Understanding how free radicals are necessary to clarify that all the cells of our body need oxygen constantly, to convert the nutrients absorbed from food into energy. However, the burning of oxygen by cells (rust) has its price.

• Releases molecules of free radicals – molecules with an odd number of electrons, which are unstable and it have a negatively charged electron that tends to associate very quickly to other positively charged molecules, which can react or oxidize our organism.In this way, these free radicals can damage healthy cells of our body, generating possible chronic inflammations. So the excessive bombardment by these molecules damage the DNA of cells as well as other genetic materials.

However, the cells of our body (exposed to dozens of free radical attacks per day) has protective enzymes that repair the damage caused by oxidation. Thus, our body could control the level of these radicals produced through metabolism of oxygen, since all our organs/cells were in perfect working. Indeed,this process of oxidation( that occurs within our body) is not the only source of free radicals. There are external factors that may contribute to the excessive formation of free radicals,that can cause irreparable damage. Some of the likely causes of formation of free radicals in our body are:

• environmental pollution
• sun exposure
• Smoke from cigarette and fires
• harvests of vegetables, fruit and vegetables premature (makes them poor in nutrients)
• electromagnetic radiation ( such as Cell phones, microwave ovens, power lines etc.)
• Gases and effluent water expelled by polluting industries.
• Residues of pesticides and herbicides ,in which is infiltration into water sources and food crops.
• Substances present in foods and drinks such as pesticides, chemical additives, hormones in cattle and chickens, among others.
• Alcohol, alcoholic beverages, chemical drugs and synthetic drugs.
• Psychological and physical stress.
• Remedies containing oxidants.
• Excessive consumption of saturated fats like fried foods (the rancidification of fats and the color change of the ingredients is an indicate of oxidation process what causes the decrease of nutrients and increased toxicity.)
• Transplants of skin or organs.
• Heavy metal toxicity.

These elements will generate the oxidative process, which can vary from cellular injury to death going through various stages,since clinical symptoms,aging, degenerative disease to autoimmune disease.

Action of free radicals.

Free radicals must not be considered as villains, as the oxygen metabolism of our body the generate and control them. It should be clear that the excess of these substances generated and not removed for inability organic incapacity,it is toxic to our body and quite detrimental to our health.

Oxygen paradox means that oxygen is absolutely necessary for our organism, but it is extremely dangerous because it produces unstable particles called free radicals,that generate the oxidation of our cells are not neutralized immediately by our body's immune system or antioxidants. The most popular theory about the aging process is the result of free radicals that damage our cells. The longer people are exposed to external factors,the greater is the amount of free radicals that accumulate in the body - without neutralization or disposal capacity. Over time, this cumulative effect, can cause irreversible changes in the cells. For instance,it can encourage the growth of cancer cells and other fatal diseases.

In fact,the formation of free radicals that are not self- destroyed cause the weakening of the immune system, thus old age- such as pigmented spots on the skin, early wrinkles, cataracts, glaucoma, atherosclerosis, arthritis, among others are attributed to the action of free radicals. According to the scientific community some deadly diseases are caused by the presence of these radicals in the human body. The list is from cases of emphysema or something, strokes, Parkinson's disease, Alzheimer's disease, among others. In 1954, it was concluded that free radicals are the root cause of aging and this action can be enhanced by genetic and environmental factors. Nonetheless, free radicals are useful when you work in the fight against infectious microorganism.A concrete example is chemotherapy, which is managed large amounts of free radicals.

Nevertheless,the oxidation of proteins is reversible through action of antioxidants.These constitute a set of substances that disrupt the harmful effect of free radicals. It can be said that anti-oxidant system of aerobic organisms is essential for protection from free radicals, damaging what is characterized by oxidation/reduction actions in order to achieve a stable configuration.

Absolutely, an imbalance results in oxidative stress, which results in cellular damage, triggering physiological disorders and favoring the emergence of pathological processes (such as the oxidation of menbrana lipoprotein, glycoxidation and oxidation of DNA) that lead to cell death. From the damaged cells, necrotic, proteases and reactive oxygen attack adjacent cells, thus resulting in tissue damage. Almost all biological macromolecules can be oxidized by free radicals. The lipids are the most affected by oxidative stress. The various cells of the body, in particular the immune system cells, consist of high percentages of polyunsaturated fatty acids, and lipoproteins. These molecules are the most sensitive to the action of free radicals, resulting in lipoperoxidation process that causes the of the cell. In this way, the oxidative stress can harm the organism as a whole.

Antioxidants and Bioflavonoids

The production continues of free radicals during the metabolic processes generate the development of mechanism, supported by endogenous antioxidants as some metabolic and vitamins, enzymes that limit the existing levels of these elements in the human body, in order to prevent cell damage.

