Artificial sweetener in diet soft drinks 'suppresses T-cell immune system'

Sucralose, a common sugar substitute, has broader biological effects beyond taste, research indicates

A study has found that consuming a high amount of sucralose could suppress the immune response to disease in mice.

Scientists at the Francis Crick Institute in London have found that consuming a high amount of sucralose, an artificial sweetener commonly used in hot drinks and diet soft drinks, could suppress the immune response to disease in mice.

The study suggests that sucralose could potentially be used to treat people with autoimmune disorders, including conditions such as Type-1 diabetes.

The study, published in Nature, found that consuming high doses of sucralose lowered the activation of T cells — a type of white blood cell — in mice.

Dr Karen Vousden, senior author and principal group leader at the Crick, told The National: “T-cells are activated when an external signal binds to the T-cell receptor on the surface of the T-cell. Our data show that sucralose works by dampening this signalling cascade, so the T-cell is less efficiently activated.

“We don’t know the exact details, but it seems that sucralose can interact with the cell membrane and impedes changes in the membrane that are necessary for proper T-cell receptor activation”.

The doses tested were within recommended consumption limits, but would be the equivalent of drinking about 30 cups of sweetened coffee in a day or 10 cans of a diet fizzy drink.

Dr Vousden said: “We did not see a similar effect with two other sweeteners, AceK and saccharin”.

The researchers hope the findings could lead to a new way of using much higher therapeutic doses of sucralose in patients, but they stressed that their findings should not sound alarm bells for those wanting to ensure they have a healthy immune system or recover from disease.

“It is important to remember that the amount of sucralose we gave the mice was around the maximum recommended doses by the American and European food agencies, which is much higher than those reached by people simply consuming food or drinks containing sucralose as part of a normal diet,” Dr Vousden said.

The researchers cautioned against taking away the message that sucralose is harmful if consumed in the course of a normal balanced diet.

“Our study does not suggest that normal intake of sucralose will affect any heath condition treatment, nor that it should be avoided as part of a regular diet”.

Dr Vousden said: “We’re hoping to piece together a bigger picture of the effects of diet on health and disease, so that one day we can advise on diets that are best suited to individual patients, or find elements of our diet that doctors can exploit for treatment.”

The effects on the immune system observed seem reversible, and the researchers believe it may be worth studying whether sucralose could be used to ameliorate conditions such as autoimmunity, especially in combinational therapies.

Julianna Blagih, co-first author and former postdoctoral training fellow at the Crick, said: “We’ve shown that a commonly used sweetener, sucralose, is not a completely inert molecule and we have uncovered an unexpected effect on the immune system.

“We are keen to explore whether there are other cell types or processes that are similarly affected by this sweetener.”

Karis Betts, senior health information manager at Cancer Research UK, said: “The results of this study don’t show harmful effects of sucralose for humans, so you don’t need to think about changing your diet to avoid it.”

The study raises questions about the effects of artificial sweeteners on the body, and the need for further research in this area.

Dr Vousden told The National: “Assuming we can exclude all safety concerns, we think high doses of sucralose could be useful in T-cell dependent autoimmune diseases, most likely in combination with existing therapies.

“But we need to do a lot more work in collaboration with our clinical colleagues before we know whether we can use this work effectively for therapy”.