Organic diet intervention significantly reduces urinary pesticide levels in US children and adults

In a new study published in Environmental Research last week, EHS doctoral student Carly Hyland found that an organic diet intervention significantly reduced exposure to a range of common agricultural pesticides among four U.S. families. The study, co-authored by EHS faculty Dr. Asa Bradman and EHS alum Dr. Robert Gunier, enrolled families from Oakland, Minneapolis, Atlanta, and Baltimore and monitored urinary pesticide levels over six days on a conventional diet and six days on an organic diet.

The researchers observed decreases in urinary biomarkers of exposure to over 40 of the most commonly used agricultural pesticides following the switch to an organic diet. The greatest reductions were observed for markers of exposure to classes of insecticides known as organophosphates (OPs) and neonicotinoids.  For example, concentrations of metabolites of the OPs malathion and chlorpyrifos decreased by 95% and 61%, respectively, among all participants following the switch to an organic diet. They also observed an 83% decrease in concentrations of clothianidin, which is one of the most highly used neonicotinoid insecticides in U.S. agriculture.

This study contributes to the growing body of literature indicating that an organic diet can significantly reduce exposure to a range of potentially harmful pesticides. While the majority of Americans cannot afford to eat a fully organic diet, Hyland highlights that there are still steps we can take to reduce exposure to pesticides, such as washing produce properly. Additionally, each year the Environmental Working Group puts out a list of the “Dirty Dozen” produce items that have the greatest amount of pesticide residues, and Hyland encourages trying to prioritize purchasing those fruits and vegetables organically.

Dr. Bradman is the Associate Director of the Center for Environmental Research and Children’s Health and has been involved in CHAMACOS, a longitudinal birth cohort study investigating the impact of prenatal exposure to pesticides and other environmental contaminants, since its inception in 1999.  Dr. Gunier is an Assistant Researcher at CERCH and Carly Hyland is a Graduate Student Researcher at CERCH working on the CHAMACOS study.