Tea contains ellagic acid and theophylline, both of which affect the body's digestion of food. Gastric and intestinal juices are essential for the body to digest food, but when ellagic acid enters the gastrointestinal tract, it inhibits their secretion, leading to indigestion. In addition, ellagic acid will also produce coagulation with proteins in foods such as meat, eggs, soy products, dairy products, etc., forming ellagic acid protein concretions that are not easily digested. Need to be especially reminded that, if you eat food containing metal elements, such as iron, magnesium, etc., tannins may also react with them, over the years may form stones.