Health
Benefits of Green Tea
Black Tea and White Tea
Here's how tea helps your health:
Saves arteries. Drinking tea
helps prevent deadly clogging of arteries and reverses poor arterial
functioning that can trigger heart attacks and strokes, two major
new studies have found. In a large 10-year study in the Netherlands,
men who consumed the amount of antioxidants called "catechins" found
in three cups of black tea were 50% less likely to die of ischemic
heart disease, caused by narrowed clogged arteries, than were men
who consumed only the catechins in half a cup of tea. In another
recent test, Joseph Vita, M.D., of the Boston University School
of Medicine, had heart patients drink either plain water or four
cups of black tea daily. In a month, impaired blood vessel functioning
(a risk factor for heart attack and strokes) improved about 50%
in the tea drinkers.
Inhibits cancer growth. Tea
has long been tied to a lower risk of stomach, colon and breast
cancer, although the connection is not proven. Now lab studies find
that tea chemicals actually may stop cancer growth. Rutgers University
researchers showed that a compound in black tea called TF-2 caused
colorectal cancer cells to "commit suicide"; normal cells were unaffected.
"The effect is quite dramatic," said Rutgers professor Kuang Yu
Chen, who speculates that the chemical might one day be made into
an anti-cancer drug.
Tames inflammation. Researchers
at Case Western Reserve University gave arthritis-prone mice either
green tea or water. The human equivalent of four cups of green tea
daily halved the mice's risk of developing arthritis. Also intriguing:
TF-2, the newly discovered anti-cancer compound in black tea, suppresses
the Cox-2 gene that triggers inflammation, says research at Rutgers.
That's the same way the drugs Vioxx and Celebrex work. Also, in
a UCLA study of 600 Chinese men and women, drinking green tea halved
the risk of chronic stomach inflammation, which can lead to cancer.
Wipes out viruses. Previous
tests prove tea can neutralize germs, including some that cause
diarrhea, pneumonia, cystitis and skin infections. New research
by Milton Schiffenbauer of Pace University finds that black tea
and green tea deactivates viruses, including herpes. When you drink
tea, he says, chances are good you will wipe out viruses in your
mouth. Flu viruses, too? Possibly. A recent Japanese study showed
that gargling with black tea boosted immunity to influenza. Recent
research at Harvard indicated that tea chemicals stimulated gamma-delta
T-cells that bolster immunity against bacteria and viruses.
Burns calories. Most surprising,
green tea's antioxidant EGCG stimulates the body to burn calories,
notably fat. In a Swiss study, a daily dose of 270mg EGCG (the amount
in 2 to 3 cups of green tea) caused men to burn 4% more energy -
about 80 extra calories a day. Green tea did not increase heart
rate, and the calorie burning was not due to caffeine.
Plus: Canadian researchers
block cavities in mice by replacing their water with tea. Indian
eye researchers have retarded cataracts in rats by feeding the animals
tea extract. Israeli scientists block Parkinson's-like brain damage
in mice by giving them green tea extract or pure EGCG. W
For the best benefit ... Drink
both black and green tea, the regular kind sold in bags or leaves
in grocery stores. Their antioxidants are equal. But green tea boasts
special-acting EGCG. Bottled tea and instant tea have few antioxidants,
research shows. Herbal teas do not have the same health properties
as real tea (Camellia sinensis). Tea with caffeine has slightly
more antioxidant activity. Steep tea leaves or bags in hot water
3 to 5 minutes to thoroughly release antioxidants. Adding milk to
tea does not block absorption of antioxidants, new Dutch research
finds. Don't give much tea to kids. Tea "chelates" iron, removing
it from the body. That may help combat chronic disease but can cause
anemia in young people.
SCIENTIFIC
SOURCES
Tea
saves your arteries Arts IC, Am J Clin Nutr 2001 Aug; 74(2): 227-32.
Vita, J, Circulation, July 10, 2001.
Tea
tames inflammation Haqqi TM, Proceedings of the Nat. Academy of
Sciences, 1999; 96;4524-4529. Zuo-Feng Zhang, International Journal
of Cancer 2001; 92:600-604.
