For anyone wondering what way of the fruit perk is: it boosted my strength 2 times +1 (+2 for morons)by eating like 10 apples Perhaps other stats do change too.
Yes, permanently. This was the last perk I gave to my main character, and I had him eat a bunch of apples. He gagged at most of them. I'm not sure how many I ate, but it was all the ones I managed to gather up until the end of the Mardin mission. His stength went from 5 to 9, and it hasn't declined at all.