“Strengthen the immune system” or “increase defenses” are currently the main claims when talking about certain foods, supplements, or nutritional preparations, but it is not news that what we eat can help our body to better cope with the action of viruses and bacteria. There it is, for example, the classic chicken broth that our grandmothers prepared at the slightest sign of “autumn breakdown” and that it relieved discomfort almost instantly (an effect at the immune level, by the way, confirmed by several investigations, which have shown how the amino acids and other nutrients present in this type of broth reduce the inflammation that accompanies colds and flu).
“Food and the immune system have a very close relationship: on the one hand, the intake of nutrients as vitamins and minerals play a very important role, since they act as metabolic pathway cofactors, being essential for the integrity and perfect functioning of the immune system. And, in the same way, the deficit or lack of certain nutrients can lead to immune deficiencies that cause clinical manifestations in our body ”, explains nutritionist-dietician Ana Sofía Mendoza, nutrition consultant at Sprimfood.
Nutrients against the virus: the “winning team”
However, and against the current trend, experts are reluctant to speak of nutrients or diets that are specifically considered “anti Covid” “Currently the Spanish Academy of Nutrition and Dietetics, together with the General Council of Colleges of Nutritionist Dietitians, establish that there is no specific food that can prevent or reduce the risk of contagion of the coronavirus in healthy people, and neither is anyone capable of treating the disease in already infected patients, ”says Mendoza.
Once this issue has been clarified, the experts insist on the importance of having a diet as varied and balanced as possible To ensure that the body will be able to react adequately to the action of pathogens (it must be remembered that SARS-CoV-2 is not the only one, but, as every year at this time, other viruses, like the one flu, they are “warming up on the band”).
And, to further fine-tune immunoprotection, it is advisable to prioritize in autumn menus the nutrients that have proven to be most effective in this regard. Ana Sofía Mendoza explains who are the members of that winning team: “The Vitamin A, the folic acid, vitamin B6, vitamin B12, vitamin C, the vitamin D, he iron, zinc, copper and selenium. All of them contribute to the normal functioning of the immune system, so we should make sure to include foods that contain them in adequate amounts in the diet ”.
Vitamin C Supplements: Are They Overrated?
Citrus fruits have traditionally led the group of foods associated with the prevention of viral infections seasonal, mainly due to its high content of vitamin C, so it is not surprising that there has been a parallel between these diseases and the coronavirus, which has led to a spectacular increase in the intake of oranges, mandarins and other citrus fruits and also that many people have chosen to self-prescribe supplements of this vitamin with the idea of protecting themselves against the coronavirus.
Vitamin C is known to be especially effective in strengthening body cells (including those of the immune system) against oxidative stress. Likewise, there is evidence of its ability to accelerate certain chemical reactions related to immunity, speeding up the body’s reaction to the presence of viruses and bacteria.
Regarding supplements, the nutritionist clarifies a bit what can be expected of them: “With regard to the common cold, there is no evidence that the use of vitamin C reduces its incidence. However, it has been seen that those who take supplements of this vitamin regularly could suffer colds of slightly shorter duration or have milder symptoms ”.
Therefore, as Mendoza points out, the best option to enjoy the immunoprotective effect of vitamin C (and also of others, such as its antioxidant capacity) is eating a variety of foods such as citrus fruits, melon, potatoes, or red peppers, among others, “which help meet the daily requirements of this vitamin, allowing you to enjoy the benefits it produces in the body.
Vitamin D: good news
In accordance with the recommendations issued by the Spanish Society of General and Family Physicians (SEMG) during the months of confinement, vitamin D has specific receptors in some cells of our body (including lymphocytes and macrophages) responsible for cellular immunity, hence the need to ensure adequate levels of this vitamin since its deficit can influence the proper functioning of the immune system, weakening it and, therefore, hindering its defense action against external agents, such as the coronavirus.
The experts of this society remember that the first measure to ensure adequate levels of vitamin D is to sunbathe for about 10-15 minutes every day, “and the second is an increase in the diet those vegetable and animal products that provide this nutrient, for example, bluefish (salmon, anchovies, herrings or sardines), mushrooms and mushrooms such as mushrooms, shellfish, animal liver, eggs (yolk), avocado, cereals and foods enriched with this vitamin, such as dairy) ”.
