Genetically modified foods
Genetically modified foods (Encyclopedia of Environmental Issues, Revised Edition)
Humans rely on plants and animals as food sources and have long used microbes to produce foods such as cheese, bread, and fermented beverages. Conventional techniques such as cross-hybridization, production of mutants, and selective breeding have resulted in new varieties of crop plants and improved livestock with altered genetics. However, these methods are relatively slow and labor-intensive, are generally limited to intraspecies crosses, and involve a great deal of trial and error.
Recombinant deoxyribonucleic acid (DNA) techniques developed in the 1970’s enable researchers to make rapid, specific, and predetermined genetic changes. Because the technology also allows for the transfer of genes across species and kingdom barriers, an infinite number of novel genetic combinations are possible. The first transgenics (animals and plants containing genetic material from other organisms) were developed in the early 1980’s. In 1986 the United States and France conducted the first field trials of transgenic plants, which involved tobacco engineered to contain an herbicide-resistance gene. In 1990 the U.S. Food and Drug Administration (FDA) approved chymosin, an enzyme used in the production of dairy products such as cheese, as the first substance produced by engineered organisms to be used in the food industry. That same year a transgenic bull was developed that had been engineered to pass certain human genes along to his offspring; those...
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Benefits of Genetic Modification (Encyclopedia of Environmental Issues, Revised Edition)
The goals for altering food-crop plants by genetic engineering fall into three main categories: to create plants that can adapt to specific environmental conditions to make better use of agricultural land, increase yields, or reduce losses; to increase quality, nutritional value, or flavor; and to alter transport, storage, or processing properties for the food industry. Many genetically engineered crops are also sources of ingredients for processed foods and animal feed.
Herbicide-resistant plants such as the Roundup Ready soybean can be grown in the presence of glyphosphate, an herbicide that normally destroys all plants with which it comes in contact. Beans from these plants have been approved for food-industry use in several countries. Herbicide-resistant rice and sugarbeets, corn and potatoes made insect-resistant thanks to a bacterial gene that encodes for a pesticidal protein (Bacillus thuringiensis, or B.t.), and a viral disease-resistant squash are but a few other examples of genetically engineered food crops on the market. Scientists have also created plants that produce healthier unsaturated fats and oils rather than saturated ones, coffee plants that produce beans that are caffeine-free without processing, zucchinis equipped with insect proteins that make their smell and taste unappealing to insect pests, and cold-tolerant tomatoes that owe their frost resistance to a fish...
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Disadvantages and Controversies (Encyclopedia of Environmental Issues, Revised Edition)
Food safety and quality are at the center of the controversies related to genetically engineered foods. Concerns include the possible introduction of new toxins or allergens into human and animal diets and changes in the nutrient composition of foods. Proponents of using genetic engineering to modify food products argue that it would enable the enhancement of some foods’ nutritional value.
Critics opposed to allowing genetically modified products to enter the environment cite the danger of outcrossing, or “genetic pollution”—that is, the transfer of genetic material to wild relatives—leading to the development of new plant diseases. The emergence of “superweeds,” either the engineered plants themselves or new plant varieties formed by the transfer of recombinant genes conferring various types of resistance to wild species, is another concern. These weeds, in turn, would compete with valuable plants and have the potential to destroy ecosystems and farmland unless stronger poisons were used for eradication.
Opponents also note that crops engineered to be herbicide-resistant encourage excessive use of herbicides. Where glyphosphate herbicides are liberally applied, the local weed population has come to be dominated by glyphosphate-tolerant species. B.t.-resistant insect pests have also been found attacking engineered crops.
Use of rBGH has become controversial because of...
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Further Reading (Encyclopedia of Environmental Issues, Revised Edition)
Falkner, Robert, ed. The International Politics of Genetically Modified Food: Diplomacy, Trade, and Law. New York: Palgrave Macmillan, 2007.
Fedoroff, Nina V., and Nancy Marie Brown. Mendel in the Kitchen: A Scientist’s View of Genetically Modified Foods. Washington, D.C.: Joseph Henry Press, 2004.
Lambrecht, Bill. Dinner at the New Gene Café: How Genetic Engineering Is Changing What We Eat, How We Live, and the Global Politics of Food. New York: St. Martin’s Griffin, 2001.
