Background: To explore the associations of green tea, coffee, black tea, and oolong tea consumption with mortality from chronic kidney disease (CKD) as the underlying cause among Japanese adults.
Methods: We conducted a prospective cohort study of 110,585 men and women aged 40-79 years at recruitment from 1986 to 1990. Baseline information on the consumption of tea and coffee, lifestyles, and medical histories was obtained via self-administered questionnaires. We used multivariable Cox regression models to estimate sex-specific hazard ratios and 95% CIs of mortality from CKD associated with the consumption of green tea, coffee, black tea, or oolong tea.
Results: After a median 19-year follow-up, the hazard ratios of mortality from CKD in women were 0.49 (95% CI, 0.22-1.06) for 1-2 cups of green tea per day, 0.56 (0.31-0.99) for 3-4 cups per day, and 0.55 (0.32-0.93) for ≥5 cups per day, compared with <1 cup per day. No such association was found in men. Coffee, black tea, and oolong tea consumption were not associated with CKD risk in either sex.
Conclusions: Daily consumption of green tea was associated with a lower risk of mortality from CKD in women.
Keywords: CKD; Coffee; Epidemiology; Green tea; Mortality.