Besides the high temperature of tea may increase the risk of cancer, Zhang, a nutritionist in Taiwan Province Province, warned that if pesticides remain in tea, it may also be harmful to health. If you are worried about the problem of pesticide residues, you can pour out the first bubble of water, open the lid when making tea, and don't suffocate the steam, so that some pesticide substances will evaporate with the steam. When buying tea, try to choose organic tea, which is safer.
Some studies at home and abroad have proved that no matter what kind of tea, it has different preventive and therapeutic effects on chemical carcinogenesis or metastatic tumors in experimental animals. Both endogenous and exogenous free radicals have carcinogenic effects, but natural antioxidants can scavenge free radicals, so people pay attention to the anti-cancer and anticancer effects of this natural antioxidant. Green tea is rich in natural antioxidants such as "tea polyphenols". Drinking before or after meals, all kinds of antioxidants will have a synergistic effect in scavenging free radicals, which can better show the anti-cancer and anticancer effects of green tea.
After comparing the efficacy of many kinds of green tea, it is concluded that Pu 'er tea has a strong killing effect on cancer cells. After drinking Pu 'er tea for a long time, the polygon of cancer cells shrinks and turns round, and the pseudopoda shrinks, losing the ability to attach and swim, and even falling off and floating. Residues also become smaller, rounder and denser, the nucleus contracts, chromatin concentrates or disappears, vacuoles appear in the nucleus and cytoplasm, nucleoli contracts or breaks away, chromosomes contract or concentrate with each other, ribosomes decrease, mitochondria and endosomes expand; RNA synthesis decreased and nuclear division stopped. These changes prove that cancer cells often degenerate and die under the pharmacological action of Pu 'er tea.
Don't drink too hot tea. Many people like to drink tea just brewed with boiling water. They think this kind of tea tastes best. Some people are used to drinking hot tea, and it seems that their mouths are used to this temperature. But you know what? The highest temperature that the oral cavity can tolerate is nearly 70 degrees, while the problem that the test tube can tolerate is only about 40 degrees. In other words, when we drink tea with moderate temperature, it may be a kind of injury to the esophageal mucosa. In the process of continuous destruction-repair-destruction-repair, abnormal hyperplasia of esophageal mucosa is likely to occur, leading to precancerous lesions, and the final result will be esophageal cancer. So, don't be greedy for tea.
People with peptic ulcer should drink less tea. Tea contains polyphenols, which can prevent cancer and protect health, but it is not recommended for people with digestive system ulcers. Tea contains caffeine, which can promote gastric acid secretion, and the digestive tract environment of patients with ulcers is very afraid of acid, which will lead to aggravation of the disease. Therefore, if it is clear that people with gastric ulcer or duodenal ulcer should drink less tea or not. If there is no definite diagnosis, people who have obvious regular abdominal pain before or after meals should also avoid drinking tea frequently, and it is suggested that digestive system ulcers should be ruled out through routine physical examination.
People with iron deficiency anemia should not drink tea. The reason of iron deficiency anemia is that the body lacks hematopoietic raw materials protein and iron, while tea contains tannic acid and theophylline, which can affect the absorption of protein and iron, thus aggravating the degree of iron deficiency anemia. If it is iron deficiency anemia during medication, it is not suitable for drinking tea. The principle is that theophylline and tannic acid in tea can inhibit the absorption of iron preparation and affect the therapeutic effect.
It is not advisable to drink tea during taking medicine. As the old saying goes, tea can be an antidote. Especially after taking dietary supplements to supplement mineral elements, avoid drinking tea within 2 hours, because tannic acid in tea will combine with metal ions, prompting it to be excreted, which will affect the supplement effect.
Pay attention to the temperature of making tea, not all tea can't be brewed with boiling water. Green tea, especially the buds of all kinds of tea, is suitable for using water of about 80 degrees, so that the tea soup is fresh and bright, and the nutrients in it can be avoided. However, when oolong, Pu 'er or tea leaves are coarse and old, it is necessary to use 100 degree boiling water, and in order to keep the water temperature, it is necessary to brew the tea cups with boiling water in advance. So the water temperature depends on the tea.