Demystifying Science | Are Sweeteners Dangerous?

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There is growing evidence that yes.

“More and more studies are showing the harmful effects of ultra-processed foods, particularly sweeteners, on health,” explains Rémi Rabasa-Lhoret, an endocrinologist at the Montreal Clinical Research Institute (IRCM). “But the list of sweeteners is long and we still need to know more. They are all different, it is difficult to imagine a common mechanism for these harmful effects.”

Last September, in the magazine Diabetes Carea study found that high use of sweeteners increased the risk of type 2 diabetes by 60 percent over a nine-year follow-up period. The sample size is “remarkable,” 100,000 people, and several tests have been done to see if this is truly a causal link, according to Dr.^r Rabasa-Lhoret. The French authors of the study of Diabetes Care warn that people who take a lot of sweeteners may be doing so to counteract unhealthy eating habits.

The study looked at about ten sweeteners, including aspartame, sucralose and saccharin. These low-calorie products are used in foods and drinks that are considered “diet.”

Type 2 diabetes, a risk factor for which is obesity, is caused by the body’s poor use of insulin. It accounts for 90% of diabetes cases.

Another study, published a year ago in Advances in Nutritionnoted that sweeteners are linked to various types of health problems: 25% more cardiovascular mortality, twice as many kidney problems, 13% more cancers, 51% more obesity, 24% more diabetes and 22% more strokes.

This was a meta-analysis of several studies on the topic.

The D^r Edward Giovannucci, a Harvard University epidemiologist and lead author of the latest study, confirms that the biochemical diversity of sweeteners complicates the analysis. “They are so different that it is unlikely that the same harmful mechanisms are at play,” says Dr.^r Giovannucci.

Often, the effects, especially for cancer, are small on an individual level, the Boston researcher notes. “A 13% effect for cancer is large at the population level, but with such a small relative risk, it’s hard to rule out confounding factors.” In some cases, studies seem to show that people who take a lot of sweeteners also diet a lot, so they lose and regain weight regularly, which can be bad for their health.

In 2023, the World Health Organization recommended avoiding sweeteners when trying to lose weight, with diabetics being excluded from this recommendation.

For diabetes, some researchers suggest that sweeteners stimulate the same receptors as sugar and therefore increase the desire to consume certain harmful foods or even alter metabolism. “This is a valid hypothesis; studies have suggested that after eating sweeteners, we have sugar cravings,” says Dr.^r Rabasa-Lhoret.

Lifestyle

The D^r Rabasa-Lhoret points out that lifestyle changes have been shown to reduce the progression from prediabetes to type 2 diabetes by 60%: exercise, losing 5 to 10% of weight, eating more fruits, vegetables and fish, and less fat and meat. “We can also reduce our consumption of ultra-processed products as part of our dietary changes.”

The next step, according to D^r Giovannucci, is to determine the mechanisms that could link sweeteners to health problems. According to him, it could be problems with the microbiota or inflammation.

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