Noticias
y campañas
de la OCA
en español
To Subscribe to the Non-GMO Report call 1-800-854-0586 or visit http://www.non-gmoreport.com/
The potential of genetically engineered foods to cause allergic reactions in humans is a big reason for opposition to such crops. To date, there have been no definitive tests to determine if GE crops do cause food allergies. However, scientists at Michigan State University are confident they can develop such a test, and theyÂ’ve received $447,000 from the US Environmental Protection Agency (EPA) to validate the test.Serious health problem
Genetically engineered crops are created by inserting a protein from a different organism into the genome of a food crop, such as corn or soybeans. This protein may have never been in the food supply before, and could potentially cause food allergies.
Food allergies are a serious health concern affecting an estimated 12 million Americans. Food allergy symptoms include difficulty breathing, hives, vomiting, abdominal cramps, diarrhea, drop in blood pressure, and even loss of consciousness and death. Eight foods account for 90% of all foodallergic reactions: milk, eggs, peanuts, tree nuts, such as cashews and walnuts, fish, shellfish, soy, and wheat.
Examples of GE crops causing allergies
There are examples of the allergy-causing potential of GE crops. In the mid-1990s, scientists at Pioneer Hi-Bred seed company introduced a gene from Brazil nuts into soybeans to improve their nutritional content. A University of Nebraska scientist found that the GE soybean would cause allergies in people who are allergic to Brazil nuts. The fearsome prospect was that people with the allergy, which can be extremely serious, would not think to avoid eating soybean products. More recently, researchers at AustraliaÂ’s national research organization, Commonwealth Scientific and Industrial Research Organization (CSIRO), took the gene for a protein capable of killing pea weevil pests from the common bean and transferred it into a pea. When extracted from the bean, this protein does not cause an allergic reaction in mice or people. But when the protein was expressed in the pea, its structure changed, and it caused allergic lung damage in mice. As a result, the project was scrapped.
Mouse model test
Such examples demonstrate the pressing need for an allergy test for GM foods, especially since they are so widely grown in North America and in other parts of the world.
The Food and Agriculture Organization within the World Health Organization has a structured approach, involving a decision tree, to determining whether GE foods cause allergies, according to Venu Gangur, assistant professor of food science and human nutrition at Michigan State University. “But it has a major flaw. A critical question in that process asks, ‘Does the protein cause an allergic reaction in animals?’ The problem is that there has been no good animal model available to test this,” says Gangur.
Gangur believes he has developed the first animal model to test whether genetically engineered foods could cause human allergic reactions. He recently received a $447,000 grant from the EPA to validate the test.
The EPA has wanted to develop an allergen test for GM foods since the StarLink GE corn controversy in 2000. StarLink contained the cry9C protein from a common soil bacterium, a strain of Bacillus thuringiensis. The cry9C protein protected the corn from several types of corn borers and black cutworms. StarLink was approved by the EPA for use in animal feed and nonfood products in 1998. But in 2000, fragments of cry9C DNA were detected in taco shells and other food products, and many consumers reported allergic reactions.
“Many people believed that StarLink was responsible for their asthma attacks and other allergic reactions,” Gangur said. “The Centers for Disease Control took samples and tried to figure out if StarLink was the cause, but the data were inconclusive. There was really no good method to determine if StarLink caused allergic reactions. This is why our model will be such a valuable tool. We’ll be able to determine the allergenic potential of genetically engineered crops before they’re released into the human or animal food chain.”
Test expected to be 85% to 90% accurate
Gangur and students in his lab will use the EPA grant to examine whether the mouse model works on a variety of proteins. If successfully validated, the testing could be available commercially in about five years. “Our aim is to develop a test that would show whether GM foods cause allergic reactions or not,” says Gangur.
Gangur says he has already successfully tested his mouse model on foods known to contain allergens, such as peanuts and sesame seeds, as well as non-allergenic foods, such as vanilla beans. Based on these results, Gangur is confident that his test will be successful with GE foods. “Our hypothesis is that the test will be highly probable, 85% to 90% accurate in detecting potential allergens,” he says.
“We want to test the hypothesis over the next three to four years to be sure the model can be applied to humans.”
GangurÂ’s research will involve feeding mice GE foods to see if they exhibit allergic reactions. He says mice exhibit the same allergic reactions as human beings, including physical reactions such as difficulty breathing, lower body temperature, and diarrhea, as well as molecular responses, such as increased production of anti-bodies.
Will it work?
A test to determine the allergenic potential of GM foods is definitely needed, says Doug Gurian-Sherman, senior scientist at the Center for Food Safety. “Allergy testing is something that we in the science community who are concerned about GMOs have been pushing for. If it can be made to work it would be a significant improvement over what we have now,” he says.
However, Gurian-Sherman says developing an accurate allergen test is very difficult. “Allergies are a complex, biochemical process, and animals may react differently to proteins than humans.”
There are also concerns about the reliability of such a test. “The problem is the level of reliability. It’s rare that a test is accurate 100% of the time,” says Gurian-Sherman.
In particular, such tests can produce false negative results, which indicate that no allergen is present when in fact it is, and false positive results, which indicate that an allergen is present when in fact it is not. Gurian-Sherman says a test that produces more false positive results is preferable. “We would rather err on the side of caution,” he says.
