I. What is free radicals The cells of the body produce redox reactions during the process of metabolism, so free radicals are produced in the body. Free radicals oxidize the cells of the body and can cause cell death or mutation. The free radical theory of aging has been recognized worldwide, which means that most of the diseases and aging that occur in the body are related to the presence of oxidative free radicals. Therefore, many chronic diseases are caused by the aging and functional decline of organs due to oxidation, such as cardiovascular diseases, high blood pressure, hypertension and diabetes. How to eliminate free radicals We are using the antioxidant system in the body to eliminate free radicals in the body, antioxidants are roughly divided into six important categories: 1, superoxide dismutase; 2, catalase; 3, glutathione peroxidase, such antioxidants belong to the enzyme class, the right amount of protein intake to ensure their function; 4, VitC; 5, VitE; 6, beta-carotene; another VitB group and selenium, zinc, manganese and copper are needed as coordinating factors. All these antioxidants can be obtained from the diet, and all substances with antioxidant effect can be called antioxidants. Therefore, we should choose more foods with high antioxidant content to slow down the occurrence of aging and diseases. Since oxidation is the cause of aging, we need antioxidants. The 21 foods we recommend for you are mainly foods with antioxidant nutrients, hoping that you can get younger and healthier from the intake of natural foods. 3, 21 recommended foods 1, asparagus ① Asparagus contains antioxidants glutathione and rich in folic acid, antioxidants can directly protect cells from free radical damage, can help and prevent all chronic diseases. ②Buying essentials: green stem skin tip is not rotten, thick and tender is good, April-October every year is the peak production period. ③What is glutathione: a kind of antioxidant, which can inhibit the activation of carcinogenic substances. 2, bell pepper (yellow, second, green, orange) ① rich in vitamin C, beta-carotene, effective in preventing atherosclerosis and cancer. For the strong antioxidant, can prevent LDL cholesterol is oxidized, to prevent arterial embolism. ②Purchasing and cooking tips: layers with intact shape, shiny and fresh skin, crispy flesh and no shrinkage are good. The green pepper layer is in full production from January to August and December, while other colors of bell peppers are mainly produced in spring. ③Vitamin C will be lost by boiling and steaming or Sichuan hot a large part, can be changed to microwave heating, the loss of vitamin C only 0-15%, or change to raw food. 3, green cauliflower ① contains a variety of antioxidants: beta-carotene, glutathione, vitamin C and lutein, antioxidant, anti-cancer and cholesterol. ②Purchasing and cooking tips: bright green flower bulbs, dense and tightly packed buds, no pests or diseases, no yellowing, and no hollow stems are preferred. The best season is from November to April of the following year. ③Cooking to raw or slightly Sichuan hot is better. 4.Carrot ① rich in β-carotene content is the highest of all vegetables, can fight cancer and protect arteries, contains soluble fiber and pectin can lower cholesterol, prevent cholesterol from being oxidized into harmful substances, increase immune function and prevent infection. ②Selection and cooking tips: The skin is gorgeous and orange-red, and the shape is straight without lumps or scars. The production period is from December to February and there is no shortage throughout the year. ③It will be better absorbed after heating. 5, garlic ① contains a lot of adenosine (glycoside), can relax smooth muscle to make blood vessels dilate, lower blood pressure, can also lower cholesterol, and also contains allicin and selenium, zinc and other substances, selenium is the body’s anti-cancer ingredients indispensable substances. Zinc can improve the body’s immune function, stimulate the amount of T cells and macrophages, and also increase the amount of natural killer cells, which can kill more bacteria and cancer cells. ②Purchase and cooking essentials: large garlic cloves, white and intact particles, not shriveled. ③prevent blood clots to cooked food is better, anti-cancer is better to eat raw or eat pickled effect. 6, onion ① contains prostaglandin A can diastolic blood vessels, reduce blood pressure and blood viscosity, can prevent coronary heart disease. Rich in hemiphosphoric acid, hemiphosphoric acid is a kind of anti-aging substances, can postpone cellular aging, can be a food anti-aging. Onions also contain selenium, which is one of the components of the antioxidant glutathione, and needs selenium as a cofactor to play the role of glutathione, so eating more onions can be an antioxidant. ②Choosing and cooking tips: The production period is from December to February, so buy smooth and intact skin without sprouting or rotting. ③There is a study that raw onions can increase HDL cholesterol (good cholesterol), and cooked onions are less effective in increasing HDL cholesterol. 