Lurquin, Paul. High Tech Harvest: Understanding Genetically Modified Food Plants. Boulder, Colo.: Westview Press, 2002.
McHughen, Alan. Pandora’s Picnic Basket: The Potential and Hazards of Genetically Modified Foods. New York: Oxford University Press, 2000.
Martineau, Belinda. First Fruit: The Creation of the Flavr Savr Tomato and the Birth of Biotech Food. New York: McGraw-Hill, 2001.
Nestle, Marion. Safe Food: Bacteria, Biotechnology, and Bioterrorism. Berkeley: University of California Press, 2004.
Rissler, Jane, and Margaret Mellon. The Ecological Risks of Engineered Crops. Cambridge, Mass.: MIT Press, 1996.
Weasel, Lisa H. Food Fray: Inside the Controversy over Genetically Modified Food. New York: AMACOM, 2009.
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Genetically modified foods
The Technology (Genetics & Inherited Conditions)
Genetically modified (GM) foods are food products derived from genetically modified organisms (GMOs). GMOs may have genes deleted, added, or replaced for a particular trait; they constitute one of the most important means by which crop plants will be improved in the future. The advantage of using genetic engineering is quite obvious: It allows individual genes to be inserted into organisms in a way that is both precise and simple. Using molecular tools available, DNA molecules from entirely different species can now be spliced together to form a recombinant DNA molecule.
The recombinant DNA molecule can then be introduced into a cell or tissue through genetic transformation. When a particular gene that codes for a trait is successfully introduced to an organism and expressed, that organism is defined as a transgenic or GM organism.
Most of the GM crops in production thus far have modified crop protection characteristics, mainly improving protection against insects and competition (herbicide resistance). Some have improved nutritional quality and longer shelf life. Yet others under development will lift yield caps previously not possible to overcome by conventional means. Because of the direct access to and recombination of genetic material from any source, the normal reproductive barrier among different species can now be circumvented. All these modifications offer great potential for creating transgenic animals and...
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Conceivable Benefits of GM Foods (Genetics & Inherited Conditions)
The potential benefits of using genetic engineering to develop new cultivars are evident. Crop yields can be increased by introducing genes that increase the crop’s resistance to various pathogens or herbicides and enhance its tolerance to various stresses. The increased food supply is vital to support a growing population with shrinking land. One well-known example is the introduction of the Bt gene from the bacterium Bacillus thuringiensis to several crops, including corn, cotton, and soybeans. When the Bt gene is transferred to plants, the plant cells produce a protein toxic to some insects and hence become resistant to these insects. The grains of Bt maize were also found to contain low mycotoxin, thus exhibiting better food safety than non-GM corns. Another example is the successful insertion of a gene resistant to the herbicide glyphosate, reducing production costs and increasing grain purity.
Food quality can be improved in other ways. Soybeans and canola with reduced saturated fats (healthier oil) have been developed. Alterations in the starch content of potatoes and the nutritional quality of protein in maize kernels are being developed. More precise gene transfer is also being used to produce desirable products that the plant does not normally make. The potential products include pharmaceutical proteins (for example, vaccines), vitamins, and plastic compounds....
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Concerns About GM Foods (Genetics & Inherited Conditions)
Like any other technological innovation, genetic engineering in crop breeding and production does not come without risk or controversy. Some of the common questions raised by consumers include concerns over what plant and animal organisms they are now putting into their bodies, whether these are safe, whether they have been tested, why they are not labeled as GM foods, and whether GM foods might not contain toxins or allergens not present in their natural counterparts. Although most of these questions are understandable, the public uproar concerning the GM crops and other foods, particularly in Great Britain and Europe, are, from a scientific standpoint, an overreaction. Most of the general public does not understand much about the genetic engineering technology, and scientists need to increase their efforts to educate the public.
Second, most people are not aware of the strict regulations imposed on GM research and active safeguards by most governments. In the United States, research and chemical analyses by many scientists working with the Food and Drug Administration(FDA), the U.S. Department of Agriculture (USDA), or independently have concluded that biotechnology is a safe means of producing foods. Thousands of tests over fifteen years in the United States, along with the consumption of GM foods in the United States for four years, have revealed no evidence of harmful effects related to GM foods. Most food safety...
