山药是一种家常菜，也是一味功用广泛的中药。《神农本草经》将之归为上品，认为它“主伤中，补虚，除寒热邪气，补中益气力，长肌肉，久服耳目聪明。”《本草经读》注曰：“凡上品，俱是寻常服食之物，非治病之药，故神农提出久服二字……多则终身，少则数年，与五谷之养... Yam is a home cooking, but also blindly use a wide range of traditional Chinese medicine. “Shen Nong’s Materia Medica” will be classified as the top grade, that it “the main injury, tonic, in addition to cold and evil, Bu Zhongyi strength, long muscles, Jiufu eyes smart.” “Materia Medica read” Note: , Are all common things to take, non-cure medicine, so Shennong proposed Jiufu word ... ... as many as life, ranging from a few years, and raising grain ...