A HEALTHFUL plant-based diet may do more than support heart health and lower diabetes risk — it could also help protect the eyes and nervous system, according to new research from the UK Biobank. In a large-scale study involving nearly 14,000 participants, researchers found that people who ate more healthful plant-based foods had thicker retinal sublayers, a sign of better nerve cell health in the eye.
The retina’s structure is increasingly recognized as a valuable marker for neurodegenerative diseases, including Alzheimer’s and Parkinson’s. Thinning of the retina’s ganglion cell layers is known to precede symptoms in various neurodegenerative conditions. Using high-resolution optical coherence tomography (OCT) imaging, the study linked higher scores on the Healthful Plant-Based Diet Index (HPDI) — a measure of diets rich in fruits, vegetables, whole grains, and legumes — with greater thickness of key retinal sublayers, including the macular ganglion cell-inner plexiform layer and the macular ganglion cell complex.
“These findings highlight the potential for diet, particularly a healthful plant-based one, to play a role in early neuroprotection,” the authors said. They also noted that cholesterol levels appeared to partially mediate this link, suggesting complex interactions between diet, blood biomarkers, and nerve health.
The associations were strongest in younger adults and women, pointing to possible differences in how demographic factors influence the benefits of plant-based eating on retinal and neurological health.
Experts say the research underscores how dietary patterns could help detect or even slow neurodegenerative changes long before clinical symptoms appear — with the retina offering a non-invasive window into brain health.
Further studies are needed to confirm these findings and to understand how long-term adherence to plant-based diets influences eye and brain health over time. But for now, the evidence adds another reason to reach for those leafy greens.
Reference
Zhu Q et al. Neuroprotective effects of healthful plant-based diets on retinal structure: insights from a large cohort. JNHA. 2025;29(1):100431.