There are also exogenous abundant sources of antioxidanres in nature, where we can highlight, for example, vitamins A, C. E and Bioflavonoids. Flavonoids are polyphenolic substances, natural pigments widely distributed in plants, fruits and vegetables.

It has already been identified more than 5000 flavonoids. The term phenolic or polyphenol can be defined as a substance that has one or more aromatic hydroxy substituents containing kernels and/ou functional derivatives esters, glycosides and others.

The most common flavonoid found in nature are Flavonols, flavonones and flavones.The main sources of bioflavonoid are the citrus fruits, where are found the quercitine, hesperidin, rutin, narangina and limonene. Quercitine is a flavonoid present in the green/ yellow onions, apples, brocules, cherries, grapes and red cabbage. Hesperidin is found in Orange and lemon peel. Naranjina gives the bitter taste the fruit like Orange and lemon. Limonene is found in Orange and lemon-lime.

Recently, the medical investigations were intended to prevent diseases. Scientists have been focusing on the role of nutrients and their influence on health. In particularly, it concerns focus on reducing the risk of chronic and degenerative disease. Many investigations have focused on food with vitamin A, E and beta carotene. It is thought that they may commit a significant role in reducing the risk of chronic diseases by the ability to neutralize free radicals.More than these compounds, recently the xanthones show have antioxidant capabilities are much more intense than any of the traditional referred to as antioxidant nutrients. The process of generation of free radicals, antioxidants lose an electron without convert to equal the number of electrons that the free radical contains, make it less harmful.

There are 2 types of antioxidants:

1. Antioxidant enzyme systems - The body's defenses Act through enzymes containing a metal ion in its structure. These transfer an electron ion of metal to free radical by decreasing its capacity for reaction. These antioxidant enzymes contains iron, selenium, manganese, zinc and copper. No word yet on whether high doses of these minerals can have adverse consequences to the body. The investigations are focused mainly on nutrients Antioxidants.

2. Antioxidant nutrients-The antioxidant nutrients have active role against the attack of free radicals. For example, vitamin and attack by free radicals, acting as a buffer. This vitamin becomes a radical until it receives vitamin C, which return it in to the normal state. VitaminC can react with free radicals, acting as a blocker. The beta carotene plays a more important role than vitamin E in menbranas cellular protection, proteins and DNA. A molecule of beta-carotene may decrease the energy of 1000 unpaired oxygen molecules. In fact, the Bioflavonoids have great importance in protecting the body against the action of free radicals. The high antioxidant power of Bioflavonoids protect the cellular menbranas of lipoperoxidation. Moreover, it can indirectly minimize the effect of free radicals immunosuppressive by inhibiting the action of cyclooxygenase for reducing the formation of hydroperoxides (process fundamental to the transformation of arachidonic acid into PG H2, from which form the PGE2, PGD2 and PGF2. The laboratory test known as ORAC (Oxygen Radical Absorbance Capacity) measures the radical absorption capacity for a given substance.

According to some studies, a serving of Mangosteen Juice has 20-30 times more absorption capacity of free radicals than the same serving of fruits and vegetables. The ORAC test is one of the most accurate ways to measure the ability of antioxidants to absorb free radicals. It is important to note that a good diet, rich in vegetables, fruits and vegetables is the best way to prevent free radicals.

Furthermore, a portion of the oxygen that sigh turns into free radicals, therefore the own physical exercise is an important generator of these molecules. It must be remembered that free radicals also plays an important role by acting to combat inflammation by killing bacteria, controlling the tone of "smooth muscle". Antioxidants protect the bodies of damaging action of free radicals. Some antioxidants are produced by our own bodies when the vitaminase C, E and beta carotene are ingested. Considering that of all oxygen we breathe, 95% will be used to generate energy required for life and the remaining 5% are transformed into free radicals, i.e. are catabolic reactions, of destruction of the oxygen. As an example of free radicals include: superoxide, hydrogen peroxide and hydroxyl radicals. In the case of superoxide, it acquires an electron of an atom of iron, making it a free radical.

Indeed, the organism has own means of destroying undesirable substances, through the enzyme superoxide. It eliminates the enzyme superoxide, however “in doing so” creates a second toxic hydrogen peroxide. This substance is neutralized by another enzyme called peroxidase, which is found in great amount in the liver and Red globulos.

The combinations of reactions of superoxide with hydrogen peroxide will produce other more damaging and toxic that the above-the hydroxyl radical, which seems to be neutralised by antioxidants found in food. Free radicals are unstable substances of very short life that reproduce quickly and disappear when two of the free radicals and then occurs the destruction of these radicals.

The harmful effects caused by free radicals occurring in lipids, proteins, carbohydrates, nucleic acids in us and in lipoproteins.

