True or False: An Apple a Day Keeps the Doctor Away

So it's official. I think I have the weakest immune system ever. First, it was a trip to the hospital because of some serious pain around my appendix. Seven hours in the emergency room to tell me that its just a gas bubble. How awesome is that? Now I have a sinus infection and a fever that punished me to bed rest all day yesterday. I think my body is trying to tell me something. Good thing it's the holidays. Plenty of time to catch up on some rest and spend some time with the Family. I love the holidays!
So while I was laying in bed all day yesterday, I thought to myself: "Gabi...Do you think an apple a day really does keep the doctor away?" And I thought to myself again and said: "Well if it does then I would eat three apples a day just in case."

So, I was just wondering what you thought...Do you think an apple a day keeps the doctor away?

Or do you think its just an old saying? And if it just an old sayings, which just adds to my recent suspicion that all old sayings are almost completely false, then why do we use them anyway?