For this, it has two levels of immune response. The first is the non-specific or innate, which is formed by physical barriers, antimicrobial peptides and the complement, among others. The second is the specific or adaptive, where the T and B lymphocytesas well as antibodies.
For a person’s immune function to be adequate, it is necessary to meet their energy needs. Especially when the immune system is activated (when infections occur, for example).
However, this system requires not only energy for its operation, but also specific nutrients. Therefore, it is important to know what these nutrients are, as well as the foods that provide them, when planning a proper diet.
Immune system friendly foods
As indicated, the first thing will be to meet the energy needs of the person. It is essential since situations of energy deficit (malnutrition) have been linked to immunodeficiency.
But it is also necessary to avoid excessive energy intakes that can lead to obesity. This is characterized by a chronic state of inflammation, as well as by excessive adiposity. Both situations negatively affect a person’s immune function, making them more susceptible to infections.
As for whats macronutrients, both simple carbohydrates (sugars) and saturated fatty acids are considered to have a pro-inflammatory effect. Therefore, it will be necessary to limit the consumption of sweets and sugary drinks, as well as red meat, fatty dairy products and industrial bakery products (rich in saturated fat).
Conversely, docosahexaenoic acid (DHA) and eicosapentaenoico (EPA), ambos of the o3 series, have been shown to have anti-inflammatory effects, as well as protection against infections. Therefore, include foods such as Blue fish and nuts in the diet will help ensure the intake of these nutrients.
Proteins and fiber
In the case of proteins, meeting a person’s intake needs has been shown to promote immune function. The consumption of proteins of high biological value (from foods of animal origin and soy) is recommended. These play a fundamental role in the production of antibodies. In addition, they provide amino acids with immunomodulatory function such as arginine and glutamine.
On the other hand, ensure an intake adequate fiber (between 25 and 30 g / day) It will also be essential for the immunocompetence of the immune system due to its prebiotic effect. This will allow to maintain an adequate microbiota, which will favor a correct intestinal barrier function.
It will also provide a direct anti-inflammatory effect (lower production of pro-inflammatory cytokines) and indirect (through the production of short chain fatty acids, which in turn have an anti-inflammatory effect).
On the other hand, the therapeutic use of probiotics has been proposed. These have been shown to have an anti-inflammatory effect (such as Lactobacillus rhamnosus y el Bifidobacterium lactis) to restore the immune system response.
The role of vitamins
As with macronutrients, minerals and vitamins also play a role in the functioning of the immune system. For example, the importance of vitamins A and D in protecting us from infections, especially respiratory infections, is well known.
To ensure an adequate intake of these vitamins we have to include in the diet meat, fish and eggs (sources of vitamins A and D), brightly colored vegetables and fruits (sources of β-carotenes, precursors of vitamin A) and milk and derivatives fatty dairy (vitamin D).
In the case of vitamins E and CThese are also involved in immune function. They reduce oxidative stress and prevent the oxidation of both polyunsaturated fatty acids (such as EPA and DHA) and cells of the immune system.
In this case, oils of vegetable origin (especially sunflower) and dried fruits ensure the vitamin E supply. For their part, Fruits (especially citrus) and vegetables are the main source of vitamin C.
It should also be noted that fruits and vegetables provide polyphenols. These are compounds that help the immune system due to their effects antioxidants and anti-inflammatories.
Lastly, vitamin deficiencies B6 (present in foods rich in protein), B9 (green leafy vegetables, legumes and cereals) and B12 (foods of animal origin) have been related to alterations in the humoral and cellular immune responses, inflammation and less protection against infections.
And the minerals?
Regarding minerals, it is worth noting the importance of all of them, but in zinc special (red meat, legumes, crustaceans and mollusks), in the immune system. The latter that participates in the maintenance of membranes, as well as in the growth and differentiation of cells of the immune system.
The iron (meat, fish, legumes and green leafy vegetables) is another mineral to take into account due to its importance in the growth and differentiation of T lymphocytes, as is copper (whole grains, nuts, legumes, crustaceans and mollusks) and selenium (red meat, fish, eggs, seafood, and whole grains). They are necessary in proliferation of T cells, antibody production and cellular immunity.
Finally, it should be noted that maintaining an active lifestyle can be beneficial for the immune system. Numerous studies have shown that the practice of physical activity not only has an anti-inflammatory effect, but also helps regulate the immune system and delays age-related loss of function.
Authors: Iñaki Milton Laskibar, Postdoctoral Researcher at Cardiometabolic Nutrition Group, IMDEA Food. Researcher at Center for Biomedical Research Network on the Physiopathology of Obesity and Nutrition (CiberObn), University of the Basque Country / University of the Basque Country
Alfredo Martinez Hernandez, Director de Precision Nutrition and Cardiometabolic Health Research Program y Cardiometabolic Nutrition Group, IMDEA.
Irene Besné Eseverre, University of Navarra.
Maria Puy Portillo, Professor of Nutrition. Center for Biomedical Research in Network of the Physiopathology of Obesity and Nutrition (CIBERobn), University of the Basque Country / University of the Basque Country