What does other research 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 erythritol.

In a paper in 2017, Hiller and colleagues showed 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 . ... 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.

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.