Research Links Sucralose to Reduced Effectiveness of Cancer Immunotherapy

Recent research from the University of Pittsburgh and UPMC Hillman Cancer Center indicates that sucralose, a widely used artificial sweetener found in many diet products, may interfere with cancer treatments that rely on immunotherapy. The study, published in the journal Cancer Discovery, examined how high consumption of sucralose impacts patients undergoing immune-based cancer therapies like anti-PD1 treatments.

The findings revealed that patients with melanoma and non-small cell lung cancer who consumed significant amounts of sucralose showed diminished responses to immunotherapy and had poorer survival outcomes compared to those with lower intake of artificial sweeteners. Experiments in mouse models demonstrated that sucralose disrupts gut bacteria, specifically increasing bacterial species that degrade arginine, an amino acid crucial for T cell function and immune response. This depletion of arginine hampers the immune system's ability to fight tumors effectively.

The research team discovered that supplementing with arginine or citrulline—an amino acid that converts into arginine—could counteract the negative effects caused by sucralose in mice, restoring the efficacy of immunotherapy. These promising results suggest that targeted nutrient supplementation could be a simple, practical approach to improve outcomes in patients who regularly consume sucralose.

Lead researcher Dr. Abby Overacre emphasized the importance of considering patients' diets during treatment, noting that drastic dietary changes might be challenging for those already dealing with the stresses of cancer. Instead, supplementation may offer a feasible strategy. Senior author Dr. Diwakar Davar explained that sucralose alters the gut microbiome, leading to decreased arginine levels, which impairs T cell activity and reduces immunotherapy effectiveness. These findings highlight the need for further clinical trials to evaluate whether arginine or citrulline supplements can enhance immune response and improve treatment success.

The researchers are also exploring the impact of other sugar substitutes like aspartame, saccharin, xylitol, and stevia on the immune system, aiming to identify dietary factors that could influence cancer therapy outcomes. Overall, this study underscores the potential risks posed by artificial sweeteners in cancer treatment and points toward dietary intervention as a supportive measure for improving immunotherapy responses.