Ask the doctors: Xylitol’s effect on the heart

Dear Doctors: I read your column about dry mouth. One of the recommendations was to use gum or candy that has been sweetened with xylitol. I was surprised because I have read that xylitol can have a negative effect on the heart. Can you address that?

Dear Reader: We have heard from other readers who share your concerns. Recent headlines about a possible link between xylitol and heart risk have raised questions. Much of the alarm comes from the results of a single study. While the findings provide important and useful information, they also need context. Your question, and those of the other readers, open the door to a closer look at the study. What did the investigators find, and what does that mean for people who use products that contain xylitol?

Xylitol is a sweetener used to replace sugar, often in hard candy and gum. It falls into a class of compounds known as sugar alcohols. These are carbohydrates with a chemical composition similar to sugar, so they impart a sweet taste. Due to their structural differences, sugar alcohols have a markedly smaller effect on blood glucose. This makes them useful for people living with diabetes. Some sugar alcohols, including xylitol, also increase saliva production. This has led to their use to ease severe or persistent dry mouth.

The concerns about xylitol that you have cited come from a study by researchers at the Cleveland Clinic, published in 2024. They reported a possible link between higher levels of the sweetener in the blood and an increase in cardiovascular risk. In that study, conducted in phases, the researchers first added xylitol directly to samples of human plasma and whole blood. They also measured its effect in mice. The results showed that xylitol increased the sensitivity of the blood to clotting signals and increased how fast clots form. Then they tested 10 human volunteers in good health. The volunteers ingested a drink with 30 grams of xylitol. This produced the same chemical signals that they observed in the blood samples and in the mice.

While this can sound alarming, the amount of xylitol in each phase of the experiment was much higher than what people typically consume. Hard candy contains 1 or 2 grams of xylitol per piece. Gum has less than a gram per piece. Also, they consumed the 30-gram dose of the sweetener in a single portion for the study. This explains why blood levels rose so high and so fast. It was more than the liver could metabolize efficiently.

So, what does this mean for the average consumer? Xylitol remains approved for use in foods and oral-care products by the Food and Drug Administration. The caveat is the quantity. As with any sugary gum or candies, use these products in moderation. Anyone with existing cardiovascular disease, or who is worried about personal risk, should discuss the pros and cons of xylitol with their health care provider.

Send your questions to askthedoctors@mednet.ucla.edu.