Exploring the association between composite dietary antioxidant index and ocular diseases: a cross-sectional study.

Objective: Globally, approximately 2.2 billion people suffer from visual impairments or blindness. Dietary patterns are closely associated with the prevalence of multiple ocular diseases. This study aimed to explore the association between Composite Dietary Antioxidant Index (CDAI) and ocular disorders.

Methods: The data were derived from 1706 subjects aged 40 years and older who participated in the 2005-2008 National Health and Nutrition Examination Survey (NHANES), which utilized undersampling techniques. Trained staff interviewed participants to gather information about their dietary habits using the 24-h diet recall method. The CDAI, incorporating six antioxidants, was then computed using a validated method. Eye diseases were diagnosed through a combination of examinations and questionnaires. Multinomial logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for potential confounders.

Results: After adjusting for potential confounders, higher CDAI quartiles (Q4) were significantly associated with reduced odds of diabetic retinopathy (OR: 0.55, P = 0.041), cataracts (OR: 0.37, P < 0.001), glaucoma (OR: 0.48, P = 0.003), and macular degeneration (OR: 0.19, P < 0.001). Carotenoids showed a significant negative correlation with ocular diseases, diabetic retinopathy (OR: 0.57, P < 0.001), cataracts (OR: 0.75, P = 0.014), glaucoma (OR: 0.59, P < 0.001) and macular degeneration (OR: 0.55, P < 0.001). Compared to the lowest quartile (Q1), higher quartiles (Q4) of zinc intake were associated with lower odds of DR (OR: 0.32, P < 0.001) and glaucoma (OR: 0.73, P = 0.001). Similarly, Q4 of vitamin C intake were associated with lower odds of cataracts (OR: 0.70, P = 0.001) and glaucoma (OR: 0.71, P = 0.003) compared to the Q1.

Conclusion: Higher CDAI scores are correlated with a decreased odds of ocular diseases, suggesting that an antioxidant-rich dietary pattern may be associated with better ocular health. Understanding these correlations could contribute to the development of preventive strategies and intervention measures for ocular diseases.