Scientists argue about the health properties of green tea. The spectrum of its actions is very wide - from the stimulation of immunity to antioncogene effects. However, what components of green tea perform all these useful steps, still one can only surmise.

The researchers emphasize that antioncogenes effect has a real green tea, not diluted fruit and other additives consumer goods. (Photo Beau Lark.)

However, scientists from Columbia University (USA) managed to reach the certain successes: they figured out how green tea limits the growth of cancerous tumors. The study involved 40 women with breast cancer, not amenable to hormonal therapy. Some of them twice a day for several months gave green tea extract called politekonom that is a mixture of tea polyphenols which as believe, and do all the good work. Dose Polyphenon E were different, in the tea equivalent they ranged from 8 to 24 cups.

On the results of the experiment, scientists reported at the annual conference of the American Association of cancer research, is dedicated to preventing cancer. It turned out that women who were given the green tea extract was suppressed synthesis of two proteins factor and vascular endothelial growth (VEGF) and growth factor of hepatocytes (HGF). Both enhance tumor growth, and green tea, reducing their concentration in the body, helps to slow down the development of tumors.

Similar data were made by the researchers from the University of California in Los Angeles (USA), which, however, worked with prostate cancer and given to patients not extract tea polyphenols, and the tea. In them participated 67 men who had surgery to remove the tumor. A few weeks before the operation, some of them were ordered to drink six cups of tea a day. Compared with those who instead of tea drinking plain water, decreased protein level of PSA, or prostatespecific antigen, which is a sign of prostate cancer. It is, however, be noted that in both papers were investigated first of all biochemical effects of green tea. That is how has anything changed in the malignant tumors, we do not know.

Partly in favor of the anti-cancer effect of green tea and says the statistics of cancer of the prostate and breast cancer in Japan and the USA: in Japan, the number of such cases is three times less. (However, it is naked comparison does not take into account many other factors, ethno-genetic and ethnocultural, which also may affect the statistics.) In the future, the researchers want to Refine your results by using a larger sample of patients, and also to find out whether tea polyphenols affect other types of cancer.

Prepared according to LiveScience.