This article originally ran at Forbes and has been republished here with permission of the author.
Chipotle Mexican grill announced that beginning today (April 27), none of the offerings at its more than 1,800 restaurants will contain ingredients from “genetically modified organisms.” According to Steve Ells, founder and co-chief executive, “This is another step toward the visions we have of changing the way people think about and eat fast food.”
If Chipotle makes good on that commitment, their menu will certainly accomplish that. In fact, it will be the strangest ever in an American restaurant. Mr. Ells and his colleagues need a primer on genetic modification, which I am happy to provide.
There is a seamless continuum of techniques for genetic modification of crops, animals, and microorganisms that both predates and includes the advent of molecular techniques, which were invented during the 1970’s. Farmers and plant breeders have been selecting and hybridizing plants to enhance their desirable characteristics for millennia. See, for example, the second figure here, of modern corn and its antecedents, an illustration of how drastically corn has been modified by selective breeding. Tomatoes and wheat and innumerable other food plants have similar histories.
Another common technique for creating new plant varieties, which originated about a century ago, is radiation mutagenesis–subjecting seeds to radiation to scramble their DNA and create mutants. Thousands of plant varieties–including lettuce, wheat, rice, oats and the popular Rio-Sweet and Rio Star pink grapefruit–that we consume routinely were derived this way.
Some of the skeptics about modern genetic engineering would remonstrate that using “conventional,” or pre-molecular, techniques, adds no “foreign” genes to the genome of the resulting plant. They’re wrong.
Since the 1930′s plant breeders have performed “wide cross” hybridizations, in which large numbers of “foreign,” or “alien,” genes have been moved across what used to be thought of as “natural breeding boundaries” to create plant varieties that cannot and do not exist in nature. In these hybridizations, which are performed between organisms of different species or genera, the parental plants may be sufficiently compatible to produce a viable zygote but not compatible enough to permit the embryo to develop into a mature plant. To overcome this obstacle, laboratory scientists devised mechanical and biochemical ways to “rescue” the embryos and make them viable, and common commercial crops derived from wide crosses include tomato, potato, sweet potato, oat, rice, wheat, corn and pumpkin, among others.
Wide-cross hybridizations and radiation-induced mutagenesis represent far more drastic “tinkering with Nature” and create far greater attendant uncertainty about the results than the modern molecular techniques. As the U.S. National Research Council said in a groundbreaking 1989 analysis:
With classical techniques of gene transfer, a variable number of genes can be transferred, the number depending on the mechanism of transfer; but predicting the precise number or the traits that have been transferred is difficult, and we cannot always predict the [traits] that will result. With organisms modified by molecular methods, we are in a better, if not perfect, position to predict the [traits].
Let’s consider a real-world example, the man-made species Triticum agropyrotriticum, which was created by wide-cross hybridization from the combination of bread wheat and quackgrass (also known as couchgrass). The entire genome of quackgrass was transferred haphazardly into wheat. This new variety could in theory pose several types of problems because it takes an established plant variety, wheat, and introduces tens of thousands of foreign genes into it. Concerns include the potential for increased invasiveness of the plant and the possibility that quackgrass-derived proteins could be toxic or allergenic for some humans.
But neither regulators nor activists nor, apparently, the deep thinkers at Chipotle have evinced any concern about these possibilities. Plant varieties like T. agropyrotriticum, which harbor “foreign” genes and are indeed “genetically modified” according to any reasonable definition, are subject to no mandatory testing or review before entering the food chain. In contrast, if a single gene from quackgrass (or any other organism) were introduced into wheat using modern, precise molecular genetic engineering techniques, the resulting variety would be subject to hugely expensive—and increasingly biased and politicized—regulation. Inevitably, they would be targeted by activists…and shunned by Chipotle.
Where, then, does that leave Chipotle’s “no genetic modifcation” promise? That should limit their menu to wild berries, wild game, wild mushrooms, and wild-caught fish and shellfish. Virtually all of the other foods in our diets come from organisms that have been genetically modified in some way; and about three-quarters of the processed foods in American markets contain ingredients from organisms genetically engineered with molecular techniques.
I hope the chefs at Chipotle are cleverer than the people who run the company.
Henry I. Miller, a physician, is the Robert Wesson Fellow in Scientific Philosophy & Public Policy at Stanford University’s Hoover Institution. He was the founding director of the FDA’s Office of Biotechnology. Follow him on Twitter @henryimiller.
