Background: The popular beverage tea, brewed from infused leaves of camellia sinesis, contains non-phytoestrogenic polyphenols such as flavonoids, anthocyanidins, flavanols (epigallocatechin gallate); phenolic acids (ellagic acid) and stimulants (caffeine, theophylline). Laboratory studies report tea promotes antioxidant enzyme formation, slows cancer cell proliferation and unblocks apoptosis. Clinically, the Pomi-T randomised study reported tea extract (along with three other foods) reduced PSA progression in men with prostate cancer¹. Evidence of prostate cancer prevention, however, from prospective cohort data is conflicting with one recent study even implying an increased risk². Methods: We analysed 25,097 men within the intervention arm of the 155,000 participant PLCO screening trial. Histological confirmed cases of prostate cancer were reported in 3,088 men (12.3%) during the 11.5 year follow up. Tea consumption was assessed with a food frequency questionnaire (FFQ). Baseline characteristics were compared between groups using Chi-square and Kruskal-Wallis tests. Cox regression models were used to assess the association between tea intake and prostate cancer incidence. Results: Overall tea consumption was associated with a significantly lower risk of prostate cancer (p = 0.009). More precisely, the participants in the highest third of consumption group had a significantly lower risk compared to those in the lowest third (HR 1.16 (CI 1.05-1.29, p = 0.004). This pattern persisted with adjustments for age, sex, race and education level (p = 0.034), family history of cancer (p = 0.037). Those who never drank tea, however, had no statistical lower risk of prostate cancer compared to other groups (p = 0.501). Conclusions: Among tea drinkers, this data revealed a positive association between drinking tea and a reduced risk of prostate cancer. This data supports the consideration of future prospective intervention studies investigating the role of tea as part of a prostate cancer prevention programme.

1. Thomas et al. The NCRN Pomi-T RCT. Prostate cancer & prostatic diseases (2014), 2,180.

2. Reger et al. Dietary isoflavones and prostate cancer risk. Int J. Cancer (2017), 142; 4, 719.