In line with this, and in the context of the current pandemic, several studies have suggested the potential role of “shielding” that this vitamin would have specifically against SARS-CoV-2. Although the level of evidence has varied since the first investigations, the most recent data seem to confirm the importance of the role of vitamin D in this disease. This is clear from a study carried out by Michael F. Holick, a professor at the Boston University School of Medicine (USA), who in previous research had already suggested that adequate levels of vitamin D could reduce the risk of contracting covid by up to 54%. In this new study, published in the journal Plos One, Holick goes a step further in this direction, by demonstrating that people hospitalized for the coronavirus with adequate blood levels of vitamin D (25-hydroxyvitamin D of at least 30 ng/ml) have a significantly lower risk of complications and also to die as a result of this disease.
The shopping list: with the market in favor
Fortunately, many of the foods high in these immunity nutrients are in season, which makes it even easier to include them in the daily diet, so much so that they could even be the absolute protagonists of the shopping list. Ana Sofía Mendoza advises how to do the more “immunoprotective” selection Among the wide offer that we can find now in the market:
Nectarine, blackberry, raspberry, and melon, due to its high vitamin C content. “Raspberries and melon are also considered important sources of folic acid.”
Within the group of seasonal vegetables, The consumption of peppers and spinach is recommended, due to their high vitamin C content. “Other foods rich in this nutrient are chard, zucchini, lettuce, potatoes and squash.”
These vegetables also provide other vitamins positively related to the immune system: vitamin A (chard), folic acid (lettuce, spinach) and vitamin B6 (potato, pepper).
The carrot is a very complete food in this sense: it stands out for its high content of vitamin A and also provides high doses of vitamin B6.
Another recommended food is corn, for being a source of folic acid and vitamin B6.
Royal Jelly: a natural ally to take into account
Another substance that takes on special prominence at this time of year is the Royal jelly, whose role in the prevention of diseases caused by pathogens such as coronavirus was analyzed by Miguel Martín Almendros, member of the Spanish Society of Primary Care Physicians (Semergen) and member of the Board of Directors of the Center for Research on Phytotherapy (Infito) during his participation in the webinar How to face the arrival of autumn this year? Special attention to children and people with diabetes, recently organized by Arkopharma: “Royal jelly provides all the essential amino acids and other nutrients that give it some first-order therapeutic potentials from the point of view of the immune system ”, commented Dr. Martín Almendros.
Specifically, it is known that one of the substances it contributes, albumin (a glycoprotein), increases the release of TNFalpha, a protein that mediates the immune response, 16 times, thus enhancing the “defensive” activity of the organism. In addition, it increases the proliferation of immune cells more than 8.5 times.
“To this must be added the anti-inflammatory effect of royal jelly, decreasing the secretion of pro-inflammatory cytokines by the cells of the immune system. This immunomodulatory action is of great importance in the case of COVID, due to the famous cascade of cytokines that the infection produces and which is the cause of the worsening of many patients ”, said the expert, who also highlighted the important antibiotic and anti-fatigue effect of this substance.
Microbiota and defenses: this is the relationship
The microbiota plays a fundamental role in the proper functioning of the immune system, as Ana Sofía Mendoza explains: “When there is a balance of the microbiota, its alliance with the immune system allows the induction of protective responses to pathogens and the maintenance of the regulatory pathways involved in the defense of antigens.”
And the diet is, probably, the factor that most influences the correct balance of our microbiota: “A varied and healthy diet leads to a more diversified microbiota and resistant to the aggressions or alterations produced by antibiotic treatments or various diseases. Therefore, the more varied the diet (including foods of natural origin such as fruits, vegetables and vegetables high in fiber and nutrients), the more varied the microbiota will also be and, consequently, the greater its ability to face the challenges faced by the immune system ”, says Mendoza.
In line with this, and to further reinforce the good state of the intestinal microbiota, the nutritionist emphasizes the Importance of also including prebiotics and probiotics in the diet: “Prebiotics are complex fibers or polysaccharides that can be added to the diet or found naturally in foods such as fruits, vegetables and legumes. When you consume a prebiotic or a food rich in fiber, you are feeding the microbiota and, therefore, diversifying it. As for probiotics, they are very beneficial to live bacteria for health that can be found in various fermented foods, such as yogurts, kimchi and kombucha, among others ”.