So, the book Omnivore's Dilemma asks a question which I'm not sure is sufficiently answered by this study, but may be answered elsewhere (and I just don't know): Is it correct to treat food as a commodity. For example (ripping straight from the book here) is a carrot grown in Michigan the same as a carrot grown in Florida? There is a base assumption that we can treat the foodstuffs as commodities, but if this is not true, we cannot believe this study.

If the organic is grown in already marginal land, while the "standard" food is grown somewhere fertile, is it possible to get these results, or possibly results indicating organic food is less healthful?