COVID-19 has sparked interest in how to boost immunity and the role of diet in stimulating the immune system’s reaction. Our immune system is not only important in times of pandemic, but throughout our entire lives.
Why is a healthy immune system important?
The main function of our immune system is to protect us against intruders and avoid infections caused by bacteria and viruses. This same system must, however, guarantee that the external elements necessary for our survival, such as ingested food or microorganisms housed in the intestine (the microbiota), are tolerated. Nor should it attack the cells of our own body (as in the case of autoimmune diseases).
As Ranjit Kumar Chandra suggests , our immune system can be seen as a shield that protects us against attacks by pathogens, toxins, and other invaders. Let’s not forget that the immune system develops at the same time as the intestinal microbiota from the first moments of life and that the intestinal microbiota is like a kind of coach for the immune system , insofar as it prepares it to fight against infections and Certain diseases.
Immune health and the health of the gut microbiota start with a good diet. Malnutrition, whether due to a poor diet or an excess of foods rich in sugar, fat or sodium, can put the immune system in check and cause a greater sensitivity to infections. Other factors such as age, stress, lack of sleep and rest or chronic diseases can also impact the immune system and cause the deactivation of this protective shield.
For our immune system to enjoy good health, it is necessary to guarantee sufficient supplies of nutrients through a balanced diet.
Diet supplies us with the nutrients that are at the heart of our health and the proper functioning of our immune cells, which require large amounts of energy and nutrients. But the functioning of immune cells sometimes causes increased energy demand (for example, in viral infections like COVID-19 ), and specific foods or nutrients consumed individually are unlikely to offer greater protection.
Andrea Hardy , a Canadian dietitian specializing in gut health, explained by email to GMFH that when it comes to diet and immune function, “it is important to remember that more does not necessarily mean better. Obtaining adequate amounts of each nutrient and preventing deficiencies is essential, especially in risk groups such as the elderly or people suffering from chronic diseases, since their diet tends to be less varied for medical or social reasons ”.
In humans, certain nutrients allow the immune system to function efficiently. These include:
Proteins: Proteins are important structural elements of cells, including immune cells and antibodies that help fight disease.
Essential fatty acids : a good balance between Omega 3 and Omega 6 fatty acids is crucial for the proper functioning of immune cell membranes and to slow down inflammatory processes.
Vitamins and minerals : vitamins B6, B12, folate, vitamins C and D, zinc, copper, iron and selenium.
All of them are found in different foods of animal and plant origin.
On the other hand, it is necessary to take care of our intestinal microbiota to preserve the balance of our immune system. In this sense, the beneficial bacteria of probiotics – provided especially by fermented products – as well as prebiotic fibers (present in onions, garlic, bananas and artichokes) that nourish our intestinal microbiota are essential.
Probiotics and prebiotics can act individually or in synergy with proteins, essential fatty acids, vitamins and minerals to improve the health of our gut microbiome and the integrity of the gut barrier, thus preventing pathogens from entering the gut.
It also recognizes that given the impossibility of getting fresh fruits and vegetables “canned and frozen foods also contain essential nutrients present in fruits and vegetables” and can be used occasionally to get out of trouble.
And one last argument …
Obviously, no diet will prevent us from contracting infections or diseases, but a rich and varied diet will contribute to the proper functioning of our immune system and our intestinal microbiota. Instead of strengthening our immune defenses with a specific regimen or consuming certain types of nutrients, it is preferable to opt for a balanced, healthy and varied diet that will provide us with the necessary nutrients to maintain our immune system and our intestinal microbiota.