Sucralose artificial sweetener could make cancer treatment less effective (arginine or citrulline helped)

Medical Xpress / University of Pittsburgh / Cancer Discovery ^ | July 31, 2025 | Diwakar Davar, M.D. et al

[ConservativeMind]

Sucralose is a popular sugar substitute, but new research suggests that the artificial sweetener may not be the best choice for patients undergoing cancer immunotherapy.

The study found that patients with melanoma and non-small cell lung cancer who consumed high levels of sucralose had worse response to immunotherapy and poorer survival than those with diets low in the artificial sweetener.

Strikingly, supplements that boosted levels of the amino acid arginine mitigated the negative effects of sucralose on immunotherapy in mice.

Diwakar Davar, M.D. used mouse models to show that the negative impacts of sucralose are driven by disruption to gut bacteria.

Sucralose shifted the composition of the mouse gut microbiome, increasing bacterial species that degrade arginine, which reduced levels of this amino acid in the blood, tumor fluid and stool.

Immune checkpoint inhibitor immunotherapies such as anti-PD1 work by ramping up T cell activity so that they can more effectively kill cancer cells. Arginine is essential for T cell function, especially in cancer.

"When arginine levels were depleted due to sucralose-driven shifts in the microbiome, T cells couldn't function properly," said Overacre. "As a result, immunotherapy wasn't as effective in mice that were fed sucralose."

In mouse models of adenocarcinoma and melanoma, adding sucralose to the diet inhibited anti-PD1 therapy, leading to larger tumors and poorer survival. But when the researchers gave sucralose-fed mice arginine or citrulline, which is metabolized into arginine in the body, the effectiveness of immunotherapy was restored.

To assess the relevance of these findings for humans, the researchers looked at 132 patients with advanced melanoma or non-small cell lung cancer who received anti-PD1 therapy alone or in combination with chemotherapy.

"We found that sucralose impeded the effectiveness of immunotherapies across a range of cancer types, stages and treatment modalities," said Davar.

[ConservativeMind]

Sucralose caused a gut bacteria shift toward arginine destruction in the gut, causing a large reduction of arginine in the body, making T-cells perform poorly against cancer cells.

The best option is to stop using sweeteners like sucralose. Otherwise, it appears loading up more on arginine food or supplement sources countered the lost arginine.

[ConservativeMind]

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[Responsibility2nd]

I quit artificial sweeteners and even quit Stevia, honey and monkfruit.

Good old sugar is best.

[sauropod]

Bkmk

[E. Pluribus Unum]

Sucralose is nasty stuff. Doesn’t even taste sweet to me. More like a petroleum derivative.

[Veto!]

My friend’s Naturopath says the only safe sweetener is Sweet Leaf Stevia. I buy it at my local Natural Grocer or on Amazon. One half a little paciet is enough for a large cup of tea or coffee.

[nickcarraway]

I can’t believe they are giving arginine and citrulline credit.

[Tom Tetroxide]

I suggest Sucanat if you want sugar. It is minimally processed cane sugar.

[Responsibility2nd]

Cool. I looked this up.

https://www.perplexity.ai/search/sucanat-or-sugar-uZf4F1ODReiAyjBjw56BMw

Its calorie and carbohydrate content per teaspoon (about 16 calories, 4g sugar) are virtually the same as white sugar.

[SaveFerris]

🔝🔝

[dennisw]

Sucralose...I saw this today in some whey powder protein. It is sugar that is treated with chlorine. The result is that it still tastes sweet but cannot be absorbed. So no extra calories.