Finnish researcher challenges study linking xylitol to heart risks

A study has linked high blood xylitol levels with an increased risk of heart attack and stroke, but Eva Söderling, an associate professor at the University of Turku’s Institute of Dentistry, says the findings do not show that using xylitol causes the increased risk, Yle reports.

The study, published by the European Society of Cardiology, examined 17,710 people in Canada and Europe. Researchers compared participants in the highest quarter of blood xylitol concentrations with those in the lowest quarter.

Over six years, people in the highest quarter were 57 percent more likely to die, suffer a heart attack or have a stroke, according to the study. Over a 30-year observation period, the likelihood of events such as a heart attack was 18 percent higher among those with higher blood xylitol levels.

Söderling said the study did not state that any of the participants had consumed xylitol during the observation period. A direct link between high blood xylitol levels and the increased health risk therefore cannot be established, she said.

“You cannot say that using xylitol carries this risk or that the risk is specifically related to its use,” Söderling said.

Xylitol is a natural sweetener that the human body also produces daily. In Finland, it is typically consumed in small amounts in products such as chewing gum and pastilles. Outside Europe, including in the United States, it is added as a sweetener to drinks and food in considerably larger quantities.

Söderling said daily doses of five to six grams are absorbed directly into the metabolism and do not remain circulating in the blood because xylitol is familiar to the body’s metabolism.

The study was led by cardiologist Marco Witkowski of Charité University Hospital in Berlin. Witkowski also took part in a related study two years ago. Söderling and Kauko Mäkinen, an emeritus professor at the University of Turku’s Institute of Dentistry, published a response to that study in Helsingin Sanomat.

“It appears that the conclusions of the new study are the same as those of the 2024 study. The increased risk of cardiovascular disease is in no way related to the use of xylitol,” Söderling said.

Dell Stanford, lead dietitian at the charity British Heart Foundation, told The Guardian that the study showed only an association between higher xylitol levels and cardiovascular events. Söderling also noted that the latest study has not been peer-reviewed.

Yle reported on a domestic shortage of xylitol in early 2024. Finland imports xylitol from various parts of the world.