From low-carb ice cream and keto protein bars to "sugar-free" soda, the artificial sweetener erythritol has become a staple for anyone trying to cut calories or carbs.
However, new research suggests the popular sugar substitute may come with serious downsides -- including changes in brain blood vessels that could increase the risk of stroke.
Scientists at the University of Colorado Boulder have found that erythritol can alter human brain blood vessel cells in ways that could raise stroke risk. Their findings, published in the Journal of Applied Physiology, add to growing evidence that these so-called "safe" sugar substitutes may not be risk-free.
"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," senior author and integrative physiologist professor Christopher DeSouza said in a statement.
First approved by the Food and Drug Administration (FDA) in 2001, erythritol is a sugar alcohol often made by fermenting corn. It has almost no calories and is about 80 percent as sweet as table sugar, with a minimal impact on insulin levels. That's made it a favorite among people trying to lose weight, manage blood sugar, or follow low-carb diets.
The FDA allows the use of sugar alcohols -- such as erythritol, lactitol, maltitol, mannitol, sorbitol, xylitol -- as sugar substitutes in foods. These sweeteners range from 25 to 100 percent as sweet as sugar, have fewer calories and do not cause tooth decay or rapid spikes in blood sugar.
In 2023, the FDA reviewed research suggesting a possible link between erythritol and cardiovascular events but concluded that the observational studies did not prove a causal relationship. The agency says it will continue to monitor and evaluate new evidence on erythritol and other sweeteners as it emerges.
But recent research has begun to shine a light on its potential dangers. One large study of 4,000 people in the U.S. and Europe found that those with higher circulating levels of erythritol were significantly more likely to have a heart attack or stroke within three years.
To understand why, DeSouza and graduate student Auburn Berry exposed human brain blood vessel cells in the lab to roughly the same amount of erythritol found in a typical sugar-free drink. The cells were treated for three hours -- long enough to simulate a real-life dietary exposure.
They saw several troubling effects:
"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."
The study used only a serving-size amount of erythritol, raising concerns for people who consume multiple sugar-free products daily. However, the researchers are careful to note that their study was done on cells in a laboratory dish. More research in people is needed to confirm real-world effects.
Even so, DeSouza encourages caution: "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.
He advises consumers to read ingredient labels carefully for erythritol or "sugar alcohols," and to be mindful of how much they're consuming, even in products marketed as "sugar-free."