Wednesday, June 13, 2012

Industrially Produced "Organic" Food

  • Organic Food

Wal-Mart sells organic produce. So does Kroger, Giant Eagle, and most other large chain grocery stores. Many people, if they can afford the cost differential, will choose organic produce over conventionally produced produce. We feel better about buying the organic produce at Kroger; it makes us feel we are eating healthier food. Unfortunately, we are being duped. The UDSA label of "organic" as applied to food is not what it appears. Little of this food comes from small organic farms and it is not truly organic. It comes from the same industrial producers as conventional food, and a significant portion comes from other countries such as Chile.

Most of the small companies that started out marketing true organic and natural food have been bought by the conglomerates: Horizon Organic Milk by Dean Foods; Odwalla by Coca-Cola; Naked Juice by Pepsi; Bear Naked and Kashi by Kellogg; Seeds of Change by M&M Mars; Garden of Eatin', Earth's Best, and Arrowhead Mills by Cargill, among about two dozen others Cargill owns. Big agriculture has sucked up these profitable small companies and perverted the definition of the word organic, and this fact is not widely known. For example, large agricultural companies (> $1M in sales) constitute just 8% of organic farms in California, but produce 72% of the organic agricultural products. If you live in New York or Ohio, is it responsible to buy organic produce if most of it is produced in California by big agricultural companies and trucked across the country?



  • Synthetic Chemicals in Organic Food

Unfortunately, organic farming according to the USDA's regulations is not farming without the use of pesticides or synthetic chemicals. Quite the opposite. Among the many synthetic chemicals allowed by the USDA to be used in organic farming are sodium hypochlorite (bleach), copper sulfate, tetracycline, streptomycin, hydrogen peroxide, and salts of zinc, copper, iron, manganese, molybdenum, selenium, and cobalt. Fortunately, the USDA prohibits the use of arsenic and lead salts, but allows the use of sodium nitrate as a fertilizer even though nitrates are implicated in a wide variety of health issues. Ethylene can be used to induce ripening in organic fruits and citrus, just as it is used to ripen those delicious store-bought tomatoes. In organic livestock production, farmers can use dozens of drugs and antibiotics, including the diuretic furosemide and the anthelmintics fenbendazole, ivermectin, and moxidectin. Certainly, these drugs are organic chemicals, but I'm not sure I see how something can be labeled as organic when any sort of selenium compound has been used in its production or how meat can be natural when an animal has been treated with the synthetic anthelmintic fenbendazole. Synthetic methionine is even allowed in organic poultry production, which I suppose is better than the alternative of feeding chickens feather meal. Personally, I don't have a big problem with this, but we're talking about the USDA designation of "organic." Surprisingly, non-organic food products can be used in food labeled as organic.

That word, "organic," I don't think it means what the USDA thinks it means.

  • Synthetic vs. Natural Pesticides

So what about pesticides? First of all, there is no such thing as a non-toxic pesticide. Pesticides by definition are toxic: the Latin root –cide means "death" or "to cause death," as in "genocide." Pesticidal chemicals are harmful to insects, nematodes, molds, or fungi, or as they're also known, pests. Natural versus synthetic is a distinction that in many instances is irrelevant. To take a somewhat extreme example of a natural product that is used as a pesticide, strychnine is an alkaloid produced in the seeds of a tree native to India and SE Asia. It is highly toxic to animals and is used to control gopher, mole and coyote populations. It acts by blocking ligand-gated ion channels, largely the glycine receptor. The oral LD50 (lethal dose) in humans is 100 mg and in mice 2 mg. For a second example, and one whose use is allowed in organic food production is Spinosad. It is orally active in agricultural pests and acts at nicotinic acetylcholine receptors, which are ligand-gated ion channels. The active natural chemical, spinosyn A has low mammalian toxicity, a broad spectrum of pest control, but is highly toxic to honeybees (LD50 = 2.5 microgram/bee). Good for us, bad for bees. Both strychnine and spinosyn A are 100% natural.

