by Margaret Wertheim
LA Weekly - Quark Soup
September 13 - 19, 2002
Can the Exorcist save us from genetically modified foods, or is it another freak in disguise?
STRANGE THINGS ARE HAPPENING among the corn rows, quite apart from crop circles. More and more foreign bits of DNA are being woven into our food supply: viral DNA, bacterial DNA and insect DNA are now routinely engineered into crops destined for the table. Asleep at the wheel for decades and largely ignorant of modern farm practice, consumers are finally waking up to the less than delectable reality of industrial food production. The question is, If we shouldn't have to inhale secondhand smoke, why should we be forced to ingest secondhand genes?
Zambians don't think they should be, and so recently rejected U.S. food aid because the offer included genetically modified maize. Vying for the Marie Antoinette "Let Them Eat Cake!" award, a USAID representative declared that "Beggars cannot be choosers." But Zambians fear that their own crops could be contaminated with foreign genes, polluting native strains and damaging exports to nations that do not want GM produce. When asked about the matter at the World Summit in Johannesburg, U.S. delegation head John Turner claimed that the United States does not use aid as a political weapon; nonetheless he added, in a masterpiece of coded understatement, "We leverage our assistance to our expectations."
No technological innovation except nuclear power has engendered more public disapprobation than genetically modified food, particularly in Europe, where the anti-GM movement is huge. Yet in the U.S., GM food is a fait accompli: Close to 100 million acres of GM crops will be planted here this year, and 60 percent of items on the average supermarket shelf already contain GM ingredients. Unless you're growing your own, chances are you are eating "frankenfoods" at pretty much every meal. Now, you might think, as many Europeans clearly do, that the right to know what you are eating is pretty fundamental, but in that case you'd have failed to appreciate the force of the trade winds blowing across the Atlantic.
In March, the U.S. muscled through the Codex Alimentarius Commission -- a U.N. panel that adjudicates issues about international food trade -- a ruling that consumers have no intrinsic right to know if food they are eating ultimately derives from genetically modified plants. Under intense pressure from the U.S., supported by its usual flunky Australia, the CAC rejected calls from the European Union to allow governments to demand genetic "traceability" of GM foods. Disclosure of genetic heritage will be required only "when a risk to human health has been identified." The Codex's acquiescence to the U.S. lobby was a triumph for Monsanto and its Big Biotech buddies, as well as for the forces of globalization, who will brook no speed bumps on the drag strips of international commerce. In effect, the CAC ruling has made it a trade violation to embargo GM produce.
As the last few rounds of WTO talks proved, and as the meeting in Johannesburg has confirmed, if you're a big, rich nation, stand-over tactics will get you everywhere. Still, the biotech industry is aware of the GM public-relations nightmare, and now one of its own scientists has proposed a solution that he believes will make everyone happy. Dubbed "Exorcist," this clever genetic trick would snip out all foreign genes from a plant before the crop is harvested -- agricultural producers could get the benefit of GM strains, but consumers would still eat au naturel (more or less).
In the land of having-your-cake-and-eating-it-too, Exorcist is as nifty a concept as they come. The idea was dreamed up and presented earlier this year in the journal Nature Biotechnology by Pim Stemmer, vice president of research at the Redwood, California, company Maxygen, and his colleague Robert Keenan. Exorcist is made possible by a little protein called Cre that comes from a bacterial virus. Cre acts like a pair of molecular scissors that snip out any DNA that lies between two special DNA markers called loxP. Stemmer's notion is that whenever scientists insert a foreign gene into a plant they would also insert the genes for Cre and loxP. Snipping out the foreign genes can then be triggered by another gene called a "promoter" that turns the Cre/loxP mechanism on or off when needed. Stemmer has even proposed a modification so you could delete all traces of the Exorcist genes themselves. The deleted DNA forms little loops that quickly break down or are diluted to undetectable levels -- that's the theory, at any rate.
EXORCIST IS A HIGH-TECH SOLUTION to a high-tech problem, and it's pretty darn ingenious. But then, so was Olestra. You remember Olestra, the fat substitute that mimicked the creamy taste and silky-smooth feel of real fat but that wouldn't make you fat. Several years ago, this fat-free fat was touted as the final solution to America's ever-expanding waistline.
But as they say, there are no free lunches. The problem with Olestra was what the manufacturers coyly termed "anal leakage." Since the fat wasn't going onto your waist, it had to go somewhere, and where it went was straight through your system and into your bowels -- and, well, out again. After a good helping of Olestra, a person better have Depends on.
If Olestra was meant to be fat-free fat, what we're being sold with Exorcist is GM-free genetic modification -- in other words, another brilliant invention from the department of wishful thinking. Stemmer is right in that the Cre/loxP system can excise foreign genes, but how efficient is this mechanism? One researcher whose work Stemmer cites notes that while Exorcist can be extremely effective in plant tissues such as leaves, in his experiments on seeds it has had a high failure rate. David Ow at the U.S. Department of Agriculture's Plant Gene Expression Center in Albany, California, has also shown that even when foreign genes are deleted they can mysteriously persist inside a plant's cells -- a ghost in the genetic machine. Ow doesn't know how this works, but these gene wraiths are clearly still haunting the organism.
Norman Ellstrand, a professor of genetics at the University of California, Riverside, warns that we must be careful of such high-tech mechanisms, which may work well in one environment but not necessarily in another. Ellstrand worries that while a technology like Exorcist might be effective in a U.S. field, that would not guarantee it'd work in the highlands of Mexico, say. Since vast amounts of U.S. grain are exported to Mexico and other places, we would have to be sure that any such genetic mechanisms would function properly under all potential field conditions.
For most GM opponents, moreover, the primary problem is not toxicological, it's political. Sure, there's concern about the health risks of foreign genes (such as when the gene for a protein that causes Brazil-nut allergy got into a GM soybean), but a desire for culinary caution is not the driving energy behind the anti-GM movement. To those of us who are skeptical about genetic modification of our food supply, the real question is not how to make this technology safer, but whether we should be using it at all. You only need an exorcist if you let the demons in.
Opposition to GM crops is first and foremost a political stance against the industrialization of our food supply and the takeover of agriculture by big business. Exorcist will do nothing to allay these concerns. Indeed, it only exacerbates the problem by piling on yet more genetic modifications, thereby increasing agricultural reliance on proprietary technology that enriches a few mega-corporations at the expense of small farmers the world over. That is why in 1998 Zambia and a dozen other African nations endorsed a statement to the U.N. Food and Agriculture Organization's negotiations on "The International Undertaking on Plant Genetic Resources" declaring that any science imported to help alleviate the continent's food problems "should be building on local knowledge, rather than replacing and destroying it."
The very soul of agriculture is at stake here; what we need is not some genetic conjurer with a magic disappearing wand, but a serious social debate about how our food is produced and what price we are prepared to pay for a GM-free tomato.