A recent review published in Science China Life Sciences by Professor Yan-Jiang Wang and colleagues explores why progress has been limited. The researchers argue that focusing on a single cause has not worked because Alzheimer’s is far more complex. It arises from the combined effects of amyloid-beta (Aβ) buildup, Tau protein tangles, genetic risk factors, aging-related changes, and broader health conditions. Because of this complexity, they suggest that future treatments must take a more comprehensive and coordinated approach.

Alzheimer’s Disease Involves Multiple Interconnected Factors

The review highlights several key areas that are reshaping how scientists understand Alzheimer’s.

Beyond Amyloid-Beta (Aβ)

Amyloid-beta has long been a central target in Alzheimer’s research, but treatments aimed only at this protein have produced limited results. Scientists are now paying closer attention to Tau hyperphosphorylation, a process that leads to the formation of neurofibrillary tangles and the loss of brain cells. Addressing both Aβ and Tau may be necessary to slow disease progression more effectively.

Genetic Risk and Emerging Gene Therapies

Genetics play a major role in determining Alzheimer’s risk. While APOE ε4 remains the most widely recognized genetic factor, researchers are identifying additional variants linked to specific populations. Advances in genome editing (CRISPR/Cas9) are also being explored as potential one-time treatments that could modify disease risk at its source.

Aging and Whole-Body Health Shape Alzheimer’s Progression

Aging as a Central Driver

Aging is the strongest risk factor for Alzheimer’s and involves a range of biological changes. These include declining mitochondrial function, the buildup of damaged cells, and increased DNA damage. The review points to “senolytic” therapies, which aim to remove aging glial cells, as a possible way to improve brain health and slow decline.

Systemic Health and the Gut-Brain Connection

Alzheimer’s is also influenced by conditions that affect the entire body. Issues such as insulin resistance, high blood pressure, and imbalances in gut bacteria can worsen disease processes. Researchers are investigating whether existing diabetes medications and therapies targeting the gut-brain axis could help reduce these effects.

Toward Integrated and Multi-Target Alzheimer’s Therapies

The authors emphasize the need to move away from “reductionist” thinking and toward “integrated strategies.” This shift involves developing treatments that target multiple aspects of the disease at once. It also includes using advanced laboratory models, such as human iPSC-derived organoids, to test new therapies more effectively. In addition, precision medicine approaches based on early biomarkers like plasma pTau217 could allow doctors to identify and treat Alzheimer’s earlier and more accurately.

“Success in defeating Alzheimer’s hinges on interdisciplinary collaboration and holistic innovation,” the authors conclude. Their findings outline a path forward, suggesting that with the right combination of strategies, Alzheimer’s could eventually become a manageable or even preventable condition rather than an inevitable decline.

“We were surprised to find that zeaxanthin, already known for its role in eye health, has a completely new function in boosting anti-tumor immunity,” said Jing Chen, PhD, Janet Davison Rowley Distinguished Service Professor of Medicine and senior author of the study. “Our study show that a simple dietary nutrient could complement and strengthen advanced cancer treatments like immunotherapy.”

How Zeaxanthin Activates Cancer-Fighting T Cells

The research builds on years of work from Chen’s lab exploring how nutrients shape immune responses. By analyzing a large library of nutrients found in blood, the team identified zeaxanthin as a compound that directly enhances the performance of CD8+ T cells. These immune cells play a central role in identifying and destroying cancer cells.

CD8+ T cells rely on a structure called the T-cell receptor (TCR) to detect abnormal cells. The researchers found that zeaxanthin helps stabilize the formation of this receptor complex when T cells encounter cancer. This leads to stronger internal signaling, which increases T-cell activation, boosts cytokine production, and improves the cells’ ability to kill tumors.

Boosting the Power of Immunotherapy

In mouse studies, adding zeaxanthin to the diet slowed tumor growth. The effect became even more pronounced when combined with immune checkpoint inhibitors – a type of immunotherapy that has transformed cancer treatment in recent years. Together, the combination produced stronger anti-tumor responses than immunotherapy alone.

The team also tested human T cells that had been engineered to target specific cancer markers. In laboratory experiments, zeaxanthin enhanced these cells’ ability to destroy melanoma, multiple myeloma, and glioblastoma cells.

“Our data show that zeaxanthin improves both natural and engineered T-cell responses, which suggests high translational potential for patients undergoing immunotherapies,” Chen said.

A Safe, Accessible Nutrient With Broad Potential

Zeaxanthin is already widely used as an over-the-counter supplement for eye health. It is naturally present in foods such as orange peppers, spinach, and kale. Because it is inexpensive, easy to obtain, and well tolerated, researchers believe it could be quickly tested as a complementary approach to cancer treatment.

The findings also highlight the broader importance of diet in immune health. In earlier work, Chen’s team identified trans-vaccenic acid (TVA), a fatty acid found in dairy and meat, as another compound that enhances T-cell function through a different pathway. Together, these discoveries suggest that nutrients from both plant and animal sources may work in complementary ways to support the immune system.

What Comes Next for Zeaxanthin in Cancer Care

While the results are promising, the researchers stress that the work is still in its early stages. Most of the evidence so far comes from laboratory experiments and animal models. Clinical trials will be needed to determine whether zeaxanthin can improve outcomes for people with cancer.

“Our findings open a new field of nutritional immunology that looks at how specific dietary components interact with the immune system at the molecular level,” Chen said. “With more research, we may discover natural compounds that make today’s cancer therapies more effective and accessible.”

The study, “Zeaxanthin augments CD8+ effector T cell function and immunotherapy efficacy,” was supported by grants from the National Institutes of Health, the Ludwig Center at the University of Chicago, and the Harborview Foundation Gift Fund.

Additional 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, Chicago; Yuancheng Li and Hui Mao from Emory University School of Medicine, Atlanta; Lei Dong from University of Texas Southwestern Medical Center, Dallas; and Rui Su from Beckman Research Institute, City of Hope, Duarte, CA.