Tea
wipes out viruses Chou CC. Int J Food Microbiol 1999; 48:125-130.
Interview with Milton Schiffenbauer of Pace University. Kansenshogaku
Zasshi 1997 Jun; 71(6): 487-94. Jack F. Bukowski, Harvard Medical
School, Science News, August 21, 1999. p. 127.
Tea
burns calories Dulloo, AG. Am J Clin Nutr 1999; 70:1040-5.
Tea
vs. cavities Touyz LZ, Quintessence Int 2001 Sep; 32(8): 647-650.
Tea
vs. cataracts Thiagarajan G., Exp Eye Res 2001 Sep; 73(3): 393-401.
Tea
vs. Parkinson's-like brain damage Levites Y. J Neurochem 2001 Sep;
78(5): 1073-82.
As if the huge variety of exquisite, sensory pleasures that fine
tea affords us werent enough, the medical community continues
to shower praise in the form of reports about the positive effects
tea has on health and well being. As you continue reading you will
find a brief summary of the more substantiated accounts. Many of
the studies were conducted in Japan and China, predominantly green
tea-drinking countries, and are therefore based on green tea. Currently
there are, however, countless research programs being run in Europe
and America to examine the benefits of black tea - so we can expect
new results in the near future.
To understand the health benefits of tea, we must
look at the properties of teas that
are most frequently referred to in the reports:
Polyphenols - the primary biological
active ingredients of (green) tea are powerful antioxidants (catechins).
Antioxidants counteract free radicals in the body, which are thought
to contribute to cancer.
Essential Oils - they develop during
the production process from the active substances in the leaves
and give tea much of its aroma and fragrance.
Vitamins and Nutrients - Vitamin
C makes an impressive appearance in green teas. It is stated that
2 small cups of green tea have as much Vitamin C as a large glass
of orange juice. Tea is also a good source of manganese, potassium,
niacin, folic acid and trace amounts of Vitamins B1, B2 and K.
Cancer - Laboratory
studies have shown that the antioxidant properties of tea have an
effect against cancer by inhibiting formation of cancer causing
substances. This is one of the most important and widely studied
areas of the health benefits of tea.
Immunity -
Polyphenols have been shown to help increase the white blood cell
count which is responsible for fighting infection. The high vitamin
C content found in green tea also contributes, as it is a well studied
and accepted use in helping prevent and fight colds.
Cardiovascular
- Cardiovascular research suggests that a diet rich in the antioxidants
found in tea, is able to prevent heart disease and stroke. The tea
constituents have been shown to stimulate the circulatory system,
to strengthen the blood vessels and to decrease the cholesterol
level in the blood stream.
Digestion -
Essential oils and polyphenols aid digestion by increasing the flow
of digestive juices. Drinking tea during or after a high-cholesterol
meal has been shown to lower the increase in the fat content of
the blood.
Body Weight
- There are indications that certain teas such as Pu-Erh can assist
in reducing weight by having an effect on the fats in the blood
stream and in the tissues.
Teeth and Bones
- Many dentists recommend drinking tea because it is rich in fluorides,
a mineral that strengthens both tooth enamel and bones in a fight
against osteoporosis. The Polyphenols in tea were shown to affect
the bacteria in the mouth, thereby reducing the formation of plaque.
Germicide & Antibacterial
- Some studies indicate that tea acts as a mild germicide. In the
digestive tract it helps fight food poisoning and diseases like
cholera, typhoid, and dysentery. (Did you say that you were going
to Bangladesh this year?). Its antibacterial properties help to
inhibit certain throat
infections. In China, green tea is being used as a home remedy to
disinfect cuts and abrasions and to cure or prevent skin disease
and athletes foot.
Mental Activity
- Tests have shown that tea drinking improves concentration, alertness
and problem-solving ability.
Longevity -
The sum of the curative and preventive health benefits of tea tends
to indicate a healthier and longer life. Research continues to work
at finding more evidence by studying the different tea drinking
cultures.