SAITAMA, JAPAN. Numerous animal studies have concluded that green tea and green
tea extracts are effective in preventing cancer and inhibiting tumor growth.
Now Japanese researchers report that green tea also prevents cancer in humans.
Their study involved 8,552 Japanese men and women aged 40 years and older. The
participants were followed-up for nine years and over this period 384 of them
developed cancer; 262 of the cases were fatal. At the start of the study the
participants filled out a comprehensive questionnaire covering such lifestyle
factors as diet, smoking, alcohol use, medications, and consumption of green
tea. Statistical analysis of the data showed that women who drank 10 or more
cups of green tea per day had a 43 per cent lower risk of developing cancer than
did women who consumed three cups or less per day. Men who drank large
quantities of green tea also had a lower risk, but this was not statistically
significant when adjusting for other factors such as smoking. Women with a high
intake of green tea also developed cancer much later in life (nine years later
on average) than did women with a low intake. The researchers calculate that 10
cups (150 ml each) of green tea provides 300-400 mg of epigallocatechin gallate
which is believed to be the active ingredient. They conclude that "Strong
potency of green tea in preventing cancers of various organs observed in
vivo and among humans points us toward a new strategy of cancer
chemoprevention without toxic effects."