Study linking sugar substitute ‘erythritol’ to heart attack and stroke is wrong

Sugar-replacing sweeteners can’t stop. First it was aspartame, then sucralose, now erythritol. One by one, a pesky study appears and questions their safety. But there were good reasons to be skeptical about the previous research on aspartame and sucralose, and now there are good reasons to be skeptical about the new research on erythritol.

First, what is erythritol? It is a non-caloric sweetener (meaning it is not used by the body for energy) that is naturally found in small amounts in fruits such as grapes, peaches and pears, as well as other foods such as mushrooms and soy sauce. It is about 70% sweeter than sugar, making it a reliable substitute for everyone’s favorite food treat. Erythritol can be found in many ketogenic diet foods, such as zero-sugar cookies, bars, syrups, and monk fruit extract.

Regular erythritol users were no doubt enjoying their low-sugar lifestyle until the end of February, when a large group of researchers, mostly from the Cleveland Clinic, published a study in natural medicine identifying an association between higher plasma sweetener levels and an increased risk of death and cardiovascular disease such as heart attack and stroke. The researchers followed 2,149 US subjects who sought medical attention for heart problems, as well as 833 European participants who sought the same care. They found that over three years, participants with the upper quartile of plasma erythritol levels were about twice as likely to have major adverse cardiovascular events (MACEs that included stroke, heart attack, or death) compared with participants in the lower quartile. .

This relative opening is shown above in the Kaplan-Meier curve, a very common statistical method that estimates the “survival” of people in a study. In this case, “survival” does not necessarily mean death; instead, it means anyone who has not yet had a stroke or heart attack or died. In other words, if someone has had a stroke but is still alive, they are no longer considered a “survivor” for the purposes of this study.

Fewer people in the top quartile (Q4), i.e. those with plasma erythritol levels between 6 and 46 µM (micromolar), survived over three years compared to people in the bottom quartile (Q1), i.e. those who had a plasma erythritol level of less than 3.75 µM. In other words, people in the Q4 group were more likely to have a heart attack, stroke, or die compared to people in the Q1 group.

In another experiment, researchers showed that erythritol leads to increased blood clotting, potentially clogging blood vessels. They also showed in another experiment that drinking a drink containing 30 grams of erythritol can increase plasma levels to 10,000 µM, before dropping back to below 6 µM after a couple of days. Thus, a person does not need to consume a lot of erythritol to raise their blood levels to levels that the authors consider dangerous to health.

Together, these data seem pretty strong that we should reconsider our high erythritol intake, but outside experts aren’t sure.

Analyzing research on a recent episode The Skeptics’ Guide to the Universe, Dr. Steven Novella, a neuroscientist at Yale University, warned that the study does not establish cause and effect, meaning it is just as likely that people who consume a lot of erythritol are already at higher risk of cardiovascular disease, possibly because that they are overweight and trying to go on a diet. Novella co-host Dr. F. Perry Wilson, a nephrologist at Yale University, added that we shouldn’t think about the results of the study in a vacuum. Even if erythritol does increase the risk of heart attacks and strokes, it still replaces sugar, which almost certainly has more detrimental health effects.

Writing for the American Council on Science and Health, Dr. Chuck Dienerstein pointed to an even bigger reason for the skepticism about the new study. Previous research has shown that the body converts excess glucose into erythritol. So it is possible, even likely, that people with higher plasma erythritol levels have such high levels because they eat too much sugar. Since the new study did not control the subjects’ diet, it cannot be ruled out that the study actually shows that people who eat more sugar have an increased rate of heart attacks and strokes, which is not surprising at all.