Lipid-lipoperoxidation occurs, which is nothing more than the destruction of the cell menbrana. Proteins-enzymes inactivation occurs and the acceleration of oxidative phenomena with the structural change in collagen, which causes atherosclerosis.

Carbohydrates-occurs the depolymerization of polysaccharides, nucleic acids, the mutation of DNA and RNA. Lipoprotein-cholesterol oxidizes, favoring the production of LDL (harmful cholesterol) It is important to understand that a high level of free radicals plays a crucial role in processes infectious and inflammatory. Some of the white blood cells release enzymes that give rise to free radicals are essential to combat infectious States. The process of when oxygen gets to the site of inflammation and it is oxidized, generating free radicals that cause the death of the bacteria.

Antioxidants are substances that react and neutralize the reduced forms of oxygen are: Superoxide, hydrogen peroxide and hydroxyl radical. Some antioxidants are produced by our own bodies - such as vitamins C, E and beta carotene. The simplest definition for antioxidants is: Any substance that prevents other substance being oxidized. In a nutshell, free radicals are formed from the metabolism of cells of our body. Typically, it is formed by our organism, but in larger quantities becomes a problem for the maintenance of normal functions, causing conditions such as premature aging, certain cancers, arthritis and heart diseases. On the other hand, there are the compound antioxidants that fight free radicals formation. These compounds inhibit and reduce the damage caused by free radicals. To decrease the amount of free radicals and the increase the amount of antioxidants, here food plays an important role. The key is to consume every day foods rich in vitamins C, E, beta carotene and flavonoids. It's like a scale - increase the good factors and decrease bad factors.

Tips

• Foods to be consumed every day:
• Papaya and carrot (beta-carotene)
• Broccoli, salsa, grape, Apple (flavonoids)
• Orange, Tangerine, strawberry and pumpkin (vitamin C)

Don't forget, to improve your health and prevent disease, to make use of foods rich in antioxidants.

Athletes suffer more the action of free radicals?

Not necessarily. It is true that the polls will detect that the exercises cause an increase in the action of free radicals, but Edmund Bunker, Ph.D.,referes on his site "Endurox" some important points to be considered. First, the action of free radicals increases temporarily until return to the normal level. Second, in well trained people increased action of free radicals due to exercise is much smaller. This happens because the Regular physical activity increases levels of enzymes that destroy free radicals. A demonstration of this is the study conducted by the University of Tubingen Germany,in which men trained and untrained men performed a test of progressive intensity treadmill Ergometer until examination. The damage to the DNA in the cells of the blood was lower in decreased trained men, bearing in mind that the trained men ran longer and so consumed more oxygen (international Journal of Sports Medicine, 1996, 17:397-403)

Low/moderate exercises Intensity combat free radicals?

Yes, according to Dr. Kenneth Cooper the exercises come in 65-80% of maximum heart rate matter essential to combat free radicals. Without them the inner defences of the organism are at risk.

What is the amount of vitamins to fight the free radicals?

Most doctors and nutritionists recommend daily amounts of vitamin of the American Government's Department of agriculture (USDA). However, the superdoses of some vitamins have the endorsement of renowned researchers As the American scientist Linos Pauling (nobel prize in chemistry in 1954). Pauling self prescribed 10gramas vitamin C daily, equivalent to 200 glasses of orange juice. Dr. Cooper already recommends a daily antioxidant cocktail based on vitamins to combat the harmful action of free radicals. Beta carotene is a kind of vitamin A dismantled that the body mounts if it is necessary. Otherwise, it eliminates the leftovers, what is highly toxic. So, it is not recommended to purchase vitamin A supplements.

It’s actually the Nebula between the area needed for health and the harmful excesses. Opponents of megadoses claim that the body doesn't need more than a few milligrams of vitamin C a day, since the excess is eliminated through urine.

The American doctor Stephen Lawson, Director of the Linus Pauling Institute surveys, rebates saying that vitamin C takes 6 hours to be eliminated, so that during this period it becomes active, circulating in the blood. So the best strategy when supplementation of vitamin C is split the intake in smaller doses throughout the day. The National Institute of health, USA, revealed that the habit of eating vegetables rich in vitamin C decreases 13% the risk of heart attack. If this good habit is added to vitamin, the incidence falls 37%. It is not known the quantity of extra dose for preventive effect. But the question does not erase the fact that: 37% less likely to die of heart for having a healthy diet. Talking about vitamin E, Liz Applegate, Consultant Nutritionist Runner's Word, remember that several studies have shown that daily intake of 400ui protects athletes from damage caused by oxidative long-distance training. As nutritionist she'd love to say that it is possible to obtain 400ui by feeding but recognizes that this is very difficult.