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Tea Does A Body Good
Michael Seidman, director of the Center for Integrative
Medicine at the Henry Ford Health System in Detroit, hates the
taste of green tea. But that doesn't stop him from drinking a
cup five days a week. When he's done, Seidman squeezes the liquid
out of the tea leaves and then -- get this -- eats them.
The leaves are so bitter that Seidman immediately brushes
his teeth to remove the taste and to be sure that the tea doesn't
stain his tooth enamel. "My wife just looks at me and rolls her
eyes," says Seidman, an ear, nose and throat surgeon who also
has a degree in nutrition. "But there's no doubt in my mind that
green tea has many health benefits."
Other scientists are not so convinced. "There are
hundreds, if not thousands of papers on tea, but the results are
often split," notes tea researcher Jack F. Bukowski, an assistant
clinical professor of medicine at Harvard Medical School.
So where one study finds that tea boosts immune function,
another shows no effect. Most of the research has been limited
to animals. Scientists have yet to examine all the properties
of green, black, oolong and white tea. They don't yet know if
the variety of tea -- Darjeeling vs. jasmine green tea, for example
-- could make a difference. Or what effect there may be from drinking
tea straight or mixing it with milk, sugar, lemon or other spices.
There isn't even agreement on whether a cup of tea means the barely
four ounces you sip from fine china or the hefty 16 ounces in
an oversize mug.
"Tea has big possibilities," says Bukowski, who has spent
15 years studying the ancient beverage. "But we have a long way
to go before we can confirm the health benefits."
None of that has stopped interest in tea from coming to
a full boil. In January, Coca-Cola introduced Enviga, a green
tea beverage said to "help you burn calories" by boosting
metabolism. Last year, a Japanese company petitioned the Food
and Drug Administration for permission to label green tea as offering
protection against heart disease. (The agency denied the request,
citing "supportive but not conclusive results.")
One substance in tea, the tongue-twisting epigallo-catechin
gallate (EGCG), appears to reduce psoriasis, prostate cancer and
colon tumors (at least in animals) and is now an ingredient in
a growing number of foods, beverages and dietary supplements.
But that's just one of the components of tea that may have health
benefits.
Second only to water as the most widely consumed beverage
in the world, tea is also one of the oldest. Introduced about
5,000 years ago in China, tea became a common drink in the Sui
dynasty of the 6th century and reached Japan around 580, according
to "The Romance of Tea," an authoritative history of
the beverage published by William H. Ukers in 1936. In 1662, Catherine
of Braganza -- the Portuguese-born wife of King Charles II --
became the first tea-drinking British queen. William Penn is credited
with introducing tea to Pennsylvania.
Tea drinking plummeted in the Colonies after the Boston
Tea Party. But by the early 20th century, many were drinking enough
tea to invent the tea bag and introduce iced tea.
In 2006, more than 2.25 billion gallons of tea were sipped
in the United States, according to the Tea Association, an industry
group. That works out to about 132 cups per person per year. Even
so, consumption here lags behind that in much of the world, particularly
China, Japan and other parts of Asia, "where they drink tea
all day long like we drink bottled water," Bukowski says.
U.S. tea drinkers are concentrated in the Northeast and
the South, where sweet tea is the rule. As in most Western countries,
black tea is preferred over green tea. Unlike people in the rest
of the world, Americans consume 85 percent of tea iced rather
than hot, according to the Tea Association.
Tea leaves are plucked from a warm-weather evergreen shrub,
Camellia sinensis, that is indigenous to China and India
but now also thrives in mountainous regions from Argentina to
Malawi. Oolong tea is exposed to the air to oxidize for two to
three hours after harvesting, while black tea is oxidized for
up to four hours. (As for the wide range of herbal teas, they're
made from the roots, leaves and flowers of other plants and are
not technically tea at all.)
Neither green tea nor white tea, which is made from the
tender, young leaves of the tea plant before they turn color,
is allowed to oxidize after harvesting. Some scientists think
that may give them a nutritional edge, since they may contain
higher amounts of antioxidants. These substances help protect
against cancer and appear to counteract the chronic inflammation
that contributes to heart disease, arthritis and other chronic
illness.
A growing number of studies suggest such potential benefits
from tea as improved mental alertness, lower blood cholesterol
and triglyceride levels, reduced blood pressure, lower risk of
breast, colon, lung, ovarian and prostate cancer, as well as possible
protection again Type 2 diabetes and maybe even help with weight
loss. But even if such findings are confirmed, you'd need to drink
a lot of tea to reap any benefit.
"The research suggests that drinking one to two cups of
tea per day may not be enough," Bukowski says. "You may need more
like five to 10 cups per day." Ounce for ounce, tea contains about
half the caffeine found in coffee, so that could be a lot of caffeine.
Whether decaf works as well is not yet clear.
For the biggest punch of antioxidants and other potentially
healthful ingredients, drink tea shortly after brewing it. And
resist the temptation to reuse tea bags, since that produces a
less potent brew.
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