The Indians were drinking green tea before the Brits came and
made them ferment it
excerpt
Green is the new black

It's too early to get overly excited - but green tea might just be a
wonder drug

Edzard Ernst
Tuesday June 7, 2005
The Guardian

In Japan, 5.5bn bottles of green tea were consumed last year. Yet in
Britain, green tea is drunk by few. Which is a pity, because it is
probably the healthiest choice. Like black tea, green tea is made from
the leaves of the tea plant, Camellia sinensis. The difference is
essentially that, for black tea, the leaves are fermented, while for
green tea they are not. Green tea therefore contains plenty more
chemicals called polyphenols. These are powerful antioxidants with
exotic names, such as catechins, epicatechin, catechins gallate and
epigallocatechin gallate. It is these Years ago, epidemiologists noted
that cancer rates in populations that consume green tea were lower
than expected. We should not get too excited about such findings. For
instance, tea drinkers could also be avoiding things that cause cancer
or have a lifestyle that protects them. But encouraging results about
green tea kept coming in and eventually formed a compelling body of
evidence. The curiosity snowballed and, currently, research into the
health aspects of green tea is buoyant.
Studies in test tubes show that the ingredients of green tea inhibit
tumour growth and cause the death of cancer cells. In animal
experiments, green tea impedes the development of chemically induced
cancers. Some green tea ingredients seem to enhance the effect of
anticancer drugs. Other compounds protect our organs against the
damage that cancer drugs can have, for instance, on the heart. Taken
alongside chemotherapy, green tea could maximise the benefits of such
drugs and minimise their risks.

These effects may be valuable for a range of cancers. Importantly,
they are supported not just by one or two investigations but by dozens
of studies from around the world.

But the proof of the pudding is in the eating. Do we have data from
clinical trials, or is all this based on lab experiments? So far few
such studies have been completed. A rare exception is a prospective
investigation from China of 254 women with ovarian cancer. While 78%
of the green tea drinkers survived for longer than three years, the
figure was only 48% for the abstainers. The authors of this study
therefore believe that "increasing the consumption of green tea ...
may enhance epithelial ovarian cancer survival". Another analysis
found similar effects for sufferers of prostate cancer.

Antioxidants in green tea are not only important for cancer; they
might also play a role in cardiovascular disease. Regular green tea
consumption normalises lipid metabolism, reduces blood pressure,
slightly lowers body weight, stabilises glucose metabolism in diabetes
patients, and might even neutralise some effects of smoking.
Collectively these effects are likely to amount to a significant
protection from heart disease, stroke and other cardiovascular
problems.

However, clinical trials are again scarce. A Japanese team observed
203 patients who underwent a coronary angioplasty. Of these, 109 had
coronary artery disease while the rest had normal coronaries. Patients
with normal coronary arteries consumed significantly more green tea
compared to those who had diseased coronary arteries. The authors were
optimistic: "The more green tea patients consume, the less likely they
are to have coronary artery disease."

Before you rush out to buy a car load of green tea, a word of caution.
All these findings are encouraging but, to be sure, we really need the
results of clinical trials. These will take a while to come through.
The good news is that green teais delicious and refreshing. The bad
news is that to match the dose used in the research studies, you need
to drink up to 12 cups a day