JOEL - In 2 Nephi 2:11 and 15 we read;

11."For it must needs be, that there is an opposition in all things.
15 And to bring about his eternal purposes in the end of man, after he had created our first parents, and the beasts of the field and the fowls of the air, and in fine, all things which are created, it must needs be that there was an opposition; even the forbidden fruit in opposition to the tree of life; the one being sweet and the other bitter."

I believe the tree of life is mostly a representation of the eternal doctrine of opposition in all things. A concept that existed even in the garden of Eden. It stood as the opposite of the tree of knowledge of good and evil. And since God needed to place cheribum and a flaming sword near it to prevent Adam from partaking it after the fall, it is possible that Adam and Eve were eating from that fruit while they were in Paradise. It may be a figurative representation of the love of God they were able to experience first hand as they lived and walked with God there. It is something we all will enjoy again when we return to live with God in heaven.