The free-radical theory of aging
The free-radical theory of aging states that organisms age because cells accumulate free radical damage over time. Human beings are composed of cells that each performs specific functions (i.e. skin cells, heart cells, muscle cells, etc). As we age these cells become more and more damaged. Eventually, the collective cells that make up organs can become so damaged that the organ fails to function, such as the loss of vision or hearing as people age. This process of damage and dysfunction of the vital organs eventually leads to death.
A "free radical" is any atom or molecule that has a single unpaired electron in an outer shell. For most biological structures, free radical damage is closely associated with oxidative damage. As the name suggests, antioxidants like vitamin C prevent oxidation, because they are reducing agents. Dr. Denham Harmon, famous for having "discovered" free radicals or, developed the "free radical concept of aging” in the 1950’s." To summarize his theory: The nucleus of an atom is surrounded by a cloud of electrons. These electrons surround the nucleus in pairs. Occasionally an atom loses an electron, leaving the atom with an "unpaired" electron. The atom is then called a "free radical". When cells in the body encounter a free radical, the reactive radical may cause destruction in the cell. According to Dr. Harmon's free radical theory of aging, cells continuously produce free radicals, and constant free radical damage eventually kills the cell. It is these free radical molecules which rapidly react with other molecules, setting off a chain reaction of free radical formation. A molecule which is missing an electron now takes an electron from another molecule, which causes the other molecule to become a free radical. This goes on for quite some time. We therefore call this process the chain reaction of free radicals.
Cell membranes are made of unsaturated lipids. The unsaturated lipid molecules of cell membranes are particularly susceptible to this damaging free radicals process and readily contribute to the uncontrolled chain reaction. Oxidative damage, another name for the chemical reaction that free radicals cause, can lead to a breakdown or even hardening of lipids, which makeup all cell walls. If the cell wall is hardened (lipid peroxidation) then it becomes impossible for the cell to properly get its nutrients, get signals from other cells to perform an action (such as firing of a neuron) and many other cellular activities can be affected. In addition to the cell walls, other biological molecules are also susceptible to damage, including RNA, DNA and protein enzymes.
The primary site of free radical damage is the DNA found in the mitochondria. Mitochondria are small membrane-enclosed regions of a cell which produce the chemicals a cell uses for energy. Every cell contains an enormous set of molecules called DNA which provide chemical instructions for a cell to function. This DNA is found in the nucleus of the cell, which serves as the "command centre" of the cell, as well as in the mitochondria. The cell automatically fixes much of the damage done to nuclear DNA. However, the DNA in the mitochondria cannot be readily fixed. Therefore, extensive DNA damage accumulates over time and shuts down mitochondria, causing the cells to die and the organism to age. Dr. Harmon's theory implies that antioxidants such as vitamin C and vitamin E, which prevent free radicals from oxidizing (removing electrons from) sensitive biological molecules, will slow the aging process.
Dr. Harmon launched his theory by showing, for the first time, that feeding a variety of antioxidants to mammals extended their life spans. Common Cold The role of vitamin C in the prevention and treatment of the common cold has been a subject of controversy for at least 60 years. Public interest in the subject, stimulated originally by the vigorous advocacy of Nobel laureate Linus Pauling during the 1970s, continues to be high. Comparative studies have been carried out over a period of 65 years, although differing in specific percentages, all show a reduction of symptom days. The consistency of these findings points to a genuine biological effect.
More studies suggest that vitamin C may influence interferon production. Interferon is a protein produced as the body's first line of defence against viral infection. Where people were exposed to extreme physical exertion and/or exposure to significant cold stress, the collective evidence indicates that vitamin C supplementation reduced the chances of contracting the common cold. In fact, the most recent Cochrane Database Review of vitamin C and the common cold revealed vitamin C might be most effective against cold duration and incidence following intense exercise or exposure to extreme cold temperatures. Prevention The immune system protects against harmful substances from outside the body, as well as defective cells and substances created in the body.
