No three letters strike fear in a food-lover’s heart like G. M. O. But a new documentary called Food Evolution addresses that key question about genetically modified organisms: are they safe to eat? The science is clear, and there’s nothing to fear — at least as far as our health is concerned. There are, however, questions about their environmental impact, which the film doesn’t really address. So let’s keep the conversation going. But let’s not be afraid to put these talked-about foods on our table.