Antioxidants and Free Radicals
Antioxidants are a substance that protects cells from attacks by free radicals within the body. Some antioxidants include: beta-carotene, lycopene, vitamin A, vitamin C, Nasunin, vitamin E, and Lutein. The process by which free radicals attack cells is called oxidation. This is because oxygen atoms often play an important part in the process. The most prominent free radical is often referred to as "super oxide". Free radicals generally have an extra electron, making them especially likely to bond with another molecule.
Many free radicals are a natural by-product of regular body functions, such as the ATP-ADP cycle. Free Radicals can also come from outside the body from smoking, alcohol, pollution, sunlight, X-rays, and strenuous exercise. Particularly susceptible to the free radical bonding process are proteins, which includes the DNA within a cell. Some damage is inevitable. Besides damaging cells, free radicals can actually cause mutations within the DNA. However, antioxidants help minimize the damage.
Free radicals are associated with several diseases including Alzheimer's, cancer, heart disease, and Parkinson's.
Antioxidants have two ways of preventing cell damage. First, they can combine with the free radicals before they have a chance to combine with a molecule that is already part of the structure of the cell. Second, they can stop chain reaction oxidation where one free radical forms a bond, but then another free radical breaks from it another molecule with which to combine.
Coming in many forms, antioxidants can be nutrients, such as vitamins, but some powerful antioxidants come in the form of enzymes, including: superoxide dismutase, catalase, and glutathione peroxidase. They work together to get rid of free radicals, and to repair damaged DNA. Phytochemicals, coenzyme Q10, and uric acid are also thought to be able to fight free radicals. Substances like nasunin, which is found in the skin of eggplants can also act as antioxidants.
The optimum amount of antioxidants that should be taken in has not yet been determined. But it is known that a good mixture of vitamins and minerals is best because it allows the body to deal with free radicals in all its various organs. The best way to do this is to eat a variety of fruits and vegetables. Supplements can also be helpful. But the consumers should be careful. Very high doses of vitamin C or E can be toxic, and excessive amounts of beta-carotene has led to lung cancer in smokers.
In the matter of aging, it is thought that free radicals play a considerable role in accelerating the process, while antioxidants are currently considered one of the keys to a long and healthy existence.
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