That “healthy” sweetener might be putting your brain at risk.
- Date:
- March 28, 2026
- Source:
- University of Colorado at Boulder
- Summary:
- A widely used sugar substitute found in everything from keto snacks to diet drinks may not be as harmless as it seems. New research shows that erythritol can disrupt brain blood vessel cells, reducing their ability to relax, increasing harmful oxidative stress, and impairing the body’s ability to break down clots. These changes create conditions that could raise stroke risk, even at typical consumption levels.
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From low-carb ice cream and keto protein bars to "sugar-free" soda, erythritol has become a staple ingredient in many modern foods.
However, new research from the University of Colorado Boulder suggests this widely used sugar substitute may have serious downsides. Scientists found it can affect brain cells in ways that may increase the risk of stroke.
The findings were published in the Journal of Applied Physiology.
"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," said senior author Christopher DeSouza, professor of integrative physiology and director of the Integrative Vascular Biology Lab.
What Is Erythritol and Why Is It So Popular?
Erythritol was approved by the Food and Drug Administration in 2001. It is a sugar alcohol typically made by fermenting corn and is now used in hundreds of food products. It contains almost no calories, delivers about 80% of the sweetness of regular sugar, and has little effect on insulin levels. Because of this, it is commonly used by people trying to lose weight, manage blood sugar, or reduce carbohydrate intake.
Still, growing research is raising questions about its safety.
A large study of 4,000 people in the U.S. and Europe found that individuals with higher levels of erythritol in their blood were much more likely to experience a heart attack or stroke within three years.
Inside the Study: Effects on Brain Blood Vessels
To better understand why this risk may exist, DeSouza and lead author Auburn Berry, a graduate student in his lab, examined how erythritol affects cells.
In their experiment, researchers exposed human cells that line blood vessels in the brain to an amount of erythritol similar to what is found in a typical sugar-free drink for three hours.
The results showed several concerning changes. The cells produced much less nitric oxide, which helps blood vessels relax and widen, and more endothelin-1, which causes vessels to tighten. When exposed to thrombin, a substance that promotes clotting, the cells had a reduced ability to produce t-PA, a natural compound that helps break down clots. In addition, the treated cells generated higher levels of reactive oxygen species (ROS), also known as "free radicals," which can damage cells, accelerate aging, and trigger inflammation.
Why These Changes Matter for Stroke Risk
"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."
DeSouza pointed out that the study used only a single serving amount of erythritol. People who consume multiple servings daily could potentially face greater effects.
What Consumers Should Know
The researchers emphasize that their findings come from lab experiments on cells, not from studies in people, so more research is needed to confirm the risks in real-world settings.
Even so, DeSouza recommends paying closer attention to ingredient labels and watching for erythritol or "sugar alcohol."
"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.
Story Source:
Materials provided by University of Colorado at Boulder. Note: Content may be edited for style and length.
Journal Reference:
- Auburn R. Berry, Samuel T. Ruzzene, Emily I. Ostrander, Kendra N. Wegerson, Nathalie C. Orozco-Fersiva, Madeleine F. Stone, Whitney B. Valenti, Joao E. Izaias, Joshua P. Holzer, Jared J. Greiner, Vinicius P. Garcia, Christopher A. DeSouza. The non-nutritive sweetener erythritol adversely affects brain microvascular endothelial cell function. Journal of Applied Physiology, 2025; 138 (6): 1571 DOI: 10.1152/japplphysiol.00276.2025
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Facts Only
Erythritol is a sugar alcohol approved by the FDA in 2001 and commonly used in sugar-free and low-carb products.
A study by the University of Colorado Boulder, published in the *Journal of Applied Physiology* in 2025, examined erythritol's effects on human brain endothelial cells.
The study exposed cells to erythritol levels comparable to those in a typical sugar-free drink for three hours.
Results showed reduced nitric oxide production, increased endothelin-1, impaired clot breakdown (t-PA), and elevated reactive oxygen species (ROS).
These cellular changes suggest potential increased stroke risk due to vessel constriction and impaired clot dissolution.
A prior epidemiological study of 4,000 people linked higher erythritol blood levels to greater heart attack and stroke risk within three years.
The research was led by Christopher DeSouza, professor of integrative physiology, and graduate student Auburn Berry.
The study used a single-serving amount of erythritol, with researchers noting that multiple daily servings could amplify effects.
The findings are based on lab experiments, not human trials, and further research is recommended.
Erythritol is found in products like keto ice cream, protein bars, and diet sodas.
The study was conducted at the University of Colorado Boulder and published in 2025.
The journal reference is DOI: 10.1152/japplphysiol.00276.2025.
Executive Summary
Full Take
The strongest version of this narrative is that erythritol, long considered a safe sugar substitute, may have previously unrecognized risks to vascular health, particularly in the brain. The study provides a plausible biological mechanism—disrupted endothelial function and clot breakdown—that aligns with earlier epidemiological data linking erythritol to cardiovascular events. This is a credible contribution to the ongoing debate about artificial sweeteners, as it moves beyond correlation to propose causation at the cellular level.
However, the study’s limitations—lab-based, not human trials—warrant caution. The pattern here resembles **ARC-0012 Premature Extrapolation**, where preliminary findings are framed as definitive warnings without sufficient real-world validation. The media’s tendency to amplify such studies can trigger **ARC-0040 Fear Appeal**, leveraging health anxieties to drive engagement. The article avoids outright sensationalism but leans into the "healthy" sweetener paradox, which may exploit cognitive dissonance in health-conscious consumers.
Root cause: The narrative reflects broader tensions in nutrition science—between industry-backed safety claims and emerging independent research. The assumption that "natural" or "low-calorie" equals "safe" is being challenged, echoing historical patterns like the backlash against trans fats or high-fructose corn syrup. Who benefits? Consumers gain awareness, but the sugar substitute industry faces scrutiny. Who bears costs? Those who rely on erythritol for dietary management may feel whiplash from shifting guidelines.
Implications: If confirmed, this could reshape regulatory standards for sweeteners, but premature alarmism risks undermining trust in science. Second-order effects include potential market shifts toward alternative sweeteners, which may have their own untested risks.
Bridge questions: How should consumers weigh preliminary lab findings against decades of FDA approval? What thresholds of evidence should trigger public health warnings? Would the risks differ for people with pre-existing vascular conditions?
Counterstrike scan: A coordinated influence campaign would amplify this study to discredit all sugar substitutes, using emotional framing ("brain damage") to push alternative products or ideologies (e.g., "natural sugar is safest"). The actual content avoids this, focusing on specific mechanisms and calling for further research—a clean, evidence-based approach.
Patterns detected: ARC-0012 Premature Extrapolation, ARC-0040 Fear Appeal (mild)
Sentinel — Human
This article is likely human-written, as it demonstrates a balance between presenting facts, offering context, and maintaining a personal voice. However, the text does show some signs of coordination indicators, suggesting a structured argument that may have been influenced by known template patterns.