StarLink™ Corn

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Issue in Brief:
No Evidence that StarLink™ Caused Allergic Reactions

During the summer of 2000, traces of StarLink™ corn were detected in some food products, such as taco shells. StarLink was approved for use in animal feed, but had not received approval for human consumption. The unintentional commingling of a very small amount of StarLink™ with other varieties of corn in the food chain led some to question the safety of the food supply.

StarLink™ is a type of Bt pest-protected corn that received a split approval by the Environmental Protection Agency for use as animal feed but not for food. Approval for human consumption was withheld because the Bt Cry9c protein expressed in the corn had some attributes of an allergenic protein. For example, it was found to be relatively stable and was not broken down as rapidly by the human digestive system as similar proteins. However, no conclusive evidence was found to indicate that Cry9c was an allergen.

Federal agencies and the seed manufacturer responded quickly to the accidental commingling. The Food and Drug Administration and food companies recalled affected products from the market, and the FDA and Centers for Disease Control and Prevention began an assessment of potential health effects. In addition, the producer of StarLink™ seeds voluntarily suspended sales, and the EPA later canceled registration of the product. The USDA also began working with countries concerned about importing corn containing traces of StarLink™ and developed protocols for sampling corn for export.

After news reports of the unintentional release, reports of allergic reactions to specific products that may have contained StarLink™ corn were received by the FDA and EPA. The EPA's Federal Insecticide, Fungicide and Rodenticide Act Scientific Advisory Panel examined the issue during three meetings and concluded that it was highly unlikely that infrequent consumption at the extremely low levels of StarLink™ detected in the food supply would trigger a reaction: "[T]he likely levels of Cry9C protein in the U.S. diet provide sufficient evidence of a low probability of allergenicity in the exposed population."

The FDA and Centers for Disease Control also investigated these reports. The CDC published the results of its analysis, which included an examination of bank serum samples, in June 2001, concluding: "These findings do not provide any evidence that the reactions that the affected people experienced were associated with hypersensitivity to the Cry9c protein."

As a result of this episode, and with the biotechnology industry's support, the EPA decided that it would no longer approve biotechnology crops for animal consumption unless they were also cleared for humans.

For more information on biotechnology and food allergies, click here.

Resources:
Environmental Protection Agency FIFRA Scientific Advisory Panel Meetings:

• EPA FIFRA SAP, Assessment of Additional Scientific Information Concerning StarLink® Corn (July 17-18, 2001).
• EPA FIFRA SAP, Assessment of Scientific Information Concerning StarLink® Corn (November 28, 2000).
• EPA FIFRA SAP, Food Allergenicity of Cry9C Endotoxin and Other Non-digestible Proteins (February 29-March 3, 2000).

• EPA's Regulation of Bacillus thuringiensis (Bt) Crops (May 2002).
• Cry9C Food Allergenicity Assessment Background Document.
• White Paper on the Possible Presence of Cry9C Protein in Processed Human Foods Made from Food Fractions Produced Through the Wet Milling of Corn.

• CDC, Investigation of Human Health Effects Associated with Potential Exposure to Genetically Modified Corn (June 11, 2001).
• Guidance for Industry, FDA Recommendations for Sampling and Testing Yellow Corn and Dry-Milled Yellow Corn Shipments Intended for Human Food Use for Cry9C Protein Residues, Final Guidance (January 19, 2001).

• Grain Inspection, Packers and Stockyard Administration, StarLink™ (Cry9C) Testing Program.

• AgBiosafety, University of Nebraska-Lincoln.
• Ag BioTech InfoNet, StarLink-Cry9C Protein.
• Bucchini, L., and Goldman, L.R. 2002. StarLink corn: A risk analysis. Environmental Health Perspectives 110 (1).
  Read the abstract here.
• Colorado State University, Department of Soil and Crop Science, Transgenic Crops: An Introduction and Resource Guide-StarLink Corn.
• Lin, W., Price, G.K., and Allen, E. 2002. Starlink: Impacts on the U.S. Corn Market and World Trade, International Consortium on Agricultural Biotechnology Research, 6th International Conference on Agricultural Biotechnologies: New Avenues for Production, Consumption and Technology Transfer. Ravello, Italy (July 11-14 2002).
  Read the abstract here.
• Michael R. Taylor and Jody S. Tick, The StarLink Case: Issues for the Future, Pew Initiative on Food and Biotechnology and partners at Resources for the Future (October 2001).

For more links, click here.

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