We often hear about free radicals, but what are they and what effects do they have on health? And how can we fight them?
- What are
- How to fight them
- The role of antioxidants
Free radicals are highly reactive molecules capable of damaging our cells. These are chemical species produced by oxygen metabolism and characterized by the presence of one or more unpaired electrons. Since electrons are more stable when they are in pairs, free radicals tend to react with neighboring molecules by “stealing” an electron, that is, oxidizing them. Free radicals and reactive oxygen species are called oxidants and include superoxide radical, hydroxyl radical and hydrogen peroxide.
Free radicals and other oxidizing oxygen species perform important functions within our body. For example, free radicals are able to induce protective mechanisms in case of cellular stress and help destroy pathogenic bacteria during infections. Our body has some defense mechanisms at its disposal that deactivate free radicals making it harmless. However, when free radicals are produced in excess of our body's antioxidant capacity, they can escape capture by defense molecules and react with our cells, damaging them. In particular, free radicals can oxidize our proteins and lipids and, above all, damage the DNA of cells. The phenomenon, known as oxidative stress, can occur in most of the cells of our body and is the basis of numerous diseases including diabetes, arthritis and other inflammatory diseases, cardiovascular diseases, degenerative diseases such as Alzheimer's and cancers.
How to fight them
Our body has available means to defend itself against the harmful action of free radicals. The body is in fact able to protect itself from these reactive species through enzymes capable of deactivating them, proteins that sequester iron and copper (minerals necessary for the production of the hydroxyl radical) and through antioxidants. The enzymes involved in the deactivation of free radicals are superoxide dismutase and glutathione peroxidase while the sequestering proteins are transferrin, ferritin, metallothionein and ceruloplasmin. Among the antioxidant molecules we find instead substances present in foods such as vitamin C, vitamin E and flavonoids. Vitamin E is the main fat-soluble antioxidant responsible for protecting lipid membranes and lipoproteins. Vitamin C, on the other hand, is water-soluble and performs its antioxidant function in fluids. Finally, flavonoids are represented by over four thousand different molecules present in plants.
The role of antioxidants
As we have seen, our body protects itself from the oxidizing action of free radicals also thanks to vitamins and flavonoids present in food. For this reason, a healthy and balanced diet plays a protective role against numerous diseases and helps prevent premature aging.
Vitamin E is an essential molecule with antioxidant action on fatty acids. Tocopherols are present in vegetable oils such as wheat germ oil and sunflower oil, as well as in whole wheat, walnuts, almonds, pistachios and olives. Although it is a molecule sensitive to high temperatures and degradable through boiling and frying, a good diet is able to meet the need for this vitamin, equal to about 10 milligrams per day, using raw vegetable oils and consuming dried fruit. .
Vitamin C or ascorbic acid is instead present in numerous fresh plant foods such as asparagus, kiwi, strawberries, broccoli, peppers, oranges, lemons, papaya. In addition to being an indispensable vitamin for the synthesis of collagen, ascorbic acid performs many fundamental functions for our health, including that of inactivating free radicals.
Finally, flavonoids are a group of molecules widely represented in plants, which synthesize them to defend themselves from parasites, protect themselves from sunlight, give the flowers the color to attract pollinating insects and to synthesize pollen. In addition to their antioxidant action, flavonoids also have antiviral, antifungal and antibacterial properties, which are essential for plant growth. They also have an anti-inflammatory, vasorelaxant, antitumor and neuroprotective action on the human body. Flavonoids are in practice among the molecules most responsible for the beneficial action of certain foods and various herbal and phytotherapeutic remedies: they are found in fruit and vegetables, cereals, legumes, tea, wine and beer and in many plants used as natural remedies. They are part of the great family of flavonoids: flavonols present in propolis, flavanols in green tea, isoflavones in soy, flavones in olive oil and chamomile, flavanones in oranges and anthocyanidins in grapes and wine. .
Nutrition and the use of medicinal plants with antioxidant action are therefore the best weapons we have available to support our body in fighting free radicals, to prevent damage and disease, when these molecules are produced in excess.
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