By Barry R Parker
Antioxidants (molecules that inhibit oxidation) play a central role in the body. They are, in fact, critical for life. Without them the cells in your body would soon be damaged beyond repair.
A cell can be damaged, or mutated, in several ways. Mutations usually occur when defects are created in DNA, which results in the production of defective or incorrect proteins. Many of these defects are caused by what are called free radicals. Free radicals are associated with oxygen, and since we breathe in oxygen continuously, there’s plenty of it in our bodies at any time. Basically, they are oxygen molecules that are missing an electron and are looking to snatch one from another molecule in a process called oxidation.
Despite the damage they do, free radicals play an important role in nature. An exposed apple decays and dries up, and an iron bar eventually rusts and disappears because of them. So nature uses them to get rid of things that are no longer needed. In the body, however, they can be a disaster. As you might expect, though, the body is programmed to get rid of them. To do this it uses antioxidants; it’s a highly efficient process, but sometimes a few manage to elude the antioxidants, and they can cause considerable damage. Strangely, though, they are helpful in some cases. The immune system, for example, uses them to fight infection.
But how does oxygen lose an electron and become a free radical? There are several ways. Radiation is one; others are cigarette smoke, smog, various chemicals, and they are even generated when you exercise. In addition, large numbers are produced in the “furnaces” within your cells, called mitochondria (they generate the energy that your body needs each day).
The large number of free radicals within mitochondria are, in fact, a serious problem because mitochondria has its own DNA (called mtDNA) which directs everything that goes on within it. And with so many free radicals around, the mtDNA is particularly vulnerable and gets attacked continuously.
Oxidative Stress and Disease
The constant production of large numbers of free radicals in the normal course of metabolism (plus other pressures from the environment, toxins in the air and water) places a heavy burden on our organisms, since they damage all components of our cells, including DNA, protein, cell membranes, and lipids. This produces what is called oxidative stress. And because it causes considerable damage to our cells, and it can cause cell death, it is now thought to be involved in many diseases such as cancer, Alzheimer’s disease, Parkinson’s disease, autism, MS and others.
Oxidative stress also causes the oxidation of LDL cholesterol which is a precursor to plaque formation and heart disease. And it has also been shown to be implicated in chronic fatigue syndrome.
Free Radicals and Aging
Free radicals are also now assumed to be related to the aging process, although there is some controversy about exactly how they are related. A theory referred to as the “free radical theory of aging” was put forward in the 1950’s by Dunham Harman. A few years later it was modified to include several diseases such as cancer, Alzheimer’s disease, Parkinson’s disease, diabetes and several others. Then in 1972 Harman introduced his “Mitochondrial theory of aging” in which free radicals acting on mitochondrial DNA played a central role in aging. Although there’s no doubt that free radicals play some role in aging, the problem with these theories is that dietary and supplements of antioxidants, which should control the free radicals that are produced, do not appear to extend our life, or even decrease the incidence of disease. The main problem at the present time is that we do not yet fully understand all the details of how free radicals, or even antioxidants, act in the body.
Having a good supply of antioxidants in your body is critical, and there are three ways you can get them: through the food you eat, through supplements, and your body also produces some.
Some of the major antioxidants are:
- Vitamins C, E and A
- Alpha lipoic acid
Glutathione is synthesized in your body from amino acids. It is one of the most important cellular antioxidants, and is found in all cells. Alpha lipoic acid is also present in all cells in your body. It is used in the conversion of glucose (blood sugar) into energy. It also helps recycle several antioxidants when they are used up. Selenium is not directly an antioxidant. But it is required to initiate the activity of some antioxidants. It also helps in the production of glutathione.
The Best Sources of Antioxidants
Although you can get antioxidants both from food and supplements, but it is best to get them from food. The best food sources are vegetables and fruit (it’s important to note, however, that processed food contains fewer antioxidants than fresh or uncooked foods). Other types of foods that contain smaller amounts are nuts, whole grains, with even smaller amounts in meat, poultry, fish, eggs and coffee.
Some of the best vegetables are:
- Brussel sprouts
Some of the best fruits are:
- Pink grapefruit
The Controversy with Supplements
Vitamins C, E and A, along with selenium, grape seed extract, pycnoginol and reversatrol are all well-known antioxidant supplements. But recent studies have shown that there are problems with antioxidants in supplement form. They show that supplements don’t appear to extend life; nor do they appear to be directly helpful in relation to most serious diseases such as cancer. Indeed, if taken in large amounts they may even have adverse effects. This is strange in that fruit and vegetables, which contain large amounts of antioxidants, are particularly good for you and do appear to ward off some diseases. The reason that fruit and vegetables are so much better, according to most scientists, is that they contain large numbers of other excellent nutrients besides antioxidants and they also likely have an effect.
A few antioxidants, however, do appear to be directly helpful. Lipoic acid, for example, seems to protect mitochondria, and studies have shown that it is also helpful in slowing macro degeneracy of the eyes.
Significance of Antioxidants in Relation to Exercise
Large numbers of free radicals are also created when you exercise, and they produce oxidative stress that can last up to 24 hours after the exercise. During the exercise many muscle cells break down and die and must be replaced, and they are usually replaced by larger and more powerful cells. Antioxidants play an important role in this process. But strangely, free radicals are also used for removing dead cells, and if there are too many antioxidants present they can delay recovery.
So the role of antioxidants in relation to exercise is a mixed bag. You don’t want too many, but they are used by the immune system and they also help strengthen the glutathione system which helps decrease oxidative stress.
Barry Parker is a professor emeritus (physics) at Idaho State University who now spends most of his time writing. He is the author of 26 books on science, health writing, and music, and he has written for the Smithsonian, Encyclopedia Britannica, Time-Life Books, the Washington Post, and numerous magazines such as Flyfisherman, Astronomy Magazine, and Sky and Telescope. One of his books is “You Should Write a Book: Writing it With Style and Clarity, Publishing Beautiful Pages, Selling Thousands of Copies,” It is based on a course he taught at ISU for several years, and is available through his website BarryParkerbooks.com. He is also the author of “Feel Great Feel Alive” which is on health, fitness and self-improvement, and he is CEO of Stardust Press. While at ISU he did research on the DNA molecule and on Einstein’s Theory of Relativity. His latest book is “Learn from Yesterday, Live for Today, Hope for Tomorrow.”
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