Erythritol, a popular sugar substitute found in ketogenic diet products, sweets and low- or no-calorie diet drinks, may increase the risk of heart attack and stroke, according to a new study.
A Cleveland Clinic-led study published Thursday in the journal Atherosclerosis, Thrombosis and Vascular Biology found that sweeteners increase platelet activity and increase the risk of blood clots, but that foods sweetened with sugar did not have the same effect.
The study was small, involving only 20 patients, and researchers not involved in the study say the findings should be interpreted with caution.
Erythritol is a zero-calorie sugar substitute used as a sweetener in hundreds of products, including protein bars, yogurt, cookies, and ice cream. It is a thickening agent similar to sugar and is the primary sweetener in the low-carb, high-fat keto diet. In 2001, the Food and Drug Administration Decided Erythritol is “generally recognized as safe.”
But the researchers said that participants in a National Institutes of Health-funded study who drank water sweetened with erythritol showed signs of activated platelets, but those who drank water sweetened with glucose did not see the same effect.
“Drinking erythritol-sweetened beverages increases the risk of blood clotting and alters platelet function in all subjects tested,” said cardiologist Dr. Stanley Hazen, director of cardiovascular and metabolic sciences at the Cleveland Clinic’s Lerner Research Institute.
The findings follow a larger 2023 study, also led by Hazen, linking the popular sugar substitute to cardiovascular disease. Last year’s study examined blood samples from more than 1,100 people who underwent cardiac risk assessments over a three-year period, and followed up with a separate group of more than 2,100 non-emergency patients. The study showed that erythritol was associated with an increased risk of heart attack, stroke and death. It also found that the sweetener caused blood clots in mice that consumed it.
Sweeteners and sugar
Hazen said he began asking his team what kinds of sweeteners people should eat or drink instead of erythritol after the 2023 study. The team wanted to compare the risk of blood clots for consumers who drank liquids 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 fasting overnight, participants had their blood tested before and 30 minutes after drinking 30 grams of glucose or water sweetened with erythritol. This dose is roughly the amount found in an erythritol-sweetened soda or muffin, and is comparable to the daily intake based on a 2014 national survey and Food and Drug Administration filing, the researchers said.
The average erythritol levels of the subjects who drank the sweetened water increased by more than 1,000 times compared to before ingestion. It was also reported that after consuming erythritol, the subjects’ blood clot formation increased significantly. No such changes were observed in the members of the glucose group.
The new study does not clarify how long consumers may be at increased risk of blood clots after consuming foods or drinks containing sugar substitutes.
Hazen urges consumers to consume moderate amounts of natural sweeteners, including sugar, glucose, honey and fruit, instead of erythritol. Natural sweeteners do not increase consumers’ risk of blood clots, but “erythritol consumption appears to increase the risk of blood clots several days afterward,” he said.
Research “should not alarm consumers”
Researchers not involved in the study said consumers should not be surprised by the findings.
Alice H. Lichtenstein, professor and director of the Cardiovascular Nutrition Institute at Tufts University in Boston, said the study should be interpreted in the context of other reports on the topic, because no single study can dictate policy.
“We don’t know enough about the combined effects of nonnutritive sweeteners and sugar to accurately assess their relative contributions to health outcomes,” Lichtenstein said.
Lichtenstein said there needs to be a better assessment of how much sweetener people can safely consume, and there should be a risk-benefit analysis comparing “non-nutritive” sweeteners with sugar on factors such as weight, dental health and heart risk, she said.
She advised people to drink water or soda and limit their intake of foods and drinks that are high in sugar and sweeteners.
“Choose whole foods whenever possible and use common sense,” Lichtenstein says.
Joan Slavin, a professor in the food science and nutrition department at the University of Minnesota, Twin Cities, said consumers should consider the risks and benefits when choosing alternative sweeteners.
“This study adds another piece to the puzzle, but it doesn’t signal that consumers should be alarmed that they are putting their health at risk,” Slavin said. “Avoiding alternative sweeteners is a simple but useful step for people with diabetes and others who need to avoid digestible carbohydrates.”
Food Industry Defends Erythritol
Food industry groups criticized the Cleveland Clinic study because of the limited number of participants and the amount of erythritol they ingested.
The 10 study participants were given two to three times the amount of erythritol typically found in an 8- or 16-ounce beverage sold in the United States, said Carla Sanders, president of the Calorie Control Council, an organization that represents the low- and reduced-calorie food and beverage industry.
Sanders noted that the researchers only measured erythritol levels once, after participants consumed the sweetened beverage, and the study did not take into account lifestyle factors that may have influenced the results.
Because erythritol levels were measured before and 30 minutes after ingestion, “there is no way to prove any lasting health effects from excessive consumption,” Sanders said.
The Calorie Control Council said more than 250 food and beverage manufacturers use erythritol as a sweetener in alcoholic beverages, snack foods, pet foods and supplements.
“Consumers need to rely on the science, and for 30 years the science has proven that erythritol is a safe and effective option for reducing sugar and calories,” Sanders said.
But Hazen said his latest study “is not an isolated study” and adds to growing evidence of potential harm.
“Given the widespread and ubiquitous nature of erythritol as an artificial sweetener, we hope this will spur further research on the topic,” Hazen said.
