A common sugar substitute may be linked to blood clots and heart attacks, a recent study finds.

The journal, Nature Medicine, published the research saying erythritol, typically found in keto diet products is associated to stroke, blood clots, heart attacks, and even death.

Keto diets exclude high carb processed sugar, honey, and maple syrups, so many dieters rely on erythritol for a sweet taste in their treats.

The study reported that individuals with the highest erythritol levels in the blood showed twice the risk for these health issues. The individuals did have pre-existing risk factors for heart disease.

CNN reported research leader, Dr. Stanley Hazen, director of the center for cardiovascular diagnostics and prevention at the Cleveland ClinicLerner Research Institute, said,

“The degree of risk was not modest. If your blood level of erythritol was in the top 25% compared to the bottom 25%, there was about a two-fold higher risk for heart attack and stroke.

It’s on par with the strongest of cardiac risk factors, like diabetes.”

But others urged more research to fully understand the sweetener’s connection.

Executive director of the Calorie Control Council, Robert Rankin, told CNN,

“The results of this study are contrary to decades of scientific research showing reduced-calorie sweeteners like erythritol are safe, as evidenced by global regulatory permissions for their use in foods and beverages.”

He also said that the results shouldn’t be taken to mean that people in good health have the same risk as those who were already at increased risk of cardiovascular events.