This covers a broad range of health issues, from short-term infections to long-term degenerative disease development. The most familiar infections may be the common cold and influenza, but immune care is a year-round concern. While cold and flu medications can relieve many of the overlapping symptoms, they do not shorten the duration of the illness and often come with a list of undesirable side effects. They also fail to help prevent a cold or flu. Vitamin C helps maintain healthy white blood cell counts, the strength of the immune system, and it also helps increase production of interferon, immune-cell-derived proteins that contribute to the immune response by slowing, blocking and altering foreign substances. Vitamin C concentrations in the plasma and leukocytes rapidly decline during infections and stress. Vitamin C supplementation can improve various immune functions. .................................................................................................................................................................................................................. Smokers The ScienceDaily (Feb. 25, 2006) reported that a new study has found that supplements of vitamin C can largely stop the serious depletion of vitamin E that occurs in smokers, demonstrating for the first time in humans a remarkable interaction between these two antioxidants as they work. * Vitamin E is one of the first lines of defence in human lung tissue against the ravages of cigarette smoke, which creates destructive free radicals. If the body has adequate levels of vitamin E, this protective antioxidant can interact with the peroxyl radicals created by cigarette smoke and prevent the destruction of lung membranes. In this process, however, vitamin E can itself be made into a destructive radical. If adequate levels of vitamin C are present, it can help the vitamin E return to non-radical form and continue its protective role. But in the absence of adequate vitamin C, this process breaks down. For antioxidant vitamins to play a role in disease prevention, experts say, they usually have to be present in advance. They are less successful in addressing existing disease. The research also suggests a possible mechanism by which smoking can cause cancer. The Vitamin C foundation advocates prevention of illness and the ultimate prevention of many diseases that are smoke-related is to stop or never start smoking. * Other collaborators on this research were from Columbia University, The Ohio State University, the University of Washington, and Brock University in Canada. Richard Bruno, a doctoral student at The Ohio State University, was also a co-author. The research was funded by the National Institutes of Health.
VITAMIN C & your skin In recent years, the benefits of using vitamin C and derivatives of this vitamin in skin care products have been studied, and most results show that vitamin C can enhance the look of your skin in a couple of different ways. Firstly, vitamin C is an antioxidant, which means that it can combat the effects of free radicals in your body and on your skin. Free radicals are the unstable molecules in the environment that can cause aging of the skin. We find free radicals in excessive sun exposure, cigarette smoke and environmental pollutants. Vitamin C is denatured in the skin by exposure to blue light and also to ultra violet light in the group A. As with vitamin A we probably develop a chronic deficiency of vitamin C in all the areas of skin that are exposed to sunlight. Vitamin C does not seem to have any activity on DNA itself, but certainly does work on various enzymes in the body. Therefore vitamin C has both an anti-oxidant activity and a metabolic activity. Secondly, the use of vitamin C can also boost the production of collagen in the skin. Collagen is an essential protein that keeps your skin firm and toned. When collagen is not produced properly, your skin can begin to sag and will lose its vitality. Collagen is also an important element in the health of the connective tissue throughout your body. Vitamin C plays an essential part in the incorporation of proline into collagen and is also involved in the formation of elastin. With a deficiency of vitamin C impaired collagen is created and the skin can become more wrinkled. The replacement of vitamin C boosts the manufacture collagen. Because vitamin C can enhance the production of collagen, bringing this nutrient into your diet and skin care can help you look and feel better, reduce the look of wrinkles and improve your skin’s quality.
Vitamin C plays a very important in converting inactivated vitamin E back into an active anti-oxidant form of vitamin E. This is probably the reason why vitamin C has such an important role to play in the protection of cellular membranes even though it is a water soluble product while cellular membranes are mainly composed of lipid molecules. The use of vitamin C in scarring: The use of vitamin C for scarring of the skin is a recent discovery. In this case the vitamin C has to be delivered in high dosage to the skin and as a result of that more collagen will be formed and normal collagen that is often found tethering scars will be replaced with normal collagen and the scars will fill up to a degree and become less noticeable.
