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Antioxidants are substances that neutralise free radicals. Among the antioxidants are vitamins C, E, beta-carotene; mineral nutrients such as selenium, copper and zinc; bio flavonoid, coenzyme Q 10 and many other substances, some of which are manufactured by the body.
Antioxidants react quicker with free radicals than other substances. They become radicals themselves as they give an electron to the radical.
Effect of Antioxidants
There are many studies which have been done to examine the effect of antioxidants. It is assumed that certain antioxidants such as vitamin C, E and beta-carotene reduce the risk of cancer by "catching" the free radicals as oxidative stress is seen as a cause of cancer. However, this assumption on the effect of antioxidants has not been proved in any of the studies. The Physician's Health Study [Lit-1] was a study carried out with 22, 000 physicians who took a beta-carotene supplement or a placebo (inactive pill that looks like the vitamin) daily for twelve years and it could not be proven that the intake of beta-carotene could reduce the risk of cancer and heart disease.
The Finland Study [Lit-2] was a double-blind study carried out with 30,000 smokers who took vitamin E, beta-carotene and a placebo daily for eight years. The results showed that the group of smokers who took the placebo medication had the lowest mortality rates. The group of people that took beta-carotene showed an 18% increase in cancer-related deaths than the other groups. The American CARET Study [Lit-3] was yet another study carried out with 18,000 participants who either took a combination of beta-carotene and vitamin A or a placebo. The study was aborted after it suggested that there was a 28% increase in lung cancer in the vitamin group and that the life expectancy of this group decreased by 17%.
The reason for the negative effects of the intake of artificial antioxidants is that the antioxidants can begin to function like radicals under certain conditions. The higher levels of antioxidants can have pro-oxidant effects. This means that the balance of the oxidising and the oxidised substances is affected as a result of the excess supply of antioxidants.
Literature references:
[Lit-1] C.H. Hennekens et al: Lack of effect of long term supplementation with beta carotene on the incidence of malignant neoplasms and cardiovascular disease. New England Journal of Medicine, 1996, 334, S.1145.
[Lit-2] The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group: The effect of vitamin E and beta carotene and the incidence of lung cancer and other cancers in male smokers. New England Journal of Medicine, 1994, 330, S.1029.
[Lit-3] G.S. Omenn et al.: Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. New England Journal of Medicine, 1996, 334, S.1150.
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Free Radicals:
Free radicals are molecules or fragments of the molecules that have unpaired or missing electrons. The radical tries as quickly as possible to pair itself with a reaction partner in order to make it a stable molecule. Free radicals are completely reckless when looking for bonding possibilities. They aggressively separate intact structures. As a result, the free radicals create further unpaired molecules which are left with the same problem - i.e. they also begin the search for bonding possibilities. A dangerous chain reaction occurs as a result of this "electron-theft".
Free radicals are very reactive which means they are capable of causing considerable damage to the metabolism of cells by "stealing" the cell membranes, proteins or DNA electrons from the molecules. Illnesses are caused by the accumulation of such cell defects. It is often discussed whether illnesses such as cancer, arteriosclerosis, eye cataracts and Alzheimer's are caused by free radicals.
What causes free radicals?
- The body's own metabolism (production of energy)
- UV-radiation (UV-radiation has enough energy to destroy chemical bonds and form free radicals in the skin.)
- Nuclear radiation
- Environmental pollution.
Normal metabolism constantly produces a restricted amount of free radicals. Our bodies are not helplessly exposed to the potential dangers of radicals. The human body has highly efficient protection and reparation mechanisms. The body's enzymes and the dietary consumed antioxidants provide the charge that free radicals are looking for. This neutralises the unpaired molecules. However free radicals do not only have negative effects on the body. For example the human immune system produces great amount of radicals to fight off pathogenic germs.
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The Antioxidant Miracle: Put Lipoic Acid, Pycogenol, and Vitamins E and C to Work for You
Earl Mindell's New Vitamin Bible,
Earl Mindell, Hester Mundis
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