The reasons a company may opt for using genetically modified (GM) food crops are many. For example, plants can be genetically manipulated to grow more robustly or contain specific nutrients. While it seems that the intention of GM crops is positive, there are reasons to approach with caution. This form of biotechnology is still relatively young, and it faces some limitations, particularly regarding the environment, health, and economics.
Environmental Consequences of GM Crops
Because GM plants are “unnatural,” there is concern that they will wreak havoc on existing ecosystems. The ecosystems that are in place evolved over a long period of time, and introducing new plants quickly can have unpredictable results.
Although many of the estimated 50,000 non-native species in the United States are harmless, some have spread violently, degrading natural ecosystems and costing the U.S. billions of dollars in control and prevention. These are known as “invasive species,” and some scientists predict that genetic modification can change a plant’s biology strongly enough that it could become one of these burdensome organisms.
Beyond creating new invasive species, GM crops might also strengthen existing unwanted plants in the ecosystem. Alison Snow’s 2003 study titled “A Bt transgene reduces herbivory and enhances fecundity in wild sunflowers,” published in Ecological Applications, found that genetically engineered sunflowers could cross-breed with nearby weeds, passing along the genetic alterations meant to make the sunflower stronger.
A final environmental concern relates to soil integrity. According to the 2004 Journal of Environmental Quality article “Impact of genetically modified crops on soil- and plant-associated microbial communities” by Kari Dunfieldand James Germida, new proteins that are present in transgenic plants can enter the soil, potentially throwing off the diversity of microbial life, which could diminish soil health and compromise ecosystem sustainability. Certainly, without careful research and monitoring, GM crops have the potential to damage ecosystems that took many years to develop.
GM Crops Cause Unintended Harm to Animals
GM crops might also destroy ecosystems by causing unintended harm to organisms. The pest-resistance engineered into modified crops targets specific pests (e.g. the toxin engineered into B.t. corn targets corn borers), but scientists cannot ensure that only the crop-damaging organisms are affected. In John Losey, Linda Rayor, and Maureen Carter’s 1999 study titled “Transgenic pollen harms monarch larvae,” published in Nature, for example, larvae of the monarch butterfly were shown to grow more slowly and develop higher mortality rates after eating plants dusted with pollen from a GM corn plant. So even if insects are not eating from the modified plants themselves, they can ingest toxic residues from pollen blown from nearby fields.
Are Genetically Modified Foods Safe?
There has also been opposition to GM food in the realm of human health. By changing the genetics of a plant, some people worry that it could have unforeseeable effects on human health.
One often-cited study found that rats that ate GM potatoes developed very different digestive tracts, but researchers at the National Institute for Quality Control of Agricultural Products in Wageningen, the Netherlands have pointed out a number of flaws in the study that render the paper’s conclusion void of validity. For example, because the rats were fed only potatoes, they did not receive adequate protein, which compromised the researchers’ ability to study toxicity.
With regard to currently available GM food products, little research has shown any negative health effects. This, of course, does not mean such effects will never be seen. GM crops are still relatively new, and only time will reveal any long-term health effects. Gregory Jaffe, director of the Biotechnology Project at the Center for Science in the Public Interest, in WebMD’s online article “Are Biotech Foods Safe to Eat?” (Webmd.com) admits that nobody can prove a food to be completely, universally safe, but he says, “the odds of having an adverse reaction to a genetically modified food are slim.”
The Effects of GMOs on Allergies
A more specific threat to human health posed by GM foods is allergy emergence. Some argue that GM foods may cause allergic reactions in consumers who previously were not allergic to the food. This could happen three ways: transferring a protein known to have allergic effects (e.g. a peanut allergen) into a different crop (e.g. corn), exacerbating allergic effects via the biotechnology process, and creating new proteins in GM foods that become allergens.
Although these are reasonable concerns, reliable assessment processes are in place to test food crops for proteins that could have allergic effects, and Samuel Lehrer of Tulane University says in his 2005 article “Risks of allergic reactions to biotech proteins in foods,” published in Allergy, “no biotech proteins in foods have been documented to cause allergic reactions.” Of course, all genetically engineered food crops should be tested for potential health risks, but based on the available evidence, there seems to be no need for concern now.
Given the many limitations and potential problems with GM crops, it is important to engage in rigorous testing and scientific research before implementing genetically engineered plants in the current food-growing system.
For a look at how GM crops can improve the food supply and offer better health to impoverished nations, see “The Benefits of Genetically Modified Food Crops.”
Andy Luttrell - I am currently pursuing a Ph.D. in psychology at the Ohio State University after having completed undergraduate education at Eastern ...
