A new study found that mice fed high levels of sucralose showed lowered activation of T cells — an immune system component. The scientists say that although reduced T cell activation might not be ideal in conditions like cancer, it could benefit inflammatory conditions like autoimmune disease or diabetes.
Artificial sweeteners, like sucralose, are commonly used in food and drinks to keep calories low without sacrificing sweetness. Sucralose, in particular, is around 600 times sweeter than sugar, and its chemical structure prevents it from being absorbed in the digestive tract.
Although considered safe, one 2022 study found that sucralose consumption may alter the gut biome in some people. Still, its impact on the body remains unclear.
Researchers from the Francis Crick Institute in London recently investigated sucralose consumption's effects on the immune system. The study, published on March 15 in the journal Nature, found that consuming high levels of sucralose lowered the activation of T cells in mice.
During their initial investigation, the scientists noticed when they fed sucralose doses close to the maximum acceptable daily intake to cancer and infection mouse models, the rodent’s T cell response decreased, and they were less able to activate these immune cells in response to cancer or infection.
"So, this prompted us to test whether sucralose could have any potential therapeutic effect in the context of T cell mediated autoimmunity," says co-first author Julianna Blagih in a March 14 Nature press briefing.
"We [then] turned to a type 1 diabetes [mouse] model and a colitis model, and we found that at very high doses of sucralose, we observed outcome T cell responses and reduced inflammation, and overall, this was beneficial for the mouse," Blagih adds.
During the briefing, Fabio Zani, co-first author and postdoctoral training fellow at Francis Crick, notes, "100% of the mice that were fed with normal water were diabetic. We still have somewhere between 35– 50% of mice […] fed with sucralose that were diabetes free."
However, when the team removed sucralose from the rodent’s diet, their immune responses returned to normal.
In the press briefing, the study authors suggest that if the effects of high-dose sucralose are similar in humans, this discovery could lead to potential therapies for T cell mediated autoimmune diseases, type 1 diabetes, Crohn’s disease, and T cell mediated organ rejection.
Still, in certain conditions — such as cancer — sucralose-induced lowered T cell responses might not be beneficial.
The scientists note that the maximum amount of sucralose accepted by the European Food Safety Authority is 15 milligrams per kilogram of bodyweight. In contrast, the FDA’s accepted level is 5 milligrams per kilogram of bodyweight.
In the briefing, Zani notes, "nothing suggests that intake of sucralose is dangerous or should be avoided. As soon as we took sucralose away, the mouse immune system normalized."
In addition, it’s difficult for a person to reach the sucralose levels used in the study through dietary intake alone. For example, senior study author and principal group leader at Francis Crick, Karen Vousden, says a person would need to drink about 10 cans of the highest sucralose-containing diet soda or 30 cups of sucralose-sweetened coffee a day to reach the maximum acceptable daily intake.
The study authors say that because their research involved mice, it is unclear what effect sucralose at these levels will have on humans. However, the team hopes to take their work into human trials in the near future.