But organic options may live up to their billing of lowering exposure to pesticide residue and antibiotic-resistant bacteria, researchers from Stanford University and the Veterans Affairs Palo Alto Health Care System found.
"People choose to buy organic foods for many different reasons. One of them is perceived health benefits," said Dr. Crystal Smith-Spangler, who led the new study. "Our patients, our families ask about, Well, are there health reasons to choose organic food in terms of nutritional content or human health outcomes?'"
To try to answer that question, she and her colleagues reviewed over 200 studies that compared either the health of people who ate organic or conventional foods or, more commonly, nutrient and contaminant levels in the foods themselves. But consumers may also wonder why they have to pay more for organic products.
On an organic farm, you may find a lot more hand labor, because we dont use any herbicides of any sort, says Dan Pratt, owner of Astarte Farm in Hadley, Massachusetts. So there's a lot more hand weeding and hand hoeing of the crops. The man-hours are a big reason why organic crops typically cost more -- sometimes even twice as much.
Included in the Stanford-Veterans Affairs study, actually a review of a number of previous were organic and non-organic fruits, vegetables, grains, meat, poultry, eggs and milk. But many of the previous studies didn't specify their standards for what constituted "organic" food. According to United States Department of Agriculture standards, organic farms have to avoid the use of synthetic pesticides and fertilizers, hormones and antibiotics. Organic livestock must also have access to pastures during grazing season.
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.
Still, many conventional farms in the United States, by contrast, use pesticides to ward off bugs and raise animals in crowded indoor conditions with antibiotics in their feed to promote growth and ward off disease. The Food and Drug Administration has beenexamining that type of antibiotic use and its contribution to drug-resistant disease in humans. 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% less likely to carry bacteria resistant to three or more antibiotics than conventionally-produced meat.
