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Antioxidants can be conceptualized in a number of different ways: as insurance against some of the more visible effects of aging; as a weapon in our fight to make our average life expectancy more closely resemble our ultimate lifespan; and as a line of defense against the risk of developing certain illnesses and diseases.
"Antioxidant" is a classification of several organic substances, including vitamins C and E, vitamin A (which is converted from beta-carotene), selenium (a mineral), and a group known as the carotenoids. Carotenoids, of which beta-carotene is the most popular, are a pigment that adds color to many fruits and vegetables -- without them, carrots wouldn't be orange, for example. Together as antioxidants, these substances are thought to be effective in helping to prevent cancer, heart disease, and stroke.
Conflicting reports on the health benefits of antioxidants and beta-carotene exist. It is difficult to know what to believe and whose advice to follow. It is best to remember that vitamin and mineral supplements should never be used as substitutes for a healthy, well balanced diet. It is also important to note that we can "over-supplement" our bodies, taking much more than the recommended daily value of certain vitamins and minerals. Vitamins A and E are fat soluble, meaning that excess amounts are stored in the liver and fatty tissues, instead of being quickly excreted, creating a risk of toxicity.
Your best bet is to eat a diet rich in fruits, veggies, and whole grains. Sweet potatoes, carrots, spinach, cantaloupe, and mangoes are great sources of antioxidants.
Function; Reasons For Use
At the molecular and cellular levels, antioxidants serve to deactivate certain particles called free radicals. Antioxidants are substances that reduce, neutralize, and prevent the damage done to the body by free radicals. Free radicals are simply electrons that are no longer attached to atoms. Instead of circling the nucleus of an atom (much like the earth circles the sun), free radicals are both free and radical enough to go careening through our cells, inflicting damage as they go.
A process called oxidation creates free radicals and this process happens in the context of normal metabolic processes and our everyday exposure to our environment. In other words, eating, breathing, and going out in the sun all contribute to the the process of oxidation, free radical formation, and the resulting damage that is caused to the cells of our bodies.
In humans, free radicals usually come in the form of O2, the oxygen molecule. The oxygen molecule wants to be oxidized, and this oxidation process can sometimes be carcinogenic. Free radicals are the natural by-products of many processes within and among cells. They are also created by exposure to various environmental factors, tobacco smoke and radiation, for instance.
If allowed to proceed unhindered, free radicals can cause damage to cell walls, certain cell structures, and genetic material within the cells. In the worst case scenario and over a long time period, such damage can become irreversible and lead to disease (e.g. cancer). This is where antioxidants come into play.
Free radicals cause deterioration of bone, joints and connective tissue; the wearing out of organs; the decline of the immune system; the irritating advance of the visible effects of aging; and even, possibly, to some extent, the aging process itelf.
Antioxidants play the housekeeper's role, "mopping up" free radicals before they get a chance to do harm in your body. Researchers have postulated that antioxidants prevent the possible carcinogenic effects of oxidation. Despite numerous studies carried out on the role of antioxidants in cancer and heart disease prevention, the jury is still out as to which groups of people, if any, benefit from taking antioxidant supplements.
Because free radicals are implicated in all these processes, minimizing and neutralizing their activity with antioxidants may allow us to live longer and healthier lives, look and feel better, and reduce or eliminate the risk of certain illnesses.
Some studies have shown that smokers with diets high in carotenoids have a lower rate of lung cancer development than their smoking counterparts whose carotenoid intake is relatively low. A more recent study, however, indicated that some beta-carotene takers, primarily smokers, actually had higher death rates.
Other research efforts have suggested that diets high in carotenoids may also be associated with a decreased risk of breast cancer. Also, vitamin C has been found to prevent the formation of N-nitroso compounds, the cancer-causing substances from nitrates and nitrites found in preserved meats and in some drinking water.
Many researchers claim that elderly people, especially those who have reduced their food intake, frequent aspirin users, heavy drinkers, smokers, and people with impaired immune systems may benefit from taking antioxidant supplements daily. In terms of heart disease and stroke, it is possible that higher levels of antioxidants slow or prevent the development of arterial blockages, a complicated process involving the oxidation of cholesterol. Moreover, antioxidants may deter the collection of plaque on arterial walls.
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Antioxidants can help with the following:
Antioxidants can help prevent the following: | | | | | Aging |  Cataracts | The risk of cataracts may be reduced by long term use of a daily multivitamin, recent study findings suggest. Researchers found that individuals who took a multivitamin or a supplement that contained vitamins C or E for more than 10 years had a 60% lower risk of developing a cataract, regardless of other risk factors. [Archives of Ophthalmology November, 2000;118: pp.1556-1563] |
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KEY | | Likely to help |  | | Highly recommended |
GLOSSARY
Antioxidant (Antioxidants)
A chemical compound that slows or prevents oxygen from reacting with other compounds. Some antioxidants have been shown to have cancer-protecting potential because they neutralize free radicals. Examples include vitamins C and E, beta carotene, the minerals selenium and germanium, superoxide dismutase (SOD), coenzyme Q10, catalase, and some amino acids.
Arterial (Arteries, Artery)
Blood that leaves the heart. When it leaves the right ventricle, it is venous blood; and when it leaves the left ventricle, through the aorta, it is fresh and oxygenated. After it has passed out to the capillaries and started to return, it is venous blood.
