I don't think they'll find that GMOs are unfit for human consumption. There is nothing inherently dangerous about screwing around with plant genetics. What I do think they are going to find, and what they have in fact already been finding out, is that the various pesticides, herbicides and insecticides that make monoculture and GMOs viable, are extremely dangerous to long-term human health. My bet is that, in a hundred years, what we now put into our bodies will be viewed similarly to how we look at people who used to drink mercury as a "cure" for various ailments: "What the f**k were they thinking? Jesus Christ, were they really that stupid back then?!"
That isn't to say that Comrade is wrong... He very well could be right, and frankly, I have very little trust in the regulatory agencies that make these safety decisions. Any cursory reading of the efficacy of these institutions shows that we underfund the holy hell out of them, that we are extremely slow to interfere with corporate interests, and that we've been hood-winked more than once by unsafe products. So I'd be sure to stay skeptical about any such safety claims, especially considering who does the research.