There are many studies demonstrating the safety of GM food. There is a great website where you can find links to over 600 studies: GENERA project at Biofortified. Each has citations and, in many cases, the full text of the study. And here’s a link to a response about the rigorous testing procedures GM foods must go through before they are put on the market: How are GMO foods regulated?
Farmers have the right to choose the types of seed that are best for their type of farming. All the member companies here at the Council for Biotechnology Information support all types of farming, including organic. This isn’t a situation where we are choosing one over the other―there’s ample room in agriculture for both.