GM food is not dangerous for human health. At all. At least the risk of it being dangerous to eat is vanishingly small. Excepting that some psycho could cause your rice to overexpress some deadly toxin.
The real risk is in driving ecology toward homogeneity. Lets say you could make a "super rice" crop which had 3x yield and was resistant to all known rice diseases. The problem would be that one day, one disease would find a way to kill your crop. Then you have lost ALL of your rice. That would cause you issues.
Also it's possible that you could get horizontal gene transfer from GM crops to non-GM crops. If for example your insect resistant crop imparted insect resistance to all the surrounding plants. Then you are going to effect the food chain all the way up.
The real risk is in driving ecology toward homogeneity. Lets say you could make a "super rice" crop which had 3x yield and was resistant to all known rice diseases. The problem would be that one day, one disease would find a way to kill your crop. Then you have lost ALL of your rice. That would cause you issues.
Also it's possible that you could get horizontal gene transfer from GM crops to non-GM crops. If for example your insect resistant crop imparted insect resistance to all the surrounding plants. Then you are going to effect the food chain all the way up.