The vast majority of studies that made it into the analysis looked at properties of food itself. And overall, the researchers report today in the journal Annals of Internal Medicine, results showed few differences in the content of vitamins, minerals, antioxidants, proteins or other nutrient measures.
The two groups did show some differences, though.
Organic produce contained more phosphorous than conventional versions, for example, though Brevata pointed out that phosphorous deficiency only occurs in people who are near starvation.
A few very small studies also suggested that organics contained higher levels of a type of antioxidant called phenols. And organic milk and chicken contained more omega-3 fatty acids than conventional varieties did, but Brevata added a caveat there as well: Omega 3s varied equally as much with brand and harvesting season.
Pesticide levels varied between the two groups, with conventional foods carrying a 30 percent higher chemical load than organics. Despite what sounds like a large difference, Brevata said, both groups were well below what are currently considered safe limits.