The
Properties of Green Tea: Dietary and Health Benefits
The properties and benefits of green tea have
been known for centuries in many Asian civilizations. However, green tea has
become increasingly popular in the west only in recent times, and it is only now
that mainstream science has started to take notice of the long purported health
benefits of green tea consumption.
Several key research studies have gathered
evidence in support of many of these claims. Studies have shown that green tea
consumption can have potentially positive impacts on cardiovascular health, can
help in the reduction of stress related health conditions and may also have a
role in preventing certain types of cancer.
This short report focuses on the effects of green
tea consumption on human health, as claimed by traditional wisdom, as well as
significant findings in recent scientific studies, with a particular emphasis
on its role in weight loss. The report will also take a look at combining the
effects of green tea, with other teas, under the process known as synergy.
Introduction
Tea, whether it is black, green or white,
originates from the leaves of different varieties of the plant Camellia
Sinensis. The difference between different types of tea (green tea, black
tea, white tea, oolong tea etc.) does not lie in the species of the plant
itself, but in the way the tea leaves are processed.
Green tea leaves undergo minimal oxidation as
opposed to black tea leaves, which helps it retain a high proportion of its
anti-oxidant content. While, there are many ways in which green tea is grown as
well as processed, the common factor between all these ways is that they ensure
that polyphenols and anti-oxidants are retained to the maximum.
Green tea in particular contains a high amount of
natural polyphenols known as flavonoids, which have become increasingly
interesting to researchers the world over due to their beneficial properties.
Green tea is also rich in minerals like chromium, zinc and manganese, and a
good source of vitamin C.
The Known Health Benefits of Green Tea
Green tea has a very long history, especially in
China, as Camellia Sinensis is
native to this region. So long has this brew been known as an agent of good
health, that it has been an integral part of ancient Chinese culture for over
4000 years.
It has been traditionally known to improve
overall health and well being, stave off disease, and maintain youth. More
specifically, green tea is thought to improve blood circulation, and maintain
good heart health. As it is thought to improve the circulatory system of the
body, it is also thought to ward off cardio-vascular diseases like angina and
stroke, as well as other conditions such as diabetes mellitus.
According to traditional Chinese wisdom, green
tea is also a stress buster and helps calm the nerves. It is known to be
generally good for mental wellbeing and is thought to help keep the mind nimble
and alert.
Green tea is traditionally thought to have
anti-ageing properties, both mentally as well as physically. By keeping the mind
agile and skin supple and youthful looking, and the body healthy, green tea is
thought to promote longevity.
Although these claims have been made for
thousands of years, it is only with the progress of modern science and medicine
that we are able to test them and understand the mechanisms which are actually
at work.
Let’s look at some specific research and findings
on the effects of green tea on health.
Research Findings on the Effects of Green
Tea
Green Tea is rich in naturally occurring
anti-oxidants known as salubrious polyphenols. The beneficial properties of
these anti-oxidants have been known to science for some time now: some of which
include boosting immunity, anti-ageing effects and anti-cancer properties.
With the help of research we have now come to
know that the anti-oxidants in green tea fight off harmful free radicals in the
body, an action which has numerous positive effects on health.
Effects on Cardio Vascular
Health
Research done specifically on green tea
consumption suggests that ingestion of green tea, either in the form of tea or
its extract, can reduce the risk of heart disease, and other cardio vascular
problems such as angina and stroke.
In a case control study conducted in Japan, subjects who consumed one
or more than one cup of green tea per day had a reduced risk of subarachnoid
hemorrhage by 26% and 44% respectively than subjects who did not consume the
green tea.
Green tea is known to improve the health and
condition of the cells that line the walls of arteries – known as endothelial
cells. Studies suggest that due to its anti-oxidation properties, it can help in
keeping these cells healthy and minimize the build-up of plaque in the blood
vessels. This finding has major implications for heart disease as well as blood
pressure-related conditions.
Stress Reduction and Mental Wellbeing
Green tea consumption seems to help reduce stress
and the symptoms of stress related disorders.
A 2009 Japanese study published in the American
Journal of Clinical Nutrition found that increased and more frequent intake
of green tea in subjects was associated with a lower incidence of depression and
symptoms related to depression.
Several other studies have suggested that green
tea may have a positive association with mental wellbeing and may also help
combat the effects of stress. Significantly, some studies have also linked
regular consumption of green tea with a reduced risk of developing Alzheimer’s.
Green Tea and Cancer
Green tea contains naturally occurring
anti-oxidants known as flavonoids in abundance. Naturally occurring
anti-oxidants are thought to have anti-carcinogenic properties and research is
still being undertaken to understand more about these properties. Based on
current findings, flavonoids are thought to include properties that may inhibit
tumor growth and invasion.
A study undertaken in China studied the eating habits of a large cohort of Chinese
women. The findings showed that the regular consumption of mushrooms in
combination with green tea was linked to a staggering 90% lower occurrence of
breast cancer.
Effects of Green Tea Consumption on Weight
Loss
There has been a lot of interest in scientific
circles in the effect green tea consumption can have on metabolism and fat
reduction. Studies have found that green tea can reduce the amount of bad
cholesterol and increase fat oxidation by a significant degree.
A study conducted in 2005 by the Division of Cardiovascular Medicine at
the Vanderbuilt University Medical Center in Nashville, Tennessee found that
subjects given enriched green tea extract for a specific period had over 16%
lower levels of LDL than the baseline as compared to the subjects that were
given a placebo drug.
