Do Genetically Modified Foods Cause Allergies?

Allergies are big news and big business in the new millennium. A hundred years ago, people would likely have been shocked that modern humans are plagued with illnesses that range from annoying to deadly due to allergic reactions. In recent years, allergy sufferers have spent billions to avoid itchy noses and bleary-eyed suffering, and anxious parents have demanded that schools and airplanes ban nuts. With all the angst over peanut dust and pollen, the potential allergy-causing properties of genetically modified organisms (GMOs) has been quietly overlooked.

© Lisa Blackshear

Genetically modified food has genes from other plants or animals inserted into its genetic structure. Scientists and environmental and health advocates have long been concerned that this practice could stimulate allergies in humans. The argument goes like this: If you are allergic to fish, and you eat a GMO tomato that includes genes from a fish, might you have an allergic reaction if you eat the tomato? A 2002 Journal of Anatomy article denies it: "No direct evidence that [GMO] food may represent a possible danger for health has been reported so far; however, the scientific literature in this field is quite poor." Only a few GMO crops (soy, corn and canola) have been widely planted and truly infiltrated the American food supply, and there have not been any widespread documented allergies to those foods.

Unpredictable Genes

However, some scientists say that gene modification isn’t as predictable as GMO advocates claim it is. "When inserted, genes can get disrupted, fused, mutated, or altered in unknown ways," says Doug Gurian-Sherman, a senior scientist at the Institute for Food Safety. Critics of GMOs say that allergic responses to an occasional dose of GMOs might not be noticeable in humans or might be attributed to another food exposure.

A 1999 study of farmworkers who worked with bioengineered corn found elevated levels of proteins that were related to known allergens in their blood. These and other exposed farmworkers have shown higher than normal skin irritation, asthma and "rhinitus" (runny noses)—all classic allergic reactions. Studies were never repeated on those subjects to prove that the allergies were due to the GMOs or some other factor. Tests on mice that have ingested genetically modified corn found increased immune responses when compared to traditional corn.

In a 2005 study by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), the Australian government’s scientific research arm, it was found that a gene from a bean that was inserted into pea plants (to make them resistant to the pea weevil) caused an immune response in mice. For an unknown reason, once the bean gene was in the pea plant, it not only repelled the weevil, but also produced a protein that caused an allergic response in mice—and could potentially cause allergies in humans. The million-dollar pea plant trial was discontinued shortly after this information came to light. "In the U.S., the tests [that found the allergen] would never have been performed since they are not required by regulatory agencies," says Gurian-Sherman.

Testing GMOs?

The unknown allergy-causing potential of GMO foods is one reason the Center for Food Safety (CFS), a nonprofit that works on public health and environmental issues, has been petitioning the Food and Drug Administration (FDA) since 2000 for pre-market testing of GMO food for allergens. The Center also wants to see GMO foods labeled and wants an environmental review before bioengineered crops are planted. Fifty other groups signed the group’s petition, including the Natural Resources Defense Council, Rodale, the National Environmental Trust, Greenpeace and the Sierra Club. According to the Center, although the FDA is required to act on any citizen petition within six months, the FDA has never responded. In June of this year, CFS filed suit against the FDA. "We think FDA is clearly in egregious violation of its own rules and is stifling public debate by not responding to our petition," says Gurion-Sherman.

The FDA refuses to comment on any ongoing court case. But the agency says that it doesn’t subject GMO foods to the same testing as, for example, a new chemical additive, because new gene introductions do not "materially change the composition" of food. "FDA has no basis for concluding that bioengineered foods differ from other foods in any meaningful or uniform way, or that, as a class, foods developed by the new techniques present any different or greater safety concern than foods developed by traditional plant breeding," says Richard Herndon, an FDA spokesperson.

Ronnie Cummins, the national director of the Organic Consumers Association, disagrees, saying that allergies are just one of the possible negative health effects of bioengineered food. "GMOs are unpredictable and dangerous," he says. "There is evidence of allergenicity, and also elevated cancer risk, and immune problems in animal feeding studies." The authors of a 2003 study in The Journal of Histiochemistry wrote, "This study further supports the idea that a diet containing significant amounts of [GMO] soybean can influence the pancreatic metabolism in mice."

Currently, all safety testing of genetically modified foods is done by the same companies that do the research, development and selling of bioengineered plants. Critics say that the government should test GMO foods to assure unbiased results, and that all new GMO crops should be tested using trials similar to those undergone by new food additives. Michael Hansen of Consumers Union agrees. "Appropriate studies have not been done on GMO foods," he says. "The studies that have been done [by the companies] are not well-designed." The FDA sees this system as adequate, and less expensive than its government-sponsored alternative. "FDA takes a case-by-case approach to the safety assessment of bioengineered foods," says Herndon.

In the European Union, all GMO foods are labeled so that consumers can choose to eat them—or not—in part due to concerns about potential allergens. In the U.S., there is no labeling of genetically modified foods, though the USDA organic label cannot be applied to gene-altered foods. While some scientists say that due to unintended crop contamination even organic foods probably contain small amounts of bioengineered DNA, the percentage is low.

Polls have shown that 80 to 90 percent of Americans would avoid GMOs if food products containing them were so labeled. For now, these foods are not labeled, and there aren’t any plans by the FDA to do so. But if you want to avoid GMO foods, you can choose organic. "Most GMOs are used in processed foods and for animal feed," says Cummins, "If you stick to a whole foods diet, you should be able to avoid GMOs."

STARRE VARTAN is a Connecticut-based freelance writer.