Green tea is one of the most ancient beverages and the earliest form of consumed tea! It contains a major class of flavonoids, the catechins, which include epicatechin (EC), epigallocaetchin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG). EGCG appears to be the most important in regards to cancer. There have been many breast cancer studies and it appears that there may be a slight recurrence reduction for moderate green tea drinkers (>3 cups/day). Please refer to a metanalysis by Min-Jing Li, et al. in the World Jour of Clin Onc, 8/14, in which pooled results from 2 studies showed a 25% reduction of recurrence in all stages (0.75, 95%CI 0.47-1.19). A subgroup analysis that included only stage I and II patients demonstrated a much greater effect with a recurrence reduction of 44% (0.56, 95% CI: 0.38-0.83, P=0.004).
Of interest, matcha green tea has ten times the amount of catechins compared to regular green tea. Please also see the metanalysis by Braakhuis, et al.
Be aware that the benefits of green tea are destroyed with excess heating. Never pour boiling water over green tea. If you are interested in a quick tutorial on how to make matcha, please also see Wildfoods.co.
*Do not take this or any other medication during chemotherapy, radiation therapy, or after therapy without first consulting your doctor. Green tea may reduce the efficacy of anthracyclines.