Beta-Carotene (Beta Carotene)
The most abundant of the carotenoids, beta-carotene has strong provitamin A activity and is a stronger antioxidant than vitamin A. It is widely accepted today as a cancer preventative. It is found in leafy green and yellow vegetables, often missing in children's diets. Beta-Carotene is believed to be a superior source of Vitamin A because it is readily converted into a more active form of the substance: your body converts it to Vitamin A as needed.
Cancer
Refers to the various types of malignant neoplasms that contain cells growing out of control and invading adjacent tissues, which may metastasize to distant tissues.
Carcinogen (Carcinogenic, Carcinogenicity)
Any agent that is cancer-causing.
Carotenoid
A group of red, orange and yellow pigments found in plant foods and in the tissues of organisms that consume plants. Carotenoids have antioxidant activity and some, but not all, can act as precursors of vitamin A. Studies have shown that several carotenoids other than beta-carotene are potent antioxidants that provide profound health benefits. Because of this, the scientific community has now recognized the importance of natural mixed carotenoids including beta-carotene.
Cataract (Cataracts)
A steadily worsening disease of the eye in which the lens becomes cloudy as a result of the precipitation of proteins. Most cataracts are caused by the functions of the body breaking down. Eye trauma, such as from a puncture wound, may also result in cataracts.
Cholesterol
A waxy, fat-like substance manufactured in the liver and found in all tissues, it facilitates the transport and absorption of fatty acids. In foods, only animal products contain cholesterol. An excess of cholesterol in the bloodstream can contribute to the development of atherosclerosis.
Free Radical (Free Radicals)
A free radical is an atom or group of atoms that has at least one unpaired electron. Because another element can easily pick up this free electron and cause a chemical reaction, these free radicals can effect dramatic and destructive changes in the body. Free radicals are activated in heated and rancid oils and by radiation in the atmosphere, among other things.
Immune System (Immune Response, Immunity)
A complex that protects the body from disease organisms and other foreign bodies. The system includes the humoral immune response and the cell-mediated response. The immune system also protects the body from invasion by making local barriers and inflammation. The process may involve acquired immunity (the ability to learn and remember a specific infectious agent), or innate immunity (the genetically programmed system of responses that attack, digest, remove, and initiate inflammation and tissue healing).
Liver (Hepatic)
The largest and one of the most complex organs of the body, the liver is responsible for much of the metabolism of fats, proteins and carbohydrates. It is the site of much of the body's detoxification. It is connected very closely with digestion and the regulation of blood sugar, among many other functions. Found behind the ribs on the right side of the abdomen, it has many important functions such as removing harmful material from the blood, making enzymes and bile that help digest food, and converting food into substances needed for life and growth. Hepatic: Pertaining to the liver.
Lung (Lungs, Pulmonary)
Organ of the body, located in the chest cavity which is designed to bring oxygen from the air into the blood stream, while also expelling carbon dioxide and other waste gases out of the body. Pulmonary: Related to the lungs.
Metabolism (Metabolic, Metabolize, Metabolizes, Metabolizing)
The chemical processes of living cells in which energy is produced in order to replace and repair tissues and maintain a healthy body. Responsible for the production of energy, biosynthesis of important substances, and degradation of various compounds. Also defined as the sum total of changes in an organism in order to achieve a balance (homeostasis): Catabolic burns up, anabolic stores and builds up; the sum of their work is metabolism.
Mineral (Minerals)
Plays a vital role in regulating many body functions. They act as catalysts in nerve response, muscle contraction and the metabolism of nutrients in foods. They regulate electrolyte balance and hormonal production, and they strengthen skeletal structures.
Selenium
An essential element involved primarily in enzymes that are antioxidants. Three selenium- containing enzymes are antioxidant peroxidases and a fourth selenium-containing enzyme is involved in thyroid hormone production. The prostate contains a selenium-containing protein and semen contains relatively large amounts of selenium. Clinical studies show that selenium is important in lowering the risk of several types of cancers. In combination with Vitamin E, selenium aids the production of antibodies and helps maintain a healthy heart. It also aids in the function of the pancreas, provides elasticity to tissues and helps cells defend themselves against damage from oxidation.
Stroke (Stroke-Type Event)
A sudden loss of brain function caused by a blockage or rupture of a blood vessel that supplies the brain, characterized by loss of muscular control, complete or partial loss of sensation or consciousness, dizziness, slurred speech, or other symptoms that vary with the extent and severity of the damage to the brain. The most common manifestation is some degree of paralysis, but small strokes may occur without symptoms. Usually caused by arteriosclerosis, it often results in brain damage.
Vitamin A
A fat-soluble vitamin essential to one's health. Plays an important part in the growth and repair of body tissue, protects epithelial tissue, helps maintain the skin and is necessary for night vision. It is also necessary for normal growth and formation of bones and teeth. For Vitamin A only, 1mg translates to 833 IU.
Vitamin C (Ascorbic Acid)
A water-soluble antioxidant vitamin essential to the body's health. When bound to other nutrients, for example calcium, it would be referred to as "calcium ascorbate". As an antioxidant, it inhibits the formation of nitrosamines (a suspected carcinogen). Vitamin C is important for maintenance of bones, teeth, collagen and blood vessels (capillaries), enhances iron absorption and red blood cell formation, helps in the utilization of carbohydrates and synthesis of fats and proteins, aids in fighting bacterial infections, and interacts with other nutrients. It is present in citrus fruits, tomatoes, berries, potatoes and fresh, green leafy vegetables.
Last updated: Apr 13, 2008
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