Popular sweetener may affect the brain, study suggests

Researchers have found that the sugar substitute erythritol interfered with several protective functions in cells that line the brain’s small blood vessels. The effects included chemical stress, changes in signals that regulate vessel relaxation, and a reduced ability of the cells to help break down clots.

The findings may help explain earlier reports that associated elevated erythritol levels in the blood with heart and blood vessel issues. Still, the study does not prove that consuming the sweetener leads to stroke, heart attack or brain disease in people.

Scientists at the University of Colorado Boulder examined human blood vessel cells in a laboratory setting. Their work was presented at the 2025 American Physiology Summit and published in the Journal of Applied Physiology.

Erythritol is a low-calorie sweetener used in some sugar-free and reduced-sugar products. It is part of a class known as sugar alcohols, which are chemically distinct from the alcohol found in beer or wine.

Because it has little impact on blood sugar compared with regular sugar, erythritol has become a popular alternative sweetener. The new study focused on a different issue: how it may influence the cells that help preserve blood flow in the brain.

Those cells line very small vessels and help determine whether they widen or narrow. They also support the processes that keep blood moving and respond when a clot begins to form.

The team exposed the cells to an erythritol level meant to mirror blood concentrations after consumption. It then measured several responses, which allowed the researchers to look for possible effects without waiting for a clinical event such as a stroke.

The exposed cells showed higher oxidative stress, a rise in reactive molecules that can damage cell components when not properly balanced. This is one way a chemical exposure can disrupt healthy cell activity.

The cells also made less nitric oxide, a signal that helps blood vessels relax, and more endothelin-1, which promotes narrowing. Together, those changes pointed to a shift away from the usual balance that controls vessel behavior.

Another change involved the release of a protein that helps dissolve blood clots. That response was weakened, raising further questions about whether erythritol could affect the vessel lining’s role in normal circulation.

These are early mechanistic results from isolated cells, so they cannot account for digestion, metabolism or the full circulation of a person. The experiment also cannot show whether different levels or patterns of everyday consumption would produce the same effects.

The study’s value is that it identifies specific functions for future research to examine. Further testing in people will help determine how important these cellular changes may be for the long-term safety of this widely used sweetener.

Source: University of Colorado Boulder.

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