Many parents who feed their children organic food believe that such a diet reduces exposure to pesticides. A recent study proves it, showing that children eating primarily organic foods are exposed to fewer organophosphate (OP) pesticides through diet than children who eat conventional foods.

The study, conducted by University of Washington scientists, is the first to test whether dietary changes can lower pesticide exposure.

The researchers followed the diets of two small groups of Seattle pre-schoolers whose parents kept food diaries. One group of children ate primarily organic foods, while the other ate primarily conventional foods. Then, the researchers tested urine samples obtained from the children for breakdown products (metabolites) of organophosphate (OP) pesticides. OP pesticides interfere with the transmission of nerve signals in the brains and nervous systems of insects and humans alike, making them potent neurotoxins.

The analysis revealed that children eating organic foods had signicantly lower levels of one particular breakdown product, dimethylthiophosphate (DMTP), than the children eating conventional foods. In fact, DMTP levels in the organic group were nine times lower than in the conventional group.

Taking their analysis one step further, the researchers determined how much exposure of OP pesticide residue on food would be necessary to produce the DMTP levels found in the children. The results reveal that children eating conventional foods are much more likely to be exposed to OP levels above standards set by the U.S. Environmental Protection Agency (EPA) as required by the Food Quality Protection Act of 1996.

Oxydemeton-methyl, azinphosmethyl, phosmet and malathion were considered the most likely sources of OP exposure by the researchers since they make up the highest annual use on fresh fruits and vegetables.