Researchers at the University of Colorado Boulder have raised fresh concerns over erythritol — a widely used sugar substitute in products like diet sodas, keto snacks, and sugar-free gums. The new study, published in the Journal of Applied Physiology and presented at the American Physiology Summit in April 2025, suggests that erythritol may exert damaging effects on brain vascular cells, potentially increasing the risk of stroke.
In laboratory experiments, the research team exposed human cerebral microvascular endothelial cells — the cells lining the brain’s tiny blood vessels — to erythritol at concentrations equivalent to a typical sugar-free beverage serving (about 30 g). The results were striking: levels of reactive oxygen species, or free radicals, spiked by approximately 75%, signaling increased cellular stress. At the same time, nitric oxide (NO), a key molecule for blood vessel dilation, dropped by nearly 20%, while endothelin-1, which constricts vessels, rose by around 30%. Perhaps most notably, the cells’ ability to release tissue plasminogen activator (t-PA), essential for breaking down blood clots, was severely impaired.
These cellular disruptions—reduced blood flow, vessel constriction, heightened oxidative stress, and clotting impairment—combine to create a biological profile consistent with increased stroke risk. Previous epidemiological studies also support this connection: a Cleveland Clinic study of more than 4,000 participants in the U.S. and Europe found that individuals with higher blood levels of erythritol were significantly more likely to experience heart attacks or strokes within three years .
Although the study did not involve human clinical trials, lead author Auburn Berry emphasized that these findings challenge the long-held assumption of erythritol’s safety. “Non‑nutritive sweeteners… may not come without negative health consequences,” remarked Christopher DeSouza, senior author and professor of integrative physiology. Berry echoed this caution, advising that individuals—especially those at higher cardiovascular risk—should be mindful of their erythritol consumption.
The Food and Drug Administration has approved erythritol since 2001, and international regulators, including the European Food Safety Authority, have generally considered it safe. However, the new findings suggest that chronic intake at typical consumption levels could have unforeseen vascular impacts. In light of this, public health experts are now calling for controlled human trials to determine whether these cellular effects translate into actual health risks.
Until more definitive clinical data emerges, consumers—especially those using erythritol for weight management or blood sugar control—may want to reconsider heavily relying on this sweetener. Alternatives like stevia or monk fruit extract may offer safer non-caloric options. The study adds an important new layer to ongoing discussions about the long-term safety of sugar substitutes, emphasizing that agents once considered benign may carry hidden biological consequences.
For further details and to monitor new developments, consult the original University of Colorado Boulder release.
