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

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.

Tea consumption is inversely associated with depressive symptoms in the elderly: A cross-sectional study in eastern China.

BACKGROUND: Epidemiological studies suggest that higher tea consumption was associated with lower risk of depressive symptoms, but this has not been found consistently. Moreover, the effect of different types of tea on depressive symptoms needs to be further explored. This study aimed to examine the association between tea consumption and depressive symptoms in Chinese elderly. METHODS: We analyzed the baseline data from Zhejiang Major Public Health Surveillance Program including 9371 participants. Depressive symptoms was assessed through the application of Patient Health Questionnaire-9 scale (PHQ-9). Logistic regression models, controlled for an extensive range of potential confounders, were generated to evaluate the association between tea consumption and risk of depressive symptoms. RESULTS: The black tea drinkers had a significantly decreased risk of depressive symptoms (p<0.01), whereas no association was found in green tea drinkers. Compared with non-drinkers, the adjusted ORs (95% CIs) were 0.48 (0.23, 0.99) and 0.35 (0.17, 0.72) for participants consuming <3 cups and ≥3 cups of black tea per day, respectively (P for trend: <0.01). A linear association between concentration of black tea and depressive symptoms was also confirmed in our study. LIMITATIONS: Cross-sectional data could not make a causation conclusion, and the observed association in our study could not be ascribed to any specific component in tea. CONCLUSIONS: Our results indicated that higher black tea consumption was associated with a lower prevalence of depressive symptoms in the elderly.