Green Tea May Stall Prostate Cancer Growth

Antioxidant Found in Green Tea May Stop Prostate Cancer Spread

Dec. 1, 2004 -- Men looking for another healthy reason to drink green tea may look no further. A new study suggests that an antioxidant found in green tea may prevent prostate cancer growth by halting the spread of cancer cells and starving the tumor.

A previous study in mice suggested that polyphenols found in green tea can stop the development of prostate cancer and its growth, and researchers say this study helps explain the mechanism behind that potential health benefit.

Researchers say the green tea polyphenols appear to fight prostate cancer by targeting the mechanisms that trigger the spread of cancer cells as well as stopping the growth of neighboring blood vessels that feed the tumor.

The results of the study appear in the Dec. 1 issue of Cancer Research. The study is the latest of many that suggest that drinking green tea provides a variety of health benefits ranging from reducing heart disease risk to fighting cancer.

Explaining Green Tea's Anticancer Effects

In the study, researchers looked at the role of the antioxidants found in green tea in prostate cancer development and progression in mice. A previous study had shown that giving the mice the human equivalent of six cups of green tea per day stopped the growth of prostate cancer.

Researchers examined how the green tea antioxidant affected a protein known as insulin-like growth factor-1 (IGF-1). Increased levels of IGF-1 have been found in men with prostate cancer.

They found that mice that received the green tea antioxidant had lower levels of IGF-1 in their blood.

"These observations bear significance in light of studies that indicate increased levels of IGF-1 are associated with increased risk of several cancers, such as prostate, breast, lung and colon," says researcher Hasan Mukhtar, PhD, of the department of dermatology at the University of Wisconsin, in a news release.

Researchers say the green tea antioxidant appeared to stall cell growth by decreasing production of several proteins that promote cell survival. In addition, it reduced the production of proteins that are known to be associated with the spread of cancer cells.

Finally, the study also suggests that the antioxidant in green tea appeared to starve prostate cancer tumor cells by inhibiting the formation of blood vessels, thereby suppressing the flow of nutrients to the cancerous cells.

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SOURCES: Adhami, V. Cancer Research, Dec. 1, 2004; vol 64: pp 8715-8722. News release, American Association for Cancer Research. WebMD Medical News: "Proteins in Blood May Indicate Cancer Risk."
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