Against external aggressions, be they bacteria, fungi or viruses, we can count on several powerful tools at our disposal. First of all, we must not forget about prevention, and therefore all those hygiene measures that can prevent infection. Then our natural defenses come into play. What can we do to support our immune system and put it in the best condition to cope with any threats? A help comes from diet and supplements that include some substances, which, as shown by scientific studies, have proved useful in modulating and reinforcing the immune response.
Quercetin
Quercetin is a flavonoid with a high antioxidant power. This precious substance is found naturally in apples, berries, vegetables of the cruciferous family, grapes, onions, tea and tomatoes. Quercetin is characterized by anti-inflammatory, immunomodulating and antiviral properties, being useful in counteracting the entry into the body of some viruses, such as that of the H1N1 or A flu but also of the new coronavirus. According to scientific studies, quercetin acts in the early stages of infection. The problem with quercetin is that it is difficult to absorb (Parisi et al, Int J Mol Sci, 2021). Therefore, it must be combined with other substances that can increase its bioavailability. For example, it has been observed that vitamin C is able to increase the absorption of quercetin. Not only that, vitamin C and quercetin also act in synergy due to their antiviral and immunomodulating action (Biancatelli et al, Front Immunol, 2020 - Nieman et al, EJCN, 2010).
Lactoferrin
Lactoferrin is a glycoprotein naturally present in human and bovine milk. Lactoferrin has antibacterial, antiviral, antioxidant and immunomodulatory properties. In the case of viral infections, lactoferrin inhibits the ability of the virus to attach itself to receptors located on the body's cells and also prevents their proliferation (Parisi et al, Int J Mol Sci, 2021).
Vitamin C
Vitamin C shows a powerful antioxidant action, useful in counteracting the damage of free radicals produced by oxidative stress and inflammatory conditions. Not only that, vitamin C has been shown to reduce the release of pro-inflammatory cytokines and this is a noteworthy fact, especially in light of what can happen in the most serious cases of new coronavirus infection. Indeed, it may happen that the body responds excessively, releasing too many pro-inflammatory cytokines that in turn increase the risk of thrombus (Parisi et al, Int J Mol Sci, 2021).
Vitamin D
Vitamin D supports the immune system, has an anti-infectious and antimicrobial action. Not only that, vitamin D protects lung health from the risk of infection (Parisi et al, Int J Mol Sci, 2021). The main source of vitamin D is the sun, but we can also find this vitamin in some foods, such as mushrooms, fish, such as anchovies or mackerel, eggs and cheeses such as crescenza, and in supplement form.
Zinc
Zinc preserves the integrity of the immune system and helps improve resistance to infections (Parisi et al, Int J Mol Sci, 2021). Zinc is also useful for the respiratory mucosa since it is capable of increasing its clearance, that is the mechanism by which foreign matter and toxins are recognized and removed. This effect also inhibits the proliferation of viruses such as influenza, rhinoviruses and coronaviruses (Parisi et al, Int J Mol Sci, 2021).
Probiotics
Probiotics support the health of the intestinal microbiota but their effects reach the whole body, even the upper respiratory tract. It has been observed that probiotics are able to modulate the immune response by increasing the production of antibodies, to ensure an adequate response of the body to external attack, and at the same time by avoiding the release of excessive amounts of pro-inflammatory substances, which could be harmful (Jayawardena et al, Diabetes Metab Syndr., 2020 - Wu et al, Front Immunol, 2018). Probiotics can be contained in supplements or in yogurt and drinks that indicate it on the label. Beware, not all yogurts are probiotics! In fact, the live enzymes with which yogurt is normally made do not overcome the intestinal barrier, it is necessary that other species of bacteria are added to the final product in sufficient quantities to reach the intestine.
