Sweetener xylitol increases the risk of heart attacks and strokes

A sweetener called xylitol, commonly used in sugar-free drinks, chewing gum and toothpaste, has been linked to a higher risk of heart attacks and strokes.

Often marketed as “low carb,” “natural,” and “keto-friendly,” xylitol is a sugar alcohol found in fruits and vegetables, but in about 1,000 times lower amounts than in commercial products. It can also be produced artificially from plant materials through chemical reactions.

Last year, Stanley Hazen of the Cleveland Clinic in Ohio and his colleagues found that the sweetener erythritol was linked to an increased cardiovascular risk. Hazen wondered whether xylitol might also affect heart health and led a study of 3,306 adults in the US and Europe.

The researchers analyzed a one-time blood sample from participants to check their xylitol levels after they had fasted overnight. Over a three-year observation period, the team found that one-third of participants with the highest xylitol levels were more likely to experience a cardiovascular event, such as a heart attack or stroke.

To better understand this trend, researchers studied the effects of xylitol on human blood cells called platelets in the laboratory and on platelet activity in mice. Platelets gather at the site of an injury to prevent bleeding, but they can also clot in blood vessels. This can impair blood supply to the heart and brain and increase the risk of cardiovascular events.

The researchers found that human platelets showed signs of a higher tendency to clot when incubated with xylitol compared to when incubated with saline solution. Blood clots also formed significantly faster in the veins of mice after the xylitol injection.

Finally, the team tracked platelet activity in 10 people after giving them water sweetened with the same amount of xylitol. Within 30 minutes, the level of xylitol in their blood plasma increased 1,000-fold and all indicators that support platelet clotting readiness increased, especially in those who had the highest levels of xylitol in their blood.

“This study again highlights the urgency of investigating sugar alcohols and artificial sweeteners,” says Hazen. “This doesn’t mean you should throw away your toothpaste if it contains xylitol, but we should be aware that consuming a product with high concentrations may increase the risk of blood clots.”

Together with previous findings on erythritol, the findings underscore “the need for systematic studies on the effects of artificial sweeteners on cardiovascular risks,” says Silvia Radenkovic of Utrecht University Medical Center in the Netherlands.