Coffee Polyphenols may help prevent breast cancer in high risk women
The gene known as BRCA1 normally restrains cell growth and suppresses tumor growth by repairing breaks in DNA. When a woman has a mutation in this gene she has a large increase in the risk of developing breast and ovarian cancer (men with the gene mutation have a greater risk of developing prostate cancer). It is estimated that women with the BRCA1 mutation have a 50% to 85% risk of developing breast cancer over their lifetime, and a 44% risk of developing ovarian cancer whereas women in the general population have a 10% to 12% risk of developing breast cancer and a 1% risk of developing ovarian cancer over their lifetime.
In this study compiled from 40 clinical centers in four countries (Canada, USA, Israel, Poland) that included 1,690 high risk women with damage to either their BRCA1 gene or BRCA2 it was found that with increasing levels of coffee consumption there was a decrease in the likelihood of developing breast cancer. For women who drank 1 to 3 cups of coffee a day there was a 10% decreased risk, for those who drank 4 to 5 cups a day there was a 25% decrease, and for women who drank 6 or more cups each day there was a 69% decreased likelihood of developing breast cancer versus women who did not consume coffee (the protection was for the women with BRCA1 gene mutations, not BRCA2). The researchers believe it is the polyphenols found in coffee that have the beneficial-protective effect. The study is published in the January 1st 2006 issue of the International Journal of Cancer.
Green Tea Polyphenols may decrease the risk of developing prostate cancer and may be useful therapeutically
Prostate cancer is the most common invasive malignancy and a major cause of cancer related deaths in men in the USA. Prostate cancer is an ideal test for chemoprevention (the use of nutrients, herbs, or drugs to decrease the risk or delay the development of cancer) due to its relatively slow growth rate usually found in the elderly population. The published data on cell cultures and animal studies by these and other researchers along with epidemiological research and case-control studies indicate that the polyphenols in Green Tea possess prostate cancer chemo preventive activity and possibly therapeutic (ability to treat the disease) effects.
In this study mice lacking immune system function were implanted with androgen receptor positive human prostate cancer. They were then given either Green Tea Polyphenols, Black Tea Extract, or EGCG (the major constituent in Green Tea) or Theaflavins (the major constituent in Black Tea). It was found that all four preparations significantly inhibited the growth of prostate cancer tumors, significantly reduced PSA levels, significantly improved the killing of prostate cancer cells, significantly inhibited levels of Bcl-2 protein, a gene that blocks the destruction of cancerous tumors, and significantly improved levels of Bax protein, a gene that both inhibits Bcl-2 and causes the destruction of cancerous tumor cells. The preparations also inhibited VEGF levels, a protein that allows the spread of prostate cancer.
It was also found that giving Green Tea Polyphenols to a mouse who already had established prostate cancer caused significant tumor regression. The study was performed at the University of Wisconsin-Madison, and is published in the December 29th, 2005 issue of the journal Carcinogenesis.