Non-caloric sweeteners such as saccharin or sucralose impair sugar metabolism and raise blood sugar levels higher than usual. This is the conclusion reached by a research group headed by Jotham Suez from the Israeli Weizmann Institute of Science. According to the study published in the journal Cell, for which the researchers examined the sugar metabolism of humans and mice, this is related to changes in the intestinal microbiome.
For their experiment, the biologists looked for subjects who, without exception, did not use sweeteners. Easier said than done given the widespread use of no-calorie sugar alternatives. Still, the team eventually found 120 such volunteers. They divided them into six groups. Four of them were to take tablets with saccharin, sucralose, aspartame or stevia every day for two weeks, the remaining test subjects were divided into two control groups.
Before, during and after the participants underwent several glucose tolerance tests. To do this, they drank 50 grams of the simple sugar dissolved in water on an empty stomach. With a continuously measuring sensor of the kind used by diabetics, the researchers were able to determine how sugar intake affected blood sugar levels.
Glucose enters the blood through the intestinal wall and causes the blood sugar level to rise. This spike was significantly higher in the saccharin and sucralose groups than before the start of the experiment. However, as soon as the subjects stopped consuming sweeteners on a regular basis, the blood sugar response returned to normal after a few days.