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Encyclopedia of Genetics, Rev. Ed. Genetically Modified (GM) Foods Field of Study: Genetic engineering and biotechnology Significance: Genetically modified foods are produced through the application of recombinant DNA technology to crop breeding, whereby genes from the same or different species are transferred and expressed in crops that do not naturally harbor those genes. While GM crops offer great potential for food production in agriculture, their release has spurred various concerns among the general public. Key Terms Bacillus thuringiensis (Bt) toxin: a toxic compound naturally synthesized by bacterium Bacillus thuringiensis, which kills insects GENETIC ENGINEERING: the manipulation of genetic material for practical purposes; also referred to as recombinant DNA technology, gene splicing, or biotechnology GENETICALLY MODIFIED ORGANISMS (GMOs): genetically modified organisms, created through the use of genetic engineering or biotechnology HERBICIDE RESISTANCE: a trait acquired by crop plants through recombinant DNA technology that enables plants to resist chemicals designed to control weeds The Technology 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, define 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 plants useful to humankind, but GMOs also pose the possibility of misuse and unintended outcomes. Conceivable Benefits of GM Foods 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 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. "Golden rice" has been engineered to produce significantly higher vitamin A precursors. This GM rice plays an important role in alleviating vision loss and blindness caused by vitamin A deficiency among those who consume rice as their main staple food. Attempts are being made to increase nitrogen availability, a limiting factor in crop production, by transferring genes responsible for nitrogen fixation into crops such as wheat and maize. In addition, the reduction in the use of fertilizers, insecticides, and herbicides for GM crops not only saves billions of dollars in costs but also alleviates the damage to wild organisms and ecosystems. Concerns About GM Foods 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. Much of this response is understandable, given that 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 problems arise from handling (for example, microbial contamination), for GM and non-GM foods alike. A third reason for the societal concern is rooted in negative media opinion, opposition by activists, and mistrust of the industry. Most current complaints about GM foods can be categorized into three major areas: the possible detrimental health effects, the potential environmental threats such as "superweeds," and the social, economic, and ethical implications of genetic engineering. Some activists have taken extreme measure to destroying field plots and even firebombing a research laboratory. Although the majority of the public do not agree with the extreme measures taken by some activists, some continue to push for mandatory labeling of all foods whose components have derived from GMOs. Activist groups and media also continue to create myths and release misinformation regarding GM foods: GMOs have no benefit to the consumer, they may harm the environment, they are unsafe to eat, the only beneficiary of GM foods is big corporations, GM crops do not benefit small farmers, or they will will drive organic farmers out of business. Broader Issues in Biotechnology 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 do 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 premium. Where Do We Go from Here? 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 today is: Will farmers and ranchers be permitted to use this new technology?" Ming Y. Zheng See AlsoBiofertilizers; Biopesticides; Cell Culture: Plant Cells; Cloning; Cloning: Ethical Issues; Cloning Vectors; Genetic Engineering; Genetic Engineering: Agricultural Applications; Genetic Engineering: Historical Development; Genetic Engineering: Industrial Applications; Genetic Engineering: Risks; Genetic Engineering: Social and Ethical Issues; High-Yield Crops; Hybridization and Introgression; Lateral Gene Transfer; Transgenic Organisms. Further Reading Borlaug, Norman E. "Ending World Hunger: The Promise of Biotechnology and the Threat of Antiscience Zealotry." Plant Physiology 124 (2000): 487-490. The father of Green Revolution and Nobel Peace Prize winner speaks of his unwavering support for GMOs. 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 perspectives on GM foods by an EU scientist. Potrykus, Ingo. "Golden Rice and Beyond." Plant Physiology 125 (2001): 1157-1161. The originator of the wonder rice presents scientific, ethical, intellectual, and social challenges of developing and using the GMOs. Illuminating and insightful. Web Sites of Interest AgBioWorld.org. http://www.agbioworld.org. This site advocates the use of biotechnology and GM foods. Agriculture Network Information Center. http://www.agnic.org. Searchable by keyword or subject category, this site offers "quality" information on topics including transgenic crops. Transgenic Crops. http://www.colostate.edu/programs/lifesciences/transgeniccrops. This richly illustrated site provides information on genetically modified (GM) foods, including news updates, the history of plant breeding, the making of transgenic plants, government regulations, and risks and concerns. This site is also available in Spanish. |
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