Purdue University, Ind.:
Researchers, Dorothy Morre and D. James Moore, found that EGCg
(epigallocatechin gallate), a compound in green tea, inhibits an enzyme
required for
cancer cell growth and kills cancer cells with no ill effect on healthy
cells. The Purdue
team determined how cancer cells died. "In the presence of EGCg, the cancer
cells
literally failed to grow or enlarge after division then presumably because
they did not
reach the minimum size needed to divide they underwent programmed cell
death, or
apoptosis".
Case Western Reserve University School of Medicine, OH.:
Researchers have found an ingredient that kills cancer cells while sparing
healthy
cells. Hasan Mukhtar, a professor of dermatology at CWRU, tested the ingredient
EGCg on cancerous human and mouse cells of the skin, lymph system and prostate
and on normal human cells. In the test tube, it led to apoptosis or programmed
cell
death in the cancer cells but left healthy cells unharmed. "The killing
of cancer cells
and sparing of normal cells is very interesting because apoptosis is a
programmed
cell death which is a normal process going on in the body all the time.
It is a
preferential way of elimination of unwanted cells from the body".
Prevention Magazine
Scientists slipped some mice a Green Tea ingredient (Polyphenols) in their
drinking
water - the equivalent of 3 to 4 cups of Green Tea for a human. When injected
with a
rheumatoid arthritis forming compound, fewer than half of the mice developed
RA,
compared to 92% of the mice who drank plain water (Proceedings of the National
Academy of Sciences, April 1999). Also, very few people develop RA in regions
of
China and India where Green Tea is grown and its consumption is high.
Green Tea's Polyphenols pack 300 to 400 times the antioxidant power of
Vitamins E
and C, says lead study author Tariq M. Haqqi, PhD, from Case Western Reserve
University in Cleveland. Also, Polyphenols seem to slam the door on dangerous
inflammatory cells that migrate into joints and do most of RA's damage.
Early test
tube studies hint that Green Tea may stop the destruction of human cartilage
cells
caused by osteo-arthritis.
Chinese Academy of Preventative Medicine, Beijing:
Dr. Junshi Chen stated for the first time his research and clinical trials
point to the
protective effects of green tea on humans with cancer. He used a liquid
mixture of
green and black tea which was rubbed on pre-cancerous lesions. This treatment
significantly reduced the growth of pre-cancerous cells. Dr. Chenís
research also
showed that tea slowed the development of lung tumors and colon cancer
in mice.
American Cancer Society:
Tea plays a possible role in preventing some types of cancer according
to
researcher, Dr. John Weisburger. His report was presented at the Second
International Scientific Symposium on tea and human health in Washington,
DC. "The
antioxidants in tea prevent the formation of hazardous products that occur
in the body
during normal metabolic reactions". "The antioxidants in tea lower the
formation of
these dangerous, oxidized form of chemicals that may cause cancer in the
human
body".
Journal of the National Cancer Institute:
A powerful antioxidant ingredient found in green tea kills human cancer
cells in
laboratory experiments, according to a report in the Journal of the National
Cancer
Institute for December 17.
Prostate Cancer and Green Tea:
Mayo Clinic researchers have identified a plant substance in green tea
that is a
potent killer of prostate cancer cells. Charles Y-F Young, Ph.D., and colleagues
tested four common components of green tea on cell cultures of three different
lines
of prostate cancer. One of the tea components, called EGCg, was found to
be most
potent in inhibiting the growth of prostate cancer cells. Young says the
chemical
structure of EGCg is similar to substances found in red wine and vegetables.
The
Mayo Clinic study, published in the August 1998, issue of the Journal Cancer
Letters,
found that green tea not only inhibited cell growth, it also produced fragmented
nuclei
and other signs of apoptosis, or programmed cell death.
More Evidence on Green Tea:
A new study by a team of Swedish researchers adds support to the growing
body of
evidence that green tea contains compounds that fight cancer. Dr. Yihai
Cao and Dr.
Renhai Cao of the Karolinska Institute in Stockholm found green tea contains
a
compound called EGCg which helps inhibit blood vessel growth. This could
be useful
in preventing tumors from forming new blood vessels, which they need to
survive. In a
study on mice, the researchers also found animals fed green tea showed
a 55% to
70% reduction in blood vessel development in the cornea of the eye, a finding
that
could prove helpful to diabetics suffering from retinopathy, researchers
say. Other
studies have shown EGCg blocked an enzyme needed for cancer cell growth
and
kept cells from becoming cancerous without harming surrounding healthy
cells. The
researchers point out heavy consumption of green tea may not be beneficial
for
women who are pregnant or for people recovering from wounds, conditions
that both
require blood vessel development. This study appears in the April issue
of Nature.
