1. Caffeine and tea polyphenols in tea have the greatest influence on brain nerves. Tea leaves are soaked for about 2 minutes, and about 70%-80% of caffeine will be dissolved in water. At this time, tea has obvious refreshing effect and makes people excited. After that, the tea polyphenols in tea gradually dissolve in water, which counteracts the effect of caffeine, so it is not easy to cause obvious physiological excitement. Therefore, when drinking tea at night, as long as you pour out the first tea that has been soaked for about 2 minutes, and then add boiling water to soak it again, the refreshing effect will not be so obvious.

2. People who are usually impulsive or sensitive, have poor sleep and are weak should 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. It is best to drink tea after meals, because drinking tea on an empty stomach will harm your health, especially for people who don't drink tea often, it will inhibit the secretion of gastric juice, hinder digestion, and even cause palpitations, headaches and other "tea drunk" phenomena. ?