Óscar de la Calle-Martín
Specialist in Immunology at the Hospital de Sant Pau in Barcelona and secretary of the Spanish Society of Immunology
The study is serious and rigorous, as it should be, given that it has been published in one of the world's leading scientific journals. That the study has been thoroughly reviewed by the editorial team and peer-reviewed can be concluded by looking at the date at which it was originally submitted (2021) and at which it has been deemed acceptable for publication (2023); rarely does more than a year go by in this process. This suggests that the authors have been forced to perform multiple additional experiments, probably those in human cells, and in the animal model of diabetes.
The conclusions are well documented by a varied set of experiments in each case. The evidence from controls is also irrefutable. The immunosuppressive effect of sucralose is on T-cell function and differentiation and does not affect other elements of the immune system.
Current evidence indicates that the replacement of natural sugars (glucose and sucrose, fructose being a case apart) by artificial sweeteners (saccharin, aspartame, cyclamate) has no beneficial effect, not even in protecting against obesity, but rather the opposite. In the case of sucralose, a very potent artificial sweetener, we also found an immunosuppressive effect, which would be enough to call into question its use in human food.
The limits have been taken into account not only by the authors with multiple experiments, but also by the editors and reviewers who have forced the former to introduce new sets of experiments, as well as controls probably using human cells. The dose range used in mice probably generates levels of sucralose similar to those that can be obtained by ingesting foods containing this synthetic sweetener. Therefore, studies should be done in people who ingest large amounts of sucralose and what effect it has on their immune system. Also, the possible benefit of sucralose intake in people with autoimmune diseases should be explored. The chosen model of diabetes is not currently useful for diabetic patients.