The epi-gallo-catechol gallate or EGCG ,a catechin-counting polyphenol , contained in the green tea have a stark anti-oxidative and anti-inflammatory effect. Japanese studies also showed strong tumor-inhibiting properties.
The substance EGCG seems to inhibit the formation of blood vessels and this process called angiogenesis is important for tumor growth. Research has shown that EGCG can inhibit the development of tumors of the prostate, breast and uterus.
Scientists at the Scottish University of Strathclyde are also researching the efficacy of EGCG. Their result: this substance counteracts the growth of tumors and could therefore be used as a basis for new therapeutic options.
For actual prevention, people would need to drink up to 10 cups of green tea a day or an infusion of green tea extract.