Pesticides on Our Plates: Is Our Food Safe to Eat?
A new report looks at the amount of pesticides that are making their way to our plates. Nutrition Diva examines the results with toxicologist and pesticide expert Dr. Carl Winter.
Monica Reinagel, MS, LD/N, CNS
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Pesticides on Our Plates: Is Our Food Safe to Eat?
The FDA recently released its annual Pesticide Residue Report. As pesticides are one of the things people worry most about, I thought we should take a look at what they found. Here to help us make sense of this very technical and complex data is Dr. Carl Winter of the UC Davis. Dr. Winter is a toxicologist who researches the detection of pesticides and naturally-occurring toxins in foods and how to assess their risks. Below are highlights from our conversation. Please click on the audio player to hear the entire interview.
Nutrition Diva: As part of their ongoing pesticide monitoring program, FDA tested 7,000 foods for residues of over 700 different pesticides and selected industrial compounds. Over half of all the samples analyzed contained no pesticide chemical residues at all. 94% of samples were compliant with federal standards. That means that 6% of the samples were NOT compliant. Does that mean that they were unsafe?
Dr. Carl Winter: When higher than expected (or “violative”) residues are found, it doesn’t mean that these foods are unsafe to consume or expose consumers to unsafe levels of chemicals. The vast majority of these violations aren’t due to levels of a pesticide being higher than expected. They usually indicate the presence of trace amounts of a compound that’s been approved, but not for this particular food.
ND: Also, we should point out that these are not random samples. The FDA is purposely testing those foods that they think are most likely to be in violation—because this part of the program is not designed to assess consumer exposure to pesticides. It’s designed to ensure that these chemicals are being used as directed to control the bugs they are intended to control.
CW: Yes, this is sort of like the cop setting up a speed trap. He or she knows exactly where to set up to catch the maximum number of offenders!
ND: This year, the FDA also used some new methods to test foods specifically for glyphosate or Roundup, in response to public concerns about the presence of this chemical in our food supply. What did they find?
CW: As you would expect, they found glyphosate residues on crops that use this product: corn and soy. About a third of the corn and soy had no detectable residues at all. And 100% of the samples were in compliance with regulations.
ND: But can we be confident that these regulations are strict enough to prevent unsafe exposure to this compound?
CW: Before a tolerance level is set, a compound first has to be determined to be safe, even for the most sensitive individuals, based on the maximum concentration that they are likely to be exposed to from all sources, including all foods on which they may be found, drinking water, and household settings. The tolerance is then set to represent the maximum residue anticipated if the pesticide is applied properly. In most cases tolerances could be much higher and still be protective of public health, but they are set lower than that to ensure compliance with proper use protocols. The bottom line here is that violative pesticide residues rarely represent residues of health concern.
ND: In addition to the pesticide monitoring program, the FDA also does something called a Total Diet Study. Foods are selected to represent a typical diet and are prepared the way they would typically be prepared. So foods may be washed, peeled, and/or cooked (or even made into a frozen pizza) before they are analyzed. The idea is to get an idea of how much total chemical residue a consumer is likely to be exposed to from a typical diet.
The TDS included 1,000 foods. Altogether, residues of 155 different pesticides were found, most frequently at trace levels. Of all the residues found in TDS foods, 87 % percent were at levels below 0.01 parts per million (ppm). So, these are very small amounts. But some argue that very small amounts of 155 different things might add up to an unsafe toxic burden. Is that a reasonable concern?
CW: At the tiny levels of detection of these pesticides, it is extremely unlikely that potential synergistic effects, resulting from the presence of one pesticide making another much more toxic, could occur. All toxicological effects require a “threshold” level of exposure before any adverse health effects would be anticipated. It goes back to the first principle of toxicology: “the dose makes the poison.”
Pesticides often enable food producers to grow more food on their land, resulting in greater food abundance and lower costs to consumers.
ND: If the levels of pesticide residues that we are exposed to are considered safe, does taking steps to reduce our exposure to these compounds have any benefit?
CW: Given the extremely low theoretical risks posed by pesticide residues, further reduction in residues would not result in any measurable improvement in public health. One of my biggest concerns is that consumers, due to their concerns over pesticide residues, might reduce their consumption of fruits and vegetables, which is the worst thing they could do if they want to improve their health.
ND: Some might ask “How can any level of exposure to a toxic substance be safe/acceptable? Why use them at all?” What do we gain from using these chemicals in agriculture? What would we lose if we didn’t use them?
CW: Pesticides often enable food producers to grow more food on their land, resulting in greater food abundance and lower costs to consumers. It is likely that they will continue to play an important role in food production as the world braces for a population of 9 to 10 billion people by 2050.
ND: Thanks Dr. Winter for helping us make sense of this very complicated data set and to understand what this report really has to say about our food supply and our exposure to pesticides.
Additional Resources:
Chronic Dietary Exposure to Pesticide Residues in the U.S.
Image of sprayed pesticides © Shutterstock
About the Author
Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes’ most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation’s leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.