New findings suggest that erythritol, a common ingredient in many “sugar-free” foods, protein bars, and energy drinks, may pose hidden risks to the brain and cardiovascular system. According to Science Alert, a research team from the University of Colorado has discovered that this sweetener can damage the cells of the blood–brain barrier — the brain’s key defense system responsible for blocking harmful substances while allowing essential nutrients to pass through.
The researchers exposed blood–brain barrier cells to levels of erythritol similar to those that appear in the bloodstream after drinking a beverage sweetened with it. They observed a chain reaction of cellular damage that could make the brain more vulnerable to blood clots, a major cause of stroke.
The study found that erythritol triggers oxidative stress, flooding cells with highly reactive molecules known as free radicals while at the same time weakening the body’s natural antioxidant defenses. This double assault impaired the cells’ ability to function properly and, in some cases, killed them entirely.
Even more troubling was the sweetener’s impact on the blood vessels’ ability to regulate blood flow. Under normal conditions, healthy vessels expand when the body needs more blood — such as during exercise — and contract when demand decreases. This balance depends mainly on two molecules: nitric oxide, which relaxes blood vessels, and endothelin-1, which tightens them.
The new study revealed that erythritol disrupts this vital system by reducing the production of nitric oxide while increasing endothelin-1. As a result, blood vessels remain abnormally constricted, potentially depriving the brain of oxygen and nutrients. This type of dysfunction is a well-known warning sign of ischemic stroke, which occurs when a blood clot blocks an artery in the brain.
The researchers also found that erythritol interferes with the body’s natural defenses against clot formation. Normally, when a clot begins to develop, blood vessels release an enzyme called tissue plasminogen activator (tPA) to dissolve it before it causes harm. But erythritol appeared to weaken this protective process, allowing clots to persist and possibly cause damage.
These laboratory results support earlier observations from large human studies showing that people who regularly consume erythritol may face a significantly higher risk of heart attacks and strokes.
Erythritol has long been considered safe by regulatory bodies such as the FDA and the European Food Safety Authority. It is also favored in the food industry because, unlike artificial sweeteners such as aspartame and sucralose, it is classified as a natural sugar alcohol that the body produces in small amounts.
However, the growing evidence indicates that even “natural” sugar substitutes may carry unexpected health risks. While erythritol can be useful for people trying to manage weight or blood sugar levels — especially those following low-carb or keto diets — the new findings suggest consumers may need to reconsider the trade-offs involved in replacing sugar.
As research continues, this supposedly harmless sweetener is likely to face increased scrutiny, raising an important question: Is any sugar substitute truly risk-free?