Risk of Stroke The amount of Vitamin C in your body may indicate how likely you are to suffer a stroke – the more you have the less the chances are of a Stroke! A Stroke is the developing loss of brain functions due to a rupture in the blood vessels supplying blood to the brain. Strokes can cause permanent neurological damage, complications and death if not promptly diagnosed and treated. It is the third leading cause of death in the United States. It is the leading cause of adult disability in the United States and Europe. It is the number two cause of death world-wide and may soon become the leading cause of death worldwide. Major strokes account for sudden death or disablement.
Of even greater importance is the slow destruction of neural tissues of the brain by many repetitive, small local thrombosis, or capillary rupture, with internal haemorrhage, in other words, little strokes. They happen, and most of the times pass unnoticed, with nothing more to indicate their passing than a slight dizziness or nausea. It is only when the summation of these minor brain injuries causes mental or physical deterioration, to a point where it is noticeable by the patient or family, that it becomes evident that something is wrong. Once the symptoms are visible, it is too late to do anything about it. In order to maintain the integrity of the vascular system of the brain, ascorbic acid (Vitamin C) is needed, as it is in any other part of the body except more so.
Several studies have shown that the higher the consumption of Vitamin C, the lower the incidence of vascular disease, including strokes. Others have shown that high plasma vitamin C concentrations are associated with a lower risk of stroke. The latest study published in American Journal of Clinical Nutrition (January 2008), confirms the previous. As a study of 20 649 people aged 40–79 y with an average follow-up of 9.5 y, it had the advantage of a large study population in whom many risk factors were measured. Plasma vitamin C was measured in all subjects. The study population had experienced 448 strokes, but those in the highest quartile of plasma vitamin C had 42% fewer strokes than did those in the lowest quartile. The authors concluded, correctly, that plasma vitamin C is a biomarker for the risk of stroke. All this research, conducted all over the world for the last four decades, indicates that the simple ingestion of 3 to 5 grams of ascorbic acid a day in several spaced doses may be sufficient to prevent the high incidence of heart disease and strokes.
The potential victims of these diseases may live a healthier and longer life. Vitamin C may slash diabetes risk According to a new study from Cambridge increased plasma levels of vitamin C may reduce the risk of developing diabetes by as much as 62 per cent. The new study, published in the Archives of Internal Medicine, was done on 21,831 men and women aged 40-75 years over a period of 12 years. The study showed a strong, inverse relationship between plasma vitamin C level and the risk of developing diabetes. Correlating blood levels of vitamin C and diabetes, the researchers found that men and women with the highest blood levels (at least 1.10 and 1.29 mg/dL, respectively) had a 62 per cent reduction in their risk of developing type-2 diabetes, compared to men and women with the lowest blood levels (less than 0.56 and 0.77 mg/dL, respectively). Authors of the report said: 'The strong independent association observed in this prospective study, together with biological plausibility, provides persuasive evidence of a beneficial effect of vitamin C on diabetes risk.
Vitamin C helps reduce both the physical and psychological effects of stress on people Vitamin C may help to reduce both the physical and psychological effects of stress on people. Recent Studies may have shown that Vitamin C abolish the secretion of cortisol. Cortisol is a hormone released by the adrenal glands in response to stress. Once it gets into the bloodstream, it is responsible for relaying the information of stress to all parts of the body and mind. People who have high levels of Vitamin C do not show the expected mental and physical signs of stress when subjected to acute psychological challenges. One recent study, published in an issue of Psychopharmacology, showed that objective and subjective stress indicators were consistently lower in people with high levels of vitamin C.
Recovery from a stressful situation was also faster. Dr. Stuart Brody led a team based at the University of Trier in Germany, which studied 120 patients. Half of those studied were given 1,000 mg of vitamin C. Such signs of stress as elevated levels of the stress hormone cortisol and high blood pressure were significantly greater in those who did not get the vitamin supplement. Those who received vitamin C reported that they felt less stressed. The amount needed to promote health under varying environmental conditions appears to be a lot greater than the amount needed to prevent deficiencies.
There is some evidence suggesting that prehistoric humans consumed large amounts of vitamin C in a tropical diet rich in fresh fruits. If so, the physiological constitution we have inherited may require far larger daily doses of vitamin C than the current recommended daily allowance, perhaps as high as 1,000 mg. Vitamin C is present in fresh, uncooked fruits and vegetables, especially citrus fruits and red and green peppers. Vitamin C is destroyed by cooking and exposure to light.
