The role of eating bananas is generally as follows: 1, can reduce the incidence of hypertension, because bananas are rich in potassium, and the role of potassium in controlling the rise of blood pressure is very obvious, eating bananas to supplement potassium can well prevent the occurrence of hypertension; 2, can laxative, because bananas are rich in dietary fiber, can mechanically stimulate intestinal peristalsis, for constipation, defecation difficulties of people appropriate to eat bananas, through lubrication of the intestinal tract and in promoting defecation, prevention of constipation is very obvious role.