But you can't drink this. It is not that overnight tea will cause cancer, nor that overnight tea will poison people.

You can't drink it for the following reasons: First, the definition of overnight is actually 15 hours or more, whether it is day or night. But we often say overnight, that is, overnight, may be about 7~8 hours, but this time is enough to provide enough time for bacteria to reproduce, especially in summer.

Tea is actually a good carrier of bacteria, especially black tea and black tea, which will breed bacteria faster than green tea. During the fermentation of black tea and black tea, microorganisms can form various polyphenol oxidase, tea polysaccharide and polypeptide. These substances are very beneficial to the human body, but they are more conducive to the growth of airborne bacteria. When the temperature is high in summer, bacteria multiply faster.

Needless to say, the consequences are similar to vomiting and diarrhea caused by eating bad things.

Why is green tea better overnight? Friends who often drink tea can see a phenomenon, that is, after tea leaves are left for a period of time, a brown film will form on the surface. In fact, this is the oxidation product of polyphenols (tea pigments). In the same way, the longer the storage time, the closer the temperature is to 37 degrees, and the darker the color will be. The reason is that oxides accumulate more and more.

Therefore, in theory, the more tea polyphenols there are, the easier it is to form such a film. Comparatively speaking, green tea contains more tea polyphenols, while black tea and black tea lose a lot during fermentation. Then it can be said that green tea is easier to form tea pigment than black tea and black tea, but this is not a disadvantage, but an advantage. This oxidized tea pigment is not only harmless, but also can block the contact between tea leaves and air, which is equivalent to forming a protective film. From this perspective, it also shows that overnight green tea is safer than black tea and black tea.

Unlike overnight water, overnight water, especially pure water, because it has no bacteria? Nutrition? So bacteria grow slowly, but overnight tea is different. Soaking for too long will inevitably breed bacteria. When bacteria grow to a certain extent, tea will go bad. The naked eye can also see that the tea leaves are gradually turbid.

Summary: overnight tea, that is, tea leaves left in the teapot the next day, green tea is slightly better, and black tea and black tea are suggested to be poured out directly.

Can overnight tea cause cancer? Overnight tea can cause cancer, mainly because nitrite exceeds the standard, but in fact it does not exceed the standard at all, even lower than the content of a cup of boiling water. Because don't forget, tea polyphenols have antioxidant effect, which can reduce the formation of nitrite and the transformation of nitrosamines, so don't worry. Moreover, authoritative departments have tested the nitrite content of overnight tea (including black tea, green tea and black tea). ) is far below the national standard.

Conclusion: It is a rumor that overnight tea causes cancer, but the problem of bacteria exceeding the standard cannot be ignored.

The most correct way to drink tea at night is what we call night. In other words, the premise of making overnight tea is to drink tea at night. Some people worry that they can't sleep after drinking tea at night, but they haven't found the right way yet. Do you have any tea? Refreshing? And then what? Recuperate? At the beginning of brewing, theophylline will dissolve in water for about 2 minutes, and then tea polyphenols will gradually dissolve in water. So when you drink tea at night, you can pour out the tea for the first 2 minutes and then add boiling water. On the one hand, there is not so much caffeine. On the other hand, tea polyphenols can also offset the effect of residual caffeine, and the comprehensive effect is that the refreshing effect is not so obvious.

But for people who are usually easily excited or sensitive, have poor sleep and are weak, it is better to drink less or not drink tea at night. In addition, when drinking tea at night, you should put less tea leaves and don't make the tea too strong. Green tea, in particular, tends to thicken and appear because of its light color? Drunk tea? Phenomenon.

If you must drink tea at night, it is recommended to drink tea on an empty stomach after meals, especially those who don't drink tea often. Try to drink black tea in the evening. Black tea is mild, while green tea is more irritating, contains higher tannic acid and has astringent effect. Excessive drinking may form or aggravate constipation. This is also the most scientific reason for green tea in the morning, black tea in the afternoon and black tea in the evening.

Conclusion: Sensitive people are not advised to drink tea at night. If necessary, black tea and black tea are recommended. It is better to brew twice after 2 minutes, which should be light and less, and should not be overnight.

How much tea is suitable for making tea at a time? Everyone has some unique habits when drinking tea. Some people have a special preference for tea, such as white tea, green tea, black tea and black tea. Some friends are even used to drinking some kind of tea, such as Tieguanyin, Biluochun, West Lake Longjing, Yunnan Pu 'er, Huangshan Maojian and Rizhao Green Tea. But for health, there is a lot of pressure. How much tea is suitable?

If only from the appearance, you can't judge the depth of tea well. Different teas feel completely different. Black tea may be brewed a little, and the color will be deep, while green tea may be added twice, and it still feels very light.

Here is the recommended amount. The ratio of 1 g tea to 100ml water is suitable for most people. Don't consider the color when making tea, the shade is only related to the tea ratio.

Not too strong. If you make a cup of strong tea, it may be okay to drink a small cup. However, if you drink too much strong tea, it may lead to accelerated blood circulation and heartbeat, and will also strongly stimulate the brain nerves, resulting in palpitations, insomnia, frequent urination and other symptoms. Drinking a lot of strong tea will also inhibit the secretion of gastric juice, and digestive function will be affected.

Summary: the recommended dosage is 1 g tea 100ml water, which can be increased or decreased appropriately within this range. Strong tea hurts, so drink less.

Don't ask me why I know so much about tea, because I am a senior tea friend!

Doctor of medicine, doctor of life science, licensed pharmacist, senior nutritionist, protect life and health, reject fake health, and care for a healthy you by yourself!