Harms of Genetically Modified Food Crops

The reasons a company may opt for using genetically modified (GM) food crops are many. Forexample, 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, particularlyregarding the environment, health, and economics.

Environmental Consequences of GM Crops

Because GM plants are "unnatural," there is concern that they will wreak havoc on existingecosystems. The ecosystems that are in place evolved over a long period of time, and introducingnew 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 incontrol and prevention. These are known as "invasive species," and some scientists predict thatgenetic modification can change a plant's biology strongly enough that it could become one of theseburdensome organisms.

Beyond creating new invasive species, GM crops might also strengthen existing unwanted plants inthe ecosystem. Alison Snow's 2003 study titled "A Bt transgene reduces herbivory and enhancesfecundity in wild sunflowers," published in Ecological Applications, found that geneticallyengineered sunflowers could cross-breed with nearby weeds, passing along the genetic alterationsmeant to make the sunflower stronger.

A final environmental concern relates to soil integrity. According to the 2004 Journal ofEnvironmental Quality article "Impact of genetically modified crops on soil- and plant-associatedmicrobial communities" by Kari Dunfieldand James Germida, new proteins that are present intransgenic plants can enter the soil, potentially throwing off the diversity of microbial life, whichcould diminish soil health and compromise ecosystem sustainability. Certainly, without carefulresearch and monitoring, GM crops have the potential to damage ecosystems that took many yearsto 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 areaffected. In John Losey, Linda Rayor, and Maureen Carter's 1999 study titled "Transgenic pollenharms monarch larvae," published in Nature, for example, larvae of the monarch butterfly wereshown to grow more slowly and develop higher mortality rates after eating plants dusted with pollenfrom a GM corn plant. So even if insects are not eating from the modified plants themselves, theycan 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 geneticsof 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 conclusionvoid of validity. For example, because the rats were fed only potatoes, they did not receive adequateprotein, which compromised the researchers' ability to study toxicity.

With regard to currently available GM food products, little research has shown any negative healtheffects. This, of course, does not mean such effects will never be seen. GM crops are still relativelynew, and only time will reveal any long-term health effects. Gregory Jaffe, director of theBiotechnology 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 becompletely, universally safe, but he says, "the odds of having an adverse reaction to a geneticallymodified 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 thatGM 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 peanutallergen) 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 foodcrops for proteins that could have allergic effects, and Samuel Lehrer of Tulane University says inhis 2005 article "Risks of allergic reactions to biotech proteins in foods," published in Allergy, "nobiotech proteins in foods have been documented to cause allergic reactions." Of course, allgenetically engineered food crops should be tested for potential health risks, but based on theavailable 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 inrigorous testing and scientific research before implementing genetically engineered plants in thecurrent food-growing system.

For a look at how GM crops can improve the food supply and offer better health to impoverishednations, see " The Benefits of Genetically Modified Food Crops."

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