Scientists from the University of Chicago have identified an unexpected benefit of zeaxanthin, a substance derived from plants and recognized for promoting vision health. Results from a study in Cell Reports Medicine indicate that this carotenoid might aid the body’s defenses in combating cancer by increasing the efficiency of vital immune cells. The research suggests zeaxanthin could serve as an affordable, readily available addition to enhance cancer immunotherapy.
“We discovered that zeaxanthin, familiar for its benefits to eyesight, plays an entirely different part in strengthening immunity against tumors,” stated Jing Chen, PhD, the Janet Davison Rowley Distinguished Service Professor of Medicine and the study’s lead author. “Our results demonstrate that an everyday dietary element might support and amplify sophisticated cancer therapies such as immunotherapy.”
Mechanism Behind Zeaxanthin’s Support for Anti-Cancer Immune Cells
This investigation extends prior efforts in Chen’s laboratory examining how nutrients influence immune functions. After screening numerous blood-based nutrients, the group pinpointed zeaxanthin as one that directly improves the capabilities of CD8+ T cells, which are essential for spotting and eliminating cancerous cells.
These T cells use a T-cell receptor (TCR) to identify irregular cells. The study revealed that zeaxanthin assists in stabilizing this receptor assembly during encounters with cancer cells. This enhancement results in more robust signaling within the cells, greater activation, increased cytokine release, and superior tumor destruction.
Enhancing Immunotherapy Outcomes
Experiments with mice showed that incorporating zeaxanthin into their diets reduced tumor expansion. The benefits were amplified when paired with immune checkpoint inhibitors, a form of immunotherapy that has revolutionized cancer care. The duo yielded more potent anti-tumor effects compared to immunotherapy by itself.
The researchers also examined engineered human T cells designed to attack particular cancer indicators. In lab tests, zeaxanthin improved these cells’ capacity to eliminate cells from melanoma, multiple myeloma, and glioblastoma.
“Our findings indicate that zeaxanthin bolsters both innate and modified T-cell activities, pointing to significant potential for clinical applications in immunotherapy patients,” Chen noted.
An Affordable and Safe Option with Wide Applications
Zeaxanthin is commonly available as a non-prescription supplement for ocular health and occurs naturally in foods like orange bell peppers, spinach, and kale. Given its low cost, accessibility, and good safety profile, experts think it could be rapidly evaluated as an adjunct to cancer therapies.
The study underscores the role of nutrition in maintaining immune function. Previous research from Chen’s group highlighted trans-vaccenic acid (TVA), a fatty acid in dairy and meat products, as another enhancer of T-cell performance via a separate mechanism. These insights imply that plant- and animal-derived nutrients could synergistically aid immunity.
Future Directions for Zeaxanthin in Oncology
Although encouraging, the researchers emphasize that the evidence is preliminary, mainly from lab and animal studies. Human trials are essential to confirm if zeaxanthin benefits cancer patients.
“Our work establishes a new area in nutritional immunology, exploring molecular interactions between diet components and immunity,” Chen said. “Further studies might reveal natural substances that increase the efficacy and reach of current cancer treatments.”
The research, titled “Zeaxanthin augments CD8+ effector T cell function and immunotherapy efficacy,” received funding from the National Institutes of Health, the Ludwig Center at the University of Chicago, and the Harborview Foundation Gift Fund.
Co-authors include Freya Zhang, Jiacheng Li, Rukang Zhang, Jiayi Tu, Zhicheng Xie, Takemasa Tsuji, Hardik Shah, Matthew Ross, Ruitu Lyu, Junko Matsuzaki, Anna Tabor, Kelly Xue, Chunzhao Yin, Hamed R. Youshanlouei, Syed Shah, Michael W. Drazer, Yu-Ying He, Marc Bissonnette, Jun Huang, Chuan He, Kunle Odunsi, and Hao Fan from the University of Chicago; Fatima Choudhry from DePaul University in Chicago; Yuancheng Li and Hui Mao from Emory University School of Medicine in Atlanta; Lei Dong from the University of Texas Southwestern Medical Center in Dallas; and Rui Su from the Beckman Research Institute at City of Hope in Duarte, California.
