1. Enhance immunity: Black tea contains a variety of antioxidant components, such as tea polyphenols, vitamins C, E, etc., which helps to improve human immunity and reduce the occurrence of infections and diseases.

2. Improve cardiovascular health: Tea polyphenols in black tea can help reduce blood lipid and cholesterol, reduce the occurrence of atherosclerosis, and thus protect the health of cardiovascular system.

3. Promote digestion: Tannic acid in black tea helps to promote gastrointestinal peristalsis and relieve digestive problems such as constipation.

4. Improve attention and mental state: Caffeine and theanine in black tea can stimulate the nervous system and improve people's attention and mental state.

5. Anti-inflammatory and analgesic: Some components in black tea can have certain anti-inflammatory and analgesic effects, which can alleviate some pain and inflammatory symptoms.

In a word, moderate drinking of black tea is good for health, but excessive drinking may lead to some negative reactions, such as palpitation and insomnia. It is recommended to drink 2-3 cups a day.