Erythritol, a common sugar substitute found in thousands of diet drinks and keto snacks, may pose a direct threat to the cells that line our blood vessels, according to new laboratory research. Scientists at the University of Colorado Boulder have detailed how the sweetener, consumed at typical dietary levels, can trigger cellular changes that are known precursors to stroke.
How a sweetener stiffens blood vessels and promotes clots
The research, published in the Journal of Applied Physiology, examined human brain blood vessel cells exposed to erythritol concentrations equivalent to a single sugar-free drink. The findings reveal a dual assault on vascular health. First, the cells produced substantially less nitric oxide, a molecule essential for relaxing and widening blood vessels. Concurrently, they generated more of the protein endothelin-1, which constricts vessels. This combination pushes the vascular system towards a state of unhealthy tension.
Perhaps more critically, the sweetener was found to compromise the body’s natural defences against dangerous blood clots. The exposed cells showed a diminished capacity to create tissue-type plasminogen activator (t-PA), a compound crucial for dissolving clots. Furthermore, the cells exhibited increased levels of damaging reactive oxygen species, or free radicals, leading to harmful oxidative stress. “Big picture, if your vessels are more constricted and your ability to break down blood clots is lowered, your risk of stroke goes up,” explained graduate researcher Auburn Berry.
Epidemiological studies flag a significant risk
This cellular research builds upon earlier, large-scale human studies that first raised significant concerns. A substantial study of 4,000 participants across America and Europe, led by the Cleveland Clinic and published in Nature Medicine, found that individuals with the highest blood levels of erythritol faced approximately twice the risk of suffering a heart attack or stroke within three years compared to those with the lowest levels. In some analyses, erythritol was a stronger predictor of future cardiovascular problems than high cholesterol.
The Cleveland Clinic team also conducted interventional studies which showed that consuming erythritol caused a dramatic, over 1,000-fold increase in blood levels in healthy volunteers. These elevated levels persisted for several days—long enough, the researchers noted, to significantly increase platelet reactivity and the potential for clot formation.
Regulators monitor findings but maintain current approvals
Despite these findings, major food safety bodies have not changed their stance on the sweetener. The US Food and Drug Administration (FDA), which classified erythritol as “generally recognized as safe” (GRAS) in 2001, reviewed the 2023 observational studies. It concluded they did not establish a causal link and continues to monitor new information.
In the European Union, the European Food Safety Authority (EFSA) has also reaffirmed its approval. However, in a 2023 assessment, EFSA set a tolerable daily intake of 500 mg per kg of body weight—primarily to avoid laxative effects—and warned that acute and chronic exposure estimates exceed this level for all population groups. While stating current evidence does not demonstrate a direct cause-effect relationship for cardiovascular risk, EFSA acknowledged that further research is needed to clarify the associations observed.
A popular choice with complex chemistry
Erythritol’s popularity is rooted in its properties. A sugar alcohol produced commercially by fermenting corn, it provides about 80% of sugar’s sweetness with minimal calories and almost no impact on blood glucose or insulin levels. It occurs naturally in small amounts in fruits like watermelon and pears, and is largely absorbed and excreted unchanged by the body, leading to fewer digestive issues than similar sweeteners. This profile has made it a staple in products aimed at weight management, diabetes, and low-carbohydrate diets like keto.
Professor Christopher DeSouza, who led the University of Colorado laboratory study, noted their experiment used only a single serving quantity, implying that higher daily consumption could produce more pronounced effects. He advises consumers to scrutinise ingredient labels for erythritol or “sugar alcohol” listings. “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. Researchers universally caution that while the evidence is mounting, further large-scale human trials are required to confirm these risks in everyday dietary contexts.