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Free Radicals
Oxygen Paradox
Oxygen is essential for life yet it is also inherently dangerous to our existence. This is known as the
oxygen paradox.
Oxygen is required in the normal metabolism within the cell to create energy (called oxidation) and in the process active free oxygen radicals are created. We produce free radicals with every breath we take.
Free radicals cause cut apples and potatoes to turn brown. They are also the cause of fatty meats turning rancid.
Free radicals are incomplete, unstable molecules.
Molecules are basic building blocks in nature such as oxygen, fatty acids, and amino acids. Electrons hold molecules together and normal molecules have pairs of electrons.
When the molecule loses 1 electron it becomes a free radical. It is unbalanced and is extremely reactive with other molecules.
In order to regain their missing electrons, they steal electrons from other molecules wherever they can and they (victim) becomes damaged in the process and become free radicals themselves. The stealing of electrons is a chain reaction. If they are not rapidly neutralized by an antioxidant they may create even more volatile free radicals or cause damage to the cell membrane, vessel wall, proteins, fats or even the DNA nucleus of the cell.
Cell damage by free radicals is called oxidative stress.
Scientific research has established that the root cause of more than seventy chronic degenerative diseases is due to oxidative stress, or cell damage by free radicals. (Calvin Davies, : Oxidative stress: The paradox of aerobic life,” Biochem Soc Symp, 61 (1995), 1-31)
Free radicals can burst through cell walls, alter the DNA thus causing the cell to malfunction.
Oxidative stress has the potential to overpower all of our protective systems and cause chronic degenerative diseases. When the damaged proteins, fats, cell membranes, and DNA structures are not properly repaired, they can create further problems in cell function. The mutations caused in the nucleus can result in cancer.
Damaged lipids lead to rigid cell membranes; oxidized cholesterol often leads to hardening of the arteries and poorly repaired DNA chains lead to cell mutation (future generation of cells) as implicated in cancer and aging.
As time goes on, our immune systems become less and less vigorous in their response to diseases and infection.
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Where do free radicals come from?
How do they enter our body?
Oxygen
As mentioned above, oxygen is one of the culprits.
4 main types of oxygen free radicals are produced in our bodies. They are singlet oxygen radicals, lipid peroxide radicals, hydroxyl radicals and superoxide radicals. Each of these destroy tissues.
Fats
Certain fats cause excessive free radical formation:
Polyunsaturated fats - these are found in mayonnaise, salad dressings and in many types of oils, such as sunflower, safflower and corn oils. These fats turn rancid easily when combined with oxygen.
They have 2 or more double bonds between carbons which make them more susceptible to lipid peroxidation. This forms significant numbers of free radicals in the form of lipid peroxide radicals.
Hydrogenated fats - these include margarine, most commercial peanut butter, vegetable shortening…. Hydrogenated fats and saturated fats both make platelets more sticky, increasing the risk of a clot, which could lead to a heart attack or stroke.
Hydrogenated fat is much more dangerous than saturated fat since it interferes with essential fatty acid functions. Hydrogenated fats also change the permeability of cell membranes, which impairs the cell membranes’ protective function.
Excessive Exercise
While researching for his book, In The Antioxidant
Revolution, Dr Kenneth Cooper realized that excessive exercise can significantly increase the amount of free radicals our body produces and he emphasized the fact.
Exercise releases free radicals. The harder you exercise, the more you release large amounts of free radicals. If they are not neutralized with antioxidants, cells, tissues, nuclear material and DNA may be destroyed and they may form cancer.
Excessive exercise can actually be harmful to our health, especially if we continue it over several years.
Dr Cooper recommends that everyone who exercise should balance it with antioxidant supplements.
Air pollution
Air pollution is a major cause of oxidative stress in our lungs and in our bodies. Air pollution contains ozone, nitrogen dioxide, sulfur dioxide, and several hydrocarbon molecules all of which generate a significant amount of free radicals. Exposure to these toxins daily can have a major effect on your health.
Occupational exposure to mineral dust such as asbestos fibers is another source. The addition of iron-containing fibers in asbestos can generate even more free radicals. Long term exposure has been shown to cause lung cancer and interstitial fibrosis (a serious scarring of the lung)
Free radicals are produced in normal day to day function such as breathing. They are also produced during exercise, after physical trauma and injury, during infections, emotional stress and aging. The level also goes up after strokes and after heart attacks.
