Against the new coronavirus, the weapons at our disposal are prevent infection, thus using hygiene measures and social distancing, and put the body in the best conditions to respond to the threat. This is why several studies have been published in recent months aimed at understanding how lifestyle and nutrition can strengthen the immune system, such as the article we are talking about today, published in the journal Frontiers in Immunology (Chowdhury et al, Front Immunol, 2020).
Previous studies had already indicated that tea, both black and green, can bring important antioxidant substances to strengthen the defenses and inhibit the replication and spread of the new coronavirus in the body. In today's article, scientists offered a more detailed analysis of the benefits of tea in the fight against coronavirus, including the beneficial action of mineral salts and volatile compounds in this drink, but let's try to understand better. Different types of tea are characterized by different substances that affect health and the immune system differently. For example, black tea in general is rich in theaflavins, which are polyphenols capable of counteracting inflammation, which instead acts by weakening the defenses. Not only that, theaflavins stimulate the Nk cells of the immune system that, on the other hand, in case of COVID infection, are reduced by weakening the immune response. Among the different varieties of black tea, Assam has been shown to have more antioxidants than other varieties that come, for example, from China or Cambodia. Instead, Darjeeling black tea is rich in volatile aromatic substances that are beneficial to the respiratory system. As for green tea, this type of tea is characterized by a high content of epigallocatechin gallate, an antioxidant of the polyphenol family, capable of increasing the secretion of interferons, which are proteins designed to block the replication of the virus within the body. Not only that, this green tea antioxidant also fights free radicals, responsible for activating various other substances that could increase inflammation levels and weaken the immune system. Tea in general, both green and black, contains alkaloids, such as caffeine, theophylline and theobromine, with an anti-inflammatory action, especially in the lungs, and that act as bronchodilators. Finally, as regards the micronutrients, the main ones, present in both green and black tea, are selenium, which stimulates the immune system and fights free radicals especially in the lungs, iron, which regulates the immune response, is anti microbial and increases the resistance of cells to incursion by pathogens. Then, in tea we find also zinc, which stimulates the immune response and fights free radicals, the group B vitamins, able to modulate the immune system, and manganese, which is present in greater quantities in black tea and which stimulates the production of interferons with antiviral action.