Polyphenols in Tea Slows Cancer

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Polyphenols in Tea Slows Cancer

 

 

> http://content.health.msn.com/content/article/1728.92741

>

> Green Tea, Glycine May Slow Tumor Growth

>

> More Evidence for Anti-Cancer Benefits of Common Food Chemicals

> By Salynn Boyles

>

>

>

> Nov. 2, 2001 -- You've probably read that green tea appears to protect

> against cancer. You may even know that its anti-cancer properties are

> attributed to an abundance of chemicals called polyphenols. But new

research

> may explain, for the first time, how those chemicals fight tumors at a

> molecular level.

> Using prostate cancer cell lines, researchers from H. Lee Moffitt Cancer

> Center in Tampa, Fla., found that polyphenols in green tea, and black and

> red teas for that matter, target a protein known to protect cancer cells

> from death. The research, along with several other studies evaluating the

> anti-tumor properties of food components, was presented this week at an

> international conference in Miami Beach, Fla.

> The amino acid glycine was found to reduce breast tumor growth in rats.

> Apparently, it blocks the growth of new blood vessels that feed tumors.

> Glycine is manufactured in the body, but is also commercially available as

a

> dietary supplement.

> " These are very preliminary studies, but they are quite interesting, "

> American Association for Cancer Research (AACR) President Waun Ki Hong,

MD,

> tells WebMD. He says that human studies are needed to verify the findings,

> but this may represent an important contribution to the research. AACR

> co-sponsored the annual meeting along with the National Cancer Institute

and

> the European Organization for Research and Treatment of Cancer.

> In the green tea research, Aslamuzzaman Kazi, PhD, and colleagues found

that

> polyphenols reduced the level of Bcl-XL protein in prostate cancer cell

> lines. Bcl-XL has been shown to protect cancer cells from death -- known

> scientifically as apoptosis

> " The higher the concentration [of polyphenols] the more apoptosis, " Kazi

> tells WebMD. " Epidemiological studies have shown that tea has anticancer

> activities. We wanted to try to understand the molecular mechanism of this

> action. "

> Studies in humans have, in fact, been inconclusive regarding the role of

tea

> in preventing or slowing cancers. While some have shown a clear protective

> benefit, others have not. The most recent large study, published last

March

> in The New England Journal of Medicine, found that drinking green tea did

> not lower the risk of developing stomach cancer in a group of Japanese

> subjects.

> In the glycine study, researcher Zishan Haroon, MD, PhD, and colleagues at

> Duke University Medical Center, found high levels of glycine reduced

breast

> tumor growth rates by 15% in rats by blocking the growth of new

> tumor-feeding blood vessels. The special diet also reduced wound-healing

by

> 30%, which, Haroon tells WebMD, explains glycine's effect on tumors.

> " Tumors and wounds have one very important thing in common -- they both

> produce new blood vessels through the same mechanism, known as

> angiogenesis, " he says. If you can block one response, you can block the

> other, he says.

>

> © 2001 WebMD Corporation. All rights reserved.

>