Zeaxanthin May Enhance Immunotherapy by Strengthening T Cells

Sat, 11 Apr 2026 12:43:00 +0200

Researchers at the University of Chicago Medical Center have discovered that zeaxanthin—a carotenoid commonly found in vegetables such as orange peppers, spinach, and kale and known for supporting eye health—may also help fight cancer. The study, published in Cell Reports Medicine, reveals that zeaxanthin enhances the activity of CD8+ T cells, key immune cells responsible for locating and destroying cancer cells. Specifically, zeaxanthin stabilizes the T-cell receptor (TCR) complex, strengthening internal signaling and enabling T cells to produce more cytokines and attack tumors more effectively. In mouse experiments, dietary zeaxanthin slowed tumor growth, especially when combined with checkpoint inhibitor immunotherapies, resulting in improved anti-tumor responses. Laboratory tests using human engineered T cells also showed that zeaxanthin improved their ability to eliminate melanoma, multiple myeloma, and glioblastoma cells. Given that zeaxanthin is widely available as an over-the-c