to a recent conference call with Dr. Larry McDade on Ellagic
Here To Listen
tea has been considered a medicinal remedy in Chinese
tradition dating back over 4,000 years. The observed health
benefits of this folk remedy now being validated by modern
scientific investigation include: lowers total cholesterol,
increases HDL cholesterol levels, reduces blood pressure,
acts as a "blood thinner" by inhibiting platelet
aggregation, reduces risk of heart attack and stroke,
reduces risk of cancer, enhances immune cell function,
improves digestion, and prevents dental cavities and gingivitis.
tea catechins are definitely included in a broad brush
approach to the health benefits of flavonoids, which includes
potential for the prevention and treatment of cardiovascular
disease, cancer, inflammatory conditions, asthma, periodontal
disease, liver disease, cataracts, and macular degeneration.
Epidemiological studies suggest that populations drinking
8-10 cups of Green tea daily have markedly reduced rates
of gastrointestinal cancers as well as lower rates of
cancer of the pancreas, breast, and lung. Japan, for example,
has a very low incidence of cancer which is thought secondary
to their relatively high intake of Green tea.
studies supporting the cancer protective effect of Green
tea demonstrate that catechins and other polyphenols inhibit
free radical precursors to cancer as well as block the
effects of other tumor promoters including estrogen, growth
factors, and cancer causing chemicals like benzopyrenes
anticancer effect of Green tea polyphenols, specifically
catechins, in human and animal studies has been impressive
enough for the National Cancer Institute to include Green
tea polyphenols in its "Designer Nutrient Program",
a research effort to investigate the cancer preventative
and therapeutic benefits of foods and food products.
international research reveals that Green tea catechins
have apoptic activity in human cancer cell lines including
prostate, skin, lymphoma, ovarian, colon, adenocarcinoma,
liver breast, lung, and stomach cancers.
tea consumption is protective for gastrointestinal cancers
in large studies. Green tea polyphenols have shown promise
in vitro as antineoplastic substances, due to their ability
to scavenge oxidative initiators of neoplasia (Yoshikawa,
and epidemiological studies indicate Green tea catechins
exert a protective effect against prostate cancer. Green
tea drinkers have lower rates of prostate cancer with
the lowest rate of prostate cancer in China with the highest
consumption of tea (Gupta).
properties of catechins against tumors found in laboratory
animals were reproduced recently when tested against four
human tumor cell lines from carcinomas of the breast,
colon, lung and melanoma. Epigallocatechin gallate was
the most potent catechin against all four tumor lines.
It was recommended that in vivo animal trials be conducted
prior to consideration of testing Green tea catechins
against cancer in humans.
tea inhibits cancer in laboratory studies by several mechanisms
including enhanced cell-mediated immunity, increased glutathione-S-transferase
activity (increases glutathione, a powerful intracellular
antioxidant), inhibits tumor growth rate, blocks tumor-induced
inhibition of intracellular communication, and scavenges
free radicals. Green tea polyphenols specifically block
the formation of carcinogenic nitrosamines.
volunteers were given Green tea in combination with 300
mg of sodium nitrate and 300 mg of proline, the formation
of nitrosoproline was strongly inhibited (Stich).
intake of Green tea polyphenols appears to have multiple
health benefits summarized below, including reduced risk
of cancer and cardiovascular disease:
Catechins protect against radiation, including increased
survival and decreased incidence of radiation-induced
Catechins have antimutagenic activity against both spontaneous
and chemically-induced mutations.
Catechins have anti-tumor activity, inducing phase I and
II metabolic enzymes that increase the formation and excretion
of detoxified metabolites of carcinogens, slowing the
rate of cell replication and thus the growth and development
of neoplasms, and preventing spontaneous and chemically-induced
Catechins are powerful antioxidants that inhibit oxidation
of LDL-cholesterol, reduce cholesterol levels, and reduce
body fat, resulting in a decreased risk of heart disease.
