I know of a study of organic foods done here in Norway only a few years ago at a state university, thus neutrally funded. The research was done on strawberry plants and found no difference in measurable content whatsoever. Mind you, she tested only the plants/berries, not the environment around. This research doesn't support buying organic foods out of a belief that it's healthier, but I still buy organic foods with the environment in mind - no artificial fertilisers can't be all that bad.