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GREEN TEA THE ANTIOXIDANT
Green tea and its catechins are perhaps best known
for their antioxidant abilities. Antioxidants, which are found primarily
in fruits, vegetables and grains, are powerful natural weapons against
heart disease, cancer, stroke, Parkinson’s disease, Alzheimer’s disease
and the effects of aging, among other things.
You might be wondering why anything that’s anti-oxygen
would be good for you! But antioxidants don't work against oxygen;
they work against oxidation - the chemical reaction that turns
bananas black, makes oil rancid, and is believed to be a major cause of
disease. The harm caused by oxidation is called oxidative damage,
and substances that fight oxidation are called
antioxidants.
Free Radicals: Loose
Cannons in the Body
Oxidative damage is primarily caused by free radicals,
which are highly reactive, unstable molecules. Free radicals can
be generated by exposure to UV rays, toxins, cigarette smoke, microbes
and other sources. But the most common source of free radicals is the
oxygen molecule itself. It happens like this:
Oxygen typically roams around the body in pairs, and these double molecules
share electrons. But sometimes the pair splits and becomes two separate oxygen molecules called singlet
oxygen. Because singlet oxygen has been
separated from its twin molecule, it ends up missing an electron.
To compensate, it races
off throughout the body in search of another electron that will make it stabile
again.
Singlet oxygen is a very active molecule. It doesn’t just wait around for a spare electron to
float on by – it goes out and snatches one from another molecule. This upsets and
destabilizes the “new” molecule which, in turn, careens off in search of a
replacement electron from a third molecule. The process of
"electron stealing" repeats itself over and over, a chain
reaction rocketing from one molecule to
the next. Eventually, the stealing of electrons damages not only
molecules, but cells,
tissues, organs and even entire body systems. The damage caused by free
radicals like singlet oxygen is believed to be a
major cause of cancer, heart disease, aging and many other diseases or
conditions.
Antioxidants to the
Rescue!
Antioxidants like green tea’s catechins
work against "electron stealing" and oxidative damage by neutralizing
and stabilizing free radicals. They do this by donating an electron, so
that singlet oxygen and other free radicals no longer have the urge to
“steal.”
To learn more, click on some these key green tea/antioxidant studies and expert
opinions:
KEY HUMAN STUDIES
- 1) Green Tea Reduces Oxidative Stress
in the Bloodstream and Red Blood Cells
Drinking 11 cups of green tea daily for 4 weeks led to a significant
reduction in measures of oxidative stress in the bloodstreams and red blood
cells of 34 volunteers.
2) 2005 Controlled Study Indicates Green Tea
Increases
Antioxidant Activity
Researchers gave healthy volunteers 2 cups of green tea per day for a study
published in the Journal of Nutritional Biochemistry. Six weeks later,
those drinking the green tea showed a significant increase in antioxidant
activity in their bloodstreams.
3) Green Tea Reduces Oxidative DNA Damage In
Heavy Smokers
A randomized, controlled study published in the Journal of Nutrition
showed that drinking 32 ounces of green tea per day led to an increase of
catechins in the blood and a decrease in oxidative DNA damage among
smokers.
4) Green Tea Extract Improves Body's Ability to
Fight Oxidative Damage
A blinded, cross-over study published in the British Journal of Nutrition
in 2002 showed that green tea extract added to food could produce a short-term
improvement in the body's ability to fight the effects of oxidation.
KEY LABORATORY STUDIES
- 1) EGCg Guards Against
Oxidative Damage to Red Blood Cells
2) Green Tea Catechins Reduce LDL Oxidation
EXPERT OPINION
- 1) EGCg Levels in the Blood Are High
Enough to
Exert Antioxidative Activity
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