Scientists Report Benefits of Green Tea:
At the Second International Scientific Symposium on Tea and Human Health
in
Washington D.C., scientists are discussing the possible benefits of consuming
both
black and green tea. A study led by Dr. Jeffrey Blumberg of Tufts University
in Boston
showed tea increased the antioxidant capacity of the blood. And Dr. Chung
Yang of
Rutgers University says both black and green tea contain phytochemicals
that
function as antioxidants. Antioxidants are molecules that help prevent
cellular
damage. Animal studies also have shown that tea may reduce the risk of
lung cancer.
Green Tea Enhances Cancer Drugs:
Cancer patients may find one day that consuming green tea increases the
effectiveness of their cancer drugs. Researchers from the Saitama Prefectural
Cancer Center in Japan say combining a chemical found in green tea with
cancer
drugs made the drugs 20 times more effective. Scientist Masami Suganuma
says
she added epigallocatechin gallate (EGCG) to a test tube that contained
the breast
cancer drug tamoxifen and breast cancer cells. According to Suganuma, the
tamoxifen with the green tea chemical killed twice as many breast cancer
cells as the
unadulterated drug. Researchers from the Show University School of Medicine
in
Tokyo also point out that people living in a tea producing area in Japan
called
Shizuoka have very low rates of some cancers. People in that region drink
an
average of 10 cups of tea daily, researchers say. These findings were presented
at
the annual meeting of the Japanese Cancer Association near Tokyo.
American Society of Cell Biology:
In a paper delivered at the ASCB, scientists reported that they found that
green tea
affects an enzyme known as NOX. According to these scientists, normal cells
express the NOX enzyme only when they are dividing in response to growth
hormone
signals. In contrast, cancer cells have somehow gained the ability to express
NOX
activity at all times. This tumor-associated NOX activity is called tNOX.
They found
that a substance in green tea, epigallocatechin gallate, or EGCg for short,
interfered
with tNOX but not with normal NOX. This was the first study to directly
link the EGCg
in green tea to anti-cancer activity. In the laboratory, EGCg limited the
activity of
breast cancer tumor cells but did not affect normal, healthy breast cells.
This might be
one explanation as to why the incidence of breast cancer in Japan is so
low.
UT Southwestern Medical Center, Dallas:
Doctors at UTSMC say you shouldnít confuse green tea with black
tea more
commonly served in the United States. Black Tea leaves have been oxidized
and
have less of the anti-cancer ingredients. On the other hand, green tea
is full of
antioxidants that help fight disease.
University of Minnesota:
A study from the University of Minnesota in Minneapolis assessed the link
between
drinking non-herbal tea (green tea) and cancer incidence by food questionnaire.
The
scientists reported inverse associations between tea consumption and risk
of
cancers of the stomach, oropharynx, esophagus and kidney. There was over
a 50%
lower risk of these cancers associated with daily tea consumption.
National Cancer Center Research Institute, Japan:
Some kinds of cancer seem to be less common in the Orient than in Europe
and the
Americas. A few of these differences are well documented: for example,
Japanese
cigarette smokers have a lower rate of lung cancer than do US cigarette
smokers. By
1987, the green tea connection was clear enough to encourage Hirota Fujiki,
a
chemist at NCCRI Japan, to analyze the brew for compounds that might be
the
source of the apparent benefit. He found a likely candidate in an antioxidant
known as
epigallocatechin gallate or EGCg. Some antioxidants are known to protect
against
tumor development by destroying the highly reactive free radicals, atoms
or
molecules that disrupt normal cell process and confound the proper operation
of
DNA. Dr. Fujiki fed mice a carcinogen known to affect the digestive tract,
63% of the
mice developed intestinal cancer. When mice were fed the same dose of the
carcinogen but also treated with EGCg, only 20% of the mice developed cancer.
In
mice specially bred to be susceptible to liver cancer, EGCg reduced the
number of
liver tumors and sometimes prevented them altogether.
Alternative Health & Medicine Encyclopedia:
Studies show that green tea can dramatically reduce the risk of many types
of cancer
including liver, breast, lung, pancreatic and skin cancers. Researchers
think green
tea compounds work as a sort of super antioxidant, able to block the interaction
of
tumor promoters. Green tea and its compounds also lower the risk of heart
disease
and stroke by preventing the development of blockages in the arteries.
It also keeps
blood sugars at a healthfully low level and helps combat viruses.
from www.lifeextension.org May 21, 2000