& Healing Centre
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Antioxidants.
An antioxidant is a
molecule capable of slowing or preventing the oxidation of other molecules.
Oxidation is a chemical reaction that transfers electrons from a substance to an
oxidizing agent. Oxidation reactions can produce free radicals, which start
chain reactions that damage cells. Antioxidants terminate these chain reactions
by removing free radical intermediates, and inhibit other oxidation reactions by
being oxidized themselves. As a result, antioxidants are often reducing agents
such as thiols, ascorbic acid or polyphenols.
Although oxidation reactions are crucial for life, they can also be damaging;
hence, plants and animals maintain complex systems of multiple types of
antioxidants, such as glutathione, vitamin C, and vitamin E as well as enzymes
such as catalase, superoxide dismutase and various peroxidases. Low levels of
antioxidants, or inhibition of the antioxidant enzymes, causes oxidative stress
and may damage or kill cells.
As oxidative stress might be an important part of many human diseases, the use
of antioxidants in pharmacology is intensively studied, particularly as
treatments for stroke and neurodegenerative diseases. However, it is unknown
whether oxidative stress is the cause or the consequence of disease.
Antioxidants are also widely used as ingredients in dietary supplements in the
hope of maintaining health and preventing diseases such as cancer and coronary
heart disease.
