If somebody tells you or you read somewhere that there are no studies that prove that GMOs (genetically modified organisms, aka transgenics) are harmful in any way, you can simply reply that there are just no independent studies on GMOs.
That is the truth. Why are there not independent studies? According to F. William Engdahl at Global Research, because they are illegal. Why are they illegal? Because researching them without the approval of the company that owns the patent would be a breach of contract.
And that is: Monsanto and the other GMO mafias (oops, I meant respectful corporations) force any customer who buys their seeds to sign a contract that forbids such research in any form.
So basically they create the little frankestein monsters, "research" them at their labs, correct whatever needs to be corrected, and then send those shiny dossiers claiming high performance and zero damage to governments like yours.
The reality is probably much different but it's illegal to investigate.