|
Green Tea
and Breast Cancer Scientists
have long been curious about the fact that breast cancer rates are lower
in countries where green tea consumption is high. Can drinking green tea
really keep breast cancer at bay? Although conflicting evidence exists,
several studies indicate that green tea may indeed be able to help.
Animal studies have
shown that green tea or green tea extract:
- delayed the
appearance of breast tumors1
- strengthened the
cancer-fighting effects of the breast cancer drug tamoxifen2,
and
-
not only reduced tumor size, but encouraged
breast cancer cells to "commit suicide," while leaving healthy cells
alone3
In lab tests, just
mixing green tea catechins with human breast cancer cells slowed the
cancer cells' rate of multiplication and encouraged them to
self-destruct.4
But test tubes and
animals aren’t the same as humans. Can green tea do anything about
breast cancer in women?
Only a few studies
exist, but their results are exciting. In a 2003 study of Asian American
women living in Los Angeles, published in the International Journal
of Cancer, the health and habits of 501 women with breast cancer
were compared to those of 594 women who did not have the disease.5
The researchers found that those who drank more than 3 oz. of green tea
per day had a 47% lower risk of developing breast cancer than those who
drank no green tea. And those who drank at least some green tea (but
less than 3 oz. per day) had a 29% lower risk. Those are pretty
impressive results for less than ½ cup of green tea per day!
In a similar study
published in the May, 2007 issue of Carcinogenesis, 1,009 women
in Southeast China with breast cancer were compared to 1,009 age-matched
healthy women. The researchers collected information on each woman’s
diet, lifestyle and green tea consumption. They found that those who
drank an average of 1/2 to 2/3 cup of green tea per day for a year had a
reduction in breast cancer risk of 41%. And even those who drank very
small amounts of green tea (less than 1 1/2 cups per week for a year)
decreased their breast cancer risk by 13%.6
Clearly, more
studies of the green tea/breast cancer link are needed. But since green
tea is nontoxic, inexpensive, and readily available (not to mention
quite tasty!), it couldn’t hurt to sip a few cups every day – and
possibly reap big health rewards down the line.
Click here for a
simplified look at the studies on
green tea's effect on breast cancer.
Footnotes:
1
Kavanagh KT, Hafer LJ, Kim DW, et al. Green tea extracts decrease
carcinogen-induced mammary tumor burden in rats and rate of breast
cancer cell proliferation in culture. Journal of Cellular
Biochemistry 2001;82(3):387-98.
2
Sartippour MR, Pietras R, Marquez-Garban DC, et al. The combination of
green tea and tamoxifen is effective against breast cancer.
Carcinogenesis 2006;27(12):2424-33.
3, 4
Thangapazham RL, Singh AK, Sharma A, et al. Green tea polyphenols and
its constituent epigallocatechin gallate inhibits proliferation of human
breast cancer cells in vitro and in vivo. Cancer Letters
2007;245(1-2):232-41.
5
Wu AH, Yu MC, Tseng CC, et al. Green tea and risk of breast cancer in
Asian Americans. International Journal of Cancer
2003;106(4):574-9.
6
Zhang M, Holman CD, Huang JP, Xie X. Green tea and the prevention of
breast cancer: a case-control study in southeast China.
Carcinogenesis 2007;28(5):1074-78.
|
Nadine Taylor, M.S., R.D. presents
GreenTeaLibrary.com,
the most comprehensive collection of scientific information
describing the health benefits of green tea.
|
|
