A new peer-reviewed study shows that eating a completely organic diet—even for just one week—can dramatically reduce the presence of pesticide levels in people, a finding that was characterized as "groundbreaking" by critics of an industrial food system that relies heavily on synthetic toxins and chemicals to grow crops and raise livestock.

Published in the Environmental Research, the study—titled Organic Diet Intervention Significantly Reduces Urinary Pesticide Levels in U.S. Children and Adults (pdf)—found that switching to an organic diet significantly reduced the levels of synthetic pesticides found in all participants.

"We all have the right to food that is free of toxic pesticides. Farmers and farmworkers growing our nation's food and the rural communities they live in have a right not to be exposed to chemicals linked to cancer, autism and infertility."

— Kendra Klein, PhD, Friends of the Earth

"This study shows that organic works," said study co-author Kendra Klein, PhD, senior staff scientist at Friends of the Earth. "We all have the right to food that is free of toxic pesticides. Farmers and farmworkers growing our nation's food and the rural communities they live in have a right not to be exposed to chemicals linked to cancer, autism and infertility. And the way we grow food should protect, not harm, our environment. We urgently need our elected leaders to support our farmers in making healthy organic food available for all."

The study tested the urine of four diverse American families in Oakland, Minneapolis, Atlanta, and Baltimore after eating their typical diet of conventional food for six days and then after a controlled diet of all organic food for six days.

Featuring the families that participated and the scientist who carried it out, watch a video produced by FOE Action about the study:

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According to FOE, the pesticide and pesticide metabolite levels detected in participants dropped by an average 60.5 percent after just six days of eating the all-organic diet. Specifically, the testing showed significant reductions in pesticides associated in the past with increased risk of autism, cancers, autoimmune disorders, infertility, hormone disruption, Alzheimer's, and Parkinson's disease.

Among the key findings:

61% drop in chlorpyrifos, a neurotoxic pesticide known to damage children’s developing brains. Exposure is associated with increased risk of autism, learning disabilities, ADHD, and IQ loss.

95% drop in malathion, another neurotoxic organophosphate pesticide and a probable human carcinogen according to the World Health Organization.

83% drop in clothianidin, a neonicotinoid pesticide. Neonicotinoids are associated with endocrine disruption and changes in behavior and attention, including an association with autism spectrum disorder. Neonicotinoids are also a main driver of massive pollinator and insect losses, leading scientist to warn of a “second silent spring.”

43-57% drop in pyrethroids, a class of pesticides associated with endocrine disruption and adverse neurodevelopmental, immunological and reproductive effects.

37% drop in 2,4-D, one of two ingredients in Agent Orange. 2,4-D is among the top five most commonly used pesticides in the U.S. and is associated with endocrine disruption, thyroid disorders, increased risk of Parkinson’s and non-Hodgkin’s lymphoma, developmental and reproductive toxicity and other health issues.

"Everyone has the right to clean organic food. That is a human right," said Tara, one study participant from Baltimore.

"This important study shows how quickly we can rid our bodies of toxic pesticides by choosing organic," said Sharyle Patton, director of the Commonweal Biomonitoring Resources Center and co-author of the study. "Congratulations to the families who participated in the study and their willingness to tell their stories in support of creating a food system where organic is available to all."

Read or download the full report here (pdf).