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Green Tea
(Camellia sinensis)
DESCRIPTION
Green and black tea are derived from the same plant. However,
the method of production varies. The tea plant is an evergreen
shrub or tree which originated in southern Yunnan and the
Assam province of India. Camellia sinensis is now widely cultivated
primarily in China, Japan, North Africa and the Middle East.
The black tea that we are more familiar with as a morning
or afternoon beverage has been allowed to oxidise, whereas
green tea is produced by lightly steaming, then drying the
fresh-cut leaf, this process keeps the polyphenols (a group
of active compounds) intact.
The herb green tea contains many useful
compounds, several of which have an identified role in the
body. Others await further investigation.
HERBAL USES
According to traditional medicine, green
tea possesses stimulant, digestive, diuretic and antitoxic
properties.
SUGGESTED INTAKES
Part of the herb used: Leaves
Leaf extract 100-300mg daily
SUPPLEMENTAL USES
Green tea has been found to protect against
Atherosclerosis, is antihepatotoxic and a powerful antioxidant.
Antioxidant
Green tea polyphenols enhance antioxidant defence systems
and the activity of certain antioxidant enzymes. Studies have
shown that green tea polyphenols are better scavengers of
free radicals than vitamins C and E. (1) Green tea is particularly
effective at protecting against free radical damage in the
gastrointestinal tract.
Anti-tumour
Numerous studies have shown that green tea extract offers
protection against tumour development, by inhibiting harmful
carcinogens and nitrosamines which are mutagens. (2)
Green tea has proven effective in protecting
the skin against UV damage. (3)
Heart disease
Green tea has been found to decrease total serum cholesterol
levels without altering HDL cholesterol (4) and it may protect
against cardiovascular disease. (5)
Anti-inflammatory
Green tea has anti-inflammatory properties. (6,7)
SAFETY AND PRECAUTIONS
Green tea is safe from side effects.
Green tea products containing caffeine may
produce a stimulant effect (Anxiety, Insomnia, irritability
etc.) Caffeine-free extracts are available.
Pregnant and lactating women should consult
with a qualified health professional before taking green tea,
due to a lack of safety data at this time.
Green tea is not recommended for use by
children.
INTERACTIONS AND CONTRA-INDICATIONS
There are no interactions or contra-indications
listed for green tea.
REFERENCES
1. Cell Biophysics, 1989, 14:175-185.
2. Prev Med, 1992, 21;377.
3. Carcinogenesis, 1992, 13;6:947-954.
4. Prev Med, 1992, 21:526.
5. BMJ, 1995, 310:693-696.
6. Cell Biophys. 1989, 14:175.
7. Carcinogenesis, 1992, 13:947.
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