Secondly, the distinction between natural and synthetic toxins is artificial. In a seminal article published in 1990, Bruce Ames at UC Berkeley, developer of the Ames assay for mutagenicity, published an article in the Proceedings of the National Academy of Sciences - a premier peer-reviewed science journal - that discussed the differences in toxicity of natural versus synthetic chemicals. Ames and co-workers found that about "half of all chemicals (whether natural or synthetic) tested" were carcinogens. The principal point addressed in the Ames paper is that over 99% of all pesticidal chemicals in the diet of humans are naturally occurring, produced by plants for self-defense against pests. At the time Ames and co-workers published their work, 52 natural pesticides had been tested in high-dose cancer assays in animals, and more than half (27) of these compounds were carcinogenic to rats. Natural pesticides are allowed in organic farming, some of them known carcinogens.

Examples of carcinogenic plant-produced pesticides include the psoralens, found in parsley and celery, which intercalate into DNA and are photoactivated in skin cells to form covalent adducts with the DNA bases. They are used in photodynamic therapy of cancer and psoriasis. Another example is sinigrin, a natural chemical found in cabbage, collards, cauliflower, and Brussels sprouts, and which is metabolized to the carcinogen allyl isothiocyanate. This compound causes chromosome breaks at 0.0005 ppm, yet sinigrin is found at 35-590 ppm in cabbage and up to 1,560 ppm in Brussels sprouts. Allyl isothiocyanate is 100% natural.

Ames' point is that there is no difference between toxicity of natural versus synthetic pesticides and chemicals, and that the vast majority of human exposure is to natural pesticides. Note that I am not advocating for synthetic pesticide use in food production, I am simply pointing out that synthetic versus natural is an artificial distinction, and that pesticides from any source are toxic by definition. In many cases, natural plant-produced pesticides are far more toxic and carcinogenic than synthetic pesticides.

  • Human Metabolism of Synthetic Chemicals

The hypothesis that humans have evolved to effectively detoxify natural but not synthetic chemicals is wrong. In fact, quite the opposite is true. Our bodies (primarily our livers) metabolize all xenobiotic (exogenous) chemicals, natural and synthetic, with the same enzymes such as cytochrome P450, the same conjugation pathways such as reaction with glutathione, and by the same excretion pathways as we do natural (endogenous) chemicals. In fact, many detoxification pathways have evolved specifically to deal with the almost limitless and constantly changing array of xenobiotic chemicals to which we are constantly exposed, regardless of origin. Consequently these metabolic pathways have low specificity; they are general and work on diverse classes of chemicals, synthetic and natural alike. The pathways to metabolize and detoxify synthetic chemicals are exactly the same as with natural chemicals. How could an enzyme know the difference?

  • Comparisons of Some Synthetic and Natural Pesticides

Consider glyphosate, a well-known and widely used synthetic herbicide that is the active ingredient in Roundup. Glyphosate interferes with the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan in plants. Animals cannot make these amino acids, and must obtain them in their diet, so the cross-species toxicity of glyphosate between plants and animals is minimal. The human toxicity of glyphosate is extremely low and the chemical is not carcinogenic. The acute oral toxicity in rodents is more than 5,000 mg/kg body weight. This is the equivalent of a 150 pound person eating 340 grams or 3/4 pounds of pure glyphosate. (For comparison, think about eating 3/4 pounds or almost 1.5 cups of sugar.) It is not a human carcinogen, it does not cause cellular mutations, and it is rapidly excreted unchanged in the feces and urine. This herbicide is broken down in soil, eventually to carbon dioxide, and is not overly persistent (half-life = 47 days). When adsorbed to soil, it is largely immobile, so it doesn't leach into groundwater or runoff. It is essentially non-toxic to birds and fish, and only slightly toxic to bees (LD50 = 100 microgram/bee). Discriminant, minimal, and correct use of Roundup to control things such as milkweed, thistles, or roses, or to keep the ground clear of weeds under electric fences can be done safely and with minimal environmental impact.

In contrast, copper sulfate, an inorganic salt that is approved for use in organic farming, remains persistent in the soil and is cumulatively toxic. Extensive use of copper-containing fungicides on fruit trees has caused the elimination of earthworms in many orchard soils. How is farming using a chemical that eliminates kills earthworms considered "organic?"

