In America, it’s impossible to have a conversation about our food and where it comes from without talking about genetically modified organisms (GMOs). Selective breeding–where organisms with desired traits are bred together to amplify those traits–is technically a type of genetic modification, but GMOs usually refer to cases where the desired genes are removed from the DNA of one organism and transferred into that of another, allowing scientists precise control over what traits are expressed in the modified organism.
According to the US National Library of Medicine, drought-, pest-, and disease-resistance, nutrition, speed of growth, and increased production density are all traits that may be selected for in GMO crops. Plums, for example, have been altered to be resistant to the plum pox virus through the addition of a protein from the virus itself. The most common GMO crops in the US are corn and soy–88% of corn and 94% of soy grown on American land is genetically modified. Aside from agriculture, GMOs hold great promise in the pharmaceutical industry. Some research focuses on finding a way to incorporate essential vaccines into the DNA of fruits and vegetables for easier distribution; meanwhile, genetically altered rice and soybean plants have been used experimentally to produce human growth hormone in the last few years.
In spite of their benefits, GM crops remain a subject of controversy, because many people are concerned that we don’t know enough about how these modifications will impact the body in the long term. Fortunately, several studies have been able to identify the actual risks and evaluate the need for policies regarding GMOs.
In 2000, suspicions rose about the allergenic properties of GMO crops when a Californian woman named Grace Booth went into anaphylactic shock after eating several Taco Bell tacos. After eliminating any other plausible allergens, Booth discovered a recent report explaining that the corn used in some of Taco Bell’s tortillas had been accidentally cross-pollinated with corn that had been modified to contain the pest-repellent protein Cry9C. The FDA was unable to find a definitive link between Cry9C and the allergic reaction, but the tortillas were recalled and a conversation was sparked. All genes present in GMOs occur naturally in other species, and, just as with any other allergy, only those who are sensitive to the specific protein produced are affected. Problems arise when people are exposed unexpectedly to allergens in foods to which they have had no negative reactions in the past. The Cry9C incident led agricultural science companies to more closely examine the products of transferred genes and to avoid lifting genes from known allergens. As of May 2014, the World Health Organization stated that “No allergic effects have been found relative to GM foods currently on the market.”
Another theoretical risk to human health is horizontal gene transfer (HGT), which is the process by which genetic material passes across cell boundaries, and leads to a transfer of genetic information without either reproduction or human intervention. Some consumers have expressed concern about HGT from GM organisms. Theoretically, HGT could lead to the transfer of antibiotic resistant genes to bacteria in the human body. This wouldn’t necessarily have any noticeable effects if these genes were transferred into the “friendly” bacteria found in all humans, but if they found their way into pathogenic bacteria, those strains could become difficult or impossible to treat with existing antibiotics. The transfer of modified genes to other organisms in an environment could also lead to unforeseen ecological impacts. Just what the ramifications of this would be are hard to predict; it would depend entirely on which genes transferred, but it is possible that weeds will become more drought-, heat-, and/or herbicide-resistant. However, a 2008 study by Paul Keese found that “In most cases the occurrence of HGT from GM crops to other organisms is expected to be lower than background rates,” and therefore that genetically modified plants do not pose a large risk to humans and other species due to horizontal gene transfer.
GMOs can also have inadvertent environmental impacts. Corn and soy have been genetically modified to grow with great efficiency and have become monoculture crops–in other words, acres upon acres of adjacent land are exclusively devoted to growing these two crops in as high a density as possible. Monoculture farming (as opposed to rotation farming, where livestock and crops with different nutrient needs are cycled across areas of land) is not sustainable in the long term because it promotes erosion and depletes the nutrients that are naturally present in the soil. Fertilizers are used to supplement these nutrients, and the subsequent nitrogen runoff leads to algae blooms in nearby water sources which can cause severe ecological disturbances.
Some crops have been engineered to contain pesticides, but unfortunately, the pests that feed on these crops can become resistant to these pesticides over time. In a similar process to the overuse of antibiotics, which leads to the rise of antibiotic-resistant bacteria that are much more difficult to treat, only the hardiest pests survive consuming the GM crops and then reproduce until the entire population is resistant. This negates the entire purpose of incorporating pest-resistant genes into crops and makes pests much more difficult to eliminate in the future.
GMOs present few direct risks to humans or the environment. However, they exist in the interconnected system of our agricultural infrastructure, and therefore they cannot be considered in isolation. For example, the enormous quantities in which corn and soy are now produced makes them a foundational element of the factory farming system because they can be used as cheap feed for livestock and poultry–and the continued demand for cheap meat in the US has in turn cemented the place of these grains in the chain of production.
Other ethical challenges arise when you consider that companies are able to patent the strains of crops that they develop, and therefore create monopolies on the most effective strains of crops. These patents can harm the smaller farmers who have to purchase these seeds at high prices or else risk being outperformed by those who can afford to grow the superior crops. The owners of the patents also enforce strong patent-violation restrictions so that farmers who keep seeds after one planting cycle are at risk of being sued for violation of intellectual property laws.
It’s undeniable that GMOs present challenges. Some of these challenges can be solved in the laboratory, but others must be tackled through regulation, research, and a careful examination of all the interconnected processes of the agricultural sector.
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