A sweetener often promoted as a healthy alternative to sugar may not be as safe as it seems.
New research presented at the 2025 American Physiology Summit in Baltimore suggests that erythritol, a common sugar substitute, could harm the brain’s blood vessels and increase the risk of heart attack or stroke.
Erythritol is found in many sugar-free products, including diet drinks, protein bars, and low-calorie snacks.
Because it has almost no calories and doesn’t raise blood sugar or insulin levels much, it’s especially popular among people with diabetes and those trying to lose weight.
It belongs to a group of sugar alcohols that are often used to sweeten food without the negative effects of regular sugar.
However, growing evidence suggests that erythritol may not be as harmless as once believed. Previous studies have shown a link between higher blood levels of erythritol and a greater chance of heart problems like heart attacks and strokes.
These findings have made scientists question how erythritol might affect the body—especially the blood vessels that are essential for healthy circulation.
In the latest study, researchers at the University of Colorado Boulder focused on brain blood vessels. They used human cerebral microvascular endothelial cells—these are the cells that line the small blood vessels in the brain. These cells are important because they help regulate blood flow to the brain, protect against damage, and help dissolve blood clots.
The researchers exposed the cells to an amount of erythritol similar to what a person would consume from just one sweetened drink. They found that the cells began to show signs of stress.
In particular, they had higher levels of oxidative stress—a harmful process where unstable molecules can damage cells. When oxidative stress is high, it can trigger inflammation and other problems that hurt blood vessels.
Another serious change was the drop in nitric oxide production. Nitric oxide is a gas made by blood vessel cells that helps them relax and widen.
This process, called vasodilation, is essential for keeping blood pressure in check and ensuring that the brain and other organs receive enough blood. When cells don’t produce enough nitric oxide, blood vessels can’t dilate properly, and this may raise the risk of clots, heart attacks, or strokes.
According to Auburn Berry, the lead author of the study and a graduate student at the University of Colorado Boulder, the results suggest people should pay attention to how much erythritol they consume.
“While erythritol is widely used in sugar-free products marketed as healthier alternatives, more research is needed to fully understand its impact on vascular health,” she said.
This study was conducted in a laboratory, not in real people, so the findings don’t yet prove that erythritol causes harm in everyday life. However, the effects seen in the cells are similar to problems that have been observed in people with high erythritol levels in past studies.
Together, these findings raise important questions about the safety of erythritol. Although the sweetener has benefits like being low in calories and not spiking blood sugar, the potential downsides—especially the effect on blood vessels in the brain—are becoming harder to ignore.
Scientists agree that more research is needed, especially studies that look at the long-term impact of erythritol in the human body.
For now, this research adds to the growing debate around sugar substitutes. People trying to reduce sugar in their diet may want to think twice before relying too much on products that use erythritol. A balanced diet with natural foods and moderate sweetness may still be the safest choice for protecting heart and brain health.
If you care about nutrition, please read studies about a breakfast linked to better blood vessel health, and drinking too much coffee could harm people with high blood pressure.
For more information about health, please see recent studies about unhealthy habits that may increase high blood pressure risk, and results showing plant-based protein foods may help reverse diabetes.
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