Erythritol, a sugar substitute commonly used in keto-friendly and other reduced-sugar products, may increase risk for negative cardiovascular events such as heart attack and stroke, according to new research from the Cleveland Clinic.

Consuming a "standard serving" of 30 grams of the sweetener — a dose "typically contained in a 'sugarless' soda or muffin," according to a news release — made platelets more active in healthy participants, which can raise the risk of blood clots, researchers found in the interventional study, published in Arteriosclerosis, Thrombosis and Vascular Biology on Thursday. Sugar did not have the same effect.

Sugar-free products containing erythritol are often recommended for people with obesity, diabetes or metabolic syndrome as ways to manage sugar and calorie intake. Erythritol is one ingredient in the common calorie-free stevia sweetener Truvia, for example. People with these conditions are already at higher risk for adverse cardiovascular events such as stroke.

"Cardiovascular disease builds over time, and heart disease is the leading cause of death globally. We need to make sure the foods we eat aren't hidden contributors," senior author Dr. Stanley Hazen said in a news release. "These findings underscore the importance of further long-term clinical studies to assess the cardiovascular safety of erythritol and other sugar substitutes."

The study did have limitations, the authors said, including a small size (20 volunteers total, half of whom consumed erythritol) and lack of long-term testing, emphasizing the importance of further research. 

Currently, erythritol is classified by the U.S. Food and Drug Administration as GRAS — "generally recognized as safe"— allowing its use without restriction in food products. This study, however, adds to increasing evidence that erythritol and other sweeteners may not be as safe as previously thought. 

Earlier this year, Hazen and his team found xylitol, a sugar alcohol found naturally in some plants, may be linked to potential negative health impacts. Last year, another study from the Cleveland Clinic found cardiac patients with higher blood erythritol levels were at elevated risk of experiencing major events like heart attack and stroke.

Both of these studies were observational, meaning they didn't definitively show causation, but then-CBS News medical contributor Dr. David Agus said there was "certainly enough data to make you very worried" following the previous erythritol study. 

Consumers should interpret the results of the latest research with "extreme caution," said Calorie Control Council President Carla Saunders ‎told CBS News, citing the limited number of participants and "excessive amount" of erythritol, which she described as "nearly double to triple the maximum amount approved in any single beverage in the United States based on standard 8-16oz serving." 

"Importantly, erythritol levels were only measured once after consumption, and the pilot lacked control over lifestyle factors that may affect the outcome, which could introduce confounding variables and impact the reliability of the findings," the statement continued. "Further, as erythritol levels were only measured at baseline and 30 minutes after consumption, there is no way to demonstrate any lasting effect of excessive consumption on any health outcome. Consumers need to rely on science, and for 30 years, science has shown that erythritol is a proven safe and effective choice for sugar and calorie reduction."

In:
• Heart Attack
• Heart Disease