Zeaxanthin is a yellow-orange carotenoid found in egg yolks and a wide range of vegetables and fruits. While it has long been celebrated for its role in protecting eye health, new research suggests this familiar nutrient may also strengthen the body’s fight against cancer, potentially enhancing immunotherapy approaches.
What the new findings show
A team from the University of Chicago reported in Cell Reports Medicine that zeaxanthin can bolster the immune system’s anti-tumor response. The study found that this nutrient increases the effectiveness of CD8+ T cells, essential immune cells that recognize and destroy cancer cells. The mechanism involves stabilizing the T-cell receptors on the surface of these immune cells, leading to stronger activation and higher production of cytokines, the signaling molecules that coordinate immune responses.
How zeaxanthin tunes the immune system
Mechanisms at a glance
By stabilizing T-cell receptors, zeaxanthin helps CD8+ T cells respond more vigorously to cancer cells. In animal models, diets enriched with zeaxanthin slowed tumor growth. The effect was even more pronounced when zeaxanthin was used in combination with contemporary immunotherapies, such as immune checkpoint inhibitors, suggesting a potential role as an adjuvant to existing cancer treatments.
Human relevance and laboratory results
In laboratory settings, researchers observed that zeaxanthin enhanced the ability of human T cells—engineered to recognize cancer cells—to identify and kill cells derived from melanoma, multiple myeloma, and glioblastoma. The senior author, Dr. Jing Chen, emphasized that the findings reveal a new function for a common dietary nutrient and open avenues for integrating nutrition with advanced cancer therapies.
From bench to bedside: what’s next
Although the results are compelling, they remain largely preclinical. Zeaxanthin is already available as a dietary supplement and has a well-established safety profile, which could streamline the initiation of early-phase clinical trials to evaluate its use as an adjuvant in oncology. However, the researchers caution that robust clinical data are needed before any adoption in cancer care guidelines.
Diet, immunity and future research
This work contributes to the growing field of immunonutrition, which studies how nutrients influence immune function and disease outcomes. Zeaxanthin is abundant in foods such as egg yolk, carrots, orange peppers, spinach, parsley, kale, oranges, peaches and pumpkin. Together with other lifestyle factors, a balanced diet that supports immune health may complement medical treatments and improve outcomes for patients.
Conclusion
If future human trials confirm these preliminary results, zeaxanthin could become an accessible, safe adjuvant to cancer therapies, helping the immune system respond more effectively to tumors. The study underscores the powerful connection between what we eat and how our bodies fight cancer, and it invites further exploration of nutrition as a partner in oncologic care.
