Green Tea Ingredient Slows Breast Cancer - Antioxidant in Green Tea May Stop Breast Cancer Growth
[[ASIN:B002K6FRX2 Yuexi Cuilan (Yuexi Green Orchid Tea) - Organic Green Tea 500g]]<br /><br />Premium Longjing Dragon Well Green Tea 150g Gift Tin<br />By Jennifer Warner<br />WebMD Health News<br />Reviewed by Louise Chang, MD<br /><br />April 7, 2008 -- An antioxidant in green tea may be a powerful weapon against breast cancer.<br />A new study shows the green tea antioxidant EGCG (epigallocatechin-3-gallate) significantly slowed breast cancer growth in female mice.<br />Cancer Videos<br /><br />Video: Cancer and Exercise<br /><br />Video: Making Chemotherapy Safer<br /><br />Video: Foods After Cancer<br />All Cancer-Related Videos<br />Related Slideshows<br />* Dangers of Sun-Damaged Skin<br />* Common Adult Skin Problems<br />Related to<br />lymphoma, leukemia, chemotherapy, radiation, mammogram, PSA test , colonoscopy, herceptin, tamoxifen, breast cancer -- Colposcopy, lung cancer, skin cancer, prostate cancer, cervical cancer, colon cancer<br />© 2008 WebMD, LLC. All rights reserved.<br />Previous studies have suggested that this antioxidant may protect against breast cancer and other cancers, but this research has been limited, and the mechanism behind these effects isn't clear.<br />Researchers say the results suggest that green tea's anticancer effects may be largely because of its high content of EGCG, which helps the body's cells from becoming damaged and aging prematurely.<br />Behind Green Tea's Anticancer Effect<br />In the study, presented this week at the Experimental Biology 2008 conference, researchers examined the effects of the green tea antioxidant on several indicators of breast cancer growth in laboratory mice.<br />One group of the female mice was fed a solution of the antioxidant in water for five weeks while the other received regular drinking water. During the second week of the study, researchers injected both groups with breast cancer cells.<br />At the end of the study, researchers measured tumor size, weight, and density as well as VEGF protein levels associated with tumor growth.<br />The results showed that treatment with the green tea antioxidant decreased tumor size by 66% and weight by 68% compared with the control group. Mice fed the antioxidant also had significantly lower density of small blood vessels within tumors and VEGF protein levels.<br />Researcher Jian-Wei Gu, of the University of Mississippi Medical Center in Jackson, says the green tea antioxidant may work against breast cancer by suppressing blood vessel growth in breast tumors as well as slowing the proliferation and migration of breast cancer cells.<br /><br />Mechanism for green tea's anti-cancer action revealed<br />17-May-2005<br />Related topics: Research, Phytochemicals, plant extracts, Cancer risk reduction<br />Green tea appears to protect against cancer by affecting a 'promiscuous' protein that pharmaceutical experts are already targeting in their work on anti-cancer drugs, according to new research.<br />The study, by PhD student Christine Palermo at the University of Rochester Medical Center, reveals a potential new mechanism to explain the tea, and particularly its active compounds' action against cancer.<br />While many studies suggest that green tea protects people against some forms of cancer, such as breast and liver cancer, exactly how it does so has been difficult to pinpoint.<br />"It's important to find out the source of green tea's protective effects," said toxicologist Thomas A Gasiewicz, whose work on the harmful effects of dioxin led the Rochester group to explore the protective effects of green tea.<br />"What is exciting here is that a completely new mechanism has been found that very well could be responsible for its protective effects, and that could help us find a compound that is much more potent."<br />Palermo, Gasiewicz, and current undergraduate Claire Westlake discovered that a chaperone protein known as HSP90 is involved in conferring green tea's protective effects. Other researchers have shown that many cancer cells have an increase in the level of HSP90 compared to healthy cells, and that when HSP90 is blocked, levels of proteins that make cancer cells grow drop.<br />Drug makers are currently working on ways to block HSP90, which is known as a promiscuous chaperone protein because it binds to many different cells and receptors in the body. It turns out that those researchers are trying to duplicate what green tea does naturally. Gasiewicz says green tea might modulate HSP-90 in a way that researchers have not seen before.<br />Gasiewicz and his group have shown how dioxin and other substances like cigarette smoke manipulate a major cancer-causing molecule, the aryl hydrocarbon (AH) receptor, which frequently plays a role in turning on genes that are oftentimes harmful.