Everything we eat is genetically modified. Everything. Decades of cross- and interbreeding produce, animals, grains, etc., has made it so that the things we eat today, no matter how many "organic" labels are on the package, are (genetically) drastically different from what they were even a few decades ago.
I am going to go ahead and assume that the FDA knows more about science than I do. I think that this is a fairly reasonable assumption.