Cigarette smoke, most drugs, alcohol and radiation are also culprits.
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Consequences of a Damaged Cell
What happens to the cell eventually affects the tissue, then the organ and eventually you.
When a free radical burst through the cell membrane seeking an electron, it damages the cell membrane and causes waste to build up.
Thus the cell's waste product cannot be released and the cell cannot be properly fed.
The mitochondria (energy factories) may also be damaged and this slows down all the actions of the cell.
If the specific protein that identifies the cell as self, in the cell membrane is damaged, the immune system may identify the cell as an invader and the cell could be destroyed by the immune system. If not destroyed it will replicate cells that are sick cell and damaged.
Free radical damage to certain cells in the eye can cause cataracts. If you have damage to an insulin-producing cell in the pancreas you might get diabetes, or damage to a nerve cell could begin a degenerative nerve disease such as multiple sclerosis. Oxidant damage to a cell can be very, very dangerous to your health.
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Free Radical Damage
Free radicals and aging
“Aging is a complex set of interactions between environmental insults and genetically defined factors….I believe oxidative damage is a major component of these environmental insults,” says Huber R. Warner of the National Institute of Aging.
Numerous animal studies show that the more free radicals loose in the body, the shorter the life span. Wear and tear is part of aging but these free radicals tend to cause our bodies to wear out fast then they have to.
Taking bodybuilders, steroids and growth enhancing drugs cause free radical harm to their bodies. Alcohol is also a major contributor to cell corruption. That’s why heavy drinkers age much faster.
Oxidative stress is the single greatest cause of aging and age-related diseases. It can be controlled by antioxidants and by calorie restriction.
Free radicals and heart disease
Cardiovascular disease is the leading cause of illness and death in many countries. Majority of these are due to atherosclerosis or blockage of the arteries, caused by the buildup of pulpy, fat containing materials in the artery walls (plaque buildup).
As the diseased arteries narrow, there is less and less blood flowing to the heart muscle, leading to heart attack. Current research suggests that oxidized low-density lipoprotein (LDL) may be the major cause in the development of atherosclerosis.
Free radicals and cancer
Cancer risk tends to increase with age. Research by Donald C Malins, Ph D. at the Pacific Northwest Research Foundation in
Washington has shown that free radical damage is involved in the development of cancer.
He was able to show that oxidant overload stressed the DNA of the cells faster than it could be repaired. As a result the DNA was damaged and set up to form cancer.
Radiation and chemotherapy also increases oxidant particles. Several studies show that adding antioxidants during radiation and chemotherapy reduces harmful side effects and improves the effectiveness of cancer treatment.
Although it is believed that genetics have a part in the development of cancer, current thinking is that the cell must get hit by free radicals a few times before becoming a cancer cell.
Free radical and Nerve and brain problems
The cells of the central nervous system are extremely vulnerable to free radical damage because they are rich in polyunsaturated fatty acids. The myelin sheath, which encloses some nerves is nearly all fatty material. Oxidative damage to this sheath causes multiple sclerosis.
Another disease of the nerves is Parkinson’s disease which results in muscle tremor, rigidity, slow movement, and loss of muscle control. A study done by Dr. Stanley Fahn, a neurologist showed that Parkinson’s is due in part to the loss of nerve cells from free radical damage.
What he did was to give one group of men and women with early Parkinson’s disease 3,200 IU of vitamin E and 3,000 mg of vitamin C a day, and another group a placebo. It was found that those taking vitamin E and vitamin C didn’t have to start medication till a few years later. The Salk Institute also reported that vitamin E prevents the death of key nerve cells. Our brain contains more vitamin C, about 50 times more than in the blood plasma, which indicates a greater need of vitamin C by this organ.
Free Radical and Macular degeneration
Age related macular degeneration is a disease characterized by a slow degeneration of a central part of the back of the eye called the macula.
This part of the eye gives us sharp focus, without which, reading, and other close work becomes impossible. It is thought that excessive oxidation causes the degeneration of the macula. Lipocuscin, the residue of oxidized cell debris and fatty acids, accumulates and damage the retina.
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