By: Dr. Michael Greger, Director of Public Health and Animal Agriculture at the Humane Society of the United States.
How might we reduce our exposure to pesticide residues on fruits and vegetables? What about staying away from imported produce? Turns out domestic produce may be even worse, dispelling this notion that imported fruits and vegetables pose greater potential health risks to consumers.
Buying organic dramatically reduces dietary exposure to pesticides, but does not eliminate the potential risk. Pesticide residues are detectable in about 1 in 10 organic crop samples, due to cross-contamination from neighboring fields, the continued presence of very persistent pesticides like DDT in the soil, or accidental or fraudulent use.
By choosing organic, one hopes to shift exposures from a range of uncertain risk to more of a range of negligible risk, but even if all we had to eat were the most pesticide laden of conventional produce, there is a clear consensus in the scientific community that the health benefits from consuming fruits and vegetables outweigh any potential risks from pesticide residues, but we can easily reduce whatever risk there is by rinsing our fruits and vegetables under running water.
There are, however, a plethora of products alleged by advertisers to reduce fruit and produce pesticide residues more effectively than water and touted to concerned consumers. For example Procter & Gamble introduced a fruit and vegetable wash in the year 2000. As part of the introduction, T.G.I. Friday’s jumped on board bragging on their menus that the cheese and bacon puddles they call potato skins were first washed with the new product, after all it was proclaimed proven to be 98% more effective than water in removing pesticides. So researchers put it to the test and it did no better than plain tap water. Shortly thereafter, Procter & Gamble discontinued the product, but numerous others took its place claiming their vegetable washes are three, four, five or even ten times more effective than water, to which the researcher replied, “That’s mathematically impossible”. If water removes like 50%, you can’t take off 10 times more than 50%. They actually found water removed up to 80% of pesticide residues, like the fungicide captan for example, so for other brands of veggie washes to brag 3, 4, 5, 10 times better than water is mathematically impossible indeed.
Other fruit and vegetable washes have since been put to the test. They compared FIT to Fruit & Vegetable Wash, to two I’ve never heard of, Organiclean, and Vegi-Clean, compared to using dishwashing soap, all compared to just rinsing in plain tap water. 196 samples of lettuce, strawberries, and tomatoes were tested, and they found little or no difference between just rinsing with tap water compared to any of the veggie washes, or the dishsoap. They all just seemed like a waste of money. The researchers concluded that just the mechanical action of rubbing the produce under tap water seemed to do it and that using detergents or fruit and vegetable washes do not enhance the removal of pesticide residues from produce above that of just rinsing with tap water alone.
That may not be saying much though, Captan appears to be the exception. When rinsing with plain water was tried against a half dozen other pesticides, less than half the residues were removed. Fingernail polish works better, but the goal is to end up with a less toxic, not a more toxic tomato. We need a straightforward, plausible, and safe method for enhanced pesticide removal, although the efficacy of pesticide removal from fruits and vegetables has been rarely reported in the medical literature. Anything we can add to the water to boost its pesticide stripping abilities?
If you soak potatoes in water, between about 2 to 13% of the pesticides are removed, but a 5% acetic acid solution removes up to 100%. What’s that? Plain white vinegar. But 5% is full strength. What about diluted vinegar? Diluted vinegar only seemed marginally better than tap water for removing pesticide residues. Using full strength vinegar would get expensive, though. Thankfully there’s something cheaper that works even better. Salt water. A 10% salt solution appears to work as good or better than full-strength vinegar. To make a 10% salt solution you just have to mix up about 1 part salt to 9 parts water, though make sure to rinse all of the salt off before eating.
There’s not much you can do for the pesticides in animal products, though. The top sources of some pesticides are fruits and vegetables; but for others, it’s dairy, eggs, and meat, because the chemicals build up in fat. So what do you do about pesticides in meat, egg yolks, or egg whites? Hard boiling appears to destroy more pesticides that scrambling, but for the pesticides that build up in the fat in fish or chicken, cooking can sometimes increase pesticide levels that you can’t just wash off. In fact washing meat, poultry, or eggs is considered one of the top ten dangerous food safety mistakes.
Next, I’m going to wrap it up with what I think the available science suggests is the bottom-line when it comes to choosing which type of produce to buy in the final two in the series:
The most important reason to wash produce is to reduce the risk of food-borne illness. Ironically, the food poisoning viruses may be found in the pesticides themselves. Check out my video Norovirus Food Poisoning from Pesticides.
About Michael Greger M.D.
Michael Greger, M.D., is a physician, author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United States.