User blog comment:AYET/(97) Other chats about chapter 704/@comment-3125914-20130404082416/@comment-6971349-20130404164323

Luffy can't eat it. (Even if he could, he shouldn't.)

The one key to whether someone can aquire multiple devilfruit abilities is this simple fact Blackbeard didn't eat Whitebeard's fruit nor whitebeard (which would have been gross). He used his own devil-fruit powers to steal them from Whitebeard's corpse. The truth behind it is going to be revealed, but for now, suffice to say that Blackbeard is the only one who can possess more than one fruit's power without eating them.