In answer to question about apples:It might depend on what a person believes about the value of a fruit diet. Some people think illness can be cured by eating large amounts of fruit and eliminating other foods at the same time: such as fats, salt and sugar.
A good book is:'THe Health Revolution' by Ross Horne, as it describes the reasons why an apple a day thinking might work, but it costs money and you have to be determined. I've tried it many times, and it can be very effective: I really recommend reading this book.
Unfortunately some illnesses are not possible to cure so easily, and might require a visit to a doctor.
For example: I recently developed what seems to be a hernia
(after a car accident
I had recently:which meant I had to carry some heavy bags on buses so maybe that was why, although nothing I had not carried many times before, so I am puzzled by it, especially since a person I know - not a doctor- told me he could not see any hernia or stomach lump) and can't avoid going to a doctor now, whereas normally I would try to cure things by a fruit diet.