Green Tea Health Benefits - Hype or Fact?
There
are actually three basic varieties of tea... green, black and oolong. All are
made from the leaves of the Camellia sinensis herb and the only difference
between them is the processes used to make them.
Green
tea is made by steaming the leaves easily. To make black tea, the leaves are
exposed to the air or fermented, which darkens the leaves and gives them taste,
while for oolong the tea leaves are only partially fermented.
The
flavours of teas vary depending on the location where the plants are grown.
Different growing conditions, horticulture methods, production processing, and
harvesting times also affect flavors. Teas from different areas can be combined
to make teas with a particular flavour, called blended teas. English Lunchtime
Tea, for example , is a blend of Chinese, Ceylonese and Indian teas.
Herbal
teas (such as chamomile and mint) are not really teas at all, as they are not
made from the Camellia sinensis plant. Drinking herbal teas is not viewed as
healthful as drinking green, black or oolong teas.
Green
tea and health
Green
tea has long been associated with a long together with healthy life in many
Eastern cultures. Nowadays, extracts from the tea are used in beverages, health
foods, and health supplements. But does it actually contribute to health?
Free
radicals are molecules that are damaged. These damaged molecules can,
successively, damage cells which may become cancerous. Antioxidants may reduce
or prevent some of this damage. Catechins are a version of antioxidant found in
tea leaves. They are part of a family of molecules called flavonoids which have
anti-oxidative and anti-carcinogenic options.
It's
the flavonoids that give green tea its reputation as a healthful drink. The
average quantity of flavonoids in a cup of this herbal tea is higher than the
quantity found in the same volume of other healthy drinks, such as fresh fruit
juices, wine or vegetable juices. Nonetheless the quantity of flavonoids can
vary widely between different teas and tea products.
Tea
making and drinking
You
get much more antioxidants from freshly brewed tea, compared with other forms
of the drink such as instant tea and decaffeinated tea. Nevertheless , to
maximise the anti-oxidants in green tea, you need to steep the tea for at least
three minutes; five minutes is usually ideal.
Most
people in most countries drink their tea hot. America, of course, is the
exception... about 85% of the dinner drunk in the US is iced tea. The problem
is that iced tea often contains relatively small amounts of catechins weighed
against hot tea. This is due to the way iced tea is made.
Iced
tea is usually made by boiling water to which often tea is added. Once the tea
has been stewed for about five minutes, the liquid is cooled by adding mineral
water to double its volume, after which it is refrigerated.
Adding
water dilutes the concentration of catechins. To make sure that ones iced tea
contains the same amounts of antioxidants as your hot tea, allow for the
dilution by adding 50% a lot more tea than usual to the boiling water.
Research
and health effects
Green
tea contains a variety of enzymes, amino acids, carbohydrate food, lipids,
sterols, polyphenols, carotenoids, tocopherols, vitamins, caffeine and related
compounds, phytochemicals and dietary minerals. Over the last several decades
it has been the subject of many scientific studies to determine the extent of
its reputed health benefits.
There
is some evidence suggesting that will regular drinkers of this tea may have a
lower risk of developing certain types of cancer and heart disease. But
practically nothing much has been proved conclusively through
rigorously-conducted clinical trials. Indeed, most of the claims made for the
health benefits of best detox teas use analyses of
its chemical composition, some in vitro experiments, and animal studies, rather
than studies made with people.
Cancer:
a systematic review conducted in 2012 stated that the evidence that green tea
can prevent cancer 'is inadequate and inconclusive'. The report did state
however that there is some evidence that this tea can cause a reduction in
confident types of cancer (ie, breast, prostate, and ovarian cancers). However
, there's no hard evidence that drinking tea may well prevent cancer in general
and more research is needed.
Heart
disease: some studies show that drinking this tea may subdue several risk
factors for heart disease, such as weight, blood pressure, and cholesterol.
However , America's FDA (Food & Drug Administration) has refused to allow
labels on packets of green tea to claim that the tea contributes to a good
heart, on the grounds that this claim is not supported by credible scientific
evidence.
Cholesterol:
green tea may lower low-density lipoprotein and total cholesterol levels in the
blood, according to several short studies. But it is not known whether the side
effects of this tea resulted in fewer deaths. In addition , the evidence does
not support the claim that this tea reduces the risk involving coronary artery
disease.
Diabetes:
there is some evidence that green tea may help control blood glucose levels.
However , this has not necessarily been widely tested in people and more
research is needed.
As
you can see, the healthful benefits of drinking green tea never have been
proved in human trials to any degree of confidence, though some recent studies
in Japan get that its consumption does result in a decreased risk of many
cancer, cardio-vascular disease, and dementia including Alzheimer's.
Out
of place concentrations: one study found that the particular catechins found in
green tea, if taken at extremely high doses, may well damage DNA. But to do so,
consumption would have to be many hundreds of times greater than the amounts
that could be obtained from taking in vast quantities of tea, which, for me,
makes the finding pretty irrelevant. Similar results from consuming out of
place concentrations of other antioxidants, such as vitamins E and C, have been
obtained in human trials.
Adverse
effects
My
own research has failed to uncover any adverse effects of drinking regular
amounts of green tea. By regular amounts I mean several cups a day.
However
this tea does contain caffeine. As people with irregular heartbeats or anxiety
disorders ought to be cautious about the amount of caffeine they ingest, they
should only drink moderate amounts of green tea, taking their other sources of
caffeine intake into account. The presence of caffeine also means, according to
the American Dietetic Association, that pregnant or breast-feeding women should
never drink more than one or two cups of green tea a day.
There
is also some evidence that green tea may interfere with the actions associated
with certain anti-cancer drugs, such as Bortezomib (Velcade) and other boronic
acid-based proteasome inhibitors. If you are taking these drugs, it's best to
consult your medical advisor about drinking this tea.
Conclusion
There
seems to be absolutely no harm in drinking fair amounts of green tea... in fact
, doing so may be very beneficial to your health, whether or not you are
diabetic.
Green
tea is also delicious and I realize it's helps me to relax. I drink at least
one cup last thing every night and always sleep like a log next.
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