PHILADELPHIA, September 3, 2012 - There is generally no difference in nutritional value or risk for bacterial contamination between organic and conventional foods, according to a new study being published in Annals of Internal Medicine, the flagship journal of the American College of Physicians (ACP). While the consumption of organic fruits and vegetables reduced exposure to any detectable pesticide residues by 30 percent, pesticide levels were generally within the allowable limits for safety.
Researchers conducted a systematic review of 17 human studies and 223 studies of nutrient and contaminant levels in unprocessed foods such as fruits, vegetables, grains, milk, eggs, chicken, pork and meat to compare the health, nutritional, and safety characteristics of organic and conventional foods. They found that the published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods.
"Some believe that organic food is always healthier and more nutritious," said Crystal Smith-Spangler, MD MS, a VA Physician Fellow at CHP/PCOR, and lead author of the paper. "My colleagues and I were a little surprised that we didn't find that."
The researchers did find weak evidence of the nutritional superiority of organic foods in that organic produce contained significantly higher levels of total phenols, a compound that may have antioxidant properties, and that organic milk and chicken contained significantly higher levels of omega-3 fatty acids. However, the researchers concluded that since few people have phosphorous deficiency, the finding has little clinical significance.
Sales of organic foods have increased dramatically is the US. Between 1997 and 2010 organic food sales have risen from $3.6 billion to over $26 billion annually. Prices vary, but consumers my pay up to twice as much for organic foods versus conventional. In general, to be certified "organic," produce must be grown without synthetic pesticides or fertilizers or routine use of antibiotics or growth hormones. Organic livestock are fed organically produced feed and are free to roam outdoors. In addition, organic regulations typically require that organic foods are processed without irradiation or chemical food additives and are not grown from genetically modified organisms.
"There are many reasons why consumers may choose to purchase organic food," said Smith-Spangler. "We examined published literature to assess the evidence for significant differences in nutrition, food safety, and health outcomes between organic and conventional foods and populations consuming these foods. However, consumers may choose to purchase organic foods for other reasons besides nutrition and food safety, such as concern for animal welfare, the environment, or preferences in taste."
About Annals of Internal
Annals of Internal Medicine is one of the five most widely cited peer-reviewed medical journals in the world, with a current impact factor of 16.7. The journal has been published for 85 years. It accepts only 7 percent of the original research studies submitted for publication. Follow Annals on Twitter and Facebook.
Media Contact: Angela Collom, ACP
email@example.com or 215-351-2653