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Green Tea
and Lung Cancer
It's been called
the "Asian Paradox" – the fact that people living in Asia, where smoking
is commonplace, have some of the world's lowest rates of lung cancer
death. In Korea, for example, the rate of lung cancer deaths per 100,000
men is less than 40, compared to 67 in U.S. men. Yet 37 percent of
Korean adults smoke, compared to 27 percent of U.S. adults. Why did the
Koreans get so lucky? Perhaps it's because they drink plenty of green
tea.
While
epidemiological studies of the tea/lung cancer connection have provided
mixed results, most animal studies show that green tea strongly prevents
the development of cancerous tumors of the lung. Researchers believe it
does this by:
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quenching free radicals
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protecting DNA from damage
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inhibiting cancer cell division
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reducing the growth of new blood vessels
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inducing cancer cell “suicide"
In human studies,
drinking green tea appears to be extremely protective against lung
cancer in those carrying the OGGI Cys(326) gene. This gene makes a
person particularly susceptible to oxidative stress and DNA damage. In a
study of 244 people, half with lung cancer, half without, carriers of
the OGGI Cys(326) gene who drank green tea daily were 72% less likely to
develop lung cancer than those who drank no green tea, whether or not
they had this gene.1
The presence or
absence of this particular gene may also be a major reason for the mixed
results of epidemiologic studies of green tea and lung cancer. If the
group studied has a high proportion of people with the OGGI Cys(326)
gene, the green tea will have greater effects, and vice versa. But many
studies don’t differentiate between those volunteers who do and don't
have this gene. In the future, studies of green tea’s effect on lung
cancer should control for the presence or absence of the OGGI Cys(326)
gene.
1Bonner
MR, Rothman N, Mumford JL, et al. Green tea consumption, genetic
susceptibility, PAH-rich smoky coal, and the risk of lung cancer.
Mutation Research 2005;582(1-2):53-60.
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Nadine Taylor, M.S., R.D. presents
GreenTeaLibrary.com, the most
comprehensive collection of scientific information describing the
health benefits of green tea.
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