Smith-Spangler and her colleagues found there was no difference in the amount of vitamins in plant or animal products produced organically and conventionally - and the only nutrient difference was slightly more phosphorus in the organic products. Organic milk and chicken may also contain more omega-3 fatty acids, they found - but that was based on only a few studies.
There were more significant differences by growing practice in the amount of pesticides and antibiotic-resistant bacteria in food. More than one-third of conventional produce had detectable pesticide residues, compared to seven percent of organic produce samples. And organic chicken and pork was 33 percent less likely to carry bacteria resistant to three or more antibiotics than conventionally-produced meat.
Smith-Spangler told Reuters Health it was uncommon for either organic or conventional foods to exceed the allowable limits for pesticides, so it’s unclear whether a difference in residues would have an effect on health.
But Chensheng Lu, who studies environmental health and exposure at the Harvard School of Public Health in Boston, said that while the jury is still out on those effects, people should consider pesticide exposure in their grocery-shopping decisions….
He said more research is necessary to fully explore the potential health and safety differences between organic and conventional foods, and that it’s “premature” to conclude organic meat and produce isn’t any healthier than non-organic versions.