Share on PinterestArtificial sweeteners raise a number of health concerns, experts say. PatriciaEnciso/Getty ImagesXylitol is a sugar alcohol that's added to many products, from sugar-free candy and gum to toothpaste. Researchers say that high levels of xylitol in the blood are associated with an increased risk of cardiovascular events over a three-year period. The researchers point out that the study has several limitations, including that clinical observational studies show an association but not a causal relationship.
Artificial sweeteners known as sugar alcohols may not have seemed like the healthiest thing for people until now, but that may not be the case.
In a study published in the European Heart Journal, researchers from the Cleveland Clinic reported that high intake of xylitol, a sugar alcohol, may increase the risk of heart attack, stroke, and other cardiovascular diseases.
The researchers said they found the association in large-scale patient analyses, clinical intervention studies and preclinical research models.
Xylitol is a sugar substitute that is low in calories and has a low glycemic index. Sugar alcohols are actually carbohydrates that do not contain alcohol.
Xylitol occurs naturally in small amounts in fibrous fruits and vegetables, corn cobs, trees, and the human body. It is used as a sugar substitute because it tastes similar to sugar but has fewer calories.
Xylitol is found in a variety of products, from sugar-free candy and gum to toothpaste, and is also used as a sweetener and in baking.
The researchers said the past decade has seen a massive increase in sugar substitutes, such as sugar alcohols and artificial sweeteners, in processed foods marketed as healthier alternatives.
Last year, a team of researchers at the Cleveland Clinic found a similar link between another sugar alcohol, erythritol, and cardiovascular disease risk. In a statement, the team noted that while xylitol is less common in ketogenic diets and sugar-free foods in the United States, it is common in other countries.
“This study reaffirms the urgent need to investigate sugar alcohols and artificial sweeteners, especially as they continue to be recommended to combat conditions such as obesity and diabetes,” Dr. Stanley Hazen, director of cardiovascular and metabolic sciences at the Cleveland Clinic's Lerner Research Institute and co-director of preventive cardiology at the Heart, Vascular and Thoracic Institute, said in a statement.
“This doesn't mean you should throw away your toothpaste just because it contains xylitol, but you should be aware that consuming products high in xylitol may increase your risk of blood clot-related events,” Hazen added.
In an analysis of more than 3,000 subjects from the United States and Europe, researchers reported that higher blood xylitol levels were associated with an increased three-year risk of cardiovascular events.
They found that one-third of subjects with the highest plasma xylitol concentrations were more likely to experience a cardiovascular event.
The research team carried out preclinical testing to confirm their findings and found that xylitol causes platelet clotting, increasing the risk of thrombosis.
The researchers also tracked platelet activity in subjects who consumed the xylitol and glucose drinks, and found that all indicators of clotting ability were significantly increased immediately after xylitol consumption, but not after glucose consumption.
The researchers said the study had several limitations, including that observational studies show associations rather than causation, and that further research is 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 consuming large amounts of xylitol until its effects are better understood.
“Based on this research, it appears that xylitol may affect the 'stickiness' of platelets in the bloodstream, potentially increasing the risk of blood clots forming in the heart or brain,” said Chen, who was not involved in the study.
Dr. Rigved Tadwalkar, a consulting cardiologist at Providence Saint John's Health Center in California, told Medical News Today that it's important to remember that the study is observational and doesn't conclusively prove that xylitol directly causes cardiovascular disease.
“However, the findings raise sufficient concern to warrant further investigation,” said Tadwarkar, who was not involved in the study. “This new research adds another chapter to the evolving story about sugar substitutes and heart health. In recent years, there has been growing recognition that these substitutes are not as risk-free as once believed.”
Tadwalkar added that it's also important to note that erythritol is more commonly used in ketogenic diets and sugar-free products in the U.S., while xylitol is more commonly used in sugar-free candy, chewing gum, and other products in other countries.
“This new study prompts consideration of the long-term cardiovascular safety of various sugar substitutes,” Tadwarkar said. “This new research on xylitol has important implications for both consumers and health professionals.”
He added that xylitol may have this effect on the heart because studies have shown it increases platelet activity, which can promote the formation of blood clots.
“This increased activity may increase the risk of unexpected blood clots forming, which could lead to cardiovascular diseases such as heart attack and stroke,” Tadwarkar said. “However, it is important to keep in mind that this is only a theory. Further research is needed to clearly understand the exact biological processes at play.”
Dr. Bradley Serwer, a cardiologist and chief medical officer at Vital Solutions, which provides cardiovascular and anesthesiology services to hospitals across the country, told Medical News Today that the issue of sugar substitutes goes back more than a century.
“Saccharin was first discovered in 1879 and was widely introduced as an artificial sweetener in the early 20th century,” Sarwer says. “Concerns that saccharin could cause cancer were prominent in the 1970s, but this issue was later clarified when the National Toxicology Program removed saccharin from its list of potential carcinogens in the early 2000s.”
Sarwar said the health value of sugar substitutes varies depending on an individual's health status.
“Ideally, you would avoid sweets completely and maintain a healthy balanced diet with a low glycemic index,” said Sarwar, who was not involved in the study. “I would encourage patients to consider their sweet cravings over their overall health, and natural options such as monk fruit extract may be reasonable.”
“Be careful — products such as stevia, which is extracted from the Stevia rebaudiana plant, are also laced with erythritol, which may also increase the risk of platelet aggregation and has been associated with increased cardiovascular events,” he added.
