1, tea contains tea polyphenols, which are easily oxidized into brown colloid-tea rust in air and water. Tea rust contains picks, lead, iron, arsenic, mercury and other substances. The tea that has not been finished or left in the cup for a long time, such as overnight tea, is exposed to the air for a longer time, and the amount of tea polyphenols oxidized into tea rust is more. Tea rust enters the human body, combines with protein, fat and vitamins in food, and precipitates, which hinders the absorption and digestion of nutrients.
2. Once these oxidants enter the human body, they can also cause inflammation, ulcer, necrosis and other diseases in organs such as kidney, liver and stomach. Therefore, overnight tea should not be drunk, and tea sets should be scrubbed frequently.
3, the summer temperature is high, tea is easy to rancidity and taste, if it is put on hold for more than 24 hours, it is best not to drink, otherwise it will cause diarrhea.
4, overnight tea because of too long, most of the vitamins have been lost, and protein, sugar, etc. in tea have become nutrients for bacteria and mold reproduction, so it is not suitable for drinking.
The harm of these overnight tea is limited to the deteriorated overnight tea. The overnight tea without deterioration has many health care functions. The overnight tea is rich in alcohol and fluoride, which can prevent capillary bleeding. If you suffer from oral bleeding, skin bleeding, sores and abscess, you can use it to treat it. If the problem lies in the nose and mouth, you can use overnight tea to wash your hands and gargle.