August 30, 2026, 5:22 am | Read time: 3 minutes
Sugar-free, reduced-calorie, fitness-friendly: Products with sugar substitutes like birch sugar (xylitol) are considered by many consumers to be a better alternative to traditional sugar. However, new research presented at the world’s largest heart congress (ESC) in Munich now suggests that xylitol may be linked to cardiovascular diseases.
Sugar Substitutes in Light and Fitness Foods in Focus
After a meal, quickly chewing a sugar-free gum or reaching for a protein bar with sugar substitutes is part of everyday life for many people. Xylitol is often used in light, diet, and fitness products. The sweetener is found in numerous products for a calorie-conscious diet.
Scientists from Germany, Canada, and the United Kingdom analyzed health data from a total of 17,710 people from two large long-term studies for the research. The result: High concentrations of xylitol in the blood were associated with an increased risk of heart attack, stroke, and cardiovascular-related death.
Birch Sugar May Affect Blood Clotting
The connection was particularly evident in a Canadian study. There, the risk of heart attack, stroke, or cardiovascular death increased by 57 percent over six years. In a European long-term study over 30 years, the risk was 18 percent higher.
“In previous studies, we were able to show that xylitol can promote the formation of blood clots,” explains study author Dr. Marco Witkowski from Charité Berlin. Thus, birch sugar could influence blood clotting.
Cardiologist Prof. Christina Magnussen from the University Medical Center Hamburg-Eppendorf also points to a possible biological mechanism. She says, “There is evidence that xylitol makes blood platelets more active. This can lead to blood clots forming more easily, which can trigger heart attacks or strokes.” Such blood clots are often considered immediate triggers of heart attacks and strokes.
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The researchers emphasize, however, that this is an observational study. It cannot prove that xylitol is actually the cause of cardiovascular diseases.
Prof. Magnussen puts the results into perspective: “The researchers found a link between high xylitol levels in the blood and cardiovascular diseases. However, they cannot say for sure whether xylitol is actually the cause.”
It is also conceivable that people with certain metabolic disorders have both higher xylitol levels and an inherently higher heart risk.
Should Consumers Avoid Xylitol?
Despite the new findings, birch sugar is still considered safe by authorities. Study author Dr. Witkowski, however, points out unanswered questions: “Our long-term data from the general population show how little we know so far about the effects of xylitol on the heart and blood vessels. Therefore, further studies are urgently needed, especially as more and more foods contain xylitol.”
Those who want to pay attention to their heart health should generally not consume large amounts of either sugar or sweeteners. The German Nutrition Society recommends limiting the daily intake of free sugars to about 50 grams, which corresponds to approximately ten to twelve sugar cubes or a half-liter bottle of cola.