Twenty-three children (aged 3-11 years) living in Seattle, WA, consumed a diet for five days in which most of their usual foods were substituted with organic food. Urine samples were collected twice a day. The median urinary concentrations of the specific metabolites for the organophosphorus pesticides malathion and chlorpyrifos decreased to undetectable levels immediately after the introduction of organic diets and remained undetectable until the normal diets were reintroduced. The median concentrations for other organophosphorus pesticide metabolites were also lower during consumption of organic foods; however, the detection of those metabolites was not frequent enough to show statistical significance.

Comment: Some people have argued that organic foods provide little advantage over pesticide-sprayed foods, because of the drift of pesticides from non-organic to organic farms through the air and water. They point out that traces of pesticides can be found even in remote areas far from civilization. However, the results of the present study strongly suggest that there is a major difference in the amount of pesticides present in organic and non-organic food. Consumption of an organic-foods diet appears to result in rapid clearance of recently consumed pesticides from the blood. Long-term use of such a diet would also presumably aid in the gradual removal of pesticides stored in organs and adipose tissue. While the debate continues about the safety of these neurotoxins in the human diet, more and more people are "just saying no" to pesticides, as evidenced by the fact that organic foods are now being sold at WalMart.

Lu C, Toepel K, Irish R, Fenske RA, Barr DB, Bravo R. Organic diets significantly lower children's dietary exposure to organophosphorus pesticides. Environ Health Perspect. 2006;114:260-263.