Sometime around 6,000 B.C., in the far reaches of what is now South America, an early human held a swollen root in their hand. The root was infected by a genus of bacteria called Agrobacterium which replaced a segment of the root’s DNA with its own, causing it to proliferate and grow tumors.
As the root’s DNA changed, it swelled and began producing sugar. That swollen root our ancestors held was the first sweet potato, and one of the first genetically modified organisms (GMOs) selected and cultivated by humans. The sweet potato’s genetic modification process is similar to what scientists now call CRISPR (clustered regularly interspaced short palindromic repeats), a process in which bacteria edit genomes by inserting foreign DNA. Despite the ancient origins of this process, the idea of producing and consuming genetically modified foods is now one of the most widely discussed and misunderstood food topics.
Genetically Modified vs. Genetically Engineered Nature has been genetically modifying organisms since the first signs of life appeared nearly 4 billion years ago. While the phrase “genetically modified organism” technically demarcates something that has been purposely altered by humans, the name is a bit of a misnomer because evolution itself is the ongoing process of genetic modification focused on survival.
Humans have been inadvertently creating GMOs since the advent of agriculture when certain species, whether plant or animal, appealed to early farmers based on taste, yield, and ease of cultivation. In many cases those plants and animals became so adapted to and reliant on agricultural production that they could no longer survive without human intervention. Both avocados and industrial corn couldn’t propagate themselves on their own. Foods such as strawberries, wheat, and cabbage now bear almost no resemblance to the ancestors they descended from. Although grocery store strawberries may not be technically genetically modified, they have been bred to contain eight sets of chromosomes, which means bigger strawberries but less flavor than those from your garden.
On the other hand, genetically engineered (GE) products fall under the GMO label but refer to any product where genetic material is specifically introduced or removed in a laboratory setting. Contemporary discussions and concerns regarding GMOs are likely focused on GE products but fall under the guise of the broader GMO label.
The modern story of GMOs began in 1973 when recombinant or man-made DNA was created at Stanford University Medical School. In 1982, the Supreme Court ruled that GMOs could be patented. Within the decade, Monsanto, which had already created the herbicide glyphosate (better known as Round-Up), introduced a glyphosate-resistant soybean. The first GE food appeared on grocery store shelves in 1994 in the form of the Flavr Savr Tomato.
Pros of GMOs Since their inception, GMOs have proven to be effective in saving various crops from viruses and pathogens. In the 1990s, the ringspot virus began killing papaya trees throughout Hawaii and wiped out many farmers’ entire crops. With the introduction of the genetically modified rainbow papaya, Hawaii’s production returned to slightly less than half of what it was in the early 1980s. Now, even though many papaya farmers in Hawaii still grow non-GMO papayas, the production of the rainbow papaya reduces virus pressure in surrounding areas and therefore benefits even organic farmers.
Genetic modification is also a response to climate change. For example, scientists are creating drought-tolerant crops through the alteration of a plant’s photosynthesis. C4 carbon fixation is a photosynthesis process that allows plants to thrive during droughts and in high-temperature environments, using about one-third less water during photosynthesis. In 2008, the International Rice Research Institute began work on C4 rice, a grain which could potentially assure food security for 1 billion people throughout the global south. But while many proponents of GMO crop production point to increased crop yields and the ability to feed a growing global population, and it’s true that GMOs are capable of increased yields, it’s not yet clear whether those increases actually feed more people.
Herbicide-tolerant (HT) GMOs have been shown to facilitate no-tillage and conservation tillage practices, both of which are essential to soil health and carbon sequestration. The absence of weeds in HT crops decreases the need for tillage after harvest. The crops potentially allow for a single, low-level application of a non-specific herbicide rather than a repeated application of multiple weedkillers.
Cons of GMOs The benefits of conservation tillage practices must be weighed against the potential risks of any herbicide application inherent in HT crop production. While herbicide and pesticide-resistant GMOs can enable ecologically friendly farming practices, they may also encourage increased chemical usage along with pesticide and herbicide-resistance among insects and weeds. GMO and non-GMO crops can also be easily cross-pollinated, contaminating both non-GMO crops and native plants.
Economically speaking, the patenting of GMO seeds can lead to high costs for farmers, especially in developing countries. Patents mean that farmers cannot save seeds and must re-purchase them each year from corporations such as Bayer-Monsanto and Cargill.
From a human health perspective, ingesting GMOs doesn’t appear to be harmful to the human genome. But there are concerns about the processes by which those genes are altered and monitored. A handful of GMO products use antibiotic-resistant markers (ARMs) to signify when a desired gene has been inserted and activated. The use of ARMs has caused concern regarding antibiotic resistance in humans. However, the most common ARM is kanamycin, an antibiotic no longer in medical use because most humans are already resistant to it.
GMOs also carry the potential for allergenic contamination. For example, to increase methionine levels in soy milk and baby formula, albumin from Brazil nuts was introduced into soybeans. Researchers quickly discovered that the specific 2S albumin is a major Brazil nut allergen and therefore the genetically modified soy would cause an allergic reaction in those allergic to Brazil nuts.
There is also an ethical dilemma when introducing genetically modified crops in areas struggling with food security when those new food products go against cultural norms. A prime example is the debate over golden rice. The beta carotene-enriched grain was introduced in the 1980s in South Asia where blindness from vitamin A deficiency affects millions of people, particularly children. Through genetic engineering, golden rice is coaxed into producing beta-carotene, something it’s capable of but doesn’t produce without modification. Advocates found it nearly impossible to convince people to adopt this rice into their daily diets despite its health benefits as it’s not considered a culturally appropriate food.
It's Complicated Most people consume and use GMOs daily without even realizing it. Much of the cotton in our clothing is made from Bt cotton crops, and rates of genetic modification among soy and grapeseed are so high that consuming anything made with soy or canola oil is usually analogous with consuming GMOs. While strict regulations must be put in place to protect public health and safety, in a world where one in eight people experiences food insecurity, there must be more nuanced conversations about the uses of GMOs in dealing with a growing global population and changing planet.