One night in 1879, while eating dinner, Constantin Fahlberg noticed that the bun he was biting into was incredibly sweet. But a lot. At first he thought the baker was wrong, but then he took another bite of another part of the bun and saw that it tasted normal. What was going on? The Russian chemist working at John Hopkins University did not wash his hands when leaving the laboratory and discovered saccharin purely by chance.

Since then, the promise of non-nutritive sweeteners (“sweetness and no calories”) has been constant.

Are these sweeteners really inert?. The key to these chemicals was that they were thought to be absolutely inactive in the body; that is, it had no effect on him. We felt the taste, but nothing more: when they entered, they are gone. The problem is that many researchers have long suspected that this is not the case. The idea that non-nutritive sweeteners make you fat is almost an urban legend: it’s a very repeated story, but there’s little scientific evidence behind it.

To be precise, in most cases it’s not just a lack of studies on whether such sweeteners are fattening; is that it is not known how they can do this because they are inactive (beyond some undefined psychological mechanism). Now, a team from the Weizmann Institute of Science and the German National Cancer Center has discovered how at least two of these sweeteners can affect us.

How did they do?. The approach is interesting: Researchers found 120 people who didn’t consume (rather strictly) non-nutritive sweeteners, divided them into groups so some continued without consuming those sweeteners, and others started doing so. Then, to avoid problems, the researchers transferred microbial samples from these humans to mice reared in completely sterile conditions (i.e. without gut microbes).

And what did they discover? “The results were pretty surprising,” said the lead researcher. They were Elinavinav.. “When we transfer to these sterile mice the microbiomes of the individuals who consume [sacarina y sucralosa]”This has not happened with all sweeteners: with saccharin and sucralose alone. Nutrient sweeteners can, at times, cause glycemic changes in consumers in a highly personalized way.”

The final results of these glycemic changes are not very clear, really; but it seems clear that we have to start assuming that these sweeteners will be many things, but not ineffective. Francisco Guarner, director of the Digestive System Research Unit at the University Hospital of Vall d’Hebron, told SMC Spain “one acceptable result, which is also important: that a substance is not absorbed and therefore passes into the blood does not mean that it is inert. The substance is thick. affects the microbiota of the gut and can cause negative or positive changes”. Everything else is still controversial, although it overlaps with other recent studies.

But I shouldn’t. And in many parts of the world, these products have been consumed in large quantities for years; something that justifies the little research we’ve managed to accumulate on this subject. Even this study does not give us a global vision on the subject. As Ascención Marcos, a researcher at CSIC, points out, “This is good work. But, as always, you can always see ‘obsessions’. Only four of the 19 EU-approved sweeteners are in this article, so no at all. The result is unpredictable”.

Image | Alexander Gray