Is eating raw sweet potato harmful?

The majority of sources state that Apple skins are very healthy and I have never peeled an Apple before consuming it, however, I have often observed gorillas in the zoo and they always seem to peel aples before eating them and they discard the skin. This made me curiOS about it. Using their thumb nail they spin the Apple and the peel is removed in seconds. Very effective. Then they discard the skin of the Apple. Perhaps gorillas know something we have yet to learn.