by Hannah Packman
The use of genetic modification in our food system is a polarizing issue. However, the current discourse often ignores the grey areas, and may be detrimental to the public understanding of GMOs.
The ability and willingness to admit mistakes is often considered the typification of the wise and modest scientist. As science is an ever-evolving discipline, it is necessary for those within the field to adapt their thoughts and beliefs with emerging discoveries. Many are reluctant to concede their errors, as they worry it will threaten their scientific authority, but those who do are frequently lauded for their honesty and bravery in doing so. This phenomenon is generally observed in the context of divisive issues, such as climate change, antibiotic resistance, and carcinogenic chemicals.
Most recently, the use of GMOs has been the hot-button issue, not just within agro-ecology, but science as a whole. A number of researchers and journalists have publically “come out” on one side of the issue or the other.
Thierry Vrain, once a high-profile biotechnologist and genetic engineer, became an anti-GMO spokesperson upon retirement. He now warns of the dangers of genetically modified crops, urging that engineered soy and corn contain toxic and allergenic proteins. Vrain also questions the environmental justification of genetic modification; that these crops have higher yields and require less pesticides is unsubstantiated. Vrain is celebrated as a luminary by the anti-GMO camp, and is frequently quoted by organizations like GMWatch, Food Integrity Now, and Natural Society.
On the other side of the equation, Bill Nye, a previous GMO skeptic, recently came out in support of genetic modification after spending time with Monsanto’s scientists. The Washington Post, Business Insider, EcoWatch, and the Environmental Working Group all praised Nye’s conversion to a pro-GMO stance.
Admitting the error of one’s ways is certainly a courageous and admirable act. However, in situations such as these, perhaps an even bolder act is admitting ignorance. Given the contradictory evidence on the safety and effectiveness of GMOs, one would be remiss to conclusively choose either side.
True, GMOs hold great promise to solve our most pressing health, environmental, and economic concerns. For instance, genetically engineered crops can be manipulated to contain concentrated amounts of certain nutrients of concern in an effort to prevent deficiency-related disease. Golden rice, an engineered variety of rice with high levels of vitamin A, is the most obvious example. Vitamin A deficiency typically afflicts those in developing countries with limited access to food; annually, it causes blindness in as many as 500,000 children, and is responsible for 670,000 infant deaths. By providing necessary vitamin A, golden rice may be a valuable tool to promote ocular health and abate infant mortality.
Similarly, GMOs have significant potential to improve the environmental sustainability of agriculture by decreasing the use of land and chemicals. Bt-corn is one of such engineered crops that have obviated the need for synthetic pesticides. This corn variety has been modified to express proteins from Bacillus thuringiensis, a bacterium that acts as a biopesticide. As such, Bt-corn is poisonous to pests, who are killed after ingesting the engineered crop. (Bt does not appear to have the same effect on humans, and the EPA says it can be ingested without deleterious consequences.)
Because this variety of corn acts as its own pesticide, the use of additional chemical pesticides is not always necessary. This could decrease exposure to and consumption of potentially toxic chemicals. According to a 2012 study at Washington State University, Bt crops have reduced pesticide use by 123 million pounds since 1996. It should be noted, however, that overall pesticide use increased by 404 million pounds, largely due to genetically engineered, herbicide resistant crops.
There are a number of other salient arguments in support of GM agriculture. Certain engineered crops enable farmers to implement no-till methods, ultimately reducing soil erosion and, less directly, water pollution and eutrophication. GM crops may be a more economically reliable option for farmers, as they are less susceptible to the contingencies of weather, weeds, and insects. Furthermore, engineered crop varieties often have greater yield than their non-modified counterparts. The benefit of this is twofold: farmers will be guaranteed a greater payback for the same amount of land, while unsuitable land can be retired without threatening food supply.
Given the aforementioned benefits of genetic modification, it seems that opposing these wonder-crops would be an act of irrational skepticism. But for every argument in support of GMOs, there is an equally compelling argument against. For one, there is the concern of safety. Although GMO proponents maintain that modified crops are safe for human consumption, the research that supports this claim are typically short-term, experimental studies. The long-term effects of consuming genetically modified foods are unknown.
Of primary concern is allergenicity, as introducing allergenic protein sequences into a non-allergenic organism could possibly render the latter allergenic. Whether allergenicity is likely to occur in GM crops is a contested issue; many argue that the probability is no greater than in non-modified foods. Regardless, the causes of food allergies are still largely misunderstood, and the research on the safety of genetically engineered crops is relatively nascent, making it difficult to accurately assess the possibility of allergenicity.
Even if allergenicity is not a problem, there are other health risks associated with genetic modification. As previously mentioned, herbicide-resistant GM crops have resulted in greater overall application of weed killers in the United States. Glyphosate (popularly known as Roundup), the most popular herbicide in the United States is, was recently identified by the World Health Organization as a likely carcinogen. Because a large portion of our food supply is treated with glyphosate, it is reasonable to ask about the ramifications of ingesting trace amounts on a daily basis. In large quantities, it can be fatal.
The toxicity of herbicides is hazardous not just to humans, but to livestock and wildlife as well. Liberal herbicide application can affect all flora and fauna within an ecosystem, poisoning pollinators, and hindering the growth of plants that rely on them. In turn, the animals that use those plants as sustenance or habitat may also be threatened, causing a chain reaction that can shatter an entire ecosystem.
The possibility of pesticide resistance is of additional concern. As we introduce more Bt crops, the number of resistant species increases. There are now five pest species that exhibit resistance, and that number is expected to grow. The issue of herbicide resistance is even more prevalent; there are at least 30 weed species worldwide that exhibit glyphosate resistance. Pesticide and herbicide resistance is not a matter of inconvenience. As weeds and insects become resistant to chemicals, they evolve into “superweeds” and “superbugs,” extremely resilient species that, in large enough populations, will threaten our food supply.
The intent of presenting these arguments is not to sway you towards or away from GMOs; indeed, it is just the opposite. Genetic modification is an extraordinarily nuanced issue, and each application varies significantly in its benefits and its risks. By framing it as a black-and-white matter, one ignores the hundreds of gradations between. It is clear, then, that the question at hand is not “yes or no?” but rather “when?” “how?” and “why?” And in allowing for greater complexity in our discussion of GMOs, we will be more pragmatic in our future development and use of biotechnology.
Hannah Packman is a first year student in the Agriculture, Food and Environment masters program. When she isn’t busy filling her head with food-related facts, she enjoys filling her stomach with food-related objects.