3.5—Starlink corn was successfully recalled, caused no allergies
The Pesticide in Starlink insect-protected corn has a very low likelihood of being an allergen
Analysis of Peer-Reviewed Research:
The Starlink episode is a very sad story in many ways. First of all, the EPA did not understand that no single test is used to determine if a protein will be a food allergen. They placed too much weight on the fact that the Bt found in Starlink, called Cry9C, does not digest very rapidly in simulated gastric fluid. They did not approve Starlink corn as a food for humans. EPA compounded the error by approving the product as a feed. They accepted the developers’ promise to advise farmers to only use Starlink as feed corn apparently not realizing how completely feed and food corn are co-mingled in the US grains system. EPA set in motion a process in which finding Starlink in the food supply was inevitable. EPA also set the stage for a recall of a most-likely safe product. FDA had no legal choice but to issue a recall when Starlink, an unapproved food product, was found in the food supply. In the process, the developing company went out of business and millions of consumers were worried needlessly about whether they had eaten, or would be exposed to, Starlink. If we treated GM crops like other crops and if agencies and consumers were not sensitized by unscientific fear-mongering, this tragic episode could have been avoided. Jeff Smith contributes to unfounded fears by asserting that GM foods may have caused an increase in food allergies in the absence of scientific evidence.
1. The Bt in Starlink corn has never been shown to be allergen and careful analysis of the Starlink event yields the conclusion that the Bt protein in Starlink, Cry9c, is mostly likely not an allergen. Contrary to Smith’s claims, most food-allergy experts believed that there was almost no chance that Starlink contained an allergen, while the EPA advisory panel apparently felt there was some very small but real chance it could become an allergen (CDC 2001, Lemaux 2008, Hefle and Taylor 2001). The problem observed with Cry9C is that it digests slowly in the simulated gastric fluid assay. This doesn’t mean it is an allergen since indigestible proteins are not necessarily allergens. At the time of the Starlink episode, known expert scientific opinion was backing away from an earlier proposition that protein indigestibility was an indicator of potential allergenicity. More recently, some experts say that we should move away from the digestion assay completely because it is not predictive of allergenicity (Goodman and others 2008). The EPA and EPA expert panels placed too much emphasis on the digestion assay. They treated poor digestibility as an indicator of allergencity and did not sufficiently weight other data such as the fact that no Cry protein has ever caused human allergy or that the Bt protein in question, Cry9c, does not possess any structural resemblance to any known allergen. It may be that EPA was too precautionary in their approach and sought 100 percent certainty that Cry9C was not an allergen.
2. The real problem with Starlink is that it was not approved for human use and had to be recalled when it appeared in the food system. The law is very clear on this, in order to protect consumers, any time an unapproved additive appears in the food system it must be recalled. The FDA did not investigate if Starlink was dangerous because the problem was that it had not been approved. The consequences were serious. The producer, Aventis, was fined millions of dollars by USDA and also had to pay out millions to consumers and companies who were hurt by the recall. As a direct result, Aventis is no longer in business. Stores, restaurants, and food manufacturers suffered losses. All corn in the U.S. had to be tested until very recently when it was determined that no measurable amounts of Starlink remained in the food system (EPA 2007).
3. People were scared by the recall and many attributed their illnesses to Starlink. It is an unfortunate and well-documented fact that when scares like Starlink are announced and people then become ill, they will naturally attribute their illness to whatever is being recalled. Think about it. If you ate a taco, became ill a couple of hours later, and then heard that taco shells were being recalled by the government, wouldn’t it enter your mind that maybe your illness was due to the taco you just ate? Consumers can’t be criticized for thinking that if something is being recalled it must be dangerous. In fact, dozens of claimed Starlink-related illnesses were carefully investigated and not a single subject had an IgE antibody that reacted with Cry9C—the Gold Standard test required to show allergenicity (Hefle and Taylor 2001). There is no evidence that a single consumer was actually hurt by Starlink.
