What is the immune system?

Although an exhaustive description of the immune system and its functioning requires a very long and complex treatment, without pretending to explain this complexity in detail, to have a general vision of what this system is and what it is for, it can be compared to an army of which our body disposes to defend itself against the attacks of pathogens.

Immunity is divided into two types:

  • the innate one;
  • the adaptive one.

Innate immunity is the non-specific and ever-present immunity that consists of physical barriers, such as the skin, mucous membranes and their secretions, soluble factors, such as lysozyme, the competitive and antagonistic action of the microbiota, inflammation and some of the blood cells.

Adaptive immunity, on the other hand, is that immunity which responds to the attack of specific pathogens and which has memory. Memory is that characteristic that, once a pathogen has been encountered and "fought", before a second encounter, the immune system will be ready to fight it more quickly and efficiently. A very important feature of this immunity is the ability to recognize and not attack the self molecules, therefore, thanks to this ability our immune system does not attack our body, but only what it recognizes as foreign and harmful. B lymphocytes, T lymphocytes and antibodies are part of the innate immunity.These two types of immunities are not completely separate, but work together to guarantee us an excellent state of health. Having made this very brief introduction on the immune system, we can focus on the role played by nutrition in enhancing it.

Role of nutrition in strengthening the immune system

Many studies have been conducted with the aim of investigating the role played by nutrition in maintaining the proper functioning of the immune system. To better understand how nutrition contributes to the maintenance of a well-functioning immune system, it is important to be clear that the selection of certain foods corresponds to the introduction of specific nutrients into the diet.

The nutrients are divided into:

  • macronutrients (carbohydrates, Protein, fats);
  • micronutrients (vitamins and minerals);
  • Fibre.

This premise is fundamental to clarify that, although some combinations of foods can ensure a correct intake of macronutrients, this may not be true with regard to micronutrients and, if this situation is continued over time, serious problems can occur. This should discourage you from starting do-it-yourself diets, completely eliminating certain food categories or even following superficial approaches that rely only on macronutrient counts without taking into account micronutrients. The lack of micronutrients is in fact a problem that concerns both poor countries, where it is difficult to ensure an adequate supply of food.

Micronutrients are fundamental both for the functioning and for the structure of physical barriers: this is fundamental, as these barriers are the first point of contact between pathogens and our body and a lack of integrity facilitates their entry. The importance of vitamins and minerals is also given by the role played in the implementation of the functions and proliferative capacity of immune cells. Furthermore, micronutrients are also important for the body to implement the inflammatory response, one of the means by which pathogens are combated. The antioxidant capacity of some vitamins and minerals is added to the activities we have just mentioned . Between fat-soluble vitamins most important for the functioning of the immune system are:

  • Vitamin A;
  • Vitamin D;
  • Vitamin E.

Among the water-soluble ones we find:

  • C vitamin;
  • Vitamin B6;
  • Folate;
  • Vitamin B12.

Among the minerals instead we find:

  • Zinc;
  • Copper;
  • Selenium;
  • Iron.

To ensure an excellent supply of vitamins it is important to consume appropriate quantities of fresh fruit and vegetables, to prefer whole grains and derivatives, to consume legumes, fish and to favor unprocessed meats over processed ones.

Macronutrients are also important for the immune system. An adequate protein intake ensures, for example, that the amino acids necessary for the synthesis of immunoproteins are available. Polyunsaturated fatty acids are used as precursors of prostaglandins, lipid compounds involved in the inflammatory process among whose actions we find vasodilation and increase in body temperature. The fatty acids EPA and DHA also increase the production of antibodies (IgM) by B lymphocytes as they increase the number of cells responsible for their production. Ensuring a balanced intake of macronutrients and fiber also helps to maintain a healthy microbiota without the prevalence of bacterial strains not typically established in a given area of ​​the intestine or pathogens. This is very important as the microbiota, through its competitive and antagonistic action, blocks the establishment and proliferation of pathogens in the intestine and therefore the passage through the intestinal barrier.

Conclusions

The vastness and complexity of the subject dealt certainly do not allow an exhaustive treatment, but a simplified, not simplistic vision can help to understand the importance of something that would otherwise be very complex and laborious. As always, the goal must be to find the stimulus to further investigate and, if you need to start a path of change in your diet, to encourage you to ask experts in the field of nutrition, such as dieticians, dieticians and nutritional biologists. , able to ensure that every decision is carefully evaluated in all its facets.

Bibliography:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019735/

https://pubmed.ncbi.nlm.nih.gov/26634839/

https://pubmed.ncbi.nlm.nih.gov/34135894/