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.
