However, new research from the University of Colorado Boulder suggests this widely used sugar substitute may have serious downsides. Scientists found it can affect brain cells in ways that may increase the risk of stroke.

The findings were published in the Journal of Applied Physiology.

“Our study adds to the evidence suggesting that non-nutritive sweeteners that have generally been purported to be safe, may not come without negative health consequences,” said senior author Christopher DeSouza, professor of integrative physiology and director of the Integrative Vascular Biology Lab.

What Is Erythritol and Why Is It So Popular?

Erythritol was approved by the Food and Drug Administration in 2001. It is a sugar alcohol typically made by fermenting corn and is now used in hundreds of food products. It contains almost no calories, delivers about 80% of the sweetness of regular sugar, and has little effect on insulin levels. Because of this, it is commonly used by people trying to lose weight, manage blood sugar, or reduce carbohydrate intake.

Still, growing research is raising questions about its safety.

A large study of 4,000 people in the U.S. and Europe found that individuals with higher levels of erythritol in their blood were much more likely to experience a heart attack or stroke within three years.

Inside the Study: Effects on Brain Blood Vessels

To better understand why this risk may exist, DeSouza and lead author Auburn Berry, a graduate student in his lab, examined how erythritol affects cells.

In their experiment, researchers exposed human cells that line blood vessels in the brain to an amount of erythritol similar to what is found in a typical sugar-free drink for three hours.

The results showed several concerning changes. The cells produced much less nitric oxide, which helps blood vessels relax and widen, and more endothelin-1, which causes vessels to tighten. When exposed to thrombin, a substance that promotes clotting, the cells had a reduced ability to produce t-PA, a natural compound that helps break down clots. In addition, the treated cells generated higher levels of reactive oxygen species (ROS), also known as “free radicals,” which can damage cells, accelerate aging, and trigger inflammation.

Why These Changes Matter for Stroke Risk

“Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” said Berry. “Our research demonstrates not only that, but how erythritol has the potential to increase stroke risk.”

DeSouza pointed out that the study used only a single serving amount of erythritol. People who consume multiple servings daily could potentially face greater effects.

What Consumers Should Know

The researchers emphasize that their findings come from lab experiments on cells, not from studies in people, so more research is needed to confirm the risks in real-world settings.

Even so, DeSouza recommends paying closer attention to ingredient labels and watching for erythritol or “sugar alcohol.”

“Given the epidemiological study that inspired our work, and now our cellular findings, we believe it would be prudent for people to monitor their consumption of non-nutrient-sweeteners such as this one,” he said.