Edited by Ilaria Carandente, nutritionist in London
Having an efficient immune system is essential to defend ourselves against disease and infections. This is always true, but even more so in a period of health emergency like the one we are experiencing due to COVID-19.
What can be done to improve our immune defenses?
The activity of the immune system it is deeply influenced by the way in which we eat and in fact, in order to fully perform its functions, it needs an adequate supply of both macro and micronutrients. To be sure of getting an adequate supply of all the compounds necessary for the functioning of the immune system every day, it is important to have a varied and balanced diet, also taking into account some important aspects of preparation and conservation aimed at preserving the nutritional value as much as possible. of different foods.
The role of micronutrients
As for micronutrients, specific vitamins and minerals are essential for maintaining a good function of the immune system:
- Vitamin C: immunostimulant and powerful antioxidant, the deficiency of which can make it more susceptible to infections. It is well known that are contained in citrus fruits, but also in peppers, tomatoes, kiwis and green leafy vegetables, this vitamin is very sensitive to light, heat and oxygen, factors that cause the reduction of its content in food. In fact, it is preferable to consume or cook the foods that contain it at the moment in which they are cut (a classic example is the orange juice that must be consumed at the moment and not kept in the refrigerator) and avoid leaving the vegetables to soak in water for a long time as it is a water-soluble vitamin. The cooking method also influences the vitamin C content of the food, in particular boiling, steaming and baking result in the loss of large quantities, while the cooking methods that preserve it the most are vacuum-packed and in a pressure cooker.
- Vitamin D: immuno-modulating whose greatest production in the body occurs thanks to the skin exposure to sunlight. Food is to a lesser extent a source of vitamin D and there are few foods that contain it in appreciable quantities. These are essentially foods of animal origin including fish such as salmon, sardines, herring, tuna and swordfish, eggs (especially yolk) and cheese. The only appreciable vegetable source of vitamin D is represented by some mushrooms, in particular porcini, chanterelles and honey mushrooms.
- VITAMIN E: owns antioxidant properties and promotes the maintenance of immune cells. The main sources of this vitamin are the nuts (almonds, hazelnuts, peanuts), vegetable oils (olive, seed, sunflower), avocado and green leafy vegetables
- ZINC and SELENIUM: they play a strong antioxidant role. Particularly rich in these minerals is the nuts (pistachios, almonds, cashews and walnuts), but fair quantities are also found in legumes and whole grains.
Omega-3 fatty acids are also powerful allies of the immune system, being able to modulate both the immune response and inflammation. The main dietary sources of Omega 3 are the fish (in particular the blue one such as sardine, mackerel and herring but also salmon, tuna and cod), dried fruit (in particular walnuts, hazelnuts and almonds), green leafy vegetables, soy and avocado.
Strong immune defenses also pass from a healthy intestine. In order to maintain an adequate intestinal balance it is necessary to take an adequate intake of fiber (at least 30g per day) deriving from the consumption of legumes, vegetables and fresh fruit (5 portions a day), as well as from the consumption of probiotics, the natural sources of which are mainly yogurt and kefir.
In general, therefore, "our Mediterranean diet" it is always a good model to follow as it ensures an adequate supply of all the macro and micronutrients also necessary for a good maintenance and functioning of our immune defenses.
Any supplements of vitamins and minerals are necessary only in the case of restrictive diets, intolerances, allergies or diseases that require the avoidance of specific foods or entire categories of foods. Even in these cases, however, supplementation through the intake of food supplements must be personalized and preferably prescribed by the doctor. We always remember that no supplement, in fact, can ever compensate for an underlying nutritional imbalance.
Ilaria Carandente is part of the Network Italian Healthcare World, the first platform dedicated to Italian doctors and health professionals residing abroad. His profile can be consulted in our very useful WebApp.