In general, the purine content of indigo naturalis is between 17.5 mg and 30.2 mg/100 g, which belongs to low purine food. Green vegetables contain more dietary fiber, which can combine with cholate and cholesterol and triglycerides in food, thus reducing the absorption of lipids, so it can be used to assist in lowering blood lipids. And vegetables contain a lot of plant cellulose, which can promote intestinal peristalsis, increase the volume of feces and shorten the time of feces staying in intestinal cavity, thus improving the symptoms of constipation. Vegetables contain a variety of vitamins, carotene, calcium, iron and other nutrients, which help to supplement human needs and enhance the body's immune ability. In addition, patients eating green vegetables can also effectively avoid indigestion and malnutrition. It should be noted that patients who are allergic to green vegetables should not eat them, because eating them may cause allergic symptoms such as skin redness, frequent diarrhea, indigestion or asthma, which is not good for their health. In addition, it is suggested to wash first and then cut, stir-fry quickly, open the soup and serve the dishes, and stir-fry for instant use. In this way, nutrient loss and nitrite content increase caused by repeated heating can be avoided.