Kidney cancer is one of the most common cancers in men and the tenth most common in women. The global incidence of kidney cancer is also increasing every year. The known risk factors are age and gender, however a few modifiable risk factors have also been established such as cigarette smoking and obesity. With such few leads on the cause of kidney cancer, there is a need to identify additional contributing factors such as diet. The purpose of this paper was to evaluate any association between green tea and coffee with the risk of kidney cancer, using data from a large prospective cohort study that was conducted in Japan, including 102,463 participants aged 40-69. The results showed that women who consumed more than five cups of green tea per day had a significantly decreased risk of developing kidney cancer, compared with women who rarely consumed green tea. Coffee did not exert the same results. In summary, these results mean that frequent daily green tea consumption may be associated with a reduced risk of kidney cancer and the reduced risk is more likely amongst women.
The study aimed to evaluate the association between green tea and coffee consumption and the risk of kidney cancer using data from a large prospective cohort study in Japan (the Japan Public Health Center-based Prospective Study: JPHC Study). A total of 102,463 participants aged 40–69 were followed during 1,916,421 person-years (mean follow-up period, 19 years). A total of 286 cases of kidney cancer (199 in men, 87 in women) were identified. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) while adjusting for potential confounders. No statistically significant association between green tea intake and kidney cancer risk was found in the total population. Among women who consumed more than five cups of green tea per day, a statistically significant decreased risk was shown with a HR of 0.45 (95% CI: 0.23–0.89), compared to women who rarely consumed green tea. For coffee consumption, the association of kidney cancer risk was not statistically significant. This large prospective cohort study indicated green tea intake may be inversely associated with kidney cancer risk in Japanese adults, particularly in Japanese women.
Article Publication Date: 24/11/2022