June 25, 2024

Xylitol may affect cardiovascular health

At a Glance

  • Higher blood levels of the artificial sweetener xylitol were associated with increased risk of heart attack and stroke in people.
  • Xylitol enhanced blood clotting in mice and isolated human blood.
  • The results highlight the need for further study of long-term cardiovascular health risks from sugar alcohols, artificial sweeteners that were thought to be safe.
Xylitol crystals in a birch bowl beside a birch branch with leaves. The artificial sweetener xylitol is often derived from birch. morissfoto / Adobe Stock

Many people use artificial, low-calorie sweeteners to reduce their sugar intake. Dietary guidelines recommend them for people with cardiometabolic diseases like obesity and diabetes. But their long-term effects on heart health have not been well studied.

A recent NIH-funded study by a team of researchers, led by Dr. Stanley Hazen at the Cleveland Clinic, suggested that an artificial sweetener called erythritol might exacerbate heart disease. Erythritol belongs to a class of compounds called sugar alcohols. Another sugar alcohol, xylitol, is also commonly used as a low-calorie sweetener and sugar substitute. Like erythritol, small amounts of xylitol occur naturally in fruits and vegetables. It is also produced in our bodies as part of normal metabolism. But levels of xylitol in artificially sweetened foods can be more than 1,000-fold greater than those found naturally in foods.

In their earlier study, the team found that blood erythritol levels were associated with future risk of major adverse cardiovascular events, such as heart attack or stroke. They also found that other sugar alcohols in the blood were associated with this risk, one of which they tentatively identified as xylitol. For the new study, the team examined a group of more than 2,000 people using a method to better distinguish xylitol from related compounds. Results appeared in the European Heart Journal on June 6, 2024.

The team found that people with the highest xylitol levels (top third) were about 50% more likely to have cardiovascular events over the next three years as those with the lowest (bottom third).

Blood components called platelets help blood to clot. In the group’s earlier research, erythritol made platelets more sensitive to blood clotting signals. In this study, the researchers exposed human platelets to xylitol to see if it had the same effect. Doing so increased the platelets’ sensitivity to blood clotting signals, much like erythritol did. Increasing blood xylitol levels also sped up blood clot formation and artery blockage in mice.

The team next tested how xylitol consumption affects blood xylitol levels and platelet function in people. To find out, they took blood samples from 10 healthy people before and after drinking a xylitol-sweetened beverage. Blood xylitol levels increased 1,000-fold within 30 minutes of drinking and returned to baseline after 4 to 6 hours. The platelets became more sensitive to blood clotting signals when xylitol blood levels were high.

These results suggest that xylitol, like erythritol, could have long-term cardiovascular health risks. Both xylitol and erythritol were associated with increase blood clot formation. This, in turn, could increase the risk of heart attack or stroke. Given these findings, further safety studies of sugar alcohol as artificial sweeteners are warranted.

“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,” Hazen says. “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.”

—by Brian Doctrow, Ph.D.

Related Links

References: Xylitol is prothrombotic and associated with cardiovascular risk. Witkowski M, Nemet I, Li XS, Wilcox J, Ferrell M, Alamri H, Gupta N, Wang Z, Tang WHW, Hazen SL. Eur Heart J. 2024 Jun 6:ehae244. doi: 10.1093/eurheartj/ehae244. Online ahead of print. PMID: 38842092.

Funding: NIH’s National Heart, Lung, and Blood Institute (NHLBI); Deutsche Forschungsgemeinschaft; Stifterverband für die Deutsche Wissenschaft.