[Editor's note: There is still no unequivocal word on whether or not it is
valuable to drink green tea either as a preventative or as part of
a treatment protocol.]
Scientists have discovered a remarkable substance that prevents many kinds
of cancer in experimental animals. It is non-toxic, easy to take and inexpensive.
It is green tea, one of the most popular drinks in Asia. Tea has long been
considered "that Excellent and by All Physicians approved China drink" (1658).
Doctors began the present study when they found that Japanese smokers had
less lung cancer than their American counterparts.
Mice given a chemical isolated from green tea develop far less cancer of
the lung, skin and digestive tract, scientists reported at the Fourth Chemical
Congress of North America, held in New York City in late August. In mice
specially bred to develop liver cancer, tumors simply would not appear when
they ingested this remarkable compound.
"Green tea cannot prevent every cancer," said Dr. Hirota Fujiki, of the National
Cancer Center Research Institute, Tokyo. "But it's the cheapest and most
practical method for cancer prevention available to the general public."
Fujiki and his colleagues focused on one chemical in the tea, EGCH, which
appears to be a "free radical scavenger," neutralizing highly reactive atoms
or molecules that could attack DNA and trigger cancer. A scientist at the
American Health Foundation suggests EGCH may prevent the activation of
carcinogens. Less was said about the health effects of the tea as a whole
or of other compounds such as chlorophyll, which independently has anti-cancer
effects.
Given orally in amounts equal to the intake of tea-drinking Japanese, EGCH
had dramatic effects. Sixty-three percent of mice given a carcinogen got
cancer of the gut, while in the green tea group, only 20 percent succumbed.
At Rutgers, scientists found that mice receiving the green tea chemical had
up to 87 percent fewer skin tumors. "There aren't that many things that have
as broad a spectrum," said a Rutgers scientist. But he refused to advise
people to actually drink it, calling such a move "premature." He hinted that
ten small teacups—drunk daily for centuries by billions of
Asians—might even be harmful. "Any kind of chemical or material that
is ingested in large amounts has potential risks," he claimed. Meanwhile,
studies of green tea continue—on animals.
A study of green tea usage in China has confirmed earlier suggestions that
imbibing this pleasant drink can help prevent cancers, including deadly cancer
of the esophagus, the tube through which food passes on its way to the stomach.
Esophageal cancer is a major cause of suffering and death in China. In the
US, too, there will be an estimated 11,000 cases in 1994, with 10,400 deaths.
US National Cancer Institute scientists studied the records of 902 Shanghai
patients as well as 1,552 healthy persons. They found that among nonsmokers
and nondrinkers of alcohol, the risk of cancer of the esophagus was reduced
by an extraordinary 57 percent for men and 60 percent for women. The research
was reported in the Journal of the National Cancer Institute (5/94). "This
is the first study to show that association, that protective effect," said
Joseph K. McLaughlin of NCI (New York Times, 6/1/94).
Eighty percent of all tea consumed is black tea. And, according to scientists
at the American Health Foundation, black tea also has health benefits. The
other 20 percent is green tea, the `unfermented' (unoxidized) kind, which
is processed by being gently steamed, rolled and crushed. Common forms of
green tea are gunpowder, jasmine, and bancha (or twig) tea. Dr. McLaughlin
attributed the extraordinary results to polyphenols in the tea that protect
against cancer by inhibiting enzymes that produce cancer-producing substances.
Essentially, the doctor said, "the more green tea you drink, the lower the
risk."
Two of the inciting causes of esophageal cancer are tobacco and alcohol. Interestingly,
green tea was not able to appreciably reduce the incidence of this cancer
among heavy smokers and drinkers, or protect people who regularly drank
burning-hot fluids, like soup.Green tea is available in most health food
stores or Asian markets. Significant cancer protection can be had for
pennies a day. Many cancer patients are now drinking green tea, believing
that what helps prevent cancer may have a beneficial effect in fighting
the disease.
