As-Suyuti, in “Medicine of the Prophet” [pbuh] said,

“The most experienced doctors use medications that contain one ingredient, the medication should be similar or related to regular foods that the patient is used to eating. Cultures that consume one or only a few types of food in their regular diet, generally suffer from few illnesses, they should not use compound medicines.”

“Those who live in cities and whose diets are complex need medicines that are a mixture of several substances or ingredients, as these are the types of medicines that most suit their illnesses.”

“The ailments of the people who live in the deserts are usually simple and thus simple medications are suitable for them. These arguments entail facts that are known in the medical profession.”