Study: Common Sweetener Xylitol Linked to Increased Risk of Heart Attack, Stroke

A sweetener found in some low-calorie food and beverage products has been linked to a higher risk of heart attack and stroke, new research found.

The study, published last month in the European Heart Journal, suggests people may want to avoid or limit their consumption of foods that contain xylitol, a sugar alcohol commonly added to low-calorie sweeteners or “diet” foods.

The findings “[represent] a significant public health concern,” said study senior author Stanley Hazen, MD, PhD, chair of cardiovascular and metabolic sciences and co-section head of preventive cardiology at Cleveland Clinic.

“The very same people most likely to be targeted for taking sugar substitutes—those with obesity, diabetes, or metabolic syndrome—are the most vulnerable, [or are] most likely to suffer an incident CVD [cardiovascular disease] event,” he told Health. “By trying to reach for something healthy, the concern is one is inadvertently adding to cardiac risks.”

Here’s what experts had to say about why xylitol may raise the risk of cardiovascular issues and whether you should consider cutting the sweetener out of your diet.

In the U.S., xylitol is regularly used as a sweetener, Amber Core, MDN, RD, registered dietitian at The Ohio State University Wexner Medical Center, told Health.

“Xylitol is a five-carbon sugar alcohol, [and] is commonly found in low-calorie sweetener [that’s added to] low-sugar or diet-labeled foods,” she said. “Some products that commonly contain xylitol include sugar-free candies, chewing gum, jams and jellies, nut butters, yogurt, baked goods, condiments, cough syrup, and toothpaste.”

In general, the sweetener is touted as a health-conscious alternative to sugar and is often used as a one-to-one replacement for regular sugar in baking recipes, Core added.

“Xylitol has been shown to possess significantly less calories than sugar, and, in humans, not to trigger insulin release,” Hazen said. “It, therefore, has been considered to be a good option for diabetics.”

Other research has found xylitol may have oral health benefits, including fighting plaque and inflammation from gingivitis. It could also help reduce diabetes, constipation, and obesity, among other diseases.

Despite previous research finding health benefits linked to xylitol, Hazen and his team wanted to investigate how the sweetener might affect health health in particular. A study they published last year found that erythritol, another sugar alcohol, was associated with an increased risk of heart attack and stroke.

For this new research on xylitol, Hazen’s team relied on data from more than 3,000 people in the U.S. and Europe across two different cohorts. On average, the participants were in their early-to-mid-60s, and almost 64% were men. The researchers examined the participants’ blood and followed them for three years.

The study results showed that people with higher levels of xylitol in their blood had an increased three-year risk of a “major adverse cardiovascular event,” such as heart attack or stroke.

The reason why xylitol raises the risk of heart health issues could be because of its connection to blood clots, Hazen said.

The study authors tested various blood samples and found that xylitol led to increased platelet clotting. They saw similar results with another test—people who drank xylitol-sweetened beverages had a much higher clotting ability than those who drank glucose-sweetened beverages.

Blood clots can help stop blood flow after an injury—but when they form inside the blood vessels and don’t dissolve, they can block normal blood flow, which can be life-threatening.

It’s not totally clear why xylitol could cause platelets to clot up. However, Hazen believes it could have something to do with the way that sugar alcohols “interact with a chemical receptor on the surface of cells—like our taste buds on our tongues,” he explained. There could be a chemical receptor on the platelets that is similarly triggered by the sweetener, leading to an unnecessarily “robust response,” said Hazen.

Though this research certainly raises concerns about whether products containing xylitol are safe, it’s important to note that the study’s findings may not be universally generalizable, Hazen said.

“Clinical observation studies show significant [cardiovascular disease] risk associated with high xylitol levels in middle-aged and elderly subjects with significant cardiovascular disease risk,” he explained. “[But] whether xylitol is associated with long-term increased risk in younger subjects, or those without significant comorbidities—obesity, diabetes, hypertension, and high cholesterol—is less clear.”

This is also the first time scientists have explored the relationship between this particular sugar alcohol and cardiovascular disease risk, Hazen added.

However, he explained, “our current studies were pretty expansive and used multiple redundant approaches, all of which point to the same conclusions.”

For now, there is still a lack of clear guidelines on how to safely incorporate xylitol into a person’s diet.

Per the World Health Organization (WHO), “the acceptable daily intake of xylitol remains as ‘not specified,’” said Core. “This study seems to suggest that more research is needed to provide a definitive answer as to the risk associated with xylitol.”

Even in light of the study’s findings, people don’t necessarily need to stop consuming all products that contain xylitol, experts said. However, people should speak with their healthcare providers to make a decision based on their overall health.

For instance, it might make sense for some people to cut back on xylitol if they’re consuming large amounts of it through “diet” products or if they’re at a higher risk of cardiovascular issues.

“Xylitol and other sweeteners are often marketed to those with diabetes or those who are looking to lose weight, as well as marketed towards children as a method to prevent the formation of cavities,” Core explained. “However, this study seem[s] to indicate that artificial sweeteners should potentially be avoided by those they are marketed towards.”

Hazen said the research should prompt a new discussion about whether xylitol is safe and for whom.

“I hope this serves as a calling for new regulatory guidelines to improve labeling mandates and remove sugar substitutes like xylitol from GRAS status [Generally Recognized as Safe],” he said.