Organic or conventional? That is the question for many people who are finding the answer from the Environmental Working Group’s (EWG) annual “Clean 15” and “Dirty Dozen” lists, which claims to reveal the 12 fruits and vegetables with the highest levels of pesticide residues. But do these lists really hold the answers? According to a peer reviewed study in the Journal of Toxicology, the EWG’s annual lists don’t pull as much weight as one might be led to believe. First, the methods the EWG uses to get their data just aren’t scientifically sound. Anything can be made to sound scary with the right wording. Second, despite the seemingly alarming pesticide levels reported on the Dirty Dozen list, research shows that the pesticides found on our fruits and vegetables are still well below the levels generally accepted as safe by the USDA. And finally, is the negligible risk posed by consuming conventionally grown produce worth the clear and undeniable health benefits of eating more fruits and vegetables overall? (Spoiler, it’s not.)
Each year, the EWG releases their dirty dozen list, which they claim contains the fruits and
vegetables with the highest levels of pesticide residues. Unfortunately, the methodology the
group uses to determine which fruits and vegetables belong on the naughty list is more than a bit misleading. According to the Journal of Toxicology, the EWG uses six indicators of
contamination to get their numbers, but only one of the six even attempts to quantify the amount of pesticide residue on a given sample. 3 The remaining criteria are only a measure of the number of pesticides present (i.e. average number of pesticides on a single sample, percent of samples with ≧ 2 pesticides). The dirty dozen and clean fifteen lists also fail to compare any potential pesticide exposure to established health criteria such as the reference dose (RfDs,estimates the amount of a chemical one can be exposed to over a lifetime with no appreciable risk (3)) or acceptable daily intake levels.Thus the results are skewed toward the number of pesticides instead of the actual amount of residue found, and do not provide a clear analysis of how much pesticide residue might actually be consumed from eating the produce.
This report in the Journal of Toxicology attempted to assess consumer exposure to pesticide residues on the foods listed on the 2010 release of the dirty dozen. Using information from the USDA Pesticide Data Program (one of the sources the EWG uses to make their list),
researchers estimated pesticide residues found on the 12 fruits and vegetables and compared these estimates to chronic RfDs (and ADIs, where RfDs were unavailable) to obtain estimates of actual consumer exposure. They found that over 90% of the exposure estimates fell more than 1000 times below the RfDs, well within the realm of safety. 3 Based on the findings of this study, it appears that risk of harm from exposure to the most common pesticide residues found on the Dirty Dozen is negligible (3).
Finally, the best possible outcome of any discussion regarding fruits and vegetables would be that people will just eat more of them. Americans already struggle to eat the recommended amount of fruits and vegetables, with only 1 out of 10 Americans meeting the daily recommended intake according to the CDC (1). We already have a wealth of information supporting the higher consumption of fruits and vegetables for better health overall and and to reduce chronic illness, so a diet lacking in fruits and veggies means missing out on the various health benefits the micronutrients that fruits and vegetables provide. That being said, the worst outcome would be for people to get scared off of buying conventional produce and instead avoid fresh fruits and vegetables altogether, which one study indicates is exactly what is happening. Already low fruit and vegetable consumption is even lower in low-income populations, for whom a lack of both knowledge and access to healthy foods, poor produce quality, and budget constraints can have a large influence on whether or not to buy fruits and vegetables (2). It is these people who are impacted the most by the scary messaging of lists like the Dirty Dozen. Researchers on the study surveyed 510 low-income consumers and found that although participants tended to prefer organic produce, the higher cost was a significant obstacle. The study also discovered that informational statements regarding organic and conventional produce failed to increase participants’ likelihood to buy more fruits and vegetables, however messages calling out specific produce containing pesticides actually made participants less likely to purchase any type of produce at all (2). For people who can’t afford or don’t have access to organic produce, conventionally grown might be the only option, and is still a far better option than foregoing produce altogether.
So organic or conventional? While there’s nothing wrong with organic produce, there is also
nothing wrong with conventionally grown produce. The methods used to place produce on the Dirty Dozen list just don’t accurately measure the alleged risk of pesticide exposure on
conventionally grown produce. Based on available research, conventionally grown fruits and
vegetables are well within safe levels of pesticide residue. So buy organic if you want to, but if you can’t or simply don’t want to, there’s no reason to live in fear of conventionally grown
strawberries. The science just isn’t there, but what is there is heaps of evidence that fruits and vegetables should be a delicious, healthy part of anyone’s diet.
“CDC Press Releases.” 2016. CDC. January 1, 2016.
Huang, Yancui, Indika Edirisinghe, and Britt M. Burton-Freeman. 2016. “Low-Income
Shoppers and Fruit and Vegetables: What Do They Think?” Nutrition Today 51 (5):
242–250. https://doi.org/10.1097/NT.0000000000000176 .
Winter, Carl K., and Josh M. Katz. 2011. “Dietary Exposure to Pesticide Residues from
Commodities Alleged to Contain the Highest Contamination Levels.” Journal of
Toxicology 2011. https://doi.org/10.1155/2011/589674 .