Now consider the pyrethrins, considered safe natural pesticides. These organic chemicals are naturally occurring in chrysanthemums, from which they are isolated. The pyrethrins are neurotoxins that attack the nervous system of insects, both pests and desirable insects such as butterflies. They are alternatives to organophosphate pesticides, which also effect the insect nervous system, but they are not without their own risks. Pyrethrins are oftentimes formulated with piperonyl butoxide (Bonide® pyrethrin insect spray contains 10% piperonyl butoxide), which has been shown to delay mental development in children of women exposed during pregnancy. The lowest lethal dose of pyrethrins in adults is 1,000 mg/kg, or similar to that of glyphosate in rats, and they are rapidly metabolized. Unfortunately, pyrethrins are extremely toxic to fish and bees (LD50 = 0.02 micrograms/bee) and moderately toxic to birds such as quail. Fortunately, the pyrethrins are not environmentally persistent and do not accumulate. A synthetic analog, permethrin, is highly toxic to cats, and because permethrin is used for flea control in dogs, problems arise from improper use in cats. The pyrethrins are 100% natural.

Another common natural pesticide is rotenone. This organic chemical interferes with the transport of electrons to ubiquinones in mitochondria, and thus reduces the production of ATP. It is considered moderately toxic in humans, and it is highly toxic to fish (it is used as a poison in the control of invasive fish species). A recent study demonstrated a possible link between rotenone exposure and Parkinson's disease in humans. This chemical has shown teratogenic effects in rats, but is apparently not carcinogenic (data are unclear). Fortunately, rotenone is broken down rapidly by sunlight, so it is not persistent in the environment. It was declassified for use in organic farming in 2005, but since has been added back to the list of allowed chemicals. Unfortunately, because most natural pesticides are less effective than synthetic pesticides, more frequent application of natural chemicals such rotenone is often required compared to synthetic pesticides. Rotenone is 100% natural.

It just isn't as simple as natural versus synthetic. Natural does not mean something is non-toxic and synthetic does mean something is toxic. Across-the-board chemophobia in any form is an absolutely unreasonable fear.

  • Public Misconceptions

Finally, the point of all this: phobia of anything "synthetic" or "chemical" is ridiculous and counter-productive. I have read natural farming books where the author bemoans the fact that processed food contains calcium phosphate. The last time I checked, calcium was an essential nutrient, and I don't know about you, but my DNA is held together with phosphates. I don't think our food should be full of additives, but fretting over the presence of essential minerals is ridiculous. It is chemophobic.

There is no simple solution, but the manner in which the USDA regulates organic food production is clearly wrong, and the value placed on this so-called organic food by the general public is misplaced as a result. Trusting large corporations such as Kraft or Cargill to remain true to the principles of organic farming is unwise, and shipping organic food to the U.S. from Chile is irresponsible.

Unfortunately, we live in a country where a significant portion of the population believes President Obama is Muslim, where many people are convinced cell phones cause brain cancer, that global temperatures are decreasing, or that vaccines cause autism. (They also believe that the plastic bottles they put in their recycling bins are actually recycled.) No amount of factual information is sufficient to counteract such denalism, and no amount of reason will change people's minds. There is no demonstrated advantage to eating USDA-defined organic food over conventionally produced food, nor is there a difference in taste. Buying organic food at Wal-Mart or Kroger is just supporting large agricultural conglomerates, in addition to supporting Wal-Mart. Reducing the use of pesticides in a desirable goal, but substituting a natural pesticide for a synthetic one is not necessarily going to accomplish anything. Moving from industrialized monoculture back to more traditional farming will.

Food should be produced as naturally as possible, it should be eaten seasonally, and it should be produced as locally as possible. It is impossible to produce food without the use of chemicals, but judicious use of pesticides, natural or synthetic, can be safe. Unfortunately, the "organic" label has been co-opted perverted, and no longer means what it is supposed to mean or what many people believe it to mean.

3 comments:

  1. Great article, Rob. I like how you use your chemistry background to deliver broader messages about the food we eat. Consider submitting to a magazine (I know, you probably want to be done with publish-or-perish).

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  2. Great article! I enjoyed reading it and have been aware of the "spin" on organic products we common folks are subjected to. Only solution - grow your own!

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  3. Rob,
    Very nicely written article, very lucid and easy to read. I would suggest submitting this to Columbus Dispatch or New York Times in the editorial section. I am sure people would appreciate the content if they come to know about the author's background in Chemistry. People need to get educated about the big corporate and their numerous ways to twist definitions, as in "organic".

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