Artificial sweeteners could cause spikes in blood sugar, glucose intolerance

Artificial sweeteners might be triggering higher blood sugar levels in some people and contributing to the problems they were designed to combat, such as diabetes and obesity, according to new findings published Wednesday in the journal Nature.

Although the precise reasons behind the blood sugar changes remain uncertain, researchers suspect that artificial sweeteners could be disrupting the microbiome, a vast and enigmatic ecosystem of bacteria in our guts.

In a series of experiments, researchers found that several of the most widely used types of non-calorie sweeteners in food and drinks - saccharin, sucralose, and aspartame - caused mice to experience increased risk of glucose intolerance, a condition that can lead to diabetes.

"We are talking about very dramatic increases," said one of the study's coauthors, Eran Segal, a computational biologist at the Weizmann Institute of Science in Israel.

The same scientists also monitored what happened to seven human volunteers who did not typically use artificial sweeteners but were given regular doses of saccharin over the course of a week. Four developed significant glucose intolerance, and the others saw no blood sugar benefits from using artificial sweeteners. Separately, the researchers analyzed nearly 400 people and found that the gut bacteria of those who used artificial sweeteners was noticeably different from people who did not.

Wednesday's findings add an intriguing new dimension to the long-running debate over the potential health benefits and risks of artificial sweeteners, which are consumed by hundreds of millions of people across the globe.

While some past studies have found that the products pose no health risks and effectively help people cut calories and sugar intake, other research has suggested that certain artificial sweeteners might actually contribute to obesity and other problems, including cancer.

Segal and Elinav insisted that their findings are preliminary and shouldn't be taken as a recommendation on whether people should reconsider using artificial sweeteners.

"We do not view that as our role," Segal said. "Rather, as scientists, we simply point to the immense body of experiments that we carried out in both humans and in mice. . . . This study and these results should prompt additional debates and study into what is currently a massive use of artificial sweeteners."