A widely used sugar substitute found in some sugar-free and low-calorie foods may not be as benign as previously thought, according to a new study.

Small amounts of erythritol, which was approved by the Food and Drug Administration (FDA) in 2001, may damage brain blood vessel cells and could lead to a higher chance of stroke, researchers from the University of Colorado said in a statement.

Erythritol is considered a sugar alcohol, produced mostly by fermenting corn. It’s found in a large number of products such as candy, sugar-free gum, soft drinks, mouthwash, ice cream, protein bars, and more.

In the July 14 statement, the researchers said that after treating human cells that line blood vessels inside the brain for three hours with roughly “the same amount of erythritol contained in a typical sugar-free beverage,” the cells were affected in several ways.

The cells “expressed significantly less nitric oxide,” which widens and relaxes blood vessels, and produced more of a protein that constricts blood vessels in the brain. Brain cells treated with erythritol also produced more free radicals, which can cause inflammatory reactions and age tissues, according to the statement.

Christopher DeSouza, a professor of integrative physiology at the university and a study author, said in a statement that the finding comes in addition to other “evidence suggesting that non-nutritive sweeteners that have generally been purported to be safe, may not come without negative health consequences.”

He noted that the study, which was published in the Journal of Applied Physiology, used a serving-size portion of erythritol, meaning that people who consume several servings per day could see more adverse impacts. The researchers also noted that their research was only done in a laboratory and was conducted on cells, noting that larger studies with people should be considered.

DeSouza advised consumers to be aware of products containing erythritol and to check product labels. Popular products sold in stores with the sweetener include Truvia, Splenda, Vitamin Water Zero, and Gatorade G2 Natural and are often in keto diet-related products, among many others.

In 2023, the FDA noted that erythritol “is a relatively new food ingredient” that is found naturally in some foods, namely several types of mushrooms. It’s been used as a sweetener since 1990 and has also been approved in Japan, Australia, New Zealand, Canada, Brazil, and Mexico.

The research published by the University of Colorado isn’t the first to find a link between the sweetener and cardiovascular health issues.

An article published in March 2023 by the National Institutes of Health found that the sweetener may pose a cardiovascular risk, noting that “higher blood levels of the artificial sweetener erythritol were associated with increased risk of heart attack and stroke,” but it suggested that more studies are needed.

A Cleveland Clinic study in August 2024 found an associated risk of erythritol consumption and heart attack or stroke. Ten people were randomly assigned to consume water that had 30 grams of erythritol mixed in, while 10 others were randomly assigned to drink water mixed with 30 grams of sugar.

“Erythritol made platelets (a type of blood cell) more active, which can raise the risk of blood clots. Sugar (glucose) did not have this effect,” the study reads.