When headlines announce harmful bacteria such as e. coli or salmonella have been found on lettuce, precut melons or other fresh foods, justifiable concerns arise. But little thought may be given to other potentially harmful substances such as pesticides and herbicides that linger on foods we’ve been told are among the healthiest we can eat.
“We do use a lot of chemicals in production in agriculture,” says Amanda Deering, a clinical assistant professor in Purdue University College of Agriculture’s Department of Food Sciences in West Lafayette. Growing, producing and selling picture-perfect apples, strawberries and grapes, for example, to ensure they are as appealing to the eyes as to the taste buds are what today’s consumer demands. More and more consumers also expect that perfect produce be available in their stores year-round.
To that end, we’ve created our own food safety dilemma.
“We want perfection; we don’t want a worm hole in the apple,” Deering says, but that leads to the use of chemicals to kill insects, increase production and deter weeds. The chemicals used by growers are tested and approved by the Environmental Protection Agency, and growers must apply them at EPA-approved levels and frequency.
But Deering cautions, “There’s not a perfect chemical,” and some farmers say if a little is good, a lot is better and may spray at a higher rate than recommended.
Buying organic foods is an option, albeit more expensive, but consumers should ensure the produce is certified organic, which means the growers adhere to U.S. Department of Agriculture regulations. Even then, some studies show that chemical drift from adjacent non-organic fields may inadvertently affect organic produce.
“Organic (growers) use chemicals too, but those chemicals have to be on a USDA-approved list,” explains Fred Whitford, director of pesticides programs in Purdue’s College of Agriculture. “Examples of approved organic pesticides include neem oil, corn gluten, horticultural vinegar and diatomaceous earth. A few organic weed killers are now available.” Still, growers should understand there is little or no proven effectiveness of organic pesticides. “Therein lies the problem with organics.”
When it comes to non-organically-grown food, “Are there (pesticide) residues? Yes, but I tell people there’s always risk no matter what you do. We cannot prove with 100 percent certainty that things are safe, even with organic pesticides,” Whitford says, adding that when talking to growers who use chemicals, he stresses they use only EPA-approved ones and follow directions carefully.
Reducing the risk
During his training as an integrative medicine specialist, Dr. Jeff Gladd of GladdMD in Fort Wayne had extensive education on how food creates or promotes health.
“I have many patients who have undergone health improvements from steering their diet away from conventionally grown produce items. We see their liver markers improve, digestive tracts work better and skin clear up.”
Gladd recommends patients print the Environmental Working Group’s (EWG) annual Dirty Dozen list of foods that contain the most agri-chemicals and encourages them to opt for organic versions. The 2018 Dirty Dozen list, compiled after EWG tests fresh produce from many sources, ranks strawberries as the No. 1 greatest offender for chemical residues, with spinach as No. 2. Others, in order, include: nectarines, apples, grapes, peaches, cherries, pears, tomatoes, celery, potatoes and sweet bell peppers. Most are foods eaten unpeeled; some have textures that make residue removal more difficult.
The known effects of lower-dose pesticide exposure can include nausea, headache, fatigue and diarrhea. At higher or prolonged exposure, neurological effects such as uncontrolled shaking or eye blinking can occur, effects Deering has seen in farmers in Afghanistan and Nigeria, where standards on chemical usage are not in place. She works there as part of a Purdue food safety education team and says, “They grow beautiful produce, but there is so much pesticide residue over there.”
Deering recommends consumers reduce risk of ingesting chemical residues by “rinsing them under water and, if you can, peel them.” Some commercial wash products containing citric acid may be effective, “but don’t replace that with also washing with water.”
When it comes to getting fruits and vegetables in your diet, Deering says don’t discount frozen. Today’s quick-frozen foods lose very little in nutrients.