A new study finds that consumers can markedly reduce their intake of pesticide residues and their exposure to antibiotic-resistant bacteria by choosing organic produce and meat.
Researchers at Stanford University reviewed a massive body of scientific studies on the much-debated issue. They analyzed more than 230 field studies and 17 human studies conducted in the United States and Europe to compare pesticide residues, antibiotic resistance and vitamin and nutrient levels in organic and conventionally produced foods. The study, published Monday (Sept. 3), is available online at the website of The Annals of Internal Medicine.
"The study confirms the message that EWG and scores of public health experts have been sending for years, that consumers who eat organic fruits and vegetables can significantly reduce pesticide concentrations in their bodies," Sonya Lunder, senior analyst at Environmental Working Group, said.
"This is a particularly important finding for expectant mothers and kids, because the risks of dietary exposures to synthetic pesticides, especially organophosphate and pyrethroid insecticides, are greatest during pregnancy and childhood, when the brain and nervous system are most vulnerable. These are two groups that should really avoid eating foods with high levels of pesticide residues," Lunder said.
Based on its review of the available research, the Stanford team also concluded that conventionally raised meat harbors more antibiotic resistant bacteria. It found that consumers of non-organic chicken or pork are 33 percent more likely to ingest three or more strains of antibiotic-resistant bacteria than those who eat organic meat.
"What jumped out at us in this study is that conventionally-raised meat treated heavily with antibiotics is much more likely to carry drug-resistant bacteria than meat produced on organic farms," said EWG Senior Analyst Kari Hamerschlag, who focuses on organic and conventional agriculture. "Antibiotics, which are banned in organic production, promote the development of resistant super-bugs that are a serious risk to human health."
Nutritional content
The researchers did not find "significant" or "robust" differences in nutritional content between organic and conventional foods. But Charles Benbrook, a professor of agriculture at Washington State University and former chief scientist at The Organic Center who reviewed the Stanford study and most of the underlying literature, had this to say in response:
"This study draws a markedly different conclusion than I do about the nutritional benefits of organic crops. Several well-designed US studies show that organic crops have higher concentrations of antioxidants and vitamins than conventional crops. For crops like apples, strawberries, grapes, tomatoes, milk, carrots, and grains organic produce has 10 to 30 percent higher levels of several nutrients, including vitamin C, antioxidants and phenolic acids in most studies."
The Stanford study also contradicts the findings of what many consider the most definitive analysis in the scientific literature of the nutrient content of organic versus conventional food.
In that 2011 study, a team led by Dr. Kirsten Brandt of the Human Nutrition Research Center of Newcastle University in the United Kingdom analyzed most of the same research and concluded that organic crops had approximately 12 to 16 percent more nutrients than conventional crops.
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