Leek is a more suitable vegetable in spring. The leek in spring is tender and fresh, which is the best in a year. Leek is rich in carotene, vitamin C, folic acid and potassium. There is also a lot of cellulose in leek, which can accelerate gastrointestinal peristalsis and prevent constipation. Isothiocyanate contained in leek also has antibacterial effect.

Spring is the season of high incidence of allergic diseases, and the substances contained in lettuce can help resist allergies and relieve the symptoms of allergic patients. Lettuce can also enhance the secretion of digestive juice such as gastric juice and promote the secretion of bile, which is beneficial to digestion. Lettuce is rich in potassium, which can promote urination and maintain water balance. Patients with hypertension and heart disease often eat it, which has many benefits.