In the fight against disease, the human immune system plays a crucial role. The level of a person's immunity is influenced by many factors, among which nutritional factors play a very important role. It is the material basis for maintaining normal immune function and health in the human body. Malnutrition can lead to impaired immune system function, decreased resistance to pathogens, and consequently, infection. Therefore, proper nutrition can improve the body's immune status and enhance resistance to disease. Nutrients closely related to immune function include protein, vitamin A, vitamin C, vitamin E, iron, zinc, and selenium. Protein is the material basis for the body's immune function. Inadequate protein intake affects tissue repair, reduces local immunity of the skin and mucous membranes, weakens the ability to eliminate pathogens, and can easily lead to the reproduction and spread of pathogens, reducing anti-infection ability. With the improvement of living conditions, protein deficiency is no longer common, but it can occur in people who diet or are picky eaters. The protein from animal foods (including the protein in soybeans and their products) is more easily utilized by the human body than plant-based protein after entering the body. Therefore, it is advisable to consume some animal foods in moderation every day. Vitamin A plays an important role in the body's immune system. Vitamin A deficiency can cause keratosis and degeneration of respiratory, digestive, urinary, and reproductive epithelial cells, destroying their integrity and making them susceptible to bacterial invasion, thereby increasing the body's susceptibility to respiratory and infectious diseases. Foods rich in vitamin A mainly include animal livers, such as lamb liver, pork liver, and chicken liver. Plant-based foods can only provide provitamin A carotenoids, which can be converted into vitamin A in the body. Carotenoids are mainly found in dark green or red-yellow vegetables and fruits, such as carrots, spinach, celery, mangoes, and sweet potatoes. Vitamin E can enhance the body's immune function and improve resistance to infection. The dietary sources of vitamin E are mainly vegetable oils, germ of plant seeds, nuts, legumes, and grains. Vitamin C is an essential vitamin for the human immune system and can enhance the body's anti-infection ability in many ways. A deficiency can reduce immune system function. Vitamin C is an essential cofactor for collagen synthesis, which can improve the body's tissues' barrier effect against foreign pathogens. Vitamin C can also promote the generation of mother cells and the production of immune factors. Vitamin C can promote the production of interferon, inhibit the synthesis of new viruses, and has antiviral effects. Fresh vegetables and fruits are the main sources of vitamin C. Such as fresh jujubes, green peppers, kiwis, spinach, hawthorn, citrus, pomelos, strawberries, etc., all have high vitamin C content. Iron deficiency can easily lead to anemia and reduce resistance to infection. Foods rich in iron include: animal blood, liver, soybeans, black fungus, sesame paste, etc. Zinc has multiple physiological functions and plays an invisible role in the development of the immune system and the maintenance of normal immune function. Moderate intake of zinc can enhance the immune function of children, the elderly, and some special patients, and plays an important role in the prevention and treatment of gastrointestinal and respiratory infectious diseases. Shellfish, red meat, and animal organs are good sources of zinc. Selenium is an essential trace element for the human body and is found in almost all immune cells. Supplementing with selenium can significantly improve the body's immunity. Recent research has found that selenium intake below the optimal level can impair the development and function of the immune system, reducing anti-infection ability. Studies have shown that the effects of vitamin E and selenium on the immune system are independent of each other, but giving them simultaneously can have a synergistic effect on enhancing the immune response. Conversely, a simultaneous deficiency of vitamin E and selenium can lead to a significant decrease in the immune response. Animal foods such as liver, kidney, and seafood are good dietary sources of selenium. In daily diet, one should adhere to dietary diversity in order to maximize the intake of various nutrients and thus obtain health. It is also possible to supplement some nutrients specifically to regulate nutritional balance. Protein: Eggs, milk, legumes and their products, lean meat, fish Vitamin A: Animal liver, carrots, spinach, celery, sweet potatoes Vitamin E: Vegetable oils (corn oil, sesame oil, soybean oil), spinach, cabbage, nuts, grains Vitamin C: Fresh jujubes, kiwis, citrus, pomelos, strawberries, spinach, green peppers Iron: Animal blood, liver, soybeans, black fungus, sesame Zinc: Shellfish, red meat, animal organs Selenium: Sesame, animal organs, garlic, mushrooms, sea cucumbers, enoki mushrooms, hairtail, pork and lamb
This article is excerpted from "Ma Guansheng Talks About Nutrition" by Ma Guansheng, authorized by Phoenix Hanzhang Books. Reproduction is strictly prohibited.