Plant Pesticides

I mentioned earlier, when discussing the case of the 88-year-old woman who suffered bok choy poisoning, that most of the toxins in our bodies come from plant foods.

This is a surprise to most, since we have been taught to regard vegetables as healthy, to fear meat and fats, and to fear above all synthetic environmental toxins like pesticides.

Yet the volume of plant toxins which our bodies must deal with from our daily food is remarkable.  Bruce Ames and Lois Gold of the University of California at Berkeley report:

About 99.9% of the chemicals humans ingest are natural. The amounts of synthetic pesticide residues in plant foods are insignificant compared to the amount of natural pesticides produced by plants themselves. Of all dietary pesticides that humans eat, 99.99% are natural: they are chemicals produced by plants to defend themselves against fungi, insects, and other animal predators….

We have estimated that on average Americans ingest roughly 5000 to 10,000 different natural pesticides and their breakdown products. Americans eat about 1500 mg of natural pesticides per person per day, which is about 10,000 times more than the 0.09 mg they consume of synthetic pesticide residues. [1]

They also note that 57% of natural plant compounds tested have proven to be carcinogens in rats and mice, compared to 60% of synthetic compounds tested. In general, plant pesticides are as potently toxic as synthetic pesticides.

Should you run in terror from the supermarket vegetable aisle? No, not at all: it’s better to back away cautiously, to avoid being noticed.  (Just kidding; in fact we recommend eating 1 to 2 pounds of plant foods per day, including vegetables!)  But it’s prudent to diversify your plant food consumption, avoid the most toxic foods like grains and legumes, and cook most vegetables.

[1] Ames BN, Gold LS. Paracelsus to parascience: the environmental cancer distraction. Mutation Research 2000 Jan 17; 447(1):3-13.

Leave a comment ?


  1. You don’t mention dairy at all. Is it verboten?

  2. Hi erp,

    No, dairy is not verboten. Dairy fats are extremely healthy, dairy proteins are potentially problematic. I eat a lot of cream (my morning coffee is about 1 part cream to 1 part coffee) and butter, and homemade ice cream with a pint of heavy cream, six egg yolks, and flavorings. We also eat cheeses.

    Someone with sensitivity to dairy might have to cut the cream and clarify the butter to remove proteins before using butter as a cooking or dressing oil.

    In general, healthy people can manage dairy, but people with damaged intestines will have difficulty with the protein portion, especially pasteurized cow casein.

    However, I do recommend avoiding skim or low-fat milk. Since the fats are the healthiest part of dairy and proteins the worst, it’s best to keep as high a fat-to-protein ratio as you can.

  3. hi,good apple in your post,I love thatelegantapple,I need to find one for me,jane

  4. This regime turns everything on its head.

  5. If it were conventional wisdom, I wouldn’t have any reason to write a blog – or a book. Unfortunately the conventional wisdom is wrong, and contributes to early aging and disease.

  6. PJ… You’ve got to get the poultry, dairy and meat boards into promoting your book! What you say makes a lot of sense.

  7. Wow, this is amazing. So there is no substantial benefit to eating organic, then. Phew, I will stop worrying about that!

    • @Andrea, not quite – organic vegetables might very well contain more nutrition than regular ones due to more focus on healthy plants and less on volume.

      On the other hand, organic means that it potentially has less synthetic toxins. It could be that they have to use varieties that have more natural toxins 🙂

      • And, of course, synthetic pesticides are biologically unexpected. We simply don’t know what the long-term result is in the human species of consuming them daily in every plant food we eat, and indirectly via every non-organic amimal food we eat.

  8. Hi Paul,

    What are your thoughts on organic vs. conventionally grown/raised food?

    And do you think this following statement is true: “Organic pesticides that are studied have been found to be as toxic as synthetic pesticides,”

    • Hi Monnyica,

      I think both are similarly healthful if fresh, but organic is generally cared for better between harvest and sale.

      The statement is peculiar because organic means no pesticides. I think they are trying to say that natural food compounds can be as toxic as human-applied pesticides, which is true. However, that doesn’t mean you want to eat pesticides. Fortunately pesticide levels are low even in non-organic food.

      Best, Paul

  9. Yeah I had always believed that organic = no pesticide, but I stumbled on articles about “myths about organic food” that stated otherwise:

    – In fact, organic farmers do use pesticides. The only difference is that they’re “natural” instead of “synthetic.”
    – there are 20 chemicals which are approved by the US Organic Standards and these are used all the time in organic food production
    – A pesticide, whether it’s natural or not, is a chemical with the purpose of killing insects
    – Sadly, however, “natural” pesticides aren’t as effective, so organic farmers actually end up using more of them!
    – “Organic pesticides that are studied have been found to be as toxic as synthetic pesticides,”
    – Organic pesticides include rotenone, which has been shown to cause the symptoms of Parkinson’s Disease
    – But just because something is natural doesn’t mean that it’s safe or healthy — consider the examples of hemlock, mercury, lead, toadstools, box jellyfish neurotoxin, asbestos — not to mention a nearly infinite number of toxic bacteria and viruses (E. coli, salmonella, bubonic plague, smallpox).

    After going through all the links below, I am still not sure what to believe. I would love to hear your thoughts. I’m just wondering if paying for organic is really worth it? I feel like someone just told me Santa doesn’t exist…

    • Hi Monnyica,

      Well thank you, you’ve taught me something. However, I still believe that the level of pesticides is going to be too low to matter for health, so I wouldn’t avoid organic because of pesticide concerns. We buy both organic and conventional but generally prefer the taste and texture of organic, which I think is superior mainly due to more careful handling after harvest and a more expeditious route to market.

      Best, Paul

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