Green tea's cancer-fighting ability great
Oct. 28, 2003 03:50 PM
The long-debated healthful benefits of green tea are now steeped in medical
research and its findings.
Four research papers presented Tuesday at the American Association for Cancer
Research conference in Phoenix show green tea is effective in fighting certain
types of cancer, in addition to lowering cholesterol, preventing heart disease,
boosting oral hygiene and possibly aiding in weight loss.
Drinking just two cups, but probably more like four cups, a day of green tea
may retard the growth of certain tumor cells, researchers agreed. Green tea is
made from leaves that are not fermented before drying.
Iman Hakim, a reseacher at the University of Arizona Cancer Center, showed
that cigarette smokers who drank four cups a day of decaffeinated green tea for
four months cut the oxidative stress caused by cigarettes.
"What we found was significant," she said, referring to a lesion measured in
the urine of the 118 smokers in the study.
The research stopped short of finding that genes damaged from smoking can
repaired by green tea, which is the subject of new research she and her
colleagues are now doing.
Other research presented Tuesday by Jia-Sheng Wang showed green tea can
prevent liver cancer, the third-leading cause of cancer deaths in the world. And
Nurulain Zaveri, a researcher at SRI International in Menlo Park, Calif., found
that green tea may not only prevent cancer but may become a chemotherapy drug
for those with the disease.
But researchers reminded cancer patients to first consult their doctors.
"If you like it, you (probably) can continue to drink it," said Chung Shu
Yang, chair of the chemical biology department at Rutgers University, which has
been studying the therapeutic effects of green tea for a dozen years.
Green tea has been shown to be effective against lung, prostate, liver and
esophagal cancer, among others.
"So, the biology actually is there and that's very exciting," Yang said. "But
the disappointing part is we really don't know how it works."
Yang said anyone who drinks hot beverages, green tea included, should avoid
drinking them too hot because of the association with oral and esophagal
cancers.
Earlier in the day, other researchers presented the benefits of ginger
extract and a traditional Chines herb, both of which may stop the growth of
cancer cells.
Mice fed 500 micrograms of gingerol (the source of ginger's spiciness) three
times a week for two weeks developed fewer tumors after being injected with
human colorectal carcinoma cells. Mice fed ginger also survived longer, implying
that the tumors grew slower, said Ann Bode, at the Hormel Institute at the
University of Minnesota.
Ginger has long been used in the treatment and prevention of various
illnesses, including cancer. The ginger family has been used for thousands of
years.
"The mice were a good (model) for human tumor development because they had no
immune system," Bode said, adding that they were more susceptible for developing
cancer once they were implanted with human colon cancer cells.
But fed gingerol, the mice developed a "marked suppression" of cancer cells,
leading researchers to conclude t he extract fueled apoptosis, or cell death, or
possibly through a cellular transcription process.
"It's likely that it's inducing cell death," she said.
Ginger has been used since antiquity for preventing digestive problems,
nausea, sea sickness and motion sickness. It also has shown to work against
skin, ovarian, colon and breast cancer tumors. But it has been scientifically
tested for halting the progression of colon cancer, until now.
Meanwhile, researchers found that the Chinese herb "Scutellaria Barbata," was
found to slow the progression of prostate tumors, also in mice. The herb is
related to mint of the Labiate family.
The work was done at Union College in Nebraska by Brian Wong, lead author of
the study, and other researchers. Wong said he hopes to apply the findings to
humans.
Wong said, as a child, his mother forced him to drink the bitter dark tea
whenevere he got sick as a child.
The herb has long been part of Chinese medicine, used by doctors to treat
everything from hepatitis t o appendicitis to sknake bites and lung and rectal
cancer.
He and other researchers explored whether the herb could stop cell growth in
prostate cancer, the second most commonly diagnosed cancer in men. They
experimented with mice, feeding them "SB," as it is known and discovered that 50
to 70 percent of those given moderate to high doses were cancer free at the end.
Wong said translated to humans, they would need to drink a few ounces but not
daily because it contains cytotoxins that can be damaging. "Too much is not
good," he said.
Wong said he drinks SB, which is available at retailers, frequently and is
running an unofficial experiment as to whether it stops acne, menstrual cramps,
balding and psychological disorders. That work, however, is not considered
scientific.
Researchers believe "SB" contains phytochemicals that modulte program cell
death of mouse prostate cancer cells and delay tumor development.
On Wednesday, researchers are expected to present findings on skin cancer.
Arizona has among the highest rates of skin cancer in the country.
Kerry Fehr-Snyder
The Arizona Republic
Site map
| 
