A Sugar Replacement May Be Linked to Heart Attacks and Strokes. Don’t Throw Out Your Stash Yet

Sugar replacements are everywhere in foods and beverages. But despite their ubiquity, the scientific verdict on whether or not they pose health risks ping pongs back and forth. Every so often, though, a study is published with a conclusion so shocking that it forces people to reassess their pantries. A Feb. 27 study published in the journal Nature Medicine now seems to have dealt such a blow to the sweetener erythritol, with data that suggest a connection between the ingredient and cardiovascular events such as clotting, stroke, and heart attacks.

But before you clear your shelves of all erythritol-containing products, bear in mind that no single study—including this one—should be taken as the final word on whether a product is healthy or not. The research is still evolving.

The researchers recruited multiple groups of people with preexisting cardiac risk factors across the U.S. and Europe, and tracked their health over time after taking blood samples to measure the amount of various compounds in the body. Stanley Hazen, director of the Center for Cardiovascular Diagnostics and Prevention at the Cleveland Clinic Lerner Research Institute, says that his team had no real intention to study erythritol, and instead stumbled across their new findings. “Our original intent was to see if we could find compounds in blood whose levels predict the future development of heart attack, stroke or death,” he says. “When looking at the data, the very top-ranking compound…was erythritol.” Of the 4,000 people included in the study’s dataset, those who had high levels of erythritol in their blood were more likely to suffer a major cardiac event within three years than those with lower levels.

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The study includes multiple other experiments to elucidate the connection between erythritol and heart disease—including feeding the sweetener to mice, which the researchers found promoted the formation of blood clots, and feeding it to eight people, which showed researchers that it was still present in blood plasma after a day of fasting. Further experiments, which included exposing blood, platelets, and plasma in a lab to erythritol, all showed the same clotting risk; on washed human platelets, an increased collagen “stickiness” was almost instantly apparent. The amounts of erythritol they tested in these lab experiments were “completely within the range of what we’re seeing in the [blood] circulation of patients,” says Hazen. “And the effect is quite rapid. Just being in the presence of erythritol for minutes was all that was necessary to change platelet function and make them more prone to clot.”

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Erythritol is considered one of the more “natural” sugar substitutes that has emerged as an alternative to the artificial options popularized throughout the last half century. This older group of synthetic sugar substitutes includes sucralose (found in the original version of Splenda), saccharin (found in Sweet’N Low), and aspartame (found in Equal, Nutrasweet, and more). While these artificial options are generally considered to be safe in small amounts, studies on animal models (and some observational research in humans) have linked them to varying heath risks. Aspartame, for instance, has been found to have a potentially causal relationship with cancers, while long-term saccharin consumption has been tied to obesity, diabetes, and other conditions in animal models.

Over the last decade or so, food manufacturers have started favoring more “natural” types of non-sugar sweeteners to help skirt these potential health concerns. This category includes sweeteners such as stevia leaf and monk fruit extracts, along with erythritol and other sugar alcohols, or polyols—recreations of low-calorie substances found in fruits and plants. (If you shop at a typical grocery store, there’s a pretty strong chance you have something with erythritol in your kitchen right now.) Erythritol is also popular as a keto-friendly sugar substitute in baking, as it’s known for having a less artificial aftertaste than some other sweeteners. Despite thorough research, erythritol and other polyols have not been previously linked to any long-term health risks or disease, though in the short term they can cause laxative effects and other gastrointestinal issues.

But when figuring out how concerned to be about the current study, it’s important to know that the appearance of erythritol in the blood before a cardiac event doesn’t necessarily mean that erythritol is causing the event. Previous research has found that excess erythritol—which is also made and metabolized by the human body—tends to stick around in higher concentrations in blood before a cardiac event, pointed out London-based dietitian Nicole Guess in an Instagram post about the study. Erythritol in the body can be an indicator for cardiometabolic disease, but it’s unclear whether that volume is determined by diet or by what the body has that it just isn’t getting rid of.

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Erythritol production in the body has even been shown to increase when a person is under oxidative stress—a state that often leads to sickness, says Dr. Idrees Mughal, a British physician with a masters in nutritional research. These potentially confounding variables mean that the scary headlines about erythritol don’t always match the more complicated reality, since correlation is not causation. “I think the major problem with the media outlets was simply the statement that was being made, which was the consumption of this sweetener was the reason for the increased risk of the strokes or the heart attacks,” he says.

Experts have also taken issue with the fact that the dataset used for the analysis included only people over the age of 60, all of whom had preexisting cardiovascular diseases or qualified as high risk for developing them.

Of course, definitively linking erythritol intake and heart disease would be difficult to do. “You’re not going to easily do a randomized trial where your intent is to try to see whether or not you cause a heart attack,” Hazen says.

So should people give up their erythritol-containing snacks? “At this point, I’d argue to certainly avoid erythritol, and not to be worried or upset about very modest amounts of sweeteners that are natural,” such as honey or pure sugar, says Hazen. In his opinion, reducing the intake of sweets is safer and more effective than using a sugar substitute. For those looking to lose weight, for instance, the data do not bear out that skipping sugar in favor of low- and no-calorie alternatives actually contributes to weight loss. Yet eating too much sugar has health risks, Mughal adds, and in his opinion, “the associated risks of excess refined sugar far outweigh any of the sweeteners.”

The bottom line? Like so many foods that are the focus of nutrition research, more research is needed before you purge your pantry.