StarLink Corn: A Cautionary Tale
In 1998, the U.S. Environmental Protection Agency (EPA) approved a transgenic variety of yellow corn called StarLink, developed by Aventis Crop Science (later Syngenta). This corn variety had been genetically engineered to contain the gene for a Bt toxin called Cry9C, which selectively kills destructive insect larvae such as the European corn borer. Nevertheless, the fact that this Bt toxin was heat- resistant and did not break down readily in the human gastrointestinal tract suggested that it might be allergenic. Although testing of the protein for allergenicity was inconclusive, EPA approved StarLink corn only for use as an animal feed and prohibited it from entering the human food supply.
Because of the biology of corn and the nature of the U.S. crop-handling system, however, segregating StarLink corn from the food supply proved to be extremely difficult. In September 2000, genes from StarLink corn were detected in taco shells and other corn products intended for human consumption, a clear violation of its registration. This discovery resulted in huge recalls of food products containing the genetically engineered corn.
The controversy over StarLink corn led Aventis to voluntarily withdraw its license for the variety, which is no longer grown.2 Nevertheless, many other types of Bt corn produce different pesticidal toxins that have passed extensive tests for toxicity and allergenicity. As a result, the U.S. Food and Drug Administration (FDA), which regulates GM foods, considers these varieties of Bt-corn to be safe and nutritionally equivalent to traditional corn, and they are currently grown on millions of acres.