Genetically Modified Foods – A Good Idea?
By Donald R. Davis, Ph.D.
Genetically modified foods are one kind of genetically modified organism (GMO), in which the genetic material (DNA in genes) has been modified by “genetic engineering,” as opposed to traditional methods such as selective breeding. Most GMOs contain a gene from another species, such as a bacterial gene in corn.
The first GM food was the Flavr Savr tomato in 1994, in which a gene for ripening was blocked, allowing longer vine ripening and improved flavor. It was labeled as GM and sold well at a premium price, despite growing protests against GM foods. However, it soon failed commercially, because it had low yields and did not harvest or ship well.
In 1996 came GM field corn and soybeans from Monsanto Company. Some contain bacterial genes that make the plants resistant to Monsanto’s glyphosate herbicide (Roundup). Others contain genes from Bacillus thuringiensis bacteria that make natural insecticides called Bt, believed harmless to humans. Some GM corn combines both traits. They make weed and insect control easier for farmers, and now dominate corn and soybeans in the U.S. (60% to 90% of acreage). Although some corn and soybeans are eaten directly by humans, most are fed to animals to produce meat, milk, poultry, eggs, and fish. Cotton and canola with similar genetic modifications are also widely grown. Both are important sources of cooking oils. Other current GM foods are a virus-resistant Hawaiian papaya and glyphosate resistant sugar beets, introduced in 2008.
Coming GM foods are intended to appeal to consumers and food processors, rather than to farmers. Plenish brand soy oil, expected in 2010, is a “zero trans-fat” replacement for partially hydrogenated soy oil used for deep frying and baking. It contains increased levels of stable oleic acid and less of the unstable linoleic and linolenic acids. Another GM soy oil has stearidonic acid, an omega-3 fatty acid partially converted by humans to EPA, prized in fatty fish. Expected by 2013, this oil is more stable and easier to cook with than fish oils. Other proposed GM foods include drought-resistant corn, canola oil with an algae gene that makes DHA (another valuable omega-3 fatty acid in fish), a purple tomato with snapdragon genes that make anthocyanins similar to those in blackberries and blueberries, and “golden rice” with daffodil and bacterial genes that make beta-carotene, a source of vitamin A for populations eating few fruits and vegetables.
So what’s not to like about GM foods? One area of concern is sustainability and environmental damage. The popular herbicide-resistant crops are losing effectiveness as weeds develop tolerance to the liberally applied herbicides. Similarly, widespread planting of Bt-containing crops encourages insect tolerance to Bt. There is also evidence that herbicide-tolerance genes and Bt genes, originally from bacteria, can transfer from GM crops to their wild relatives, subtly and permanently altering wild ecosystems. In 2001 researchers ignited an international furor by reporting that GM corn genes had to native corn species in Mexico, contaminating a major genetic resource for corn breeders. That disputed report is now confirmed, and gene transfer has proven much harder to prevent than GM advocates once claimed.
There are also concerns about harm to wildlife and humans. A 2000 report that monarch butterfly larva are killed by eating Bt-corn pollen proved to be a near miss. Only one of several Bt-corn varieties had harmful Bt levels in pollen; it is no longer grown. A 2007 report of harm to caddis-fly larvae near Bt-corn fields has drawn fierce and questionable attacks from GM defenders. In 1999 veteran Scottish researcher Arpad Pusztai was fired for reporting that experimental Bt potatoes damaged the immune systems of rats, whereas Bt itself did not. The resulting controversy hardened opposition to GM foods in the United Kingdom and Europe. Several recent studies suggest that GM corn does alter immune functions and contributes to allergies. Monsanto counters that there is not “a single substantiated instance of harm due to GM ingredients.”
GM foods are only lightly regulated by the U.S. Food and Drug Administration. In sharp contrast to new food additives and drugs that require extensive testing prior to approval, current GM foods are deemed “substantially equivalent” to their non-GM counterparts and thus need no safety testing. The FDA relies largely on industry for this determination. The 1992 “substantial equivalence” policy was a political decision, opposed by many FDA scientists. Then-Vice-President Dan Quayle said it was “designed to provide ‘regulatory relief’ for the industry so that it would remain a world leader” in biotechnology. Critics complain that this unscientific approach is unable to prevent or detect subtle or unexpected changes induced by GM foods.
The FDA also requires no labeling of GM foods. Labeling is required in many other countries, including the United Kingdom, most of Europe, Japan, Russia, China, and Brazil. In the U.S., Consumer’s Union, The Center for Food Safety, and Ohio Representative Dennis Kucinich are leading efforts to require GM food labeling, which is supported by Agriculture Secretary and GM proponent Tom Vilsack.
USDA Organic foods may not contain GM ingredients. Organic milk and other animal products must be produced without GM feed. Organic milk also must be produced without the use of bovine growth hormone (BGH), also called bovine somatotropin (BST). The only available form is a slightly unnatural version from genetically engineered E. coli bacteria (rBGH or rBST). It was Monsanto’s first GM product, and the company has tried to hinder dairies that choose to avoid this hormone and so label their milk. Canada and many other countries ban rBGH for reasons of cow health or precautions about human safety.
In my view, GM technology has received too little independent scrutiny, for political and economic reasons. The industry dominates research, including at universities, by its funding and well paid board positions. It promotes its private interest, not necessarily the public interests it touts (feeding the world and protecting the environment). The situation seems similar to modern industry domination of drug research (see “Overdosed America,” January 2007), except that FDA scrutiny of new drugs is far stronger and less political. The industry’s secrecy, aggressive tactics, and outright restrictions on independent research breed distrust and polarization. However, that does not excuse the extremism and illegal acts of some foes, such as vandalized GM study plots.
Reasonable doubts exist about the benefits and long-term risks of GM foods, and alternative farming methods have languished for lack of the funding lavished on biotechnology. We need more funding of organic and sustainable farming, and greater government and industry respect for legitimate public concerns, starting with labeling of GM foods. More information and references are available in a video talk by the author, “Genetically Modified Foods: Claims, Counter-Claims and Doubts,” available for viewing in the Center’s Mabee Library or for purchase.