Diet, Exercise, and Lifestyle in Glaucoma: Current Evidence and Future Perspectives

Glaucoma is a major ocular neurodegenerative disease and a leading cause of irreversible blindness worldwide, with prevalence projected to exceed 110 million by 2040. Although lowering intraocular pressure (IOP) remains the only proven treatment, glaucoma arises from a complex interplay of genetic, local, and systemic factors-including oxidative stress, vascular dysregulation, mitochondrial dysfunction, and neuroinflammation. Emerging evidence suggests that modifiable lifestyle factors may influence these pathogenic pathways. In this review, higher dietary nitrate from leafy greens is consistently associated with lower primary open-angle glaucoma risk, aligning with nitric-oxide-mediated endothelial support and more stable ocular perfusion pressure. Flavonoids (anthocyanins and flavanols), carotenoids (lutein/zeaxanthin), and B vitamins have strong biological rationale for glaucoma prevention but have limited support from long-term, large population-based studies. The effect of polyunsaturated fats on glaucoma remains inconsistent and warrants source-(plant vs. animal) and substitution-based analyses. Consistent protective effects of aerobic exercise and high-quality sleep may be associated with favorable metabolic profiles and ocular perfusion, potentially mitigating retinal ganglion cell loss. Conversely, smoking and alcohol use are frequently coupled with poorer diet quality (e.g., lower vegetable intake) and heightened oxidative stress, which may exacerbate glaucomatous neurodegeneration. However, much of the current literature is constrained by cross-sectional designs, reliance on self-reported food frequency questionnaires, and insufficient use of structural endpoints such as retinal nerve fiber layer imaging. This review focuses on the potential of lifestyle modification and future directions in prevention and treatment strategies for glaucoma, highlighting the need for large-scale, multi-ethnic, genotype-stratified longitudinal studies and randomized controlled trials to establish causality and define optimal intervention strategies.