Teenagers had better drink some green tea, which is good for their health, but don't drink strong tea or overnight tea. Function of green tea: 1, anti-aging: antioxidants contained in green tea help to resist aging. Because the metabolic process of human body, if oxidized, will produce a large number of free radicals, easy to aging, resulting in cell damage. SOD (Superoxide Dismutase) is a kind of free radical scavenger, which can effectively remove excess free radicals and prevent the harm of free radicals to human body. Catechins in green tea can significantly improve SOD activity and scavenge free radicals. 2. Antibacterial: Studies have shown that catechins in green tea can inhibit some bacteria that cause human diseases, and at the same time, it will not harm the reproduction of beneficial bacteria in the intestine, so green tea has the function of whole intestine. 3. Lowering blood fat: Scientists' animal experiments show that catechins in tea can reduce the contents of total cholesterol, free cholesterol, low-density lipoprotein cholesterol and triglycerides in plasma, and at the same time increase high-density lipoprotein cholesterol. Human experiments show that it can inhibit platelet aggregation and reduce the incidence of arteriosclerosis. Green tea contains flavonol, which has antioxidant effect, prevents thrombosis and platelet aggregation, and reduces cardiovascular diseases. 4. Slimming and fat reduction: Green tea contains theophylline and caffeine, which can activate protein kinase and triglyceride lipolytic enzyme through various functions, reduce the accumulation of fat cells, and thus achieve the purpose of losing weight. 5, prevent dental caries, remove bad breath: green tea contains fluorine, in which catechins can inhibit the role of dental caries bacteria and reduce the occurrence of dental plaque and periodontitis. Tannic acid contained in tea has bactericidal effect, which can prevent food residues from breeding bacteria, so it can effectively prevent bad breath. 6, anti-cancer: green tea has an inhibitory effect on some cancers, but its principle is limited to the inference stage. Drinking more tea is bound to have a positive encouraging effect on preventing cancer. 7. Whitening and UV protection: Experts found in animal experiments that catechins in green tea can resist skin cancer caused by UV-B. 8. It can improve indigestion: Recent research reports show that green tea can help improve indigestion, such as acute diarrhea caused by bacteria, which can be alleviated by drinking a little green tea.