NBC News
A new study raises questions about erythritol, a sweetener widely used as a low-calorie sugar substitute and found in keto-friendly foods, baked goods, and candy. A Cleveland Clinic study compared erythritol and sugar and concluded that only erythritol caused concerning cardiovascular effects. Although the study sample was small, it is the first comparative analysis of blood levels in people who consume products containing erythritol or sugar (glucose).
“We compared the results, and glucose did not cause any of the problems,” says Stanley Hazen, a cardiologist at the Cleveland Clinic and senior author of the study, published Thursday in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.
Erythritol is one of a growing list of non-sugar sweeteners found in low-calorie and sugar-free foods. Erythritol and xylitol are sugar alcohols that are sweet like glucose but with far fewer calories. Erythritol is often mixed with another sweetener, stevia, and xylitol is often found in chewing gum, mouthwash, and toothpaste.
Previous studies from Hazen’s lab — one published in 2023 and another in June — found possible links between sugar alcohols and an increased risk of heart attacks and strokes. The research suggested that both sugar alcohols might make blood platelets stickier and therefore more likely to clot and clog veins or arteries, contributing to these conditions.
For the new research, Hazen’s team looked at the effects of erythritol and sugar — in this case, glucose — on the heart by recruiting two groups of healthy volunteers, middle-aged men and women: 10 took erythritol and 10 took sugar.
Both groups fasted overnight. In the morning, blood was drawn to measure platelet activity. Half of the volunteers then drank glasses of water with 30 grams of glucose mixed in, and the other half drank glasses of water with 30 grams of erythritol. Hazen explained that 30 grams of erythritol is a typical amount for erythritol-sweetened foods.
About 30 minutes after each group drank the sugary drinks, their blood was drawn and tested again. Researchers found that people who consumed erythritol had increased platelet aggregation, meaning their blood was more likely to clot. Adults who drank the regular sugary drink had no changes in platelet aggregation.
The researchers measured a 1,000-fold increase in blood erythritol levels in the group that drank the erythritol drink. Those who drank the glucose water had no change in blood erythritol levels, and their blood glucose levels only rose slightly. The finding caught Hazen’s attention because it far exceeded the trace levels of erythritol that occur naturally in the blood.
“The amount contained in sugar substitutes is thousands of times greater than what our body produces, so calling it natural“That is wrong,” he said. “The best recommendation is to avoid sugar substitutes, and sugar alcohols in particular, because there is an acute increase in the likelihood of clotting events once you ingest them,” he added.
The Food and Drug Administration (FDA) considers artificial sweeteners, including erythritol and xylitol, to be GRAS, or generally recognized as safe. Hazen hopes that the growing evidence on sugar alcohols will lead the FDA to take a closer look at the data.
Outside the United States, concerns have already raised concerns among food regulators. Last year, for example, the European Food Safety Authority recommended that the European Commission request data on the amount of erythritol present in foods, which could help clarify the risks.
Do the results indicate that erythritol is worse overall than high-calorie sugar? Valisa Hedrick, a registered dietitian at Virginia Tech, said a diet high in sugary foods can raise blood glucose levels, which is also linked to the risk of stroke and blood clots. Hedrick was not involved in the Cleveland Clinic study.
The study has several important limitations. In addition to the small number of participants, the effects of erythritol and glucose were measured at a single point in time, rather than over months or years of consistent consumption, Hedrick said.
And the amount of glucose in sugar water — about 30 grams — is equivalent to about 120 calories of sugar. Sugary drinks, especially juices and sodas, tend to contain more sugar.
For example, a 12-ounce can of Coca-Cola contains 39 grams of sugar, and 12 ounces of Mountain Dew contains 46 grams.
Michael Goran, a professor of pediatrics at the Keck School of Medicine at the University of Southern California, said it’s worth comparing erythritol to fructose and glucose. The combination of fructose and glucose is more typical of sugary juices and soft drinks than glucose alone, he said. Goran was not involved in the study, which looked only at glucose.
Although the Cleveland Clinic study found no negative effects from sugar consumption, researchers agreed that the data doesn’t mean sugar is safe. Higher amounts of sugar can cause similar effects on platelets, especially in people with diabetes, who can’t effectively regulate high blood sugar. Hazen’s study focused specifically on healthy people, not diabetics.
It may also be important to look at whether the effects on the heart differ when people consume foods containing erythritol compared with water containing erythritol, said Dr. Michelle Pearlman, a gastroenterologist and director and co-founder of the Prime Institute in Miami.
“Factors such as protein, fat, fiber and other nutrients could influence this response,” he added.
Ultimately, said Virginia Tech’s Hedrick, the new study underscores the need for more research comparing the health effects of sweeteners versus sugar.
Hazen and his colleagues concluded their research by urging more studies focusing on the cardiac risks of erythritol, particularly in people who are already at increased risk for stroke and blood clots.