Vitamin C play a crucial role in the suppression of proliferation of several types of cancer A report published as recently as 1 June 2008 indicated that research done at the Department of Anatomy and Tumour Immunity Medical Research Centre, Seoul National University College of Medicine, Seoul, Korea found that Vitamin C plays a crucial role in the suppression of proliferation of several types of cancer. The study led by SK Lee and colleagues showed that vitamin C suppressed proliferation or growth of the human melanoma cells through the inhibition of cyclooxyrgenase (cox-2) expression and the modulation of insulin-like growth factor II production.
The conventional wisdom of how antioxidants such as vitamin C help prevent cancer growth is that they grab up volatile oxygen free radical molecules and prevent the damage they are known to do to our delicate DNA. Another study, led by Chi Dang, M.D., Ph.D., professor of medicine and oncology and Johns Hopkins Family Professor in Oncology Research, unexpectedly found that the antioxidants' actual role may be to destabilize a tumour’s ability to grow under oxygen-starved conditions. Many other studies suggest that people with a healthy lifestyle and a Vitamin C rich Diet are less susceptible to Cancer.
Lose weight faster with exercise & Vitamin C How can you lose weight quickly without starving yourself? A study conducted by Arizona State University found that people who supplemented their diet with extra vitamin C lost weight faster than those who didn’t consume enough of the nutrient. You only need 60 milligrams (mg) of vitamin C a day to meet your body’s basic needs, but according to the study, raising your daily intake to 500 mg could boost your fat burning potential during exercise by 39%.
You still have to exercise to reap the benefits. Probably the most interesting news from the scientific quarter is the study that suggests that vitamin C can help lower body fat levels, and that a deficiency in vitamin C may be linked to a gradual increase in body fat in people who aren't dieting. In the study, 20 obese men and women were either given a placebo or 500mg of vitamin C a day. All of the people in the study were put on a low fat diet. At the start of the trial, researchers found that those who had the most body fat also had the lowest levels of vitamin C (as measured in the blood). During the trial, those taking the vitamin C supplement had blood levels of vitamin C increase by 30%, and those taking the placebo had their blood vitamin C levels reduced by 27%.
Both groups lost the same amount of weight. However, those not taking vitamin C had an 11% drop in their ability to oxidize fat. The researchers found that body fat mass did decrease more in the group of people taking vitamin C, although they describe the difference as not being statistically significant.
High Cholesterol Information from several studies, suggest that vitamin C may help decrease total and LDL cholesterol and triglycerides, as well as increase HDL levels (the good kind of cholesterol). Cholesterol is a naturally-occurring fat which is required for good health. It performs vital functions in the body. It is the precursor to both the male hormone testosterone and the female hormone oestrogen, which cannot be made without it. Contrary to popular belief, in most people, the levels of cholesterol found in the blood have little to do with fats consumed in the diet. Cholesterol is manufactured in the liver in the amounts required by the body to perform its various functions.
Arteries are the large, elastic blood vessels which carry blood away from the heart, both to the lungs (deoxygenated blood) and to the rest of the body (oxygenated blood). They are composed of three layers which, in varying degrees are made up of various structural components, the most important of which is collagen - a soft, pliable, elastic substance, which allows the artery to stretch and contract under the control of muscle systems. Like all other cells in the body, the artery cells are constantly under attack from free radicals and other cell-damaging forces and are in a continual state or replacement and repair.
As a consequence, they need a constant supply of new collagen to replace the damaged cells, so as not to "spring a leak". Collagen is, itself, constructed of a number of components, not least Vitamin C. When there is insufficient Vitamin C in the body, new collagen cannot be formed to repair the damaged artery cells. This causes a problem for the body, which does not plan for future problems, but is only interested is surviving the "here and now". It therefore has to find something else to repair the damage and uses what could be referred to as the body's "band-aid", namely cholesterol. Molecules of cholesterol actually bind to the damaged sites, preventing blood loss and its disastrous consequences. High cholesterol is a sign of a problem, not the cause of the problem - and the problem is lack of vitamin C