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Broader Issues in Biotechnology (Genetics & Inherited Conditions)
Although some concerns are genuine—particularly ecological concerns regarding gene flow from GM plants to wild relatives—one should not ignore the fact that safety is a relative concept. Agriculture and animal husbandry have inherent dangers, as does the consumption of their products, regardless of GM or non-GM foods. In response to the demands of activist groups, the European Union (EU) and its member states adopted strict regulations over the import and release of GMOs. GM crops and foods are being subjected to more safety checks and tighter regulation than their non-GM counterparts. Through extensive studies and analyses, both the USDA and the EU have found no perceptible difference between conventional and GM foods. Of course, one cannot ensure consumers of absolute, zero risk with regard to any drug or food product, regardless of how they are produced. The demand for zero risk is more of an emotional reaction than realistically possible. Mandatory labeling on all GM foods is both impractical and technically difficult and would drive food prices to much higher levels than consumers are willing to pay. Farmers and the food industry would have to sort every GMO and store and process them separately. Realizing the complexity, federal agencies like the FDA and USDA have recommended a voluntary labeling system by which the organic and non-GM food products can be marked for consumers who are willing to pay the...
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Where Do We Go from Here? (Genetics & Inherited Conditions)
Development of new crops is vital for the future of the world. Since conventional breeding cannot keep up with the population explosion, biotechnology may be the best tool available to produce a greater diversity and high quality of safe food on less land, while conserving soil, water, and genetic diversity. To ensure the safety and success of GM crops, scientists and regulators will need to have open and honest communications with the public, building trust through better education and more effective regulatory oversights. In the meantime, the media will also need to convey more credible, balanced information to the public.
As Nobel laureate Norman Borlaug, father of the Green Revolution, stated, “I now say that the world has the technology that is either available or well advanced in the research pipeline to feed a population of 10 billion people. The more pertinent question is: Will farmers and ranchers be permitted to use this new technology?”
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Further Reading (Genetics & Inherited Conditions)
Borlaug, Norman E. “Ending World Hunger: The Promise of Biotechnology and the Threat of Antiscience Zealotry.” Plant Physiology 124, no. 2 (October, 2000): 487-490. The father of the Green Revolution and Nobel Peace Prize winner speaks of his unwavering support for GMOs.
Cummins, Ronnie, and Ben Lilliston. Genetically Engineered Food: A Self-Defense Guide for Consumers. 2d rev. ed. New York: Marlowe, 2004. Examines the scientific, political, economic, and health issues related to genetically engineered food. Argues that the new food technology has not been adequately tested for safety and that genetically engineered food is being sold without proper labeling.
Fedoroff, Nina V., and Nancy Marie Brown. Mendel in the Kitchen: A Scientist’s View of Genetically Modified Foods. Washington, D.C.: Joseph Henry Press, 2004. Argues that genetically modified foods are safe, nutritionally enhanced products that can fill a major vitamin deficiency in the Third World. Describes the technology of food engineering, maintaining that the risks associated with this technology are trivial.
Fresco, Louise O. “Genetically Modified Organisms in Food and Agriculture: Where Are We? Where Are We Going?” Keynote Address, Conference on Crop and Forest Biotechnology for the Future, September, 2001. Falkenberg, Sweden: Royal Swedish Academy of Agriculture and Forestry, 2001. Fascinating and informative...
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Web Sites of Interest (Genetics & Inherited Conditions)
Agbios. http://www.agbios.com/main.php. Contains a database of safety information on all genetically modified plant products that have received regulatory approval, information on the implementation of biosafety systems, and a searchable library of biosafety-related citations in key topic areas.
AgBioWorld.org. http://www.agbioworld.org. Advocates the use of biotechnology and GM foods.
Agriculture Network Information Center. http://www.agnic.org. Offers information on agricultural topics, including transgenic crops.
Physicians and Scientists for Responsible Application of Science and Technology. http://www.psrast.org. Developed for the general reader, this site discusses the risks of genetically modified foods. Topics include a general introduction to the topic and “Alarming Facts About Genetically Engineered Foods.”
Transgenic Crops. http://cls.casa.colostate.edu/TransgenicCrops/index.html. This richly illustrated site provides information on genetically modified foods, including new developments, the history of plant breeding, the making of transgenic plants, government regulations, and risks and concerns. This site is also available in Spanish.
World Health Organization. http://www.who.int/foodsafety/publications/biotech/20questions/en. A list of twenty questions and answers that...
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