I first watched this video lecture in 2011 when it was released.
We all need to watch this. Now. Or re-watch it if you already have seen it.
My big take away was that the body may find new synthetic proteins and growth hormones in our engineered foods, crops, and dairy products as foreign invaders that need to be attacked as if they are enemies, thus producing a food allergy reaction. O'Brien also discusses environmentally triggered (food triggered) Cancer.
TEDxAustin Robyn O'Brien 2011