Findings of a 1999 study published in the American
Journal of Clinical Nutrition showed that green tea has strong thermogenic
properties. Thermogenic substances boost metabolism which causes more calories
to burn. The study found that green tea caused a much higher level of fat
oxidation than could be attributed merely to its fat content. It was found that
as much as 4% of the overall energy expenditure in 24 hours could be attributed
to green tea extract. This expenditure was observed to be taking place during
the day. Since the body’s own rate of burning calories (thermogenesis)
contributes to 8-10% of daily energy expenditure, the burning of calories
caused by green tea translated to a staggering 35-43% increase in day time
thermogenesis!
In a 2003 study conducted in Taiwan on 1210 subjects, it was found that
test subjects who had regularly consumed tea for more than ten years had a
smaller waist circumference and waist to hip ratio, and lower percentage of body
fat. Out of these subjects, only 4% consumed regular black tea, and 96% consumed
either green or oolong tea.
In a controlled study conducted in France in 2001, the effect of green
tea extract was studied on 70 overweight men for 12 weeks. The findings showed a
4.6% decrease in overall body weight. The researchers also observed a reduction
of the waist to hip ratio by 4.5% in the test subjects.
In a Taiwanese study conducted in 2000, the effects of green tea consumption on fat
absorption in rats fed on a high sugar diet were observed. It was seen that
green tea lowered the levels of fat storage in the liver and heart, and reduced
apparent fat absorption.
Summary
Green tea has quite an impressive list of health
benefits, both claimed by traditional knowledge and wisdom, as well as those
that are proved and being proved by scientific research.
Its health effects are traditionally thought to
include boosting immunity, anti-ageing, stress reduction and the promotion of
overall good health. Many claims have received scientific backing by various
studies, and the strength of evidence for the numerous benefits of green tea is
increasing.
Some important findings have shown that green tea improves circulation, helps reduce
bad cholesterol levels, and significantly reduces the risk of
cardio vascular illness. Studies have also suggested green tea may have
anti-carcinogenic properties against certain cancers, and may also have a role
in preventing Alzheimer’s.
Green Tea.......Try something new!
Green tea consumption seems to help reduce stress
and the symptoms of stress related disorders.
A 2009 Japanese study published in the American
Journal of Clinical Nutrition found that increased and more frequent intake
of green tea in subjects was associated with a lower incidence of depression and
symptoms related to depression.
Several other studies have suggested that green
tea may have a positive association with mental wellbeing and may also help
combat the effects of stress. Significantly, some studies have also linked
regular consumption of green tea with a reduced risk of developing Alzheimer’s.
Green Tea and Cancer
Green tea contains naturally occurring
anti-oxidants known as flavonoids in abundance. Naturally occurring
anti-oxidants are thought to have anti-carcinogenic properties and research is
still being undertaken to understand more about these properties. Based on
current findings, flavonoids are thought to include properties that may inhibit
tumor growth and invasion.
A study undertaken in China studied the eating habits of a large cohort of Chinese
women. The findings showed that the regular consumption of mushrooms in
combination with green tea was linked to a staggering 90% lower occurrence of
breast cancer.
Effects of Green Tea Consumption on Weight
Loss
There has been a lot of interest in scientific
circles in the effect green tea consumption can have on metabolism and fat
reduction. Studies have found that green tea can reduce the amount of bad
cholesterol and increase fat oxidation by a significant degree.
A study conducted in 2005 by the Division of Cardiovascular Medicine at
the Vanderbuilt University Medical Center in Nashville, Tennessee found that
subjects given enriched green tea extract for a specific period had over 16%
lower levels of LDL than the baseline as compared to the subjects that were
given a placebo drug.
Findings of a 1999 study published in the American
Journal of Clinical Nutrition showed that green tea has strong thermogenic
properties. Thermogenic substances boost metabolism which causes more calories
to burn. The study found that green tea caused a much higher level of fat
oxidation than could be attributed merely to its fat content. It was found that
as much as 4% of the overall energy expenditure in 24 hours could be attributed
to green tea extract. This expenditure was observed to be taking place during
the day. Since the body’s own rate of burning calories (thermogenesis)
contributes to 8-10% of daily energy expenditure, the burning of calories
caused by green tea translated to a staggering 35-43% increase in day time
thermogenesis!
In a 2003 study conducted in Taiwan on 1210 subjects, it was found that
test subjects who had regularly consumed tea for more than ten years had a
smaller waist circumference and waist to hip ratio, and lower percentage of body
fat. Out of these subjects, only 4% consumed regular black tea, and 96% consumed
either green or oolong tea.
In a controlled study conducted in France in 2001, the effect of green
tea extract was studied on 70 overweight men for 12 weeks. The findings showed a
4.6% decrease in overall body weight. The researchers also observed a reduction
of the waist to hip ratio by 4.5% in the test subjects.
In a Taiwanese study conducted in 2000, the effects of green tea consumption on fat
absorption in rats fed on a high sugar diet were observed. It was seen that
green tea lowered the levels of fat storage in the liver and heart, and reduced
apparent fat absorption.
Summary
Green tea has quite an impressive list of health
benefits, both claimed by traditional knowledge and wisdom, as well as those
that are proved and being proved by scientific research.
Its health effects are traditionally thought to
include boosting immunity, anti-ageing, stress reduction and the promotion of
overall good health. Many claims have received scientific backing by various
studies, and the strength of evidence for the numerous benefits of green tea is
increasing.
Some important findings have shown that green tea improves circulation, helps reduce
bad cholesterol levels, and significantly reduces the risk of
cardio vascular illness. Studies have also suggested green tea may have
anti-carcinogenic properties against certain cancers, and may also have a role
in preventing Alzheimer’s.
Green Tea.......Try something new!