Tea and Risk of Age-Related Cataracts: A Cross-Sectional Study in Zhejiang Province, China.

ABSTRACT

BACKGROUND: The antioxidant properties of tea extracts are considered to be effective in protecting against cataracts. However, there is still insufficient epidemiological knowledge about the protective effects of different types of tea on age-related cataracts. METHODS: The data was derived from the Zhejiang Major Public Health Surveillance (ZJMPHS) Program on health and related factors in the elderly. The relationships between consumption of different types of tea and risk of age-related cataracts were assessed after adjusting for related covariates. RESULTS: The prevalence of age-related cataracts in this study population was 4.4% (409/9343). After adjustment for potential confounders, tea drinking was associated with reduced risk of age-related cataracts (adjusted odds ratio [OR] 0.65; 95% confidence interval [CI], 0.47-0.91). Compared to nondrinkers, green tea drinkers had a significantly reduced risk of cataracts (adjusted OR 0.58; 95% CI, 0.40-0.85). Average tea consumption of 14-27 cups (adjusted OR 0.55; 95% CI, 0.33-0.93) and over 28 cups (adjusted OR 0.58; 95% CI, 0.34-0.99) per week had a protective effect against cataracts in comparison to no consumption. In addition, ingesting a moderate concentration of tea significantly decreased the risk of cataract compared to no consumption (adjusted OR 0.43; 95% CI, 0.27-0.71). CONCLUSIONS: Tea ingestion was associated with reduced risk of age-related cataracts. In light of these findings, we suggest that reasonable tea consumption (ie, favoring green tea and consuming an average of over 500 mL per day at moderate concentration) should offer protection against age-related cataracts.