There
are observations that drinking green tea daily lowers the incidence of cancer.
Epidemiologists noted that the Shizouka Prefecture of Japan, a coastal region
southwest of Tokyo, had much lower death rate from cancer in men and women compared
with that of the country as a whole. They found that the people in this area drank
green tea as their staple beverage and to a much greater extent than the Japanese
in the other parts of the country. Obviously, this interesting discovery needs
more scientific research before the medical community accepts it as factually
and statistically valid. Why is green tea superior?
While black and green teas both
come from the same plant, Camellia sinensis, a shrubby tree native to Southeast
Asia, the difference is in the processing technique. Tea leaves normally contain
an enzyme which leads to oxidation of the leaves after they are harvested. Green
tea leaves are gently heated and steamed to abort the oxidative process. Black
tea leaves are permitted to undergo full oxidation and fermentation to achieve
its distinctive taste and dark brown or even reddish color. But this process destroys
polyphenol normally found in freshly harvested tea leaves. Thus, green tea, which
is processed without oxidation, has significantly much higher amount of polyphenols
among all varieties of teas.
Philip S. Chua, MD |
