Clearly, people are willing to pay a premium for organic fruits and vegetables. When researchers from University of Wisconsin in Parkside surveyed 770 consumers in the Midwest about their reasons for doing so, they found a range of motivations. The responses, which were published in September 2021 in the journal PLoS One, included wanting to avoid pesticides, concerns about environmental stewardship, and the perceived increased nutritional value and improved taste of organic compared with conventional produce. While these are all commonly held beliefs about organically grown produce, how many of them are actually true, and how many are what researchers call “a health halo”? Surprisingly, research shows that organic produce only guarantees one of those benefits: reduced pesticide exposure. Organic certification by the U.S. Department of Agriculture (USDA) involves a lengthy list of requirements about growing conditions, and pesticides are strictly regulated, so any produce that bears the official certification logo meets those criteria. But there isn’t currently enough evidence to say exactly what impact pesticide exposure in produce has on a variety of health conditions, or overall health for that matter. “High consumption of organic foods has been associated with reduced risks of obesity, type 2 diabetes, and cancer, particularly postmenopausal breast cancer and lymphoma,” says Julia Baudry, PhD, an epidemiologist who studies these associations at the Center of Research in Epidemiology and Statistics Sorbonne Paris Cité in France. While that sounds promising, Baudry cautions that additional research is still needed. Population-based studies are observational, which means there isn’t enough evidence to determine cause and effect. The lower incidences of these diseases could very well be attributed to other factors, such as the fact that people who can afford to eat organic foods regularly may have healthier habits overall regarding diet and exercise, for instance. “Our results need to be replicated in other cultural settings and combined with experimental studies to draw causal conclusions,” Baudry says. And the truth is, most Americans don’t eat enough fruit and vegetables of any kind, organic or conventionally grown, and are skimping on a wide range of important nutrients as a result. Just 1 in 10 U.S. adults eat the recommended 1 ½ cups of fruit and 2 ½ cups of vegetables a day, according to the Centers for Disease Control and Prevention. “That means most of us are missing out on key vitamins, minerals, fiber, and antioxidants from produce that help protect against heart disease, diabetes, certain kinds of cancer, and more,” says Libby Mills, MD, who has a private practice in the Philadelphia area and is a spokesperson for the Academy of Nutrition and Dietetics. “Iron in produce helps prevent anemia. Magnesium and potassium are important for muscle growth and development. And vitamin C is needed for strong immune functioning. Getting enough produce is a priority for good health.” So, how important is it that the produce we eat be organic? Here’s what to know.
What Does Certified Organic Mean?
Fruit and vegetables labeled “USDA Organic” must be grown and prepared for sale according to standards set by the USDA. There are plenty of requirements farmers of organic produce must follow, but some of the major rules include:
Synthetic fertilizers and pesticides are usually not permitted (growers may use beneficial insects or mulch to control pests and weeds, for example, and resort to plant-based insecticides or a short list of approved synthetics as “a last resort.”Growers must use farming methods such as cover crops, mulch, compost, and other natural substances, and chemical-free practices to maintain high-quality soil.Growers must use organic seeds (except when unavailable) that are not genetically modified or treated with prohibited chemicals, according to the USDA.Farming practices shouldn’t harm land, water, insects or animals.A farm must be free of prohibited substances (like chemical fertilizers, pesticides and weed-killers) for three years before produce can be certified organic; and the USDA conducts periodic inspections.
Because of these strict standards, organic produce does have lower levels of pesticides than conventionally grown fruits and vegetables.
Are Pesticides Bad for Human Health?
Researchers estimate that over one billion pounds of pesticides are used in the United States each year. Growers of conventional produce are required to meet federal standards for using them, according to the U.S. Environmental Protection Agency (EPA). According to the agency, types and levels in and on fruit and vegetables must have a “reasonable certainty of no harm.” The USDA tests levels annually through its Pesticide Data Program, and since 1996 the EPA has canceled or restricted the use of over 270 pesticides on food crops. Since 2004, a nonprofit called the Environmental Working Group (EWG) has released a “Shopper’s Guide to Pesticides in Produce” list based on the results of USDA testing. The list ranks 46 pieces of produce based on their level of pesticide contamination, and calls out the “Clean Fifteen” and “Dirty Dozen,” or kinds of produce with the least and most pesticide residue, respectively. Kayli Anderson, RDN, founder of the women’s health site Plant-Based Mavens, says the lists can help shoppers “prioritize when to purchase organic and when to purchase conventional.” She adds: “Of course, the specific pesticide load will vary from apple to apple or strawberry to strawberry, but the lists are still a helpful guide for lowering your exposure to potentially harmful chemicals." The EWG has faced some criticism for the lists, however. One peer-reviewed paper found no evidence that the most commonly detected pesticides on the list posed any risk to consumers, and that therefore, substituting organic produce did not benefit consumers. And results of a survey of more than 500 low-income consumers published in Nutrition Today in 2016 found that messaging about pesticide residue on produce made those consumers less likely to purchase any fruits or vegetables at all. “I can understand why some might criticize the list,” says Anderson. “The research connecting pesticides to potential health effects is limited and difficult to perform.” Also, she points out, buying organic produce is not accessible for everyone, and the inability to access organic produce should not stand in the way of eating more fruits and veggies. Still, she says, “Until safer options are available for everyone, the EWG’s Dirty Dozen and Clean Fifteen lists can be useful tools for consumers to prioritize their produce purchases. The most important takeaway is that eating more fruits and vegetables is always the No. 1 goal, regardless of whether or not they are organic. Choosing conventional produce is much better than choosing to avoid produce altogether.” Adding to the controversy, Consumer Reports reviewed five years of USDA Pesticide Data Program test results for 35 conventional and organic fruits and vegetables and published the results in a March 2020 report. The findings determined that nearly half of the nonorganic options posed little risk to human health. The 20 percent with the highest chemical scores were potatoes, peaches, and green beans, though the EPA has since banned use of the pesticide chlorpyrifos on fruit-bearing trees such as peaches due to health concerns. The report also found some chemical pesticides on organic produce, likely carried from field to field by the wind. And organic produce may be raised with natural or biological pesticides, according to the National Pesticide Information Center.
