04/09/2026
🚨 Alarming New Research: Popular Sugar Substitute Erythritol Crosses the Blood-Brain Barrier and May Raise Stroke Risk
A new study from the University of Colorado Boulder has revealed troubling effects of erythritol, a widely used zero-calorie sweetener, on the cells that form the protective blood-brain barrier.
Researchers exposed human brain microvascular endothelial cells to erythritol at levels equivalent to one typical sweetened beverage, about 30 grams or 6 millimolar, for just three hours.
The results, published in the Journal of Applied Physiology, are deeply concerning.
📊 Key findings include:
• A 75 percent surge in reactive oxygen species, causing intense oxidative stress that overwhelmed the cells' antioxidant defenses, including superoxide dismutase and catalase.
• Impaired nitric oxide production, which normally keeps blood vessels relaxed and open.
• A 30 percent increase in endothelin-1, a powerful vessel-constricting compound.
• Increased permeability of the blood-brain barrier, potentially allowing harmful substances into brain tissue.
• Blunted release of tissue-type plasminogen activator (t-PA), the body's natural clot-dissolving agent, leaving cells less able to respond to clotting threats.
Together, these changes create conditions that promote vascular constriction, oxidative damage, barrier leakage, and impaired clot breakdown.
Such effects could heighten the risk of ischemic stroke, the most common type of cerebrovascular event.
Erythritol has been marketed as a natural and safe alternative since its FDA approval in 2001.
It appears in countless keto, low-carb, and sugar-free products, including Halo Top and Enlightened ice creams, Monster and Celsius energy drinks, Quest protein bars, Truvia, Swerve, Lakanto, Lily’s chocolate, and many others.
While small amounts occur naturally in some fruits, the high doses from commercially produced erythritol are consumed regularly by millions seeking healthier options.
Previous studies have linked higher circulating erythritol levels to increased cardiovascular and cerebrovascular risks.
This cellular research now suggests a direct mechanism affecting the brain's delicate vasculature.
As one editorial starkly observes, our brains deserve better than a chemistry experiment disguised as wellness.
Zero calories does not mean zero consequences.
While additional human studies are warranted, the speed and severity of these effects at everyday exposure levels call for greater caution, particularly among regular consumers.