Sugar substitute erythritol, common in keto foods, may increase your risk for stroke

A sweetener found in nature and often added to diet products, particularly for the ketogenic diet, may actually contribute to clogged arteries and strokes, a new study suggests.

People with the highest level of the sugar substitute erythritol in their blood were shown to have twice the risk for stroke, blood clot or death compared with those with the lowest level.

Animal and lab studies reinforced the idea that erythritol might cause clots, said Dr. Stanley Hazen, who led the research and chairs the department of cardiovascular and metabolic sciences at the Cleveland Clinic.

"The very group of people most vulnerable to experiencing adverse cardiac events are the ones we're recommending these kinds of dietary foods for," he said.

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What is erythritol?

Erythritol, considered a sugar alcohol, has no calories and is found naturally at low levels in some foods, including grapes, mushrooms, pears, watermelon, beer, cheese, sake, soy sauce and wine.

The sugar substitute is added to many processed foods and beverages and is commonly found in products targeting people on the ketogenic diet because it does not affect blood glucose. Erythritol is also an ingredient in the sweetener Truvia.

Though many sweeteners provide intense flavor and need to be used in small concentrations, erythritol's sweetness is close to that of sugar, so it can be used as a substitute in baking.

The body actually produces erythritol but at levels well below what's found with the added sweetener, according to research from Karsten Hiller, a biochemist and specialist in human metabolism at the Braunschweig Institute of Technology in Germany.

Current federal guidelines do not require that erythritol has to be included on a product's ingredient list, Hazen said. The label might simply say "artificially sweetened with natural products," or "zero sugar."

Study suggests erythritol promotes blood clots

Hazen initially set out to study the factors that lead people to have heart attacks and strokes even when they're treated for high cholesterol, high blood pressure, obesity, diabetes and smoking cessation. Roughly half of treated people have this so-called residual cardiovascular risk.

For the study published Monday in Nature Medicine, his team collected blood from 1,157 volunteers undergoing cardiac risk assessment. They looked for chemical signatures in the blood and tracked who had a heart attack, stroke or died over the next three years.

Erythritol was "at the very top of the list" of compounds that predicted subjects at highest risk for a bad outcome, he said. High blood levels of erythritol seemed to lower the threshold for triggering a clot.

Then the researchers tested the sugar substitute in mice and in human blood in the lab, looking to explain why this might have happened.

That exploration strongly suggests erythritol promotes blood clots. "This is a new pathway we think is contributing to residual cardiovascular risk," Hazen said.

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What does other research on erythritol show?

“The results of this study are contrary to decades of scientific research showing reduced-calorie sweeteners like erythritol are safe,” said Robert Rankin, executive director of the Calorie Control Council, an association representing the low- and reduced-calorie food and beverage industry. The people in the study were at increased risk for cardiovascular problems, Rankin said in a statement, so the results "should not be extrapolated to the general population."

Other studies have also raised questions about the role of erythritol.

In a paper published in 2017, Hiller and colleagues showed that Cornell University freshmen who had a lot of erythritol in their blood at the beginning of their first year gained more weight than students with low levels.

Whether the erythritol was simply a sign someone was likely to gain weight or a cause of it remains a question, said Martha Field, a Cornell researcher who was not involved in the work but has studied erythritol since.

"It predicts your risk for developing disease," Field said. "Theoretically, you can intervene and make changes."

It's not clear whether people with high blood levels of erythritol are consuming more of it or whether something in their body is leading to that excess, Hiller said. But there's no question eating food with the sweetener in it will dramatically boost blood levels.

Erythritol also can convert into an acid called erythronate, which is commonly found in the tissue of many people with cancer, he said.

Initial safety studies on erythritol looked only at short-term exposure and found the body cleared it quickly. Field studied what happens in mice if they consume it chronically, and she found mice that were fed high levels of erythritol for eight straight weeks retained blood levels of erythritol 30 times above normal for at least five hours.

"It seems to be hanging around longer than we've appreciated," she said.

So, should you stop consuming erythritol?

It is too early to definitively say that erythritol causes problems for people who consume it regularly. High blood levels of erythritol might simply be a marker of problems to come rather than a cause of them.

But in the meantime, Hiller, Hazen and Field all said they intend to stay away from it as much as they can.

Hiller said the U.S. Food and Drug Administration should reconsider its classification of the sugar substitute as "generally recognized as safe" and should study it further.

"At the current knowledge we have, I would not recommend people use it."

Contact Karen Weintraub at

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This article originally appeared on USA TODAY: Sweetener erythritol may increase risk for stroke, blood clot, death