Popular artificial sweeter linked to blood clots and heart disease, study says

The popular sugar substitute erythritol found in keto products, sweets and low- or no-calorie diet drinks might increase the risk of heart attack and stroke, according to new research.

A study led by the Cleveland Clinic published Thursday in the medical journal Arteriosclerosis, Thrombosis and Vascular Biology found the sweetener made blood platelets more active, increasing the risk of blood clots, while food sweetened with sugar did not have the same effect.

The study was tiny – it looked at just 20 patients – and researchers who were not involved in it say people should be careful when interpreting its results.

Erythritol is a zero-calorie sugar substitute used to sweeten hundreds of products, including protein bars, yogurt, cookies and ice cream. It is a thickening agent resembling sugar and the primary sweetener in the low-carb, high-fat keto diet. In 2001, the Food and Drug Administration determined that erythritol was "generally recognized as safe."

However, researchers said participants in the National Institutes of Health-funded study who consumed water sweetened with erythritol showed signs that their blood platelets had been activated, while people who drank glucose-sweetened water didn't experience a similar effect.

"After drinking an erythritol-sweetened drink, you're at heightened risk for clotting, and your platelet function changes – and this was seen in every subject who was tested," said Dr. Stanley Hazen, a cardiologist and chair of cardiovascular and metabolic sciences in Cleveland Clinic’s Lerner Research Institute.

The findings follow a larger 2023 study also led by Hazen, which linked the popular sugar substitute to cardiovascular problems. Last year's study tested blood samples from more than 1,100 people who underwent heart risk assessment over three years and followed up with another group of more than 2,100 non-emergency patients. The study linked erythritol to an increased risk of heart attack, stroke and death. The study also found the sweetener led to blood clots in mice who had eaten it.

Sweetener vs. sugar

After his 2023 study, Hazen said people began asking his research team which types of sweeteners they should eat or drink in lieu of erythritol. His team wanted to compare the clotting risk of consumers who drank a liquid sweetened with erythritol or sugar.

The study recruited 20 nonsmokers with normal kidney health and no history of heart disease, high blood pressure or diabetes. After a night of fasting, participants had their blood tested before and 30 minutes after they drank water sweetened with 30 grams of glucose or erythritol. That dosage is about how much is in an erythritol-sweetened soda or a muffin and equal to daily intake based on a 2014 national survey and Food and Drug Administration filings, researchers said.

The study participants who drank the sweetened water had average erythritol levels increase more than 1,000 times compared to their pre-consumption levels. The study also reported participants showed a significant increase in blood clot formation after consuming erythritol. No such change was observed in the group members who drank glucose.

The new study does not specify how long consumers might face a heightened risk for clotting after eating food or drinking beverages with the sugar substitute.

Rather than erythritol, Hazen advised consumers to opt for moderate amounts of natural sweeteners containing sugar, glucose, honey or fruit. Natural sweeteners don't put consumers at heightened risk for clotting, "whereas we think that will happen in the days following erythritol ingestion" he said.

Research 'should not alarm consumers'

Researchers not involved in the study said consumers should not be alarmed by the findings of this study.

Alice H. Lichtenstein is a professor and director of the cardiovascular nutrition laboratory at Tufts University in Boston. She said the study should be interpreted within the context of other reports on the topic because no single study dictates policy.

"We do not know enough about the overall effect of non-nutritive sweeteners vs. sugar to accurately assess their relative effects on health outcomes," Lichtenstein said.

Lichtenstein said there's a need to better evaluate how much sweetener people can safely consume. She said risks and benefits should be analyzed by comparing "non-nutritive" sweeteners to sugar for factors such as body weight, dental health and heart risk.

She advised people to drink water and seltzer and limit consumption of foods or beverages packed with sugar or sweeteners.

"As much as possible, choose whole foods in their natural state and use common sense," Lichtenstein said.

Joanne Slavin, a professor in the department of food science and nutrition at the University of Minnesota-Twin Cities, said consumers should consider the risks and benefits in choosing alternative sweeteners.

"This study adds another piece to the puzzle, but should not alarm consumers that they are risking their health," Slavin said.  "It is easy to avoid alternative sweeteners, but they are useful tools for diabetics and others who need to avoid digestible carbohydrates."

Food industry defends erythritol

Food industry groups criticized the Cleveland Clinic study, citing the limited number of participants and the amount of erythritol participants consumed.

The 10 research participants were given an erythritol dosage two to three times the amount that is typically found in an 8- or 16-ounce beverage sold in the United States, said Carla Saunders, president of the Calorie Control Council, a group that represents the low- and reduced-calorie food and beverage industry.

Saunders noted that researchers measured erythritol levels just once after participants consumed the sweetened beverages and the study did not control for lifestyle factors that might have affected results.

Because erythritol levels were measured before and 30 minutes after consumption, "there is no way to demonstrate any lasting effect of excessive consumption on any health outcome," Saunders said.

The Calorie Control Council said more than 250 food and beverage manufacturers use erythritol as a sweetener in alcoholic beverages, snacks, pet food and supplements.

"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," Saunders said.

But Hazen said his most recent study is not "standing in isolation" and said there's growing evidence of potential harms.

"I'm hoping this will be a call to arms for more research on this topic, especially given how prevalent and ubiquitous erythritol is as an artificial sweetener," Hazen said.

This article originally appeared on USA TODAY: Popular artificial sweeter linked to blood clots and heart disease, study says