By Thomas R. DeGregori
Posted: Tuesday, February 24, 2004
ARTICLES
Publication Date: February 24, 2004
Those critics who complain about the dangers of modern food production (such as "carcinogenic chemicals") are often the first to thwart efforts to make our food even better, safer, and more abundant through such new technologies as rBST, rDNA, or irradiation.
One is reluctant to fault the consumer — who feels the food supply is pretty safe as is — for being concerned about the alleged dangers of transgenic food production. When the media attempt to be "balanced" and present "both sides" on such an issue — even though one side has no demonstrated competence — it is understandable that the public errs on the side of avoiding what they see as a small possibility of harm. Modern techniques of genetic engineering sound a bit daring and even "unnatural" (whatever that means), so the anti-biotechnology zealots have been able to play on fears of unknown and unknowable future harm. Since no reputable scientist can give a 100% certain guarantee against all unforeseen harm, the ideologue is free to sow the seeds of fear with little substantive challenge.
Rather than lecturing people about the technology that has made their food crops possible, and how easily old technologies, too, could be made to sound scary were we not all by now familiar with it, I am trying an alternate strategy: asking people twenty questions — some of which may sound scary — that I hope will make them think more rationally about food safety. Try to answer honestly, as you would without looking at the answers:
Q1 - Would you favor mutation breeding using carcinogenic chemicals or gamma rays, or techniques such as altering the ploidy or chromosomal structure that allows the crossing of diploids and haploids?
A1 - Well, this practice has been carried out in agricultural breeding since the 1920s.
Q2 - Would you favor plant breeding tissue culture or somoclonal variation, creating a plant from a cell in a cultured medium?
A2 - It has been possible to do so since the late 1930s and has become increasingly important in plant breeding, particularly for disease resistance, since the late 1970s.
Q3 - If a breeding technique is used that produces sterile crosses for plants that would otherwise not be able to produce a viable embryo, would you favor a procedure called embryo rescue to remove an embryo before it would naturally abort and then growing it in a cultured medium?
A3 - It has been done for decades.
Q4 - Would you favor a process called protoplastic cell fusion, a technique for removing the membrane of two cells and forcing the remaining protoplasm together, thereby fostering a gene transfer?
A4 - Same as the previous answer.
Q5 - Would you favor creating plant lines and irregular phenotypes that persist for some time not only in the original crop but in future crops in which they are part of the breeding stock and are difficult to eliminate by backcrossing?
A5 - Avoid eating plants foods produced by tissue culture and embryo rescue.
Q6 - Would you want to eat food products whose breeding produced "unintended consequences" such as squash that caused food poisoning, a pest-resistant celery variety that produced rashes in agricultural workers (and was subsequently found to contain seven times more carcinogenic psoralens than control celery), or a potato variety that contained very high levels of toxic solanine?
A6 - These were all the products of traditional plant breeding and were noted by Codex Alimentarius — in a meeting searching for the possible "unintended consequences" of rDNA, though none had yet been observed. The Lenape potato was promoted as an excellent new variety for producing better chips, but this product of (conventional) cross-breeding produced potentially deadly levels of the glycoalkaloid solanine.
Q7 - Would you eat a "killer zucchini" with high levels of natural toxins (curcubitan) that resulted in several recorded cases of people being hospitalized with food poisoning?
A7 - The "only food scare in recent history in New Zealand...stemmed from the farming methods of organic farmers and others who use unconventional farming practices" (LSN 2003). "The levels of toxin apparently increased among zucchini growers who did not spray their crops" against an infestation of aphids, since insect predation is sometimes associated with increased levels of toxins in plants" (LSN 2003). There was a "clear link between increased toxin levels and older open-pollinating varieties of seeds" (LSN 2003). The "most likely cause of the build-up of toxins is a genetic weakness in older varieties" (LSN 2003).
Q8 - How would you feel about pharmaceuticals and vitamins made by microorganisms whose ability to express the desired product has been greatly expanded (sometimes a hundredfold) using a variety of techniques, including recombinant DNA, to increase production capability?
A - Sorry, that is the way that most of them are produced, including an increasing number of rDNA pharmaceuticals.
Q9 - Or maybe "all-natural" foods are more to your liking, though that includes cheeses, beverages, and breads made with genetically-engineered enzymes, yeasts, and emulsifiers — would you perhaps like to wash the stuff away with detergents that contain genetically-engineered enzymes created to replcace the phosphates that were polluting our rivers and streams?
A9 - These are all exempted from labeling requirements by European regulators and have been increasingly important since the 1980s.
Q10 - In addition to protoplast fusion, might you support "incorporation of cms (cytoplasmic male sterility) without restorer genes, radiated mentor pollen, and mutation induction"?
A10 - These have been staples of organic food production, though some of the more purist believers now wish to ban them immediately or phase them out in a ten-year transition since cell techniques are "so firmly embedded in conventional breeding" that banning them "would set organic farmers back twenty years and have dramatic economic consequences" (see Lammerts van Bueren et al on the near-impossibility of finding produce, whether organic or conventional, that is not the product of the above plant breeding techniques).
Q11 - Can one avoid most of the techniques described above by eating "organic"?
