It is stated that milk was the diet of the Prophets. A person came to Imam Sadiq (a.s.) and said that after drinking milk he did not feel well. The Imam (a.s.) replied that milk was not harmful and that he must have taken something else with milk.
A person complained to the Imam (a.s.) about body weakness, at which the Imam (a.s.) ordered him to drink milk as it increases flesh on the body and strengthens bones.
According to Hazrat Ali (a.s.), cow’s milk is a medicine.
In many of the traditions ghee has been praised a lot, specially the ghee made from cow’s milk. But aged persons who are fifty and above are advised not to take ghee.