<br />Two years ago the team discovered that AH activity is inhibited by a chemical found in white and green teas, epigallocatechingallate or EGCG, now being produced and marketed as a supplement by DSM.<br />"We initially hypothesized that EGCG would work in the same way as other AH antagonists, by binding directly to it. We were completely surprised that this isn't the case," said Gasiewicz, whose work was funded by the National Institute of Environmental Health Sciences and the American Institute for Cancer Research.<br />Instead, the team found that EGCG binds to HSP90, a protein that helps other proteins stay stable, serving the same role as a tail on a kite. When the two bind, HSP90 no longer turns on the AH receptor, stopping the cascade of events that would lead to the activation of several harmful genes.<br />Another potential mechanism for green tea's action was outlined recently by a team at the University of Wisconsin and Case Western Reserve University in Cleveland, Ohio. The found that green tea polyphenols reduce levels of insulin-like growth factor-1 (IGF-1) in prostate tumour cells in a mouse model for human prostate cancer. Increased levels of IGF-1 are associated with higher risk of several cancers, such as prostate, breast, lung and colon.<br />Meanwhile, researchers at Kyushu University in Japan reported last year that EGCG appears to inhibit tumour cell growth by binding to a receptor on cells called the 67-kDa laminin receptor. A variety of tumours produce abnormally high levels of 67 LR, and the receptor is thought to be involved in the spread of cancers through the body.<br /><br />If you have problems completing your update and need to contact customer service, please report the following code with your request<br />Code: 02Oq8o2BBAXAacmKMMMF4TBY<br /><br />Is Green Tea Really an Anti-Cancer Miracle?<br />Talk to your doctor about green tea.<br /><br />By Gale Maleskey, MS, RD<br />Registered Dietitian<br />About the Author<br />July 23, 2009<br /><br />Change Text Size A | A | A<br />If you've had cancer, or a precancerous condition, it's time to talk with your doctor about using green tea extract. More and more research is showing that green tea extract can slow the progression of cancer. It doesn't work for all cancers, but it seems to have a significant effect on some types. Its effect may even depend on genetic markers and hormone sensitivities associated with your type of cancer.<br /><br />Some of the cancers that green tea can face down include prostate, esophageal, bladder, cervical, pancreatic, ovarian, lymphoma and leukemia. Green tea is also active against human papilloma virus (HPV) a sexually transmitted virus associated with cervical and anal cancer and warts.<br /><br />(Since green tea can also apparently neutralize some chemotherapy treatments, such as Velcade, used for multiple myeloma and mantel cell lymphoma, it's important that you consult with your doctor if you are undergoing treatment.)<br /><br />The most recent study, by researchers at Louisiana State University, found that men scheduled for a radical prostatectomy due to cancer who took a green tea extract had a significant reduction in the markers predictive of prostate cancer progression. In some men, the drop was more than 30%! The reductions were in biochemicals that either stimulate cancer growth or indicate continued cancer growth. The men took a total of 1.3 grams of tea polyphenols, equivalent to about 12 cups of green tea. (McLarty, J, et al. Cancer Prev Res. 2009 June 19.) [E Pub ahead of print.]<br /><br />Even though this was a small study, other evidence suggests that green tea can take on cancer. One study found that men with high-grade prostate intraepithelial neoplasia -- cellular changes that often lead to cancer -- who took green tea catechins 200 mg three times daily for a year, had a reduced risk of progression to prostate cancer. (Bettuzzi S, et al. Cancer Res .2006;66:1234-40.)<br /><br />Polyphenols (catechins, such as EGCG) in tea appear to protect cells from DNA damage that can promote cancer. Animal research suggests that the EGCG in green tea may prevent new blood vessel growth in tumors, inhibit tumor cell proliferation, and induce death in cancer cells in at least two different ways.<br /><br />The Anti-Aging Bottom Line: Green tea extract can be an important part of an anti-cancer arsenal. For general prevention, we recommend about 450 mg a day of a standardized green tea extract. Unlike brewed tea and non-standardized green tea extracts, our formula provides consistently high amounts of green tea's most active constituents. If you're being treated for cancer, it's best to talk with your doctor about dosage.
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