Concerns About Sugar Alcohol Erythritol

The health food sector has been eager to add sugar alcohols into various products, such as protein bars, zero-sugar energy drinks, and healthier desserts. This move makes sense, as sugar alcohols—unlike older artificial sweeteners—are naturally occurring and lower in calories. Interestingly, they can be processed by the body without the same risks often linked to artificial sweeteners.

However, researchers from the University of Colorado at Boulder have found troubling evidence suggesting that excessive intake of erythritol, a common sugar alcohol, could lead to increased risks of blood clots in the brain, a precursor to strokes. Their study revealed cellular responses to erythritol that seem to support a concerning 2023 epidemiological investigation, which associated elevated blood erythritol levels with a higher likelihood of heart attacks and strokes within a few years.

Erythritol is widespread, commonly found in items like protein bars, sugar-free drinks, keto snacks, and “natural” sweetener blends such as stevia and monk fruit. “Considering the epidemiological findings that prompted our research, and our own cellular insights, it seems wise for individuals to keep an eye on their intake of non-nutrient sweeteners like this,” stated Christopher DeSouza, a coauthor of the study and the director of CU Boulder’s Integrative Vascular Biology Lab.

Auburn Berry, another coauthor and a graduate researcher in DeSouza’s lab, added, “If your blood vessels get narrower and your ability to break down clots diminishes, your stroke risk goes up.”

Impact on Blood Vessels

In their study, Berry and DeSouza cultivated human brain blood vessel cells and subjected them to a typical dose of erythritol, around 30 grams—the amount found in a single zero-sugar beverage—for three hours. They observed several concerning changes in these cells.

First, the addition of erythritol seemed to decrease nitric oxide production, a molecule essential for blood vessel relaxation, while increasing endothelin-1, an amino acid known to constrict blood vessels and provoke inflammation. The researchers also noted a significant rise in reactive oxygen compounds in the erythritol-exposed cells, roughly 75% higher than in the control group.

These biochemical shifts amplified the risks identified with two other relevant compounds involved in blood clot regulation. Upon exposure to thrombin—a key enzyme in blood clot formation—erythritol appeared to inhibit the production of t-PA, a natural clot-dissolving agent. The cultures without erythritol produced about 25% more t-PA.

DeSouza remarked that deeper clinical investigations are necessary but hinted that their findings might be conservative since they only assessed a single serving of erythritol. Someone who frequently consumes multiple zero-sugar beverages or protein bars in a day might face more pronounced effects.

Natural vs. Dietary Erythritol

While the CU Boulder study does raise valuable points, some medical researchers believe it might be premature to draw broad conclusions about erythritol just yet. Scholars from Romania’s University of Medicine and Pharmacy of Craiova co-authored a letter in the same journal, stressing the fact that the human body naturally produces erythritol, particularly in response to caloric stress like obesity or diabetes. Erythritol is generated in a process akin to fermentation in various organs, including red blood cells, the liver, and kidneys.

This leaves some uncertainty, as the significant study that inspired CU Boulder’s research highlighted a correlation between erythritol levels and stroke risks, but it’s unclear how much of that erythritol was a product of the patients’ other health issues or lifestyle choices.

“Until we consider this dual source,” noted George Dan Mogoşanu, an associate professor from Craiova, “the causality between dietary erythritol and vascular risk remains uncertain.”