Common low-calorie sweetener may be riskier for the heart than sugar, study suggests

Another study is raising concerns about the safety of the widely used sugar and alcohol sweetener erythritol, a low-calorie sugar substitute found in “keto-friendly” foods, baked goods and sweets. Researchers at the Cleveland Clinic compared erythritol to typical sugar and found that only erythritol caused concerning cardiovascular effects.

Although the study was small, it is the first comparative analysis of people’s blood levels after consuming products with erythritol or sugar (glucose).

“We compared the results and glucose didn’t cause any of the problems,” said Dr. Stanley Hazen, a cardiologist at the Cleveland Clinic and lead author of the study, published Thursday morning in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.

Erythritol is one ingredient in a growing list of sugar-free sweeteners found in low-calorie, sugar-free foods. Erythritol and xylitol are sugar alcohols that are sweet like sugar but have much fewer calories. Erythritol is often mixed with another sweetener, stevia, and xylitol is often found in gum, mouthwash, and toothpaste.

Previous studies from Hazen’s laboratory – one published last year and the other in June – found potential links between sugar alcohols and an increased risk of heart attacks and strokes. Research has suggested that both sugar alcohols can make blood platelets stickier and therefore more susceptible to clotting and blockage of veins or arteries, in turn contributing to heart attacks and strokes.

For the new research, Hazen’s team looked at the cardiac effects of erythritol and regular sugar — in this case, simple glucose — by recruiting two groups of healthy, middle-aged male and female volunteers: 10 who consumed erythritol and 10 who consumed sugar.

Both groups fasted overnight. In the morning, blood was collected to measure platelet activity. Then, half of the volunteers drank glasses of water with 30 grams of glucose mixed in and half drank glasses of water with 30 grams of erythritol. Hazen said 30 grams of erythritol is a typical amount for foods sweetened with erythritol.

About 30 minutes after each group consumed the sugary drinks, 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 showed no changes in platelet aggregation.

The researchers measured a 1,000-fold increase in blood erythritol levels in the group that received the erythritol drink. Those who drank glucose water had no change in blood erythritol levels, and their blood glucose levels increased only slightly. The discovery caught Hazen’s attention because it far exceeded the trace levels of erythritol that naturally occur in the blood.

“The amount of sugar substitutes is thousands of times greater than what is produced in our bodies, so calling it ‘natural’ is not it,” he said. “Your best recommendation is to avoid sugar substitutes, and sugar alcohols in particular, because there is an acute increase in the likelihood of clotting events after ingesting them.”

The Food and Drug Administration considers artificial sweeteners, including erythritol and xylitol, to be GRAS, or generally recognized as safe. Hazen hopes that growing evidence about sugar alcohols could prompt the FDA to look at the data more closely.

Outside the US, the concerns have attracted interest 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 findings 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 lead to high blood glucose levels, which are also associated with stroke and clotting risks. Hedrick was not involved in the Cleveland Clinic study.

The study has several important limitations. In addition to the small number of participants, it measured the effects of erythritol and glucose only at a certain point in time, as opposed to months or years of consistent consumption, Hedrick noted.

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, generally contain more sugar.

For example, a 12-ounce can of Coca-Cola contains 39 grams of sugar and a 12-ounce can of Mountain Dew contains 46 grams.

Michael Goran, professor of pediatrics at the University of Southern California’s Keck School of Medicine, said it may also be worth comparing erythritol to fructose and glucose. The combination of fructose and glucose is more typical in juices and sugary sodas than glucose alone, he said. Goran was not part of the new study.

Hazen’s study looked only at glucose.

Although the Cleveland Clinic study found no negative effects from sugar consumption, the researchers agreed that the data doesn’t mean sugar is in the clear. Larger amounts of sugar can cause similar platelet effects, especially in people with diabetes, who cannot effectively regulate high blood glucose levels.

Hazen’s study focused specifically on healthy people, not people with diabetes.

It may also be important to look at whether cardiac effects differ when people consume foods with erythritol versus water with erythritol, said Dr. Michelle Pearlman, a gastroenterologist who is CEO and co-founder of the Prime Institute in Miami.

“Factors such as protein, fat, fiber and other nutrients can influence this response,” she said.

Ultimately, Virginia Tech’s Hedrick said, the new study highlights the need for more research comparing the health effects of sweeteners versus sugar.

Hazen and his colleagues concluded the research by calling for more studies focusing on erythritol’s cardiac risks, particularly in people who are already at higher risk for stroke and clotting.