From a chemical point of view, the term antioxidant means a substance capable of counteracting, slowing down or neutralizing the formation of oxygen radicals which are formed as a result of oxidation reactions. Oxidation reactions, ie all those chemical reactions that involve the use of oxygen molecules, take place continuously in the organism. Food eaten, for example, is converted into energy through oxidation processes, and cellular respiration itself is based on oxidation reactions.

During oxidation reactions, highly reactive intermediates are formed, known as oxygen free radicals, capable of causing damage to various molecules and cellular structures, first of all DNA (deoxyribonucleic acid), but also proteins and lipids that make up cell membranes.

The functions of the organism that can be a source of free radicals are many: the digestion of food, the use of drugs (whose metabolism by the liver can generate radicals), excessive exposure to ultraviolet rays (sun or tanning lamps ) (read the Bufala), cigarette smoke or exposure to pollutants of various kinds.

In the human body, however, there are named substances antioxidants which have the power to prevent the formation of radicals or to neutralize those already formed, thus limiting damage to the cells and tissues.

From a chemical point of view, antioxidants are molecules that are oxidize with extreme ease. Being so easily "oxidizable"The free radicals will react preferentially with the antioxidants, thus sparing various molecules and cellular structures. In this sense, antioxidants can be considered "traps"For free radicals. Since many functions, such as breathing and digestion, produce free radicals, the body is equipped with a series of antioxidant substances capable of preventing and / or repairing the damage induced by radicals on biological structures.

The body naturally produces a series of defined antioxidants endogenous. Among them, the glutathione, the coenzyme Q they superoxide dismutase enzymes And catalase.

Many other antioxidants are introduced into the body daily through food. Hence the importance of a healthy and balanced diet that favors the introduction of all the necessary antioxidants, many of which are found in abundance in fruit and vegetables. However, it has been observed that cooking and long storage can deactivate some antioxidants present in food. A characteristic example is vitamin C, which is easily degradable during cooking and also very volatile (for which an orange juice must be drunk quickly after its preparation in order not to lose a good part of its vitamin C content) .Other antioxidant substances, such as vitamin E, are instead more resistant.Others, such as the lycopene present in tomatoes, are activated by cooking.

When the production of free radicals is excessive, or the reserve of antioxidants is insufficient, a condition of oxidative stress can be established.

This is what happens, for example, during a bacterial or viral infectious disease, in the case of a high fever for several days, as a result of improper lifestyles (for example, cigarette smoking, alcohol or drug abuse), in those who follow diets rich in sugars and saturated fats and too poor in quantity and quality of micronutrients, those who take excessive doses of alcohol, those who practice very intense sports or carry out a physically demanding job or are subjected to high psychological stress.

The persistence of a condition of oxidative stress may be the basis for the onset of some pathologies such as, for example:

  • neurodegenerative diseases, eg Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis
  • diseases of the cardiovascular system (for example, atherosclerosis)
What are and where are the main antioxidants

What are and where are the main antioxidants

Type of antioxidant

Where can I find it?


Yellow / orange fruit and vegetables and green leafy vegetables


Mainly present in citrus fruits, currants, kiwis, peppers and tomatoes, spinach, cabbage and asparagus


Peanut and sunflower seeds, corn and soybeans, nuts, eggs




Potatoes, broccoli and spinach, red meats, liver


Fish, poultry, milk and grains


Tea, ginger, saffron, cloves, cardamom, cinnamon, wheat germ, pepper, plants and herbs


Liver, shellfish, dried fruit, legumes, oil seeds


Milk, seafood, lamb, turkey, legumes



Umberto Veronesi Foundation. Magazine. Antioxidants: the sentinels of our health

Humanitas Health. Antioxidants, the allies of well-being

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