As a naturopathic physician and faculty member at
Bastyr University in Kenmore, Paul Anderson has plenty of opportunity to
practice what he prescribes. In the case of drinking green tea for
health protection, Anderson says he is a regular -- but not daily --
drinker.
"Green tea has a significant amount of antioxidants," said Anderson the
other day, taking a break from moving to a new office. "That helps with
regulating cholesterol and burning fat."
Another positive about green tea in Anderson's view: It contains amino
acid molecules called thiamine that "can be quite calming to the brain."
This relaxing effect seems to run counter to the fact that green tea's
active ingredients include caffeine. The caffeine is less than the
typical cup of coffee or soda, but it is still, well, caffeine.
"The caffeine effect is immediate while thiamine needs to build up over
time," said Anderson. "Only regular green tea drinkers will get the
calming effect, and the thiamine sort of balances out the caffeine."
Research on the health benefits of green tea is burgeoning. Earlier this
year, researchers at the Fred Hutchinson Cancer Research Center and the
University of Washington reported that women who drank one or more cups
per day of green tea reduced ovarian cancer risk by 54 percent. Even
women who drank green tea occasionally enjoyed decreased risk. This
protectiveness is even more significant considering the difficulty of
detecting ovarian cancer until it is advanced and less treatable.
The Hutch Center scientists noted green tea has high levels of
epigallocatechin-3-gallate or EGCG, a powerful antioxidant shown in lab
studies to inhibit ovarian cancer growth. Additional studies connect
green tea's EGCG level and reduced risk for several other cancers,
including breast cancer (in experiments on mice at the University of
Mississippi) and colorectal cancer (according to a large study of
Chinese women).
Anderson said some cancer patients drink green tea to help offset the
intended ravages of chemotherapy and radiation, which kill some normal
cells as a byproduct of destroying cancer cells.
A major Japanese study concluded that individuals who
drink at least a pint of green tea per day appear to significantly decrease
their risk of death from heart disease, especially from cardiac episodes
earlier than life expectancy would predict. The 2006 research, published in
the Journal of the American Medical Association, offered that the common
green tea habit among Japanese adults might go a long way in explaining why
the mortality rate from heart disease and stroke is about 30 percent lower
in Japan than in the United States.
EGCG is considered a substance that protects cells from damage and premature
aging, which is no doubt why it has become a favorite of beauty and
cosmetics manufacturers. But there is no research to show whether topical
application of green tea extracts have the same effect as consuming the tea.
Anderson said one of the first things a naturopathic physician determines
about medicinal plants and herbs is whether there is a toxicity level for
the substance. He said green tea presents no such dangers, especially as a
brewed tea. He acknowledged that someone would have to take "extremely
large" amounts of green tea extract to cause any toxic effect. He did
include a few cautions: The caffeine in green tea might still adversely
affect someone with uncontrolled high blood pressure, similar to coffee. And
he said some people become nauseated when they drink green tea.
For his part, Anderson opts for matcha green tea, which is a fine powder
made from grinding the tea leaves. The physician says he chooses it
primarily for flavor and "ease of going down," yet he also explains that a
tea as powder is likely to "expose" your water to a greater amount of
antioxidants (more leaves, more concentrated) than if brewed with in its
loose-leaf or tea-bag versions. Plus, matcha powder is absorbed completely
into the water (you can mix it cold or hot) while the loose leaves or bag
will be discarded.
One study conducted by researchers at the University of Colorado at Colorado
Springs isolated the EGCG counts in matcha green tea compared with brewed
cups. They concluded the matcha is 137 times more potent than a China tips
leaf tea -- a fact, as you might imagine, not lost on purveyors of matcha.
There is an ongoing debate about whether the specific grade of matcha tea
matters for optimal health benefits. Anderson said he buys his matcha at a
favorite tea shop and trusts the retailer's sources. "I'm sure the grades
are better in Japan, but the quality is better in the U.S. these days," he
said.
At $15 to $20 per container, matcha might appear to be pricier than loose
tea or bags. But one container might well last three months or more, making
it economical as either a total replacement for coffee or becoming your
pick-me-up beverage of choice in the afternoon.
No matter the type of green tea you choose, be sure not to make it with
boiling-hot water. You want the tea water to reach just boiling and then sit
for a moment. When possible, pour the water first, then add the tea.
"The reason is extreme heat can change the nature and healing properties of
any herbs," said Anderson. "If you add the tea second rather than pour the
hot water right over it, there is less shock to the plant. You are trying
for the highest amount of antioxidants and flavonoids, so don't make the
water too hot."
