Some people say that overnight tea is harmful to the body. WeChat says that overnight tea is good for the body. Who is right?

Can I drink overnight tea? Many people think that overnight tea should not be drunk, and there are many opinions. One of the more "alarmist" ones is that drinking overnight tea will cause cancer. In fact, this statement has no scientific basis. 1. The concept of overnight tea is difficult to distinguish... Overnight tea does not cause cancer. Tea brewed in the morning is very common to drink in the afternoon. Tea brewed at work late at night and drank after getting up early in the morning will not change the tea more than during the day. If you have to If anything, the temperature in the daytime is high, so the tea water may change even more. 2. What changes will occur if the tea is left for a long time... How to drink tea healthily? Research shows that the most important change is the further oxidation of tea polyphenols and the deepening of the color. A cup of clear green tea, especially if left for a long time at a high temperature, will lose its green color and increase its yellow color. This is the oxidation of tea polyphenols in tea to form yellow-red and reddish-brown oxidation products, mainly theaflavins, thearubigins, theabrownins, etc. These products are non-toxic and will not cause harm to the human body. 3. Some people speculate that after tea is left overnight, carcinogens such as nitrosamines will be produced... Tasting tea will lead to health. First of all, it should be confirmed that even if there are nitrosamines in tea, it is insignificant. Many of the nitrosamines we consume daily Foods such as bread, vegetables, pickles, salted fish, bacon, etc. contain nitrosamines, and the amount is much higher than in tea. But I didn’t see anyone skipping meals. The nitrosamine content in each kilogram of meat products is 4 to 50 micrograms. Isn't it terrible? In fact, it is not, because the human body has its own function of decomposing nitrosamines. Furthermore, nitrosamines must be absorbed at 100 to 2000 mg per kilogram of body weight to cause cancer, and large doses must be taken continuously throughout the year. Generally, a normal amount of food will not cause such huge harm, and the amount of tea drunk is insignificant compared to the amount of meals consumed. If we can easily "bow down" to these trace amounts of nitrosamines, how can humans still be called the "spirit of all things"? Therefore, it is unreasonable to worry that drinking tea will cause nitrosamines to cause cancer. In addition, research shows that tea is rich in tea polyphenols and vitamin C, which are natural inhibitors of nitrosamines. Therefore, drinking tea can also eliminate the harm caused by other foods containing nitrosamines. Tea is rich in tea polyphenols, which can inhibit lipid peroxidation by scavenging oxygen free radicals, and its inhibitory effect on other carcinogens is also quite obvious. Vitamin C and vitamin E in tea also have auxiliary anti-cancer effects. Most of the vitamins in overnight tea have been lost due to being too long, and the proteins, sugars, etc. in the tea soup will become nutrients for the reproduction of bacteria and mold. Therefore, people usually think that overnight tea cannot be drunk. In fact, overnight tea that has not deteriorated is not only drinkable, but also has the following health care effects: Anti-cancer and antioxidant: Tea will turn reddish-brown after being left for a long time. This is due to the oxidation of tea polyphenols into reddish-brown tea pigments. Studies have shown that tea polyphenols and tea pigments have strong anti-cancer and antioxidant effects. Although the vitamin C content in overnight tea is greatly reduced, it still has anti-disease effects. Hemostasis: Overnight tea is rich in acid, which can prevent capillary bleeding. If you suffer from stomatitis, tongue carbuncle, rash, bleeding gums, etc., you can use overnight tea to rinse your mouth. It can also be used to bathe in sores, abscesses and skin bleeding. Improve eyesight: The tea polyphenols in overnight tea have antibacterial and anti-inflammatory effects. If your eyes appear red, you can wash them with overnight tea several times a day. Anti itching: Use warm overnight tea to wash your hair or wipe your body. The fluorine in the tea can quickly relieve itching and prevent and treat eczema. Hair growth: Washing your hair with overnight tea also has the effect of growing hair and eliminating dandruff. If you feel your eyebrows are sparse, you can use a brush dipped in overnight tea to brush your eyebrows every day. Over time, your eyebrows will naturally become thicker and brighter. Strengthen teeth and clean teeth: After the fluorine in the tea and the enamel of the teeth are calcified, it will enhance the resistance to acidic substances and reduce the occurrence of tooth decay; fluoride can also eliminate dental plaque. It is best to rinse your mouth with tea two or three minutes after meals. Eliminate bad breath: Tea contains essential oils and has a fragrant smell. Gargle a few sips of overnight tea before and after brushing your teeth in the morning or after meals to freshen your breath. Gargling with tea regularly can eliminate bad breath. Sun protection: If your skin is sunburned, you can wipe it gently with a towel dipped in overnight tea. Because tannic acid has an astringent effect on the skin, the flavonoid compounds in tea also have anti-radiation effects.

Removes fishy smell and removes greasiness: Overnight tea also has a strong effect of removing fishy smell and grease. Use it to wash your hands after eating shrimps and crabs to feel refreshed. When using overnight tea, it should be done so that it does not go rancid (deteriorated). The temperature in summer is high, and tea is prone to rancidity and staleness. If it is left aside for more than 24 hours, it is best not to drink it, otherwise it will cause diarrhea.

Although experts say it is okay, after all, it is a very cold tea, or how much Hours, no one knows whether it is good for the body for a long time. I think it’s better to drink less or not drink it