A new study published in PLOS One has identified potential associations between common environmental chemicals and age-related macular degeneration (AMD) risk, opening new avenues for understanding how everyday exposures may influence retinal health.1

Researchers from the Workers’ Hospital of Jinchuan Group Co. in Gansu, China, analysed data from 4,727 adults aged 40 and older who participated in the US National Health and Nutrition Examination Survey 2005–2008. The team examined urinary levels of perchlorate, nitrate, and thiocyanate – inorganic anions known to interfere with thyroid function – and evaluated their relationships with early and late AMD.

Nitrate exposure showed significant positive associations with both AMD and early AMD risk. Individuals in the highest quartile of urinary nitrate had 94% higher odds of AMD, while those in the highest quartile of thiocyanate showed 70% higher odds compared with the lowest quartile. Perchlorate levels showed no significant association.

The study observed a U-shaped relationship between both nitrate and thiocyanate levels and AMD risk, suggesting that both low and high exposures might influence retinal health differently.

The authors proposed several potential pathways for these effects. Nitrate, commonly found in leafy vegetables, cured meats, and contaminated water, metabolises into nitric oxide, which can disrupt vascular and oxidative homeostasis in the retina. Thiocyanate, a byproduct of cigarette smoke and certain industrial processes, may generate oxidative stress within retinal pigment epithelium lysosomes.

The authors have called for longitudinal and mechanistic studies to explore how reducing chemical exposure might complement existing AMD preventive strategies.

Reference available at mivision.com.au.