Antioxidants: What They Are, How They Operate and What Are Its Benefits

The antioxidants are in the “mouth of the world” due to the benefits it presents for health. Come and get to know better these compounds and their functions.

What are Antioxidants

When it comes to the antioxidants, all the people he knows that are substances present in some food and that are very important to the body due to the benefits that they present.

In fact, since the 80’s, a growing number of studies have confirmed that many of the most common diseases of the TWENTIETH century are associated with a shortage of antioxidant nutrients.

There is, therefore, an association between the low consumption of antioxidants and the incidence of chronic diseases, and their presence in food and their levels in the blood one of the best indicators to prevent disease.

Let’s explore, then, in a more detailed way, which are the antioxidants, the real importance of these compounds in the body and the foods where we can find.


Every day we are exposed to aggressive agents that impair the normal functioning of the body, inducing or increasing the risk of the onset of certain diseases, such as premature aging, cancer, diabetes, cardiovascular diseases, degenerative diseases, among others.

These aggressive agents are called free radicals and may come from the external environment, including stress, solar radiation, pollution, tobacco, and food, among others, or be produced internally, resulting from the metabolism of energy endogenous.

These free radicals are substances that are unstable, chemically reactive and very dangerous, to the extent that react with other molecules, including our cells, causing oxidation and consequent degeneration.

Under normal circumstances, the electrons are arranged in pairs, which gives them stability. In a free radical, there is always one or more electrons free / unpaired in its structure.

The elements of our cells that are at greater risk of damage by the free radicals are the proteins, the lipids of cell membranes and the DNA that contains the genetic information.


To gain stability, the free radical “takes” an electron from a molecule or atom neighbor or “gives” an electron to a molecule/atom neighbor.

To assist the body in combating these substances, there are antioxidants, substances able to stabilize free radicals by providing an electron missing, without being adverse or unstable. Are, therefore, molecules able to inhibit the oxidation of other molecules.

In addition to the prevention of the diseases already mentioned, the antioxidants raise the fertility, reduce inflammation and play an important role in chronic fatigue.


Even though our body has antioxidant endogenous, the supply of antioxidants through the diet(antioxidants exogenous) is fundamental to strengthen the body’s defenses and prevent the development of diseases already mentioned.

This reinforcement is particularly important in situations where exposure to free radicals is greater or situations in which the body is more weakened, for example in situations of disease.

Além disso, muitos dos antioxidantes endógenos necessitam de diversos minerais e vitaminas (antioxidantes exógenos) obtidos através dos alimentos para atuarem eficazmente.

So, to combat the oxidative stress, that is, the excess oxidation of cellular components, antioxidants can have beneficial effects for health.


In terms of the antioxidant endogenous, we have the SOD (superoxide dismutase), catalase, CoQ10 (coenzyme Q10), ALA (alpha lipoic acid) and glutathione peroxidase (along with glutathione), the latter being considered the main endogenous antioxidant.

The SOD, catalase and glutathione peroxidase act together, by converting the free radicals into neutral elements, such as water and oxygen. Glutathione can repair cellular damage, and in conjunction with the ALA and CoQ10 regenerates other antioxidants endogenous.

The antioxidants endogenous can not be obtained via food. However, to ensure a good production and action of these antioxidants, necessary vitamins and minerals that act as their cofactors.

For example, glutathione peroxidase needs selenium, an antioxidant exogenous, to be able to act on free radicals. For the system of glutathione to function properly, you are still required adequate levels of vitamin B2 and magnesium.


The antioxidants exogenous are, in most cases, vitamins and minerals / trace elements that the body cannot produce and therefore must be obtained from food.

Minerals / Trace Elements

  • The zinc is extremely abundant in oysters, being these their main food source. Can also be obtained by eating meat, fish, milk, cheese and legumes. This mineral helps strengthen the immune system and to suppress the damage caused by free radicals, being an integral part of antioxidant enzymes, such as superoxide dismutase (SOD).
  • The selenium is present in foods such as meat, fish, whole grains, and brazil nuts. It is an antioxidant vital, especially when combined with vitamin E, protects the immune system by aiding in the promotion of the synthesis of antibodies.
  • Magnesium can be obtained through consumption of dried fruits oleaginous, seeds, legumes, fish and cocoa.
  • The manganese from foods such as fish, whole grains, spinach, oleaginous fruits, and seeds.
  • The copper is present in the oleaginous fruits, but also in legumes, pork, and chicken.


  • Vitamin E is a fat-soluble vitamin, found in oils and creams, vegetables, dried fruits and oleaginous (nuts, almonds, hazelnuts) and seeds. This vitamin plays an important role in the protection of polyunsaturated fatty acids , which are particularly vulnerable to the attack of free radicals. This vitamin undergoes oxidation by the free radicals, converting itself into a free radical, until the vitamin C to return it to its normal state.
  • The vitamin C is obtained from vegetables and fruits, especially citrus fruits (lemon, orange, grapefruit, tangerine, clementine), strawberries and peppers. Acts as regenerating vitamin E and blocking the action of free radicals.
  • The carotenoids are present in fruits and vegetables. The beta-carotene (precursor of vitamin A, this last is not a true antioxidant) is found in sweet potatoes and in fruits and vegetables yellowish/orange (mango, papaya, carrot, pumpkin). The beta-carotene plays an important role in the protection of cellular membranes, proteins and DNA. One molecule of beta carotene can decrease the energy of 1000 molecules of free radicals.
    • Vitamin B2 is present in meat and liver, fish, egg yolk, whole grains, and oilseeds such as almond, and brewer’s yeast.


  • The polyphenols constitute a group much wider range of compounds, which are present in a wide diversity of foods, notably vegetables and fruits (along with carotenoids), soy – products and derived products, cocoa, red wine, and teas and herbal teas – especially green tea and white tea.


As we age, the ability of our body to produce antioxidants decreases, having arisen supplementation with antioxidants as a possible solution to combat this problem.

However, the evidence more current points that supplementation with antioxidants endogenous is inefficient, since the activities of enzymes of the digestive tract reduces its absorption and action.

Thus, with the increase of age, the dependency of the antioxidants exogenous increases, it being necessary to ensure to drink enough of these through diet.

However, by the fact that power contemporary to be rich in processed foods, low in vegetables and fruit and little varied, obtaining antioxidants is compromised, being one of the causes for the increased incidence of certain chronic diseases.

Once more, in an attempt to resolve this problem, many people turn to supplements antioxidants to compensate for these gaps in your diet.

In this case, the supplementation in addition to be in most cases ineffective, can exacerbate the problem even more, since, when on the supplements, the antioxidants are decoupled from the array to feed the original, and are in quantities much higher than those found in food.

For these reasons, can cause an effect different from the expected in the body. It is, therefore, preferable to leave aside the supplements and to obtain the necessary antioxidants by varying the power and ensuring a consumption of 3 to 5 servings of vegetables and fruit daily.

On the other hand, it is well to remember that in spite of the harmful effects of free radicals, the body produces these compounds to defend against micro-organisms.

In this sense, it is important there is a balance between antioxidants and free radicals, because the presence of too many antioxidants (as in supplementation), will condition the performance of the immune system.