A new study conducted at Stanford Center for Health Policy and published in the Annals of Internal Medicine questions whether organically-grown foods are safer or more nutritious than conventionally produced foods. This systemic review, which extracts data from English-language studies, says no. Seventeen studies in human beings and 223 studies of nutrient and contaminant levels in foods were examined. There were no long-term studies of health outcomes among people eating organic versus conventionally raised foods.
Three of the human studies researched clinical outcomes; those found no difference between populations who ate organic foods and those who ate conventional foods for allergic reactions or Campylobacter infections. Two of the human studies found significantly lower pesticide levels in the urine in children, but found no “clinically meaningful” differences among adults.
Estimates of any differences in nutrient and contaminant levels were “highly heterogeneous” except conventionally grown foods had significantly higher phosphorus levels. The risk of pesticide residue contamination was lower among organic produce, as is to be expected, but there was little difference in the risk of exceeding maximum limits. In other words, even produce that had pesticide residue had levels that were below safety limits set by the EPA.
The risk of E. coli contamination was unrelated to the farming method. But the risk for ingesting antibiotic-resistant bacteria was higher in conventionally raised chicken and pork than in organically raised meats.
The requirements for organic certification can vary, but there are some common standards. For instance, foods with the organic certified label must be grown without synthetic pesticides or fertilizers, processed without irradiation, not grown from genetically modified organisms. Farm animals used for food must be raised without antibiotics or growth hormones and given pesticide-free animal feed.
What does this mean for the consumer? If you want to buy organically raised produce and meat, you will consume fewer pesticides and lower your risk of ingesting antibiotic-resistant bacteria. But the nutritional profiles of both groups are the same. And organically grown and produced foods are not safer in terms of bacterial contamination. No matter where you buy your food or if you have conventionally raised or organically produced food, it must be handled correctly and cooked to a safe final internal temperature.