You’ve probably heard of the “Dirty Dozen,” a list of 12 fruits and vegetables named annually by the Environmental Working Group (EWG) to be the most laden with pesticides. The U.S. advocacy group’s message is that people can limit their exposure to pesticides by buying these 12 products from the organic aisle. Toddler favourites are routinely among the top offenders, and this year’s list, released in March, is no different: strawberries and grapes rank high on the list. If you’re pregnant or parenting little ones, it could drive you to buy organic versions of these foods, or, at the very least, feel guilty for eating the conventional versions—or for serving them to your kids.
But is it really necessary to buy organic strawberries and grapes ?
It’s important to note that the EWG is heavily funded by organic food companies, says Erin MacGregor, a registered dietitian and co-owner of the Toronto-based food and nutrition company How To Eat. She calls the guidelines “a marketing tactic by a segment of the food industry that really benefits from the fear of pesticides.” And she worries about the impact this list could have. “If you’re a parent that has a strict grocery budget and you’re not able to afford organic fruit and vegetables, this messaging can make you feel like you’re not doing the best you can for your children, or that you’re risking their health, when that’s not the case,” she says.
To come up with the list of fruits and vegetables to avoid, the EWG analyzes data from the US Department of Agriculture, which tests produce throughout the year and records the pesticide levels and types that it finds. The fruits and vegetables that top the EWG’s list are ones that have multiple different types of pesticides and a high “average amount of pesticides.” Carl Winter, a toxicologist at the University of California at Davis, points out that the EWG’s list raises alarm over the presence of pesticides, but doesn’t look at whether those trace amounts actually pose a risk to human health.
In 2011, Winter did his own analysis of the EWG’s Dirty Dozen. (And to be clear, Winter says he has not received funding from the food or agriculture industry.) He found that if we ate the list’s 12 fruits and vegetables routinely, our chronic exposure to most pesticides would be less than 0.01 percent of the chronic exposure level that the Environmental Protection Agency (EPA) considers potentially worrying. The highest pesticide residue in Winter’s study, found on bell peppers, would still only lead to two percent of the chronic exposure level that the EPA begins to worry about, even if you ate them routinely. The EPA is a U.S. government agency set up to protect the public, and its chronic exposure levels are conservative—they’re set at a hundred times lower than the levels that begin to cause harm in animals.
“We have a pretty good understanding in toxicology that most affects to health occur through a threshold mechanism and until you’re exposed to a specific amount of something nothing is going to happen,” says Winter. Kind of like how brushing with fluoride-containing toothpaste is safe, but we shouldn’t gulp down fluoride gel.
In addition to the science, we can rest assured that Health Canada’s food safety standards are rigorous. Like the U.S., Canada sets maximum residue limits for pesticides on produce, and they are tested routinely to make sure the residues fall well within those limits. The limits “are set only after an extensive review of scientific information and a thorough risk assessment confirms that there are no health concerns to all segments of the population (including pregnant and nursing women, infants, children and seniors), when all possible food sources are eaten every day, over a lifetime,” according to Health Canada in a statement.
MacGregor worries that the EWG list can stir anxiety around food shopping, especially in parents. The messaging can also lead to confusion and unhealthy consumption behaviours. A 2016 study of more than 500 parents, published in Nutrition Today, showed that low-income parents in particular are likely to buy fewer fruits and vegetables overall if they’re exposed to messaging that certain produce is pesticide-laden.
The bottom line is that fruits and vegetables, no matter how they’re farmed, are safe and healthy, not “dirty,” says MacGregor. “Our new food guide includes a plate where half the plate is covered with produce and that’s because we know that there is litany of research that supports the health benefits of consuming fresh fruits and vegetables.”