"Sugar-Free" but Not Risk-Free: Popular Sugar Substitute May Be Linked to Stroke, Study Finds - Video

A widely used sugar substitute found in countless "sugar-free" products may come with hidden health risks, according to a new study from the University of Colorado Boulder. Published in the Journal of Applied Physiology, the study reveals that erythritol commonly used in keto snacks, diet sodas, and low-carb desserts can adversely impact brain blood vessel cells, potentially raising the risk of stroke.

Erythritol is favored for its low calorie count, minimal effect on blood sugar, and 80% sweetness compared to table sugar. However, emerging research has linked higher blood levels of erythritol to a greater likelihood of heart attacks and strokes. Seeking to understand the underlying biological mechanism, researchers in the university’s Integrative Vascular Biology Lab examined the effects of erythritol on brain endothelial cells the cells lining blood vessels in the brain.

The team exposed human brain vascular cells to erythritol levels equivalent to those found in a single serving of a sugar-free beverage. Within just three hours, researchers observed a series of harmful cellular changes. “They expressed significantly less nitric oxide, a molecule that relaxes and widens blood vessels, and more endothelin-1, a protein that constricts blood vessels,” explained lead author Auburn Berry, a graduate student in the lab. In addition, the cells’ ability to produce the clot-dissolving compound t-PA in response to thrombin was “markedly blunted,” and levels of reactive oxygen species damaging free radicals increased.

“Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” Berry said. Senior author Christopher DeSouza, professor of integrative physiology, emphasized that these effects were seen after a single serving, suggesting that repeated consumption could heighten risks further.

While the study was conducted in a laboratory setting and not in humans, the findings align with earlier large-scale epidemiological research. DeSouza advises consumers to read product labels closely. “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.

Reference: Auburn R. Berry, Samuel T. Ruzzene, Emily I. Ostrander, Kendra N. Wegerson, Nathalie C. Orozco-Fersiva, Madeleine F. Stone, Whitney B. Valenti, Joao E. Izaias, Joshua P. Holzer, Jared J. Greiner, Vinicius P. Garcia, Christopher A. DeSouza. The non-nutritive sweetener erythritol adversely affects brain microvascular endothelial cell function. Journal of Applied Physiology, 2025; 138 (6): 1571 DOI: 10.1152/japplphysiol.00276.2025