| Our natural health
vocabulary contains a new word: Catechins. This is a type of
Polyphenol
, or plant derived substance, found in green tea, which has
shown strong antioxidant and free radical oxygen scavenging
properties.
Of course, this is not news to the people of the
Orient: in the year 1211 A.D. a Japanese monk wrote " Tea is a
miraculous medicine for the maintenance of health. Tea has an
extraordinary power to prolong life. Anywhere a person cultivates
tea, long life will follow. In ancient and modern times, tea is the
elixir that creates the mountain-dwelling Immortal". (A reference,
I suppose, to the fact that tea grows in the high hills.)
Certainly an interesting study published in the
Tohoku Journal of Experimental Medicine in 1992 bolstered this
claim: it followed the mortality rates of over 3,000 Japanese women
who, as practitioners of a specific tea ceremony, drank more than
usual amounts of green tea. The results indicated "the possibility
that green tea is a protective factor against premature death".
Some of the health benefits attributed to Green
Tea follow, some supported by studies and some admittedly anecdotal.
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I would
advise avoiding Green Tea during pregnancy.
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This is because one of the active
ingredients, EGCG, binds to folic acid, thereby increasing the
risk of certain folate related birth defects.
Green Tea is called a
cancer fighter, (drinking 2 or more cups a day reduced
cancer risk by 10% in one group of women studied) and a new study
from the University of California suggests that the way Green Tea
affects stomach cancer risk is by lowering incidence of gastritis,
or inflammation of the stomach lining. In this study of more than
600 Chinese men and women, the researchers found that green tea
drinkers were only half as likely as non drinkers to have stomach
cancer or gastritis. (International J. of Canc., 2001; 92:
600-604) Green Tea also is beneficial for ulcer healing, and it is
postulated that this is because it helps control H. Pylori, the
bacterium implicated in many stomach ulcers.
In 2005, the FDA stated it was
"highly unlikely" that green tea would prevent cancer .
At the same time,
another report on the substance in green tea that might
fight cancer came out: apparently it
affects a
'promiscuous' protein that pharmaceutical experts are already
targeting in their work on anti-cancer drugs.
H'mmm.
At the
University of Rochester, a study in 2003 concentrated on the
relationship between epigallocatechingallate (EGCG), epigallocatechin (EGC), and a harmful molecule called Aryl
Hydrocarbon, implicated in the destructive effect tobacco smoke and
dioxin have on cells. For the full report, see
RESOURCES at right.
It is also protective against a number of liver
problems, notably cirrhosis, and because of the hepatoprotective
factor, it is also found to lower cholesterol. Additionally, it
protects against the 'flu virus, has a beneficial effect on blood
sugars, helps in the control of high blood pressure, and even fights
plaque in the mouth.
In fact, the Georgia Medical College recently
(2002) published a study to show that 4 to 6 cups of green tea a day
not only prevent the growth of oral cancer cells, but encourage the
growth of healthy cells and the demise of existing cancer cells.
Even now, it is an ingredient in some mouthwashes, if you don't
enjoy drinking the tea. Or use the a Green Tea liquid
extract to swish about in your mouth. Some studies have shown
that green tea, and green tea extracts, are more efficient free
radical scavengers than Vitamin E and C! This may explain the long
list of benefits claimed for it.
| Green
tea may help you retain the information in this article |
A
Japanese study found that elderly people who drank more than
2 cups of tea a day, benefited cognitively from the intake.
| A very interesting study published in
J. Nutr. 132:341-346, 2002, which built on studies showing Green Tea
had anti-inflammatory effects: |
the researchers wished to find out
whether it was also protective of joint tissue. They found that, in
vitro at least, the catechins in Green Tea ( and particularly the gallates) appeared to inhibit the breakdown of cartilage as well as
reducing inflammation. There were no toxic effects
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Does
Green Tea contain caffeine? |
The answer is that yes, it does - between 4% and
7% of the tea leaf: however, it appears that the high levels of catechins in green tea mean that the caffeine molecule is bound when
the tea is steeped, and the effect of the caffeine in green tea is
minimized. New research from Tokyo has discovered the presence of
an amino acid called L-Theanine which also counteracts the
effect of the caffeine, so that one gets the benefit of both
stimulation and relaxation from the beverage. Isn't Nature
wonderful?
For those to whom this is still a concern ,
however, Green Tea extracts are available in capsules, which
optimally will contain a 4:1 concentration - the equivalent of 4
cups of green tea! Green Tea is also available in a decaffeinated
form. I personally do not see that this should be a concern for
most people in view of the information above, but I know that some
of us are exceptionally sensitive to caffeine: so I will only say,
be sure the caffeine has not been chemically extracted! The
chemicals may be worse for you than the caffeine.
There is also one particularly pleasant tea
extract by Viva called Chi Tea, which not only has no
caffeine, not only tastes terrific, but contains extremely high
levels of polyphenols! see RESOURCES
at right.
To me, one of the most interesting claims is that
green tea reduces the risk of stroke - a Dutch study showed
reductions of 73% in the number of strokes in men drinking even
black tea, which contains lower rates of catechins! And there is
also the suggestion that it may be as effective as aspirin in
reducing blood clotting, which is good because it is obviously a
much more all round healthy choice than aspirin, which can have
dangerous side effects.
What's out there in the way of choices? There's
your basic green tea, (look for high quality: storage and processing
methods affect nutrient levels) & there are now some teas which also
have green tea extract added for more potency: there are also the
actual capsules of green tea extract, and the concentrated extract
mentioned above. It certainly sounds as though
this important nutrient is something that should be added in some
form or another to one's diet.
You might want to consider a little soy milk in
your green tea, if you read the study below.
Science News, April 29, 2000
Soy-rich diets appear to help fight certain cancers. Tea
drinking has been linked to similar benefits. Two studies now find
that the combo offers a potent double whammy against cancer of the
breast and prostate -at least in mice.
Jin-Rong Zhou and his colleagues at
Harvard Medical School in Boston injected a million breast cancer or
prostate cancer cells into mice engineered to possess weak immune
systems. Two weeks earlier, they had replaced the drinking water of
some animals with green or black tea. Others received chow laced
with isoflavones, soy's biologically active antioxidants. Two groups
of mice got both the mix of isoflavones and one or the other tea.
Some just ate their normal diet.
Two months after implantation of the cancer cells, the researchers
surveyed for tumors and found that all the experimental diets had
conferred some benefit. Compared with animals on the normal diet,
mice given isoflavones or tea had 25 to 50 percent fewer tumors, and
their tumors weighed 15 to 25 percent less. However, benefits from
pairing tea and isoflavones equaled or exceeded the sum of either
alone--a reduction of between 72 and 87.5 percent in tumor number
and a similarly large decrease in each tumor's size.
| Keywords: green tea health
benefits, green tea capsules, green tea extract, green tea
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green tea stomach cancer, green tea helicobacter pylori, green
tea h. pylori, green tea oral cancer, green tea
anti-inflammatory effects, anti-inflammatory green tea,
inflammation green tea, green tea cartilage breakdown, soy and
tea , the vitamin lady writes about health benefits green tea |
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