阿客保
Natural and Holistic Therapy
Comprehensive Holistic Therapy that
is Good for Health and Fitness
CHINESE GREEN TEA
What's with all the hype about green tea
health benefits?
Ordinary
tea, as most people know it, comes from the leaves of the camellia
sinensis plant. There are three main types of tea: green tea, oolong
tea, and black tea, categorized according to their oxidation levels
(called the fermentation process). Green tea is steamed, baked, or pan
heated to prevent oxidation and thus the leaves remain green. Unlike
green tea, oolong tea is partially fermented, and black tea is fully
fermented.
So why is green tea getting all the attention in the science world? It's
mainly because of the antioxidant epigallocatechin-3 gallate ( EGCG ),
the main component considered good for one's health which is preserved
in green tea but lost in oolong and black varieties when fermented.
Antioxidants are thought to prevent free radicals.
Free Radicals - What exactly is a free radical?
A scientific explanation: In essence, a free radical is any molecular
species capable of independent existence, that contains one or more
unpaired electrons not contributing to intermolecular bonding, and is,
in that sense, "free". They are produced by oxidation/reduction
reactions, in which there is a transfer of only one electron at a time,
or when a covalent bond is broken and one electron from each pair
remains with each atom. Thus, a free radical has an unpaired electron.
Many free radicals are highly reactive, owing to the tendency of
electrons to pair; that is, to pair by the receipt of an electron from
an appropriate donor or to donate an electron to an appropriate
acceptor. Whenever a free radical reacts with a non-radical, a chain
reaction is initiated until two free radicals react and then terminate
the propagation with a 2-electron bond, with each radical contributing
its single unpaired electron. The free radicals of special interest in
aging are the oxygen free radicals (OH., H., O2.-). These free radicals
often take an electron away from a "target" molecule to pair with their
single free electron; this is what is commonly termed oxidation. The
term reactive oxygen species is used to refer to these oxidants and the
oxygen free radicals.
In the human body, oxidized free radicals are believed to cause tissue
damage at the cellular level, causing damage to our DNA, mitochondria
(the powerhouse of the cell), and cell membrane, and have often been
referred to as one of the causes attributed to aging, cancer, heart
disease, and other human ailments harmful to one's health. While the
green tea ion of free radicals is a normal part of metabolism at the
cellular level, things such as excessive alcohol intake, smoking, and
various chemical exposures only serve to increase the amount of free
radicals present in the body. To prevent free radical damage the body
has a defense system of antioxidants.
Antioxidants - What exactly is an antioxidant?
Antioxidants are molecules which can safely interact with free radicals
and terminate the chain reaction before vital molecules are damaged (as
in Vitamin C), or seek out and scavenge free radicals ( as in Vitamin E
). This is where it can be noted that research has indicated that one of
the main antioxidants found in green tea ( epigallocatechin 3-gallate
a.k.a. EGCG ) has been found to be much more powerful than both Vitamins
C and E. Compared to other known antioxidants, EGCG was found to be 100
times more effective than vitamin C, 25 times more effective than
Vitamin E and twice as powerful as resveratrol at neutralizing free
radicals.
Valid CSS