Catechins have regulatory effects on blood pressure and
high blood-pressure induced strokes. Individuals consuming
more than five cups a day having a 500% decrease in stroke
Catechins have antibacterial activity against foodborne
pathogenic bacteria and cavity-inducing bacteria, modifying
the intestinal microflora, reducing undesirable bacteria
and increasing beneficial bacteria.
Catechins have an antihyperglycemic action, lowering both
blood-glucose and normalizing insulin release.
Catechins show antiviral effects, inhibiting reproduction
of numerous viruses including influenza and human immunodeficiency
research is being published almost weekly on the remarkable
healing properties of Green tea catechins. Important studies
are summarized briefly below:
tea also reduces oxidative stress caused by smoking, including
decreased oxidative DNA damage, reduced lipid peroxidation,
and reduced urine levels of free radicals. Green tea appears
to significantly lower risk of cardiovascular disease,
even having a protective effect in smokers. Japanese males,
for example, have a relatively low risk of heart disease
despite the fact 75% of adults smoke tobacco.
"Japanese Paradox" is similar to the "French
paradox" in that the polyphenols in Green tea have
a protective effect against heart disease and cancer just
like the polyphenols in red wine protect the French against
cardiovascular disease in spite of their high fat diets.
Japanese males over 40, the protective effects of Green
tea against heart disease and cancer increased exponentially
in proportion to average daily tea intake comparing risk
in men drinking less than three, four to nine, and more
than ten cups of tea daily (Imai).
tea increases thermogenesis or fat oxidation. Green tea
catechins increased 24-hour energy expenditure, decreased
respiratory quotient, and increased urinary excretion
of nitrogen and catecholamines compared to controls and
those taking caffeine alone. Green tea catechins independent
of caffeine inhibit catechol O-methyltransferase, an enzyme
that degrades norepinephrine, causing a more sustained
effect of norepinephrine (adrenalin) on thermogenesis
and energy production from burning of fatty acids. This
occurred without a stimulatory increase in heart rate,
distinguishing Green tea from sympathomimetic drugs, which
can have adverse cardiovascular side effects (Dulloo).
tea inhibits viral infections by a mechanism similar to
elderberry flavonoids. Catechins bind to the hemagglutinin
of the influenza virus and inhibit its absorption to the
target cell, thereby inhibiting its ability to infect
the target cell (Nakayama).
tea correlates inversely with total serum cholesterol
in a study of 1300 Japanese males. Cholesterol level was
an average of 8 mg/dl lower in males drinking 9 or more
cups of Green tea per day compared to those consuming
zero to two cups per day (Kono).
tea lowers cholesterol by increasing fecal lipid excretion
in lab animals and may reduce levels in humans by a similar
mechanism of increasing bile acids (Yang).
summary, studies confirm that flavonoids in Green tea
have antibacterial, anti-inflammatory, antiallergic, antimutagenic,
antiviral, antineoplastic, antithrombotic, and vasodilatory
activity. Catechins from Green tea are potent antioxidants
that scavenge hydroxyl radicals, superoxide anions, and
lipid peroxyl radicals. In most experimental studies catechins
demonstrate superior antioxidant properties than Vitamin
C or E.
tea catechins have bacteriocidal activity at concentrations
of catechins found in a single cup of Green tea.
tea catechins inhibit oxidation of LDL cholesterol, lower
total serum cholesterol levels, and increase levels of
tea also contains components unrelated to the flavonoids.
Approximately 3.5% caffeine, 6.5% lignan, 1.5% organic
acids, 15% proteins, and 2% theanine, an amino acid that
has recently been shown to reduce blood pressure. Standardized
Green tea extracts contain on average 60-80% total polyphenols,
but may be as high as over 90%.
suggest that 200-400 mg of Green tea polyphenols approximates
the amount of catechins found in 8-10 cups of tea daily.
Unfortunately, it is difficult for most individuals to
consume the 5-10 cups of Green tea daily that research
has shown to be beneficial. Approximately 200 mg of Green
tea catechins in this formula corresponds to the amount
of catechins found in 5-8 cups of Green tea.