7.Mushrooms (Shiitake, Enoki, Abalone, Hidrophonium, Coral) ① Contain nucleic acid substances can inhibit the increase of cholesterol in serum and liver, promote blood circulation and prevent arteriosclerosis. Contains polysaccharides with tumor suppressing effect can increase the function of macrophages and T cells, improve immunity and the ability to destroy tumor cells. Contains ergocalciferol which can be converted into VitD2 after sunlight exposure. ②The key to buying and cooking: the flowers and stalk are intact and not decayed. ③Mushrooms tares cooked before eating, in addition to soup, fried, but also available cold. 8, tomato ① for the main source of lycopene, can inhibit the activity of oxidative free radicals. Also contains glutathione as a strong antioxidant, is the maintenance of normal cell metabolism is indispensable substances. ② shopping and cooking essentials: fresh color and luster, shape and appearance of the complete, not soft and flat. ③ cooked tomatoes absorption rate will be better than raw ones. 9, soybeans and soybean products ① contains isoflavones, phytoestrogens and other phytochemicals that help capture free radicals, with antioxidant properties, can prevent the generation of lipid peroxide, delaying the onset of aging. ②Purchase and cooking essentials: fresh is the main, soy should be cooked before eating. 10, swordfish ① containing n-3 fatty acids can reduce triglycerides and increase HDL cholesterol (good cholesterol), can prevent atherosclerosis. ②Purchase and cooking essentials: fresh fish, bright eyes, with elasticity. 11, olive oil ① rich in n-3 fatty acids, can reduce LDL cholesterol (bad cholesterol), prevent LDL cholesterol from being oxidized into foamy form, this type of LDL cholesterol can harm arteries. ②Cooking tips: The best way to cook olive oil is to serve food cold. 12, tea containing tannins can quench thirst and relieve grease, catechins can increase the toughness, elasticity and permeability of blood vessels, reduce the ability of blood clotting, can prevent vascular sclerosis, black tea, green tea are available, another green tea contains a large number of antioxidants polyphenols can prevent stroke; containing polyphenols can inhibit cell mutation and the generation of cancer cells, can effectively block the synthesis of carcinogenic substances in the body. 13, apples ① contains soluble fiber can lower cholesterol. ②Essential points of food selection: complete particles, bright color, crisp sound. 14, orange ① contains VitA, B, C, Ca and pectin, VitA, C is an antioxidant can resist the damage of free radicals to cells. ②Essential points of food selection: complete grains, bright color, consumption should be eaten together with fiber. 15, papaya ① rich in VitC, B and β-carotene, with antioxidant effect. ② shopping tips: can be used to pinch the index finger, such as the indentation can be left, the table has been cooked to eat. 16, yogurt ① yogurt function is to balance the body’s good and bad bacteria, can improve the function of the gastrointestinal tract, some functional yogurt can enhance the function of the immune system. ②The key point of purchase: drink up within 2 days after opening the bottle. You can change various yogurts frequently so that the gastrointestinal tract can generally absorb the benefits of a variety of yogurts. 17, oats Rich in dietary fiber, can lower cholesterol. 18, sweet potato ① contains VitC, E and dietary fiber, dietary fiber can reduce the amount of cholesterol, can prevent constipation. ② shopping and cooking essentials: complete grain, no sprouting and broken skin. ③ steamed way to ingest better, groundnuts are starchy and should not be ingested in large quantities. 19, pumpkin Rich in potassium, zinc and beta-carotene, pumpkin is rich in zinc, zinc for immune function required. 20, nuts ① rich in a variety of antioxidants such as VitE, Se and monounsaturated fats such as n-3 fatty acids, with anti-cancer, prevention of arteriosclerosis damage. ② purchase and cooking essentials: pay attention to the preservation period. 21, fungus: black and white fungus ① contains polysaccharides, black fungus has anti-platelet agglutination, can slow down atherosclerosis and prevent coronary heart disease, polysaccharides can stimulate the transformation of lymphocytes, increase the phagocytosis of macrophages, improve the immune function of antibodies, and indirectly inhibit the growth of tumors. ②Purchase and cooking tips: Black fungus: large thick flesh without impurities, intact and unbroken is better; White fungus: white with a slight yellow color, intact and without impurities. The above recommended foods are recommended to be eaten in many ways, not just a few, so that the antioxidants obtained will be diversified.