Study shows pesticide levels drop dramatically after 1 week of eating organic
Originally posted in the MOSES Organic Broadcaster newspaper.
Can eating organic really reduce levels of pesticides in our bodies? A new peer-reviewed study published in the journal Environmental Research found that switching to an organic diet significantly reduced the levels of synthetic pesticides found in all participants in just one week. On average, the pesticides detected dropped by 60.5% after six days of eating an all-organic diet.
The study was led by researchers from the University of California-Berkeley and Friends of the Earth. We found families that didn’t typically eat organic food in four cities across the country — Minneapolis, Baltimore, Atlanta, and Oakland. (MOSES was the partner organization for the Minneapolis study. The Birchwood Cafe, a local, organic restaurant, prepared organic meals for the family for the family’s week on an organic diet.)
The study lasted 12 days. During the first six days, each family ate only conventional foods and beverages. During the second six days, each family ate only organic food, all the way down to oils and spices. To ensure that they were able to eat a completely organic diet, each family wrote up a grocery list and research assistants shopped for them; dinners during the organic week were prepared by licensed chefs. All of the organic food was provided free of charge to the families.
Each participant provided a urine sample every morning. These were shipped to labs at the University of California at San Francisco and the Québec National Institute of Public Health. These labs looked for 18 different pesticides and the chemicals that pesticides break down to in our bodies, called metabolites.
Our study was designed to assess whether an organic diet could reduce exposure to pesticides, not to provide insight on the health risks associated with the pesticides in our diets. But we chose the pesticides we tested for because they’re among the most commonly used in U.S. agriculture and because they have been associated with harm to human health.
The most significant declines in our study involved organophosphates, a class of highly neurotoxic pesticides linked to brain damage in children. We found a 95% drop in levels of malathion, a probable human carcinogen, a nearly two-thirds reduction in chlorpyrifos, and a 70% drop in DAPs metabolites that represent exposure to organophosphates as a class. Organophosphates are so toxic to children’s developing brains that scientists have called for a full phase out.1 Organophosphate exposure is associated with endocrine disruption, autism, learning disabilities, reduced IQ, attention disorders, delayed motor development, Alzheimer’s, Parkinson’s, decreased sperm quality, and cancers.2,3,4,5,6
The neonicotinoid pesticide clothianidin dropped by 83%. Neonicotinoids are among the most commonly detected pesticide residues in baby foods.7 They are associated with endocrine disruption and changes in behavior and attention, including an association with autism spectrum disorder.8,9,10 Neonicotinoids are also a main driver of massive pollinator and insect losses, leading scientists to warn of a second “silent spring.”11,12
Levels of pyrethroids were halved. Exposure to this class of pesticides is associated with endocrine disruption, adverse neurodevelopmental, immunological and reproductive effects, increased risk of Parkinson’s and sperm DNA damage.13,14,15,16
Finally, 2,4-D dropped by 37 percent. 2,4-D is one of two ingredients in the Vietnam War defoliant Agent Orange. It is among the top five most commonly used pesticides in the U.S.17 and is associated with endocrine disruption, thyroid disorders, increased risk of Parkinson’s and non-Hodgkin’s lymphoma, developmental and reproductive toxicity and damage to the liver, immune system and semen quality.18,19
Small Exposures Matter
Although we used to believe that “the dose makes the poison,” in recent decades, science has shown that even extremely small exposures to pesticides matter. Consider the fact that chemicals prescribed by doctors to alter behavior, like the drug Ritalin, are active at levels that are the same or lower than some pesticides detected in children’s bodies. We now know that small amounts of pesticides can act like drugs and alter our brain development, hormones, immune systems, and more. Chemicals that affect our hormone systems, called endocrine-disrupting chemicals, can be especially problematic at very low doses.
We’re also increasingly understanding that even if the level of each pesticide is below legal limits, mixtures of pesticides can have an additive “punch” in total toxicity. Various studies have sought to assess this cumulative exposure, including one that looked specifically at organophosphates and found that if you consider the totality of U.S. children’s exposure from diet, approximately 40 percent may be exposed to levels that exceed benchmarks for neurological harm like ADHD and learning disabilities.20
Other recent studies show that reducing pesticide exposure by choosing an organic food can improve health, suggesting that the pesticide residues on our food matter. One study found a 25% reduction in cancer risk for participants who ate the most organic food.21 Another study found fertility benefits for women who ate organic food.22
Organic For All
Organic works. But the U.S. government’s food policy favors pesticide-intensive agriculture while failing to provide adequate incentives to farmers to transition to organic practices. As a result, pesticide-intensive agriculture is subsidized to the tune of billions of dollars while organic programs and research are woefully underfunded. This misdirection of public dollars makes pesticide-laden food the norm and is a significant reason why many people across the country still don’t have access to, or can’t afford, organic food.
Friends of the Earth, along with over 40 organizations across the country, believe that we all have the right to food that is free of toxic pesticides. The farmers and farmworkers who grow our nation’s food, and their communities, have a right to not be exposed to chemicals linked to serious health problems. And the way we farm should protect rather than harm the biodiversity, soil and water that sustain all life.
We can work together to pass laws in our cities, states and nationally that decrease pesticide use and expand organic farming. We can change the national Farm Bill and can advocate for policies that support fair pricing and fair contracts for family-scale farmers in order to support the increase in organic farming that we need to provide organic food for all. We can tell food companies and grocery stores to end the use of toxic pesticides in their supply chains and expand organic offerings. And we can support farmers markets, CSAs, and independent retailers and food companies that source from local, organic growers.
Together, we can demand that our leaders step up and shift support, research, and policies to create a system where organic is for all. The solution is here — we just have to grow it. For more information and ways to take action, go to www.OrganicForAll.org.