The great Muslim scholar Ibn al-Qayyim stated in his most excellent book, "The Prophetic Medicine" (contained in Zaad al-Ma'aad, 4/201, Mu'assisat ur-Risaalah):

He (the Prophet, sallallaahu alayhi wa sallam) used to eat from the fruit of his land when it was in season and did not refrain from it. This too is from amongst the greatest means of preserving health. For Allaah, the Sublime, in His wisdom, created for every land such (varieties) of fruit that provide benefit for its local inhabitants when it is in season. Thus, consuming it is from the causes of their health and well-being, and it makes unnecessary the use of many medicines. Rarely does one refrain from eating the fruit of his land fearing sickness except that he is the most sick of people bodily, and the furthest of them from bodily health and strength.

And the moisture that is contained in the fruit will be cooked by the heat of the season and earth, and by the heat of the stomach which will repel any harm it may have. This is so long as he does not eat it in excess, nor overload the [bodily] constitution with more than it can bear, nor corrupt other food by it by consuming it while that food is still undigested, nor corrupt the fruit by drinking water over it, or eating food immediately after it. For colic often results from that. Whoever eats from the fruit that is in season, in the desirable amount, in the desirable manner will find it a most beneficial medicine.

From this great statement of this great Scholar, we can see that:

• Local fruit, in season is a means of great nourishment, strength, health and well-being.
• When consumed, it does away with the need for medicine and treatment, as it as a means to sound health.
• It should be eaten in moderate amounts.
• It should not be eaten whilst food is still being digested.
• Food should not be eaten immediately after it.
• And water should not be drunk over it.

You may also want to follow up with this article on fruit and how to eat it properly.