From a total of over 52,000 articles, there were 162 (137 on crops and 25 on livestock products) that met the researchers' first level of inclusion criteria but only 55 of these were of satisfactory quality and went into the analysis.
Conventionally produced crops had a significantly higher content of nitrogen.
Organically produced crops had a significantly higher content of phosphorus and higher titratable acidity.
There was no evidence of a difference among the remaining 8 crop nutrient categories.
Analysis of the few quality studies on livestock products showed no evidence of differences in nutrient content between those that were organically and those that were conventionally produced.
However, researchers say it’s difficult to provide a definite answer until longer studies have been completed. In the meantime, stick with organic food, at the very least it’s safer. Pesticides and chemicals certainly don’t help. Eek!
UPDATE: Dr. Fuhrman had some thoughts on this:
Lower nitrogen residue in the organic food is another important reason to eat organic that this study documented. The over-use of nitrogen fertilizers is polluting our oceans, removing ozone and damaging the ecosystem, plus excessive nitrogen compounds in the non-organic food is also not healthy.