Organic Produce Has Pesticide Residues, Too—and a Little Pesticide May Not Be So Bad

By Sophie Bushwick | September 25, 2012 11:34 am

organic produce

Unlike pesticide-laden conventional food, organic produce is more natural, healthier, and better for you…right? Organic food does contain less synthetic pesticides. But the natural pesticides that replace them can also have harmful effects. For example, the organic pesticide copper sulfate is more toxic than some synthetic pesticides, and it can cause genetic mutations, cancer, liver disease, and anemia. No matter what you choose to eat, both conventional and organic produce can expose you to low levels of pesticides. Before you forswear all greens, however, bear in mind that low pesticide levels aren’t the worst thing in the world.

At her Science Sushi blog on Scientific American’s network, Christie Wilcox explains that a little bit of pesticide exposure can actually be good for you.

While it might seem that decreasing exposure to pesticides in any way could only be good for you, toxicologists would differ. Contrary to what you might think, lower exposure isn’t necessarily better. It’s what’s known as hormesis, or a hormetic dose response curve. There is evidence that exposure to most chemicals at doses significantly below danger thresholds, even pesticides, is beneficial when compared to no exposure at all. Why? Perhaps because it kick starts our immune system. Or, perhaps, because pesticides activate beneficial biological pathways. For most chemicals, we simply don’t know. What we do know is that data collected from 5000 dose response measurements [pdf] (abstracted from over 20,000 studies) found that low doses of many supposedly toxic chemicals, metals, pesticides and fungicides either reduced cancer rates below controls or increased longevity or growth in a variety of animals. So while high acute and chronic exposures are bad, the levels we see in food that are well below danger thresholds may even be good for us. This isn’t as surprising as you might think—just look at most pharmaceuticals. People take low doses of aspirin daily to improve their heart health, but at high chronic doses, it can cause anything from vomiting to seizures and even death. Similarly, a glass of red wine every day might be good for you. But ten glasses a day? Definitely not.

Wilcox suggests that the difference between conventional and organic foods may not really be that great. In fact, there is a great deal of variation within the organic system: two random organic farms may use completely different standards. At the end of the day, the pesticides you ingest with your fruit and veggies do less harm to your health than avoiding greens altogether.

For more on organic versus non-organic pesticides and practices, check out the full post at Science Sushi.

Image courtesy of val’sphotos / flickr

CATEGORIZED UNDER: Health & Medicine, Living World
  • Erax

    pesticide-laden conventional food?????

    Pesticides start breaking down into their harmless constituents almost immediately after their application on crops. Conventional food is NOT laden with pesticides!

    It’s no wonder the public is so confused by eco-maniacs.

  • Rider

    Sorry, I do not believe that any amount of a toxic substance could in any way be good for me. The analogies used with aspirin and red wine do not make any sense in comparison because they are simply not toxins.

  • DS4119268002

    @Rider, I think you are making a false dichotomy between “toxins” and “drugs”. In fact they are all chemicals which can have a variety of different biological effects, both positive and negative. The net effect from any one substance is different at different dose rates and must actually be measured in order to make the determination of what is beneficial, safe, and/or harmful. It’s exactly what the article is describing, regardless of whether you choose to believe it.

  • Jim Bartels

    This article is remarkably misleading for a supposedly scientific magazine. The analogies are missleading at best as “Rider” says. Also, all “organic” are not the same( as the author points out), so why speak as if they are in the article. I can only assume she is talking about US mega food giants organic products. If growing yourself you need no pesticides in most cases. You can also buy from local growers where you can find out from the farmer if he uses any pesticides and what they are. The avoid farmers who use them. The need for lots of pesticides is usually a product of large mono cultures or growing products in inappropriate areas. Again, a remarkably poor and missleading article, though unlike “Rider” I would be willing to accept that some pesticide or other harmful things might actually be good for us if the impartial science proves so. Just like a reasonably amout of dirt is good for kids growing up.

  • Kaviani

    No doubt an USAF sponsored statistical analysis would provide such glowing conclusions when the Air Force is responsible for so many “exposures”.

    Also, I’m not so sure a study from 2002 is exactly contemporary. Is this a science history article?


  • Archwright

    @Rider Ethanol is toxic (Red Wine). Tannin is toxic (Tea, and Red Wine). Caffeine is toxic (Coffee, Tea). They can kill you, but in low doses they are at least not harmful.

    Even water can kill you if you consume to much of it. (Hold your wee for a wii contest:

  • floodmouse

    I’m reserving judgment on the science, but in the meantime, you can eat my share of the pesticides if you want. 😉

  • Scott

    Silly crazy conclusion: A little pesticide (poison) may be good for us?

    Feel free to eat my helping.

  • Oh Science

    The best part about science is that even if you refuse to believe it, it’s still true.

  • Superchkn

    @floodmouse, I’m curious to know where you are getting all your pesticide free food, as both organic and non-organic labeled produce will have traces of pesticides on/in them, per this article.

    My criticism of the view expressed in this blog post is that it is often the case that a combination of challenges to an organism is the problem and we’re typically not exposed to just one chemical at a time. This is a problem I don’t see organic-labeled produce addressing.

    Increasingly, I see the scientific evidence pointing towards a failure of organic-labeled produce from delivering on the goals of those purchasing the products. That’s driven by a widespread misunderstanding over what the “organic” really means when applied to our food supply combined with the equally widespread misconception that organic is universally better than synthetic. Reality is far more nuanced than that.

  • Glenn

    Interesting denials in these responses.
    Another data point: Effcts of hormesis has been found with the effects of ionizing radiation. Since we all recieve exposure to ionizing radiation during our entire lives, it makes some sense that evolution has adapted to it.

  • Louise Helshaw

    I think growing your own organic vegetables is a great thing to do. Growing your own is so much healthier than supermarket rubbish. My dad is quite green-fingered and he pointed me to this website – – that taught me all about growing organic vegetables at home.

  • Aaron Hathaway

    Rider, please do a little research before posting. You have a very black and white approach to what’s safe and what’s toxic. Everything is toxic at different doses: even pure oxygen is toxic. Nearly all prescription drugs are very toxic substances, we can only take as much as our liver can safely process. If you take more of the drug than you liver can process you then experience the toxic effects which include poisoning symtoms, liver failure, coma, and death. Some drugs are especially hard on the liver (tylenol, ibuprofen, asprin). There’s a whole field in medicine that evaluates the ratio of the toxic dosage and the minimum effective theraputic dosage, it’s called the theraputic index:


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics.

See More

Collapse bottom bar