March 6, 2006
Green Tea May Reduce Breast Cancer Risk - Black Tea May Increase RiskTopics: Health Issues
"Overall summary odds ration [a measure of risk] showed an approximately 20 per cent statistically significant reduction in risk of breast cancer associated with high intake of green tea" ...
A meta-analysis of previous studies indicates that drinking five cups of green tea a day can reduce the risk of breast cancer by 22 per cent, the same studies that the FDA recently said contained very little science to support the claims. Although this article is a couple of weeks old, the information is still just as useful.
This particular meta-analysis involved relative risk of green and black teas with breast cancer, but there have been animal studies that indicate both green and black teas show inhibition in dimethylbenz[a]anthracene (DMBA) - induced carcinogenesis. I've previously worked on research with natural compounds in attempting to prevent DMBA induced carcinogenesis, and have to admit that I'm impressed with the fact that green and black teas shows inhibition in the face of such a powerful tumor promoter.
By the way, I've been a real fan of green tea for almost five years, drink 6 to 8 cups of strong tea a day (5 minute seeps of a high quality tea I order out of Japan), and take capsules of green tea extract with 470 mg. each of EGCG (epigallocatechin gallate) along with my daily nutritional regimen. I'm not a heatlh nut, just had to adapt due to my own personal health issues (I have MS and am a five year survivor of head and neck cancer - rather rare for Stage IV when found). Although drinking much greater quantities of green tea are not only safe but healthy, taking capsules of green tea extract should be done with caution, owing to some reports of liver toxicity.
For those that wish to have the health benefits of green tea but don't like the taste of it, consider doing what I often do. Use 1 tsp of high quality sencha green tea to each 1.5 tsp of high quality unfermented Rooibos tea -of your favorite flavor (not flavoring, rather natural citrus peel). If you absolutely have to have it sweetened, use a very small amount of stevia instead of sugar or artificial sweetner (stevia actually lowers glucose levels).
Diabetics should also be interested in green tea for it's effects on glucose metabolism.
Green tea promoted glucose metabolism in healthy human volunteers at 1.5 g/body in oral glucose tolerance tests. Green tea also lowered blood glucose levels in diabetic db+/db+ mice and streptozotocin-diabetic mice 2-6 h after administration at 300 mg/kg without affecting serum insulin level, whereas no effect was observed in control mice (+m/+m and normal ddY mice).
Mechanism of action of (-)-epigallocatechin-3-gallate: auto-oxidation-dependent inactivation of epidermal growth factor receptor and direct effects on growth inhibition in human esophageal cancer KYSE 150 cells.
Posted by Richard at March 6, 2006 10:32 AM
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