Antioxidants And Common Cold

Anti-oxidants have attracted a lot of interest in dealing with certain diseases including common cold. This apparently benign ailment affects humanity with a frequency that is probably not matched with any other disease. Though usually a self limiting condition, common cold can sometimes lead to complications, making it all the more important to find simple remedies that can deal with it.
Antioxidants and Common Cold
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Common Cold is still not mastered by modern medical remedies. One of the most promising options in its prevention and treatment are the antioxidants, substances that kill free radicals and thereby prevent damage to the body. In many ways, they are the bridge between modern allopathic theories of treatment and the ancient wisdom of alternative medicine and traditional cures.


Antioxidants like Vitamin C offer one of the very few medical options for dealing with common cold, a self limiting disease that is never the less responsible for a lot of suffering especially among children.

Antioxidants: An Overview

ANTIOXIDANTS are substances that slow

down the oxidation of lipids, proteins and other components of the cells of our body, thereby reducing the formation of free radicals - partially oxidized molecules that are very unstable and damage the cells by combining with its constituents.

In the human body, the antioxidant machinery consists of two components - METABOLITES that get converted in to active antioxidants by the ENZYME SYSTEMS. While the enzyme systems are produced within the body, the metabolites are essentially part of food and nutrition.

The main antioxidants in the body are VITAMINS C and E, CAROTENOIDS like Beta-Carotene, Lutein and Lycopene, ANTHOCYANINS, flavonoids and Selenium. Among these, vitamin C has been used in large doses of 0.2 to 8 gm per day for treating as well as preventing common cold. Other antioxidants are also considered to be beneficial for cold but experience with them is more limited.

Food Sources of These Antioxidants

Vitamin C is consumed commonly in the form of citrus fruits like lemon and oranges. Other sources are green pepper, cabbage, spinach, broccoli, kale, cantaloupe, kiwi and strawberries. Aronia berries and Indian gooseberries are also very rich in this vitamin.

Vitamin E or alpha-tocopherol is available in nuts and seeds like hazelnuts, fish, especially cold water oily fish and fish oils, whole grains like wheat germ, some cereals, apricots, avocados, mangos, sweet Potatoes, vegetables and peanut butter.

Beta carotene is the precursor of Vitamin A which is not an oxidant. Its main sources are egg yolks, milk, butter, liver, richly colored orange, yellow and green fruits and vegetables like spinach, pumpkin, carrots, broccoli, yams, sweet potatoes, cantaloupe, peaches, mango, tomatoes and whole grains.

Selenium, a trace element also has antioxidant properties and is found in Brazil nut which is its richest source. It is also present in some meats, some fish, including Tuna, and some nuts like walnut and Brazil nut. Lycopene is found in tomato in significant amounts. Lutein is present in eggs, dark leafy green vegetables and richly colored orange and deep yellow fruits and vegetables.

Antioxidants & Common Cold

Antioxidants have been used and advocated as a remedy for common cold, even though there remain many controversies and debates about their use in common cold.

The most widely used of all antioxidants in common cold is vitamin C. It strengthens the immune system and its role in treating cold has been proposed ever since 1970s when Nobel Prize-winning scientist Linus Pauling advocated mega doses of 8-10 grams of vitamin C per day to prevent and mitigate the symptoms of common cold. Subsequently, many clinical studies have shown that vitamin C is superior to a placebo in reducing the symptoms, duration, and severity of colds.

Another vitamin C researcher Dr. Harri Hemila, of the University of Helsinki in Finland, found during his review of 21 studies during the past 30 years that taking higher amounts of vitamin C in divided doses throughout the day produced the best results. Study subjects given 1,000 milligrams daily showed a 19 percent decrease in severity of cold symptoms.

However, there are many studies that also refute the claim of any

benefit of vitamin C in cold. The latest meta-analyses have indicated that it might be very difficult to make any final conclusion on the basis of available medical evidence, but that also does not establish that vitamin C provides no benefit. The strongest evidence of benefits of vitamin C have been observed in cases of marathon runners indicating that vitamin C may be more useful when used in cases of extreme stress. Most studies also indicate that higher doses of one gram and above of vitamin C per day in divided doses may be helpful. Larger doses of up to eight grams are likely to be more effective. However, the overall effects are less dramatic. Once the cold has set in, its severity and duration is reduced but only to some extent. If vitamin C is taken in large doses every day, then the chances of catching cold are reduced a bit, from 8 % in adults to 14% in children.

Mode of Action of Antioxidants In Common Cold

Antioxidants primarily act by reducing the damage imposed by free radicals, by reducing the formation of free radicals from the oxygenation of lipids and proteins. Their action is completed by the help of enzyme systems like SUPEROXIDE DISMUTASE, CATALASE and PEROXIREDOXINS, which help in converting a free radical to a stable state. For example, the free radical SUPEROXIDE or the HYDROGEN PEROXIDE (H2O2) made in the process of its neutralization are converted in to water.

The common cold is caused usually by viral infections, though in cases it can also be the result of allergic reactions, which may subsequently predispose to viral infections as well. In either case, damage to the cells by free radicals increases the vulnerability to viral infection. Antioxidants do not act against viruses, but have a strong impact on the damage resulting from free radicals. Thus all cases, where free radical induced injury is the reason for cold, can be prevented by use of antioxidants like vitamin C.

Another process by which vitamin C can help in preventing cold is by stimulating the release of INTERFERON, a protein substance that increases resistance to viruses, and enhances the movement of white blood cells that can kill micro-organisms. As it is a powerful antioxidant, vitamin C also prevents further cell damage when viruses or bacteria attack the immune system.

There is another theory called ‘ORTHOMOLECULAR MEDICINE’ that believes in flow of electrons as one of the main processes of living being. According to this system, vitamin C runs the immune system, by donating electrons to antioxidants, which then neutralize free radicals. According to this theory, vitamin C is involved in almost all aspects of fighting illness, including common cold.

All these analysis suggests the reasons why antioxidants are far more effective in preventing cold than curing it. By reducing the injuries caused by free radicals and by improving resistance to viral infection through interferons, it can help in preventing cold to some extent, but once cold sets in, body immunity will take its own time to fight against this disease.

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