People often say that drinking tea can lead to insomnia, because tea contains caffeine and tea polyphenols, which can not only refresh people, but also make people feel refreshed and not sleepy. During sleep, after hypnotic adenosine binds to its receptor, the activity of nerve cells slows down and weakens, and people become sleepy and fall asleep. After drinking tea, caffeine ingested by human body will preferentially bind with adenosine receptor, which will hinder the action of adenosine. Adenosine can help sleep, increase the activity of nerve cells, make people more awake and unable to sleep, which leads to insomnia.
But drinking tea can lead to insomnia, and it can't be generalized. Everyone's physique and living habits are different, and their tolerance to tea and caffeine is also different. Some people toss and turn after drinking a small cup of tea before going to bed. And some people who love tea can still fall asleep after drinking tea before going to bed.
First of all, it is recommended to drink tea 3-5 hours before going to bed, which generally has no obvious effect on sleep at night, because caffeine will disappear in about 3-4 hours in the human body. Secondly, wash the tea once or twice, because caffeine is easily soluble in hot water. After two minutes of brewing with hot water, about 70%-80% of caffeine has been dissolved in water, and discarding the tea soup dominated by caffeine for the first two times has a certain effect on avoiding insomnia.