Safe Food_ Bacteria, Biotechnology, and Bioterrorism - Marion Nestle [105]
Surveillance of food allergies also is limited. The widespread use of soy proteins—transgenic or not—in foods such as infant formulas, meat extenders, baked goods, and dairy replacements might be expected to increase the prevalence of soy allergies, but the increase would be difficult to detect unless it affected large numbers of people. Worse, because methods to diagnose food allergies are unavailable or imprecise, the allergenic potential of most genetically modified foods is uncertain, unpredictable, and not easily tested.13
These research limitations make genetically engineered foods especially vulnerable to charges that newly introduced genes will cause plants to produce allergenic proteins. Industry-friendly scientists recognize that such charges are based on “reasoned concern” but complain that they also are based on “fear through ignorance, and political motivation.”14 Antibiotechnology advocates raise the issue of allergenicity not only because it is scientifically justifiable but also because the industry is unable—or rarely tries—to prove that a newly introduced protein is not an allergen (witness StarLink). The government does not require biotechnology companies to test for allergens, and they rarely do. For one thing, testing is difficult. For another, testing is hardly in a company’s best interest. Monsanto scientists, for example, wondered whether making soybeans “Roundup Ready” would make them more allergenic. They voluntarily tested and found the proteins in their soybeans to be similar in structure and quantity to those in conventional soybeans. On this basis, they assumed that no new allergens had been introduced but were not required to test for that possibility.15 Like testing for microbial pathogens, testing for allergens is risky: you might find one.
Indeed, finding an allergen in a new transgenic food is a disheartening experience, and not only for its maker: it is a “shadow . . . cast over the agricultural biotechnology industry.”16 One such shadow emerged in the mid-1990s when scientists working for the venerable agricultural company Pioneer Hi-Bred created a transgenic soybean to solve a nutritional problem—the need for sulfur—in poultry feed. Chicken feathers are strong because their proteins are linked tightly with sulfur. The sulfur comes from sulfur-containing amino acids, particularly one called methionine. Soybean proteins are relatively low in methionine, and soy-based chicken feed must be supplemented with this amino acid—a troublesome expense. Proteins enriched with methionine might solve this problem. As it happens, Brazil nuts contain a particular protein with two unusual characteristics: it is exceptionally rich in methionine; it also is present in large amounts (it accounts for 18% of all the proteins in Brazil nuts). Pioneer Hi-Bred scientists isolated the gene for the Brazil nut protein and transferred it into soybeans. They recognized, however, that a protein present in such high concentration might be the very one responsible for allergies to Brazil nuts.
Thus, they thought it prudent to find out if their transgenic soybeans caused problems for people allergic to Brazil nuts. Ordinarily, this study would be impossible because few laboratories have the biological materials needed to test for food allergens. By coincidence, Nebraska researchers had collected blood samples from people known to be allergic to Brazil nuts, and they happened to have on hand all the components necessary to do the tests. To the company’s dismay, the experiments “succeeded.” People allergic to Brazil nuts exhibited the same kinds of blood and skin reactions when exposed to proteins extracted from the transgenic soybeans. Despite a substantial investment in development of the soybean feed, Pioneer Hi-Bred discontinued the project.17
It must be understood that the Food and Drug Administration (FDA) did not require the company to do such studies, nor do most companies conduct