A British research team has shown that sucralose, a food additive, taken in high doses, reduces the effectiveness of T-cell responses, which help the body protect itself from infection and fight cancer. The results of this study do not indicate harmful effects of this sweetener in humans.
Excessive consumption of sucralose reduces the immune response in mice, suggests an article published in Nature. While the results do not prove that normal intake can be immunosuppressive, the research highlights an unexpected effect of high doses on mouse immune responses and functions.
Sucralose is commonly used as a sugar substitute in many food products because it has no calories and is about 600 times sweeter than sugar. It has generally been considered safe. However, for some time now, and especially with studies like this one, the long-term consumption of certain sweeteners has raised some concerns.
Effects of excessive sucralose consumption
To investigate the effects of excessive sucralose consumption, a British research team fed large amounts of the sweetener to mice. “We found that feeding mice with very high doses of sucralose somewhat decreased their ability to properly activate T cells”, explains Karen Vousden, a biologist at the Francis Crick Institute (UK) and author of the article, to SINC. These results “don’t occur with the other sweeteners tested,” she adds. Similar effects have also not been identified in other immune cells.
“In some rodent cancer models or infection models, we observed that the T cell response was attenuated in mice fed sucralose.”, points out the scientist.
Specifically, the administered dose affects intracellular calcium release in response to stimulation and therefore dampens lymphocyte function. These cells are components of the immune system and the high intake of this sweetener reduced their signaling efficiency in the studied mice.
The scientist lists some benefits: “In T cell-mediated autoimmune models of type 1 diabetes and colitis, these very high doses of sucralose limited the development of T cell responses and reduced inflammation.”.
In addition, according to research, the effects of this sweetener are reversible, as T cell responses normalize after withdrawal of the additive.
Often used in the food industry
Sugar substitute sweeteners are very common in many foods. “Sucralose is used in diet sodas and sports drinks, chewing gum, protein bars, yogurts and a wide variety of diet products.”, comments the author of the article.
“Sucralose is also found in Splenda, which many people use for tea and coffee.”, notes.
Regarding the possibility of some negative effect of sucralose ingestion in humans, the Francis Crick Institute team states that they have not studied the consequences of consuming high doses of this type of sweetener in people. “In any case, several recent papers have shown an effect of sucralose on the microbiome, although the precise impact of this has yet to be determined.”, explains the researcher.
Similar consequences for humans of sucralose consumption
If high doses of this sweetener have similar consequences in humans, this could be useful in the development of targeted therapies to dampen T-cell responses. For example, in patients with autoimmune diseases who suffer from uncontrolled activation of T-lymphocytes.
However, Vousden emphasizes that sucralose “has been considered an inert moleculeand that “tests by the food and drug agencies have shown it to be safe.” To add: “Our study does not contradict this statement.”.
For the scientist,Importantly, the amount of sucralose given to the mice was much higher than that obtained by people who simply consumed foods or drinks containing sucralose as part of a normal diet.“. Therefore, he clarifies that his research does not suggest that “sucralose as part of a normal diet is unhealthy or should be avoided“.
The European Food Safety Authority estimates that the maximum acceptable daily intake is 15 milligrams per kilogram of body weight, while the United States Food and Drug Administration recommends not to exceed 5 milligrams.
Study first co-author and former postdoctoral fellow at the Francis Crick Institute, Julianna Blagih, says scientists are currently interested in “explore whether there are other cell types or processes that are similarly affected by this sweetener“.
In turn, Karis Betts, head of health information at Cancer Research UK, says that the work contributes to analyzing “how high-dose sucralose could be used in new treatment options for patients, although it’s still early days” to know.
Vousden, K. “The Dietary Sweetener Sucralose Is a Negative Modulator of T-Cell Mediated Responses” Nature (2023)