by Fondazione Valter Longo Onlus in collaboration with the Create Cures Foundation
Iron is an essential mineral that performs important functions. It is involved in the synthesis of hemoglobin, a protein that carries oxygen in the blood. Iron is necessary for the formation of two other proteins: myoglobin, which constitutes the structure of the muscles, and collagen, with a structural function in our tissues. Iron is always bound to specific proteins: hemoglobin in the blood, myoglobin in the muscles, hemosiderin in the liver, ferritin in the intestine, etc.
THE IMPORTANCE OF IRON FOR OUR BODY
Iron participates in the processes of cellular respiration and constitutes the oxygen reserve for our muscles, guaranteeing their efficiency and performance even under stress. The supply of iron, in fact, provides us with energy, ensuring the strength to carry out physical activity and sport. In addition, iron is also involved in the metabolism of nucleic acids and in the activity of some important enzymes, like the prosthetic group.
Another important function of iron is linked to the synthesis of neurotransmitters, including serotonin, dopamine, and noradrenaline. In addition to muscles, therefore, our nervous system also needs iron. It helps concentration and promotes learning, as well as being essential for ensuring a good mood. Finally, iron protects us against disease, as it strengthens the immune system and supports us in countering oxidative stress and cellular aging.
THE DIFFERENT FORMS OF IRON IN THE BODY
Iron in our body is present in two forms: 1) heme iron, linked to hemoglobin in the blood or to myoglobin in the muscles; 2) non-heme iron, bound to storage proteins like ferritin in the intestine. Hemic iron is the most bioavailable form, that is, it is more easily assimilated by our body. Non-emic iron, on the other hand, is less easy to metabolize.
Heme iron constitutes 75% of the iron present in the human body, bound to hemoglobin in the blood for 65% and to myoglobin in muscles for 10%. Non-heme iron, on the other hand, amounts to 20-25% and is present with a storage function in the liver, spleen and bone marrow, linked to ferritin and hemosiderin. Iron is also present in small quantities in transferrin and in some intracellular enzymes.
DAILY AMOUNT OF IRON AND DEFICIENCY
The daily amount of iron varies according to age and gender: 10 mg for men and 18 mg for women (30 mg in pregnancy and 10 mg in menopause), 12 mg for adolescents. An iron deficiency can be due to several causes: unregulated diet, absorption problems, blood loss, anemia, endocrine dysfunction, or chronic diseases.
If iron is not consumed in sufficient quantities, its deficiency can cause various problems. Chronic fatigue, sleepiness, physical weakness, muscle fatigue, mental listlessness, difficulty concentrating, irritability and nervousness are symptoms of moderate iron deficiency. More serious symptoms are pallor, shortness of breath, insomnia, palpitations, headache, dizziness, menstrual pain, gastro-intestinal disorders, and a weakened immune system, up to anemia in severe cases.
SOURCES OF IRON
Iron is assimilated through food. The richest source of heme iron, which is the bioavailable form, is meat (as a residue of myoglobin in the muscles). Iron is also present in other foods of animal origin, such as blue fish (tuna, salmon, anchovies, and sardines), shellfish (oysters, mussels, clams, shrimps, shrimps, lobsters, etc.), and in egg yolk.
Non-heme iron is present in all foods, even in plant ones. Green leafy vegetables (spinach, broccoli, rocket, parsley etc.), legumes (beans, lentils, chickpeas, and peas), nuts (almonds, cashews, pistachios, peanuts, sesame, and sunflower), dried fruit are particularly rich in iron (apricots, raisins, figs, and dates). Cereals also contain iron, such as oats, buckwheat, millet, rye and rice, preferably whole grain. Another iron-rich food is cocoa. To promote its absorption, the advice is to combine it with vitamin C, for example lemon juice.
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