The Health Risks of Genetically Modified Corn

With symptoms including headaches, nausea, rashes, and fatigue, Caitlin Shetterly visited doctor after doctor searching for a cure for what ailed her. What she found, after years of misery and bafflement, was as unlikely as it was utterly common.

A short walk down the hall, his colleague Amal Assa’ad, MD, also a professor at the medical school, dismissed anxiety over GMOs’ safety as almost magical thinking. “What’s wrong with chemicals?” she asked. “We’re so afraid of chemicals because they are man-made, right? A lot of chemicals have helped us—a lot of medications are chemicals.” If anything, GMO foods have been a boon to mankind, Assa’ad said. GMO seeds “produce better crops that have increased production, that are resistant to pesticides—crops that can feed the rest of the world.”

She echoed the federal government’s position—given voice through the regulatory policies of the USDA, the Food and Drug Administration, and the Environmental Protection Agency—that there is nothing inherently dangerous about inserting the gene of one species into that of another, since the end product is essentially identical with that grown from regular seeds. This is also, perhaps needless to say, the biotech industry’s stance. “There are several hundred studies that contribute to a huge body of evidence that GM crops…are as safe as their conventional counterparts,” says Monsanto spokesman Thomas Helscher.

To experiment with a new GMO food in this country, a developer must first get a permit from the USDA to conduct field trials (literally, trials in open fields), following guidelines largely intended to prevent GMO crops from mixing with conventional ones. In addition, according to Helscher, biotech firms like Monsanto are required to compile a document that compares the biology of the modified plant to the unmodified one, determining, for example, if there is a “statistically significant difference” in the levels of nutrients such as carbs and fats between the two plants, or, if new proteins are introduced, whether they’re included in the database of known allergens. If nothing goes obviously wrong, the crop is free to go to market.

It all sounds fine, until you dig a bit deeper, critics of this process say. For one thing, they question the objectivity of the allergen database because it’s compiled at the University of Nebraska–Lincoln, whose facilities are funded by the six major biotech companies: Monsanto, Syngenta, Dow, Dupont Pioneer, Bayer, and BASF. Indeed, no GMO proteins are on the list, but that’s for lack of “sufficient evidence” to put them there, says Richard Goodman, PhD, a UNL research professor and former Monsanto employee. He does add, however, that much of the existing data regarding the allergenic potential of GMO foods simply examines them for amino acid sequences similar to those in known allergens—like peanuts or milk—which limits the usefulness of the whole enterprise to people like Mansmann: They think GMOs may be carrying heretofore undiscovered allergens. (If you’re thinking, Well, what do the clinical trials with humans show? The answer is: They’re nonexistent because, the biotech firms say, they are impractical, and, again, GMO foods are basically presumed safe and thus don’t undergo near the level of scrutiny as new drugs.)

The most fundamental complaint from those worried about the health risks of GMO foods is that hardly any of the research is independent; the biotech firms either conduct or pay for the studies forwarded to the government, and they also pick and choose which ones to submit. “The scandal is that the USDA does not force the companies to give results of trials that had negative outcomes,” says Harwood Schaffer, PhD, a research assistant professor at the University of Tennessee’s Agricul-tural Policy Analysis Center. “We’ve seen this in medicine: You only get the data that the [industry] wants you to see.” Schaffer also points out that the biotech firms consider their research proprietary, so there’s no record for the public to inspect: “Maybe the GMO companies aren’t hiding anything, but the question is: Does the public have the right to know?”

One of my last stops in Cincinnati was the office of affable Australian-born immunologist Simon Hogan, PhD, who, interestingly, was the lead author of one of the few independently funded GMO-food studies. In the early 2000s, Hogan’s interest was piqued when he learned GMO peas were being developed in his native country, so he decided to investigate the new product. “I felt there was a fundamental lack of knowledge on whether GMOs could have an effect” on animals (and possibly people).

He was surprised by the results: Mice given the GMO peas had inflammatory reactions such as “mucus hypersecretion,” “pulmonary eosinophilia” (eosinophils in the lungs), and airway hyperresponsiveness (“the lungs were twitchy,” says Hogan). Most important, the peas may have “perturbed” a tolerance mechanism in the mice, leading to enhanced immunreactivity. When the study was published in 2005 in the Journal of Agricultural and Food Chemistry, there was a deluge of media coverage both lauding and decrying it—most notably on the con side, a Nature Biotechnology article called Hogan’s study “mush” and charged, among other things, that mice probably aren’t analogous to humans when it comes to allergies.

With all the uproar, the pea project was abruptly canceled. But eight years later, another team published a contradictory report showing that mice react to proteins in GMO peas and in conventional ones. It was funded by the European Union. (Hogan’s very measured response? Good science requires multiple studies before conclusions can be drawn.)

While most people seem to tolerate GMO corn, I asked Hogan if he thought it could be making a small cohort of the population sick, as his peas did the mice. “I don’t think definitive analysis has been done to answer that question, and because you don’t know definitely what these [GMO] proteins could do…that’s sufficient for me to say ‘halt’ until we know more.”

With the level of penetration of GMO foods, and the fairly widespread acceptance of them in America (certainly compared with Europe, where they’re banned in many countries), saying “halt” seems unlikely at this point. Definitely in the air, however, is better labeling of such products. The Connecticut legislature passed a measure this June to require it, and a whopping 96 percent of people favor GMO labeling, according to a 2011 MSNBC poll. Whole Foods Market announced this March that by 2018 everything it sells in the U.S. and Canada will be labeled for GMOs. How the store will implement that is hard to fathom given the ubiquity of industrial corn: Will the bastion of healthy eating plaster GMO stickers on practically every item on its shelves? “We’re very aware of how much of a challenge [labeling] is going to be,” a company spokesman admitted, adding that they’re committed to it nonetheless.

My small family has been able to jettison GMOs, thanks to the local farmers we’ve found and our willingness to do without the vast majority of prepared foods. But my husband and I both have jobs, and there are days when we can’t imagine preparing everything from scratch forever. Yet when I was sick for all that time, my life felt totally out of control. I still rue the day when I was desperate enough for a diagnosis to believe I had chronic Lyme disease, which necessitated weaning my small son from my breast before either of us was ready so I could be bombarded with antibiotics. When I think back to how suffocatingly powerless I felt, how sidelined as a wife, mother, and productive person, I just feel, well, sick. Although Dr. Mansmann told me that most people allergic to GMO corn can end up tolerating small amounts after a couple years of abstinence, each time I’ve dared cheat, I’ve awoken the next morning with a frozen left hand, a sore hip, and a facial rash. So for now, at least, the extra work isn’t really a choice; it’s a way of life, one that reminds me daily that our modern world is full of challenges—dietary, economic, environmental—that at times feel overwhelming. And perhaps that’s the gift in this: I’ve had to slow down and think about my food—how it was grown, what’s in it, and which trade-offs were made in the journey from a seed to my plate. That consciousness has to be worth something bigger than just my health.

Leave a Reply

Your email address will not be published. Required fields are marked *