Imaam al-Dhahabi wrote in Al-Tibb al-Nabawi (Dar Ihyaa al-Uloom, Beirut, pp. 228-229):
Chapter: Regarding the Encouragement of Teaching medicine
His (alayhis salaatu was-salaam’s) saying, “Allaah did not send down a disease except that it has a cure” has already preceded. We say: This (hadeeth) necessitates the mobilization the people’s [lofty] concerns [for medicine] and incitement of (their) determinations to learn medicine. And it has already preceded that medicine is a skill. Imaam al-Shaafi’ee said, “I don’t know of a knowledge more noble than medicine after the halaal and haraam.” And he used to be concerned (and grieved) over what the Muslims had neglected of medicine, and he would say, “They have neglected one third of knowledge and have entrusted it to the Jews and Christians.” And he used to say, “Indeed the Ahl al-Kitaab have dominated us with respect to medicine.” And al-Shaafi’ee, alongside his greatness in the knowledge of the Sharee’ah, and his great skill in Arabic was also insightful in medicine. The writer (i.e. al-Dhahabi) says: And I have seen our Shaykh, Shaykh Ibraaheem al-Raqiyy to be insightful in medicine, and likewise our Shaykh, Shaykh Taqi al-Din Ibn Taymiyyah, and Shaykh Imaad al-Din al-Waasitee (rahimahullaau ta’aalaa) [were insightful in medicine]. Hippocrates and others have said, “Medicine is inspired by Allaah,” and Hippocrates is the chief of this discipline. His school of thought regarding it is the sound, correct school of thought. He was followed therein by Galen who is the leading scholar of this discipline as well, and both of them are venerated a great deal by the physicians.
There are some nice benefits from this quote, from them:
That a Muslim should strive to educate himself about that in which his health and well-being lies and to be familiar with the foundations of medicine. A great starting point for this is to get a good basic grounding in biochemistry and nutrition. This ought to become common knowledge.
That the great Scholars of Islaam were insightful and knowledgeable of medicine, and from them Aa’ishah (radiallaahu anhaa), and likewise al-Shaafi’ee, Ibn Taymiyyah and others.
That there were from the Muslim scholars who grieved at the fact that the Muslims were not at the forefront of medicine and had left this discipline to others, being reliant on them with respect to it.
That Muslim Scholars acknowledge that the correct and sound madhhab (school of thought) with respect to medicine (as in its basic foundations) can be found in the teachings of Hippocrates and Galen.
Following on from the last point, that the core principle of medicine is founded upon healthy-eating and a healthy life-style, and as the saying goes, “food is medicine and medicine is food.” The nature of one’s diet and lifestyle also determines the type and nature of the diseases that one succumbs to. Simple natural, wholesome diets (offering wholesome nutrition) suited to locality and environment lead to simple diseases which are short-lived and resolve easily, and which can be treated with the simplest of (natural) medicines. Complex diets consisting of refined foods and what in reality cannot even be said to be food, not providing the required nutritional intake the body needs for it to function properly at the biochemical level, lead to complex, chronic (long-term) diseases, requiring complex interventions. Precaution in diet is the foundation of all medicine, and this is what all nations and civilizations and cultures affirmed (through centuries of experience), and each of them developed their own forms of Natural medicine upon this basic foundation.