4. Human exposure to Starlink was very low. Less than 0.5 percent of the corn in the U.S. was Starlink. It is likely that far more than 75 percent of Starlink corn was fed to animals—remember that farmers were asked to use it strictly as animal feed and many did follow that procedure. About 1 percent of all corn is eaten as whole corn in the U.S., most corn used for foods is processed into corn oil and starch. The exposure to Cry9C would have been further reduced by the fact that the process used to make corn meal “masa” for tacos, called nixtalization (treatment with heat and alkali) essentially destroys Cry9C (Shillito and others 2001). The typical human exposure would have been less than fractions of billionths of a gram and 99th percentile consumers under the worst case assumptions might have been exposed to a few micrograms (millionths of a gram) per day (Shillito and others 2001, Peterson and others 2001). It is unfortunate that in the midst of a recall consumers are usually not given very clear information that the material in question was not known to be unsafe and that the probable level of exposure was very low indeed.
5. Smith makes unproven, illogical and inflammatory claims about GM crops. We call your attention specifically to the statement, “Allergies have skyrocketed since GM crops have been on the market. Without post-market surveillance or better allergy-screening methods, GM crops must be considered a suspect for contributing to this situation.” To begin with, food allergies are not skyrocketing, although they are on the increase (Tomaselli 2009). If in fact a slow, steady increase in allergy has occurred over the years, the increase started long before GM crops were introduced and most experts are looking for other reasons— some have attributed food allergy to modern sanitation and a failure to achieve normal tolerance to allergens (Tomaselli 2009). Smith is never able to provide proof that GM crops cause allergy or any adverse effect, but he accuses GM crops with a classical logical fallacy called a post hoc fallacy. In logic, just because one event follows another event does not mean that the first event caused the second event. Evidence of causality must be shown to establish a link and Smith has shown none.
CDC (2001). Investigation of Human Health Effects Associated with Potential Exposure to Genetically Modified corn. A Report to the U.S. Food and Drug Administration from the Centers for Disease Control and Prevention June 11, 2001 www.cdc.gov/nceh/ehhe/Cry9cReport/ accessed January 7 2009
EPA (2007). US Environmental Protection Agency Office of Pesticide Programs (Draft White Paper) Concerning Dietary Exposure To Cry9c Protein Produced By Starlink® Corn And The Potential risks Associated With Such Exposure October 16, 2007
Goodman RE., Vieths S, Sampson HA, Hill D, Ebisawa M, Taylor, SL, van Ree, R. 2008. Allergenicity assessment of genetically modified crops: what makes sense? Nat. Biotech. 26: 73-81.
Hefle S and Taylor S (2001). Will genetically modified foods be allergenic? J Allergy Clin Immunol. 107: 765-771.
Lemaux P (2008). 3.9. Were Foods Made From Bt Corn Removed from the Market Because of Allergenicity Concerns? In Genetically engineered plants and foods: a scientist’s analysis of the issues (Part I). Annual Review Plant Biology 59:771–812.
Petersen BJ, Rachman NJ, Watters JL (2001). Estimated potential dietary intake of cry9c protein based on measurements of cry9c in processed foods made from 100% Starlink™ corn Aventis Corporation filing with EPA, April 21, 2001.
Shillito RD, MacIntosh S, Kowite WJ. “Detection of Cry9C protein in dry milled, wet milled and masa processed fractions and processed foods made from 100% StarLink™ grain.” Aventis Corporation filing with EPA, April 17, 2001.
1. Starlink corn, considered potentially allergenic by the U.S. EPA, was approved as an animal feed but not for human consumption
2. The tiny amount planted in the United States nonetheless contaminated the food supply, prompting massive food recalls.
3. Thousands reported health effects, including life-threatening episodes they thought may be related to Starlink.
4. The FDA was unable to rule out allergenicity and experts say it has a “medium likelihood” of being an allergen.
5. A small amount remains in the food supply.
The Bt protein in Starlink corn is not digestible and therefore may be an allergen.