Researchers at the University of Chicago Medical Center found that zeaxanthin, a nutrient in leafy greens, can strengthen the body’s immune response against cancer. It enhances the activity of T cells, helping them detect and destroy tumor cells more effectively. In studies, zeaxanthin slowed tumor growth and improved the results of immunotherapy treatments. Scientists say this safe and widely available nutrient could become a simple way to boost cancer therapies, though human trials are still needed.