A new study from the University of Colorado Boulder suggests that erythritol, a popular sugar substitute found in many “sugar-free” and low-carb products, may harm brain cells and raise the risk of stroke.
The research, published in the Journal of Applied Physiology, found that even small amounts of erythritol can cause damage to the cells that line brain blood vessels. This damage could lead to blood vessel constriction, blood clotting, and inflammation—all of which may increase the chance of a stroke.
Erythritol is commonly used in low-calorie, sugar-free, and keto-friendly foods. Approved by the U.S. Food and Drug Administration in 2001, it is a sugar alcohol typically made from fermented corn. It contains almost no calories, is about 80% as sweet as regular sugar, and has little effect on insulin, making it a preferred option for people with diabetes or those trying to lose weight.
However, recent research has raised concerns about its safety. A previous study involving 4,000 people in the U.S. and Europe found that those with higher levels of erythritol in their blood were more likely to have a heart attack or stroke within three years.
In the new study, researchers treated human brain blood vessel cells in a lab with the amount of erythritol typically found in a single sugar-free drink. They observed that the treated cells produced less nitric oxide, a molecule that helps relax and widen blood vessels, and more endothelin-1, a protein that narrows them. The cells also had a reduced ability to break down blood clots and showed increased levels of harmful “free radicals,” which can damage tissue.
“If your vessels are more constricted and your ability to break down clots is lowered, your risk of stroke goes up,” said Auburn Berry, lead author of the study.
Senior author Christopher DeSouza, director of the university’s Integrative Vascular Biology Lab, warned that people who consume multiple servings of erythritol per day could face greater risks. He added that more research in humans is necessary to confirm these findings.
In the meantime, DeSouza advises consumers to read product labels carefully and monitor their intake of erythritol and other sugar substitutes.