Is Organic Produce More Nutritious?
Despite older research claiming higher levels of some vitamins and minerals in organics, newer studies have found few differences. A landmark Stanford University analysis of more than 300 studies, published in 2012 in Annals of Internal Medicine, concluded that organic and conventionally-grown vegetables have similar nutrient levels. And Mills notes that there can be nutritional differences in fruit and vegetables grown in different weather conditions and soils: “Even two red peppers grown in neighboring fields can have slight differences in nutrient levels,” she says. Organics may contain higher levels of antioxidants, however, according to an analysis of 343 studies, published in 2014 in the British Journal of Nutrition.
Does Organic Produce Have Other Benefits?
While organic produce may not necessarily be more nutrient-dense than conventionally grown fruits and vegetables, there is some evidence that lower levels of pesticides in a diet may play a role in the risk of developing several chronic diseases. Among the findings, compared with eating mostly conventional produce, a diet high in organic fruits and vegetables was linked to:
A 25 percent lower risk of cancer, according to a report published in JAMA Internal Medicine in December 2018 (the only study included that did not specifically note adjusting for other lifestyle factors and overall diet quality)A 35 percent lower risk for diabetes, in a report published online in 2020 in the International Journal of Behavioral Nutrition and Physical ActivityA 31 percent lower risk for metabolic syndrome, in a report published in October 2018 in the European Journal of Nutrition.A 20 percent lower risk for type 2 diabetes, according to a University of Iowa study published in December 2018 in Nutrition
Although some researchers speculate that the association may be the result of higher levels of cell-protecting antioxidants in organic produce, it’s hard to say without additional studies, says Yangbo Sun, PhD, lead researcher of the 2018 Nutrition study and now an assistant professor of epidemiology at the University of Tennessee Health Science Center in Memphis. “Although our study provided some evidence for the possibility of potential health benefits of purchasing organic produce, our study was a cross-sectional study,” she says. That means it looked at data for a group of people at one point in time. “As a result, we could not establish a temporal relation and causality for the association between organic foods and diabetes,” Sun says. “Further research is needed to comprehensively evaluate the long-term effects of organic food consumption on chronic diseases, including diabetes.” Mills notes that these studies tend to look at what participants report that they eat, and then at their health status. They can detect associations, not links between food and medical conditions. “These are not cause-and-effect studies,” she says. And while researchers try to factor out things that may contribute to higher or lower risk for health problems — such as overall diet, weight, physical activity and income — they may miss important, emerging factors, such as overall environmental exposures where people live. Major medical groups including the American Academy of Pediatrics, American Heart Association, and American Institute for Cancer Research (AICR) agree that more research is needed. For now, simply eating enough produce should be the priority, the groups note. “Whereas little scientific evidence indicates that eating organic foods lowers cancer risk, an abundance of evidence points to other diet and lifestyle factors that can reduce risk, such as maintaining a healthy weight, keeping active, and eating a diet that includes plenty of fruits and vegetables — whether they are organically or conventionally produced,” the AICR advises. Sun agrees. “Eating enough fruit and vegetables are essential for maintaining health, regardless of whether it is organic or conventionally grown.”
Will Washing Produce Reduce Pesticide Exposure?
The good news is, you may not have to pay a premium to reduce your pesticide exposure. Since many pesticides are applied topically, washing fresh produce under running water can remove pesticide residue, according to the National Pesticide Information Center (NPIC). The EWG website, however, does make a point to note that the samples the Dirty Dozen and Clean Fifteen lists are based on are tested for pesticides after they have been prepared to be eaten. “This means the produce has been thoroughly washed and, when applicable, peeled,” the site states. Washing is a good idea even for organic produce, though, because, like any food grown in the earth, it may have soil as well as bacteria and other organisms on the surface, says Mills. No method of washing is 100 percent effective, but following these steps from the NPIC can help: Wash all fresh produce. Clean it whether it comes from your own garden, a local farm stand, or the supermarket. The only exception: prewashed boxed or bagged salad greens. It’s also important to wash fruits and vegetables with rinds or peels you won’t eat, such as melons, winter squash, pineapple, and avocado. “If you cut into unwashed produce, you can transfer dirt, bacteria, and chemical residue to the edible parts,” Mills says. Use running water. Rather than dunking a piece of fruit into a bowl of water or giving it a quick spritz, hold it under running tap water and rub the outside. Running water alone is sufficient, Mills adds. You don’t need special soaps or products. For smaller fruits like berries, or cut-up vegetables, place them in a colander and spray gently, rubbing the outside of each. Let them air dry. Soak leafy greens. Give spinach, kale, collards, leaf lettuce, and other greens a thorough washing by soaking in a large bowl of water as you gently massage them. Rinse and repeat until there’s no debris at the bottom of the bowl.
