Saint John’s Health Center in California, told Medical News Today it’s important to remember the study was observational and doesn’t definitively prove xylitol directly causes cardiovascular problems.

“However, the findings raise enough concern to warrant further investigation,” Tadwalkar, who was not involved in the research, said. “This new study adds another chapter to the evolving story of sugar substitutes and heart health. In recent years, there has been a growing awareness that these alternatives might not be as risk-free as once believed.”

Tadwalkar added it’s also important to note erythritol is more prominent in the United States within keto and sugar-free products, whereas xylitol finds wider use in other countries as well as in some sugar-free candies and chewing gums.

“This new research prompts consideration of the long-term cardiovascular safety of various sugar substitutes,” Tadwalkar said. “This new study on xylitol has significant implications for both consumers and healthcare professionals.”

He added that xylitol may have this impact on the heart because, according to the study, xylitol may increase platelet activity and enhance blood clot formation.

“This heightened activity could raise the risk of clots forming unexpectedly, potentially leading to cardiovascular events like heart attack or stroke,” Tadwalkar said. “It is important to note, however, that this is ultimately just a theory. More research is needed to definitively understand the exact biological processes at play.

Dr. Bradley Serwer, a cardiologist and chief medical officer at VitalSolution, which provides cardiovascular and anesthesiology services to hospitals nationwide, told Medical News Today that problems with sugar substitutes go back more than a century.

“Saccharin was first discovered in 1879 and widely introduced as an artificial sweetener in the early 20th century,” Serwer said. “There was notable concern that saccharin could cause cancer in the 1970s, but this was later clarified in the early 2000s when the National Toxicology Program removed saccharin from its list of potential carcinogens.

Serwer said the health value of sugar substitutes depends on someone’s medical conditions.

“Ideally, one would avoid them altogether and maintain a healthy balanced diet with a low glycemic index,” said Serwer, who was not involved in the research. “I would encourage patients to consider their desire for sweets over their overall health. The natural options such as monk fruit extract may be reasonable.”

“Take caution. Even products such as Stevia, which is derived from the Stevia rebaudiana plant, is mixed with erythritol, which may also increase the risk of platelet clumping and was associated with higher cardiovascular events,” he added.