Azam Ghorbani - MSc, Nursing & Midwifery Faculty, Ardabil University of medical sciences, Ardabil, Iran
Sima Ghezelbash - MSc, Nursing & Midwifery Faculty, Ardabil University of medical sciences, Ardabil, Iran.
Sahar Ghezelbash - BSc, Emam Ali hospital of Kermanshah, Kermanshah, Iran

Tea is the second most consumed beverage worldwide after water. Tea is a mixture of a large number of bioactive compounds, including catechins (Epigallocatechin-3-gallate (EGCG) flavonols, lignans, and phenolic acids, which have many cancer chemo preventive attributes including anti-oxidation, antiinflammatory, antiproliferative, and anti-angiogenic.Methods This study was a comprehensive literature review performed through searches in databases such as Medline, PubMed, Science Direct, Scopus, and Google Scholar using the terms Cancer, green tea, anti-oxidant, and breast cancer . Findings Extensive laboratory studies in multiple animal models have consistently shown the inhibitory activities of green tea polyphenols against tumorigenesis at different organ sites. Green tea’s estrogen reduction activity may result from tea polyphenols inhibiting aromatase, the key enzyme converting androgens to estrone or estradiol 21. Evidence from animal models provides convincing risk reduction effects of green tea against mammary tumors. Statistically significant association between green tea and breast cancer risk reduction. However, supportive evidence from prospective cohort studies is lacking. ConclusionsAlthough many in vitro and animal studies have demonstrated a protective effect of green tea against breast cancer, findings from epidemiological studies have been inconsistent.

Breast Cancer, green tea, anti- oxidation