In short, no, I do not believe it valid to associate GM foods with the rise in food allergies. According to the Food Allergy Research and Education Center, 90 percent of the food allergies in the United States stem from eight foods: peanuts, tree nuts, milk, eggs, wheat, soy, shellfish and fish. Of those eight foods, only one of them — soy — has varieties that have been genetically engineered. None of the others has. Non-GM soy, of which I am a grower, is also allergenic, so the fact is, people with soy allergies need to avoid non-GM, as well as organic soy as much as they need to avoid GM soy.
Contrary to what is circulated in the media, foods made from GM crops do not produce any “new” allergenic proteins. The proteins that are used are well documented and researched before those crops are commercialized. Researchers conduct extensive analysis on these proteins before they are inserted into a specific crop and placed in field trials, many stages before commercial approval is given or the seeds are produced and farmers are given a green light to plant in their fields.
First, testing includes analysis and comparison of the protein intended for GM with all other allergenic proteins to detect any similarities that may induce an allergenic response. Scientists compare the gene sequence of the potential GM protein with other allergenic proteins. If there are similarities, then that protein is not introduced into any foods. Second, tests are conducted to determine if the protein is stable enough to survive digestion. Our gut secretes hydrochloric acid that degrades protein in our stomach when we eat, allowing pepsin, a digestive enzyme, to break down all proteins into smaller parts. If the proteins survive acidic stomach digestion, they are then passed along into the small intestine and exposed to additional enzymes that break the small proteins down even further, to allow the cells to be used as amino acids to absorb them. This digestive process is mimicked in the lab to determine the survivability of the potential GM protein in digestion.
Another level of testing of GM happens when the proteins are tested on the blood serum drawn from people with known food allergies to determine if their serum exhibits an allergic response to the protein. Reaction in this decision tree of these methods of research and analysis means that the proteins that were being considered for use will in fact not be used.
This scientific testing process actually proved successful when, years ago, researchers introduced a protein from the Brazil nut into soy. This allergenic detection response method determined that the protein sequence was in fact allergenic, and the research was halted.
Likewise with so-called Tacogate in 2000, when Starlink corn, a GM corn approved for animal feed but not for human consumption, was found in the food supply. Twenty-eight people reported allergic reactions to consuming foods that may have contained Starlink corn. The CDC investigated and tested the blood serum of these individuals, and none displayed an allergic response. While the corn should have been kept segregated for the animal-feed supply chain for which it was approved, there was no scientific evidence that the protein, which was derived from Bacillus thuringiensis, was the cause of any allergic response.
For comparison, proteins that are crossed during “traditional” breeding or in mutation breeding (which is chemical- or radiation-induced genetic changes used by both organic and conventional plant breeders) are not tested for or compared with known allergens. So, hypothetically speaking, in response to your question, it could be more likely that those proteins contribute to higher incidence of allergies, since there is more crossing of DNA in traditional and mutation breeding. This, though, is also highly doubtful, because researchers and plant breeders’ careers are at stake and businesses that are producing foods for human consumption would lose vast amounts of business by not doing due diligence in ensuring food safety at the plant breeding level.
Furthermore, the next generation of GM foods may very well be less allergenic than conventional or organic foods. The technology has advanced such that existing allergenic proteins can be “turned off,” so to speak, and therefore do not elicit a response from a person with a known food allergy. This research has been conducted at the University of Georgia, with the result that two peanut varieties have not caused an allergic response in people who are in fact allergic to peanuts. Biotechnology is a tool that can continue to be used to improve the foods in our food supply, but only if the research isn’t so fiercely opposed and held up in the approval process, such as Golden Rice has been, to the detriment of many children suffering from vitamin A deficiency in developing countries.
As to what is the potential cause, that is likely to be multifactorial. One potential contributor that is being researched is the medical standard of care to avoid foods that cause allergies in early childhood and introduce them later in childhood. Researchers have found that extended delay in the introduction of food allergens is more likely to induce a response and increase allergy risk. Conversely, a study published in the Journal of Allergy and Clinical Immunology found that early introduction of peanuts resulted in lower peanut allergies. As moms, we listen to our pediatricians, and it has been generally accepted that delaying introduction of allergenic foods was the standard. Given the rise of food allergies, this area needs more investigation.
As to the allergenicity testing of GM foods, there are quite a few studies that have shown no difference in allergy response to GM foods, as compared with non-GM foods. In their 2010 publication “A Decade of EU Funded GMO Research,” researchers conducted an extensive review of the scientific literature and concluded that the DNA in GM foods does not differ from DNA already present in our food supply, nor does it pose any higher risk from ingestion than any other type of DNA.
While there are likely many factors, what’s important is that we fund the research and support the technology as one of several tools in our toolbox so that greater good can be done for a variety of human health conditions and environmental sustainability, and can feed a growing population. Nobody has called biotechnology the silver bullet except those who are out to prove it’s not part of any solution. That would be a sad day for humankind.