Genetically modified foods

DEFINITION: Foods derived from living organisms that have been modified by gene-transfer technology

Applications of genetic engineering in agriculture and the food industry have the potential to increase world food supplies, reduce environmental problems associated with food production, and enhance the nutritional value of certain foods. However, these benefits are countered by food safety concerns, the potential for ecosystem disruption, and fears of unforeseen consequences resulting from the alteration of natural selection.

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.

Deoxyribonucleic acid (DNA) techniques developed in the 1970s enabled 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 1980s. 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 US Food and Drug Administration (FDA) approved chymosin, an 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 genes would enable his female descendants to produce human milk proteins for infant formula. The well-publicized Flavr Savr tomato obtained FDA approval in 1994. By 1996, field trials had been conducted for more than 3,500 genetically engineered plants.

Though the United States began requiring food labels to state the presence of bioengineered ingredients in the late 2010s, the debate over labeling and its effects on public perception and sales continued. So, too, did the long-running debate over whether genetically modified foods should be promoted, both in the US and globally, to address pressing nutritional and environmental concerns or whether their risks are too great. By 2022, eleven genetically modified crops were grown in the US, including varieties of potato, sugar beet, papaya, soybean, and corn. While this number may seem relatively small, many of these comprise a large percentage of the total crop grown. For instance, in 2020 genetically modified soybeans made up 94 percent of all soybeans planted in the US.

Benefits of Genetic Modification

The goals for altering food-crop plants by fall into several main categories: to create plants that can adapt to specific environmental conditions to make better use of agricultural land; to increase yields or reduce losses; to increase the hardiness of plants to minimize the use of pesticides; 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 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 to a fish gene.

Animals can also be genetically engineered food sources, although transgenic research involving plants presents fewer technical challenges. One of the best-known applications of genetic engineering in animals involves recombinantbovine growth (rBGH; also known as recombinant bovine somatotropin, or rBST) synthesized by containing the BGH gene found in cattle. When rBGH is given to cows as a supplement, their milk production can increase 11 to 16 percent. The FDA approved the use of rBGH in 1993, and a 2014 survey by the US Department of Agriculture (USDA) found that roughly 15 percent of the dairy cows in the United States were being treated with rBGH.

Cloning is not genetic engineering per se, as it does not involve adding, removing, or modifying genes. Rather, it is a method for copying an organism’s genetic traits to create one or more living replicas of the organism. While cloning is too expensive to be used to produce food animals, it can be employed to replicate breeding animals that can pass desirable traits to their offspring. The technology used to clone Dolly the sheep in 1996 represented a significant advancement. In 2001, by which time other mammal clones had been created, the FDA asked livestock producers and researchers to keep animal clones and their offspring out of the food supply until a food consumption assessment could be conducted. In 2008, an FDA report concluded that meat and milk from cow, pig, and goat clones and their offspring are as safe as any other animal products. By the 2020s, the FDA report stood valid and was unchallenged by the scientific community.

Genetically engineered microbes are used for the production of food additives such as amino acid supplements, sweeteners, flavors, colorings, vitamins, and thickening agents. In some cases, these substances previously had to be obtained from slaughtered animals. Altered organisms are also used for improving fermentation processes in the food industry. Proponents also note that farmers have benefited enormously from genetically modified food technology, seeing an increase in farm income by US$261.3 billion worldwide from 1996 to 2020, according to a 2022 study. 

Disadvantages and Controversies

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 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 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 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 concerns regarding the health of treated cows and the safety of the milk. Cows receiving rBGH are more susceptible to udder infections than are other cows, and thus are treated with more antibiotics and other drugs; those who consume the milk ingest residues of those drugs as well as residues of the hormones themselves. Further, studies have shown links between rBGH and heightened rates of cancer in humans, though more research is needed. Canada, all members of the European Union, Japan, New Zealand, and Australia have banned the use of rBGH in cows producing milk intended for human consumption.

Cloning technologies have been similarly controversial. Animal rights issues, vegetarian and religious objections to animal-based components in plant foods, worries about infectious agents that could be transferred to humans, and concerns regarding the application of animal cloning technologies to produce human beings have all hindered developments in this field.

Environmental problems such as deforestation, erosion, pollution, and loss of have all resulted, in part, from conventional agricultural practices. Proponents of genetically engineered crops point out that such crops could allow better use of existing farmland and lead to decreased reliance on pesticides and fertilizers. A large percentage of crops worldwide are lost each year to drought, temperature extremes, and pests. Plants have already been engineered to exhibit frost, insect, disease, and drought resistance. Such alterations can increase yields, allow food to be grown in areas that are too dry or infertile to support nonengineered crops, and have positive impacts on the world food supply, particularly in the face of global climate change.

Also, it is argued, genetic engineering might be necessary to develop food sources that can survive rapidly changing environmental conditions. Pollution, climate change, and increased ultraviolet because of decreased stratospheric ozone result in stress conditions for living organisms, and all have impacts on agriculture. The processes of natural selection and may be too slow to keep up with the food needs of the earth’s ever-increasing human population.

Opponents counter that genetic modification does not automatically lead to higher production, nor does higher production automatically reduce hunger. It is poverty, they maintain, that determines who goes hungry, not the availability of food. The production costs of genetically modified crops are beyond the means of many small farmers in the developed world and most farmers in the developing world. One of the most widely voiced criticisms of genetically modified foods thus centers on the ethics of allowing consolidated control by agribusiness of the world’s food production.

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