Green Tea and Prostate Cancer Health

From Wire Services-- Prostate cancer is the most commonly diagnosed cancer among men and the second leading cause of male cancer deaths in western countries. Japanese and Chinese men, on the other hand—who regularly consume green tea—have the lowest prostate cancer incidence in the world. New research set for publication in the journal Cancer Research indicates that polyphenols present in green tea help prevent the spread of prostate cancer.
Dr. Hasan Mukhtar, at the University of Wisconsin in Madison, and colleagues previously showed that feeding mice green tea polyphenols blocked the development and progression of prostate cancer. In the current study, the researchers clarified the chemical basis for this observation. They found that polyphenols inhibited a chemical pathway that plays a key role in the development of prostate cancer.
"My most recent studies," Dr. Mukhtar says, "show that green tea has great potential as a treatment for some cancers because of its observed anti-metastatic properties."
The University of Wisconsin researchers found that the consumption of GTP—the polyphenols found in green tea—led to reduced levels of IGF-1 (an insulin-like growth factor), that shut down the proliferation and spread of tumor cells, as well as inhibiting the growth of tumor-nurturing blood vessels in a mouse model for human prostate cancer.
Prostate cancer normally occurs in men over 50 years of age, Mukhtar told Reuters Health, but the chemical process that starts it all begins decades earlier. “If we can somehow shift the progression of prostate cancer from 20 years to even 25 years,” he said, “then this could be a significant achievement.”

Dr. Mukhtar noted that drinking up to 12 cups of green tea per day has no known toxic effects on the human body.
Now, Dr. Mukhtar now plans a clinical study with prostate cancer patients. By measuring change in PSA (prostate specific antigen) levels among patients drinking green tea, he will try to see how effective a cancer treatment green tea could be. He estimates that an ability to kill cancer cells can be attained by drinking six eight-ounce cups of green tea (each brewed from 1.25 grams of tea leaves) a day.

References

SOURCE: Cancer Research, December 1, 2004.

Saleem M et al. Tea beverage in chemoprevention of prostate cancer: a mini-review. Nutr and Canc. 2003;47:13-23.

Adhami VA et al. Molecular targets for green tea in prostate cancer prevention. J Nutr. 2003;133:2417S-24S.

Jian L et al. Protective effect of green tea against prostate cancer: a case-control study in southeast China. Interntl J Canc. 2004;108:130-5.

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