By Sarah Jacoby

Erythritol is a sugar substitute found in many low-calorie and diet-friendly foods and drinks. But new research suggests the compound may have an unexpected link to heart disease.

The study, published last week, suggests that erythritol may play a role in blood clotting, and consuming a large amount of erythritol can increase the risk for two days or more afterward. While that link isn't conclusive, it's worth keeping an eye on how much erythritol — and other sugar substitutes — you consume on a regular basis.

What is erythritol?

Erythritol is what's known as a reducing sugar or sugar alcohol, said Dr. Stanley Hazen, chairman for the department of cardiovascular and metabolic sciences in the Lerner Research Institute and co-section head of preventive cardiology at the Cleveland Clinic.

“It tastes very similar to sugar, but we don’t derive calories from it,” he explains.

Sugar alcohols, including erythritol, and other artificial sweeteners “have actually been fairly well studied because we’ve seen such an increasing use of them in the food supply,” said Whitney Linsenmeyer, Ph.D., R.D., a spokesperson for the Academy of Nutrition and Dietetics and assistant professor at Saint Louis University.

That long-term research has been mixed overall, but the Food and Drug Administration considers sugar alcohols “perfectly safe for human consumption,” she says.

It's a particularly popular sugar substitute because it behaves a lot like sugar in cooking or baking, Hazen says, and it can be used as a "bulking sugar" in products alongside other sweeteners — like stevia, monk fruit and other sugar alcohols — to make them taste a bit better.

Our own bodies also make erythritol in response to high glucose levels, said Susie Swithers, Ph.D., professor in the department of psychological sciences at Purdue University. It usually stays inside your cells and helps to make energy, but some of it leaks out into your bloodstream, Hazen adds, and different people have different circulating levels of erythritol in their bodies.

Erythritol is also found in some foods naturally, like watermelon and some fermented foods, Hazen says. However, in those foods it’s present in much smaller amounts than you’d find in an artificially sweetened drink or dessert, he adds.

For those reasons, it's debatable whether or not erythritol falls into the "artificial" sweetener category, Swithers explains, and products that have erythritol in them may say they contain only natural sweeteners on the packaging.

Companies still need to list erythritol in the full list of ingredients, though, she says. But if there are two or more types of sugar alcohols in a product, the label won't necessarily list them independently, Linsenmeyer says. Instead, they might be listed simply as "sugar alcohols."

But when we're talking about erythritol in day-to-day life, we usually talk about it as an artificial sweetener commonly found in diet foods and drinks. And it's become increasingly popular over the last decade.

More and more, erythritol is "being used as the carrier with other artificial sweeteners," Hazen says. "In the keto food world and in the zero sugar world, it has been the darling of artificial sweeteners and really taken off in the past 10 years."

Common side effects of erythritol

The reason why sugar alcohols are so useful as alternative sweeteners is that "our bodies do not metabolize them particularly well," Swithers explains. "So we consume them and then we excrete them. And because we're not metabolizing them, we're not getting any energy or calories from them."

But that also leads to the "gastrointestinal distress" that some people might feel after ingesting a large amount of food or drinks containing sugar alcohols, she says.

So, as with any of the sugar alcohols, erythritol can cause gastrointestinal side effects such as:

-Bloating.

-Loose bowels.

-Diarrhea.

Compared to other sugar alcohols, though, erythritol tends to cause these issues less often, Hazen says. "That's really more frequent with xylitol," Linsenmeyer says. And products containing sorbitol and mannitol must have a warning on the label that they "may cause a laxative effect," the FDA says.

Erythritol and heart issues

A new study, published last week, found a strong association between erythritol and the risk for heart attacks and strokes.

In the first part of the study, researchers looked at blood test results from about 1,100 patients undergoing a cardiac risk assessment. They found that those participants with elevated levels of erythritol in their blood were more likely to have cardiac issues, such as heart attack or stroke, over a three-year period.

The researchers then repeated those findings in targeted analyses of 2,100 participants in the U.S. and 830 in Europe, all of whom were undergoing cardiac assessments for possible heart issues. From there, the researchers conducted lab studies and found that erythritol can induce platelet activity (which leads to clotting), and clotting itself in mice.

Finally, the researchers gave a group of eight healthy volunteers a drink containing erythritol and saw strikingly high levels of erythritol in their bodies for two days afterward.

"The plasma levels of erythritol were sky high," says Hazen, one of the study authors, "and above the threshold at which it causes heightened clotting risks." (Participants were given a 30 mg dose of erythritol, which is roughly equivalent to the amount in a pint of keto-friendly ice cream or a few erythritol-containing cookies, Hazen says.)