A11 - As Lammerts van Bueren et al and many others have noted, these and other techniques are even more important for "organic" agriculture than for conventional, since organic attempts to use fewer pesticides and therefore requires more disease-resistant crops.
Q12 - How would you like to eat about 10,000 different toxins for dinner today?
A12 - If you don't wish to do so, best that you skip any meal you had planned. Plants are chemical factories and produce a variety of secondary metabolites, some of which are toxins used to protect the plant. In addition, fungal or other infestation not only induces the production of more plant toxins but themselves produce potentially deadly toxins, which can occur in the field or at various stages of post-harvest storage and distribution.
Q13 - Can you avoid these toxins by going "organic"?
A13 - Quite the contrary. By being less well protected, organically grown plants are likely to produce more toxins. Since World War II, there has been a decline in stomach cancers, which many attribute to the use of fungicides in agriculture and refrigeration, reducing the need to use nitrates for meat preservation.
Q14 - Are you willing to consume a variety of unintended impurities in your dinner such as aphids, rodent hair fragments, or animal excreta?
A14 - Every food safety regulatory agency will have tolerance levels for these impurities. Modern food production and distribution technology greatly lowers these and other impurities but has yet to eliminate them totally. The best that one can say is that our ancestors ate far more contaminated food.
Q15 - Does the possibility of the routine introduction of a large number of new plant varieties into the food chain disturb you?
A15 - "Extensive experience has been gained from the routine introduction of plants modified by classical genetic methods. For example, an individual corn, soybean, wheat, or potato breeder may introduce into the field 50,000 genotypes [new experimental varieties] per year on average or 2,000,000 in a career. Hundreds of millions of filed introductions of new plant genotype have been made by American plant breeders in this century" (National Research Council 1989 Report).
Q16 - Would you feel all right about eating foods with large amounts of goitrogenic and estrogenically-active isoflavones (the so-called endocrine disrupters)?
A16 - If not, hold that tofu!
Q17 - Would you want to eat food crops that had been protected by lead arsenate as a pesticide or the alkaloid nicotine, copper acetoarsenite, potassium 4,6-dinitro-o-cresylate, lime sulfurspray, hydrogen cyanide, sodium arsenite, and potassium antimonyl tartate?
A17 - Your ancestors did before modern synthetic pesticides. Paris Green — copper aceto arsenite, a combination of copper acetate-Cu(C2H2O2) and arsenic trioxide-3Cu(AsO2) — was even more widely used as a pesticide in agriculture and for mosquito control. Other arsenic compounds were also used, such as London Purple, a by-product of the dye industry. Rachel Carson in Silent Spring compares the "endless stream of synthetic insecticides" to the "simpler inorganic insecticides" of pre-World War II days. The older insecticides were "derived from naturally-occurring minerals and plant products, compounds of arsenic, copper, lead, manganese, zinc and other minerals, pyrethrum from dried leaves of chrysanthemums, nicotine sulfate from some of the relatives of tobacco."
Q18 - How would you react to the use in agriculture of a solution of inorganic salts, called Bordeaux mixture, even though the copper (often in the form of copper oxychloride or copper sulphate and lime) in it is toxic at the levels used? Or what about the use of sulfur, methaldehyde, and derris (a.k.a. rotenone, CH23H22O6), which was originally derived from the roots of a vine from tropical Asia?
A18 - If you want to avoid it, you can't eat "organic."
Q19 - Anyone for eating a food product that is the most likely to be contaminated with E. coli 0157:H7 and salmonella? The Emerging Infections Program of the Centers for Disease Control estimated that 20,000 people in North America contracted salmonella from consuming this food product in 1995 (JAMA 1999, Van Beneden et al 1999, Beuchat and Ryu 1997, and Tauxe 1997).
A19 - Hold those raw alfalfa sprouts, as there is no certain way of eliminating contaminants except by irradiation, which is unacceptable to the purists. In addition, alfalfa sprouts contain a highly toxic substance called canavine.
Q20 - Do you believe that popular herbs, such as Echinacea purpura, St. John's Wort, Ginko biloba, ephedra, or the Chinese herbal products containing aristolochia acid are safe because they are somehow hallowed by tradition?
A20 - Think again! Echinacea purpura is one of the few substances to which a person may have an adverse allergenic response on first contact. Echinacea is a member of the ragweed family. The data supports the "possibility that cross-reactivity between echinacea and other environmental allergens may trigger allergenic reactions in "echinacea-naive" subjects" (Mullins et al 2002). Aristolochia acid, touted by some herbalists, has been shown to cause cancer and kidney failure (Nortier et al 2000, Gottlieb 2000). Nearly a hundred women with kidney damage from Chinese herbs at a "Belgian slimming clinic" were studied and several were found "in dire need of kidney transplants" and, "even worse," many of them were developing cancers in the kidney and bladder, years after taking the drug (Papp 2000; see also Greensfelder 2000; for a more complete citation of the medical literature on the dangers of herbal products, see my books, particularly Agriculture and Modern Technology: A Defense and Bountiful Harvest: Technology, Food Safety, and the Environment).
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Thomas R. DeGregori, Ph.D., is a professor of economics at the University of Houston, an ACSH Advisor, and author of the recently-published Origins of the Organic Agriculture Debate.
