Many people feel that overnight tea can not drink, there are many claims, which is more "alarmist" is to say that drinking overnight tea will get cancer, in fact, this claim is not based on science.

First of all, the concept of overnight tea and tea placed for a long time is difficult to distinguish between the morning tea afternoon drink is very common, late at night work bubble tea, early in the morning after getting up to drink, the tea changes will not be greater than during the day, if you have to say what the difference is, but the daytime temperature is high, the tea may be greater changes.

The tea is placed for a long time, what changes will occur? Studies have shown that the main change is the further oxidation of tea polyphenols and the deepening of color. A cup of clear turquoise tea, especially in the case of higher temperatures placed for a long time, will lose the green color, increase the degree of yellow. This is the oxidation of tea polyphenols in the tea water to form yellow-red, reddish-brown oxidation products, mainly theaflavin, theaflavin, theaflavin, theaflavin and so on. These products are non-toxic and will not harm the human body.

There is also speculation that tea left overnight will produce nitrosamines, a carcinogen. First of all, it should be sure that tea even if there is nitrosamine, but also insignificant, we eat a lot of food in our daily life, such as bread, vegetables, pickles, salted fish, salted meat, etc. contain nitrosamines, and the amount of tea more than more. But it's not like everyone is skipping meals. Nitrosamines per kilogram of meat products in the content of 4 to 50 micrograms, is not very terrible, in fact, not also, because the human body itself has the function of decomposition of nitrosamines. Besides, nitrosamines to reach 100 to 2000 milligrams per kilogram of body weight absorption before it is possible to cause cancer, and it is perennial persistent large doses. A normal amount of eating in general will not produce such a huge harm, and the amount of tea drinking is even more insignificant compared to the number of meals ingested. If it is easy to these trace amounts of nitrosamines "bowed down", how can people still be called "the spirit of all things"? Therefore, the fear of drinking tea will bring the danger of nitrosamine cancer, is unjustified.

In addition, research shows that tea is rich in tea polyphenols and vitamin C, are nitrosamines natural inhibitors. Therefore drinking tea can also eliminate the harm caused by other foods containing nitrosamines. Tea is rich in tea polyphenols through the scavenging of oxygen free radicals, inhibit lipid peroxidation, the inhibition of other carcinogens is also quite obvious. Vitamin C and vitamin E in tea also have the effect of assisting in the fight against cancer.

So, overnight tea or tea brewed for too long, as long as there is no deterioration, there is no toxic effect.

In the past, there has been a theory that overnight tea should not be drunk, drink easy to get cancer, the reason is that overnight tea contains secondary amines, which can be converted into carcinogens nitrosamines.

In fact, this statement is not based on science, because secondary amines are widely available in a variety of foods, especially in cured products in the content of the most, take the bread to see, usually contains 2mg/kg of secondary amines, such as bread as the main food, every day, from the bread into the secondary amines eaten in the 1-1.5mg.

While the people through the tea, from the tea into the secondary amines have 1-1.5mg.

While people through the tea, from the tea into the secondary amines.

While people drink tea, the amount of secondary amines eaten from tea is only 1/40 of the amount eaten from bread, which is negligible. Moreover, the secondary amine itself is not carcinogenic, there must be nitrate to form nitrosamines and reach a certain order of magnitude to have a carcinogenic effect. Drinking tea can be obtained from the tea leaves more tea polyphenols and vitamin C, they can effectively prevent the synthesis of nitrosamines in the body, is a natural inhibitor of nitrosamines. Therefore, drinking tea or overnight tea is not carcinogenic.

However, from the point of view of nutritional hygiene, the tea is exposed to the air, and after a long time, it is easy to breed corrosive microorganisms, so that the tea is rancid and spoiled.

Additionally, the tea broth is long tea polyphenols, vitamin C and other nutrients, easy to oxidize and reduce. Therefore, overnight tea, although harmless, but generally still with the bubble drink good.

The overnight tea is rich in alcohol, fluorine, can prevent capillary hemorrhage. If you suffer from oral bleeding, skin bleeding, sores and pus ulcers and other problems, it can be healed. If the problem in the mouth and nose part, available overnight tea wash, gargle or drink.

Skin disease can be washed, the eyes appear red or unexplained tears, overnight tea can be used to wash the eyes, has a good effect. After brushing your teeth in the morning or eating before gargling a few mouthfuls of overnight tea, not only can make the mouth fresh and crisp, but also solid teeth. Treatment of rhinitis, some of the Chinese medicine is also made of overnight tea.

Additionally, washing hair with overnight tea has the effect of relieving itching, hair growth and eliminating dandruff. Eyebrows sparse daily brush dipped in overnight tea brush eyebrow, three or five months after the eyebrow will be dense and bright up. Bad breath containing overnight tea rinse mouth, can reduce odor. Overnight tea can also get rid of oil, fishy