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News Updates--StarLink corn in the food supply

An unapproved form of Bt insect-resistant corn has been found in Taco Bell taco shells sold in grocery stores, reported the Washington Post on Sept. 18, 2000. StarLink corn, produced by Aventis Corp., has been approved in the U.S. for animal feed but not for human food. StarLink corn varieties contain the Cry9C form of the Bt gene, which is considered a potential allergen in some people although EPA believes the risks, if any, are extremely low. The Food and Drug Administration has begun an investigation. The Washington Post article is available at http://washingtonpost.com/wp-dyn/articles/A24834-2000Sep17.html

On September 22, Kraft Foods, distributor of the taco shells, announced a recall of the product from grocery stores.

On September 29, Aventis announced it will purchase this year's entire crop of Starlink corn, to prevent any further use of the corn in food products.

On October 12, EPA announced that Aventis is canceling the U.S. registration of StarLink corn, meaning that it can no longer be planted for any agricultural purpose.

On October 25, Aventis asked EPA to temporarily allow the use of StarLink corn for human consumption, because it has already shown up in many food products. To support its request, Aventis provided new data that the Cry9C protein in StarLink corn is not a human allergen. The data reportedly show that the protein did not elicit allergic reactions when tested on blood of persons susceptible to food allergies; and that the protein was digested in stomach acids faster than previously thought. (Source: New York Times).

On November 3, USDA announced plans to test corn shipments bound for Japan for the presence of StarLink grain. The move was taken to reassure consumers in Japan, the largest importer of U.S. corn. (Source: Associated Press).

On November 21, Aventis CropScience confirmed that the Cry9C protein was present in corn hybrids having no known connection to StarLink varieties. The hybrids are produced by Garst Seed Co. of Slater, Iowa, which also produces StarLink seed under contract with Aventis. USDA officials are working with the companies involved to investigate the mixup.

Aventis has set up a web site to provide information on the StarLink situation, including estimates of StarLink acreage in 2000 by state and county: http://www.starlinkcorn.com

Dec. 5. An EPA-appointed Scientific Advisory Panel concluded that the StarLink protein (Cry9C) has a medium likelihood of causing allergic reactions in humans. This conclusion is based on the biochemical properties of the protein itself, rather than its levels in the food supply. The panel felt that the apparent low level of Cry9C in the human diet made it unlikely that persons have been sensitized to the protein. More information and a link to the entire report are available at EPA's Biopesticide web site (http://www.epa.gov/pesticides/biopesticides/).

Dec. 28. Because Cry9C protein has been found in several varieties of non-StarLink hybrid corn, the USDA recommended that U.S. seed companies test all their corn seed lots for the presence of Cry9C protein. These seeds should not be sold as planting seed, but can be used as feed and for non-food industrial purposes. Seed companies should provide their customers, upon request, with verification that the seed lots they buy for planting have been tested for Cry9C protein. Seed companies should also test their parent lines of corn before using them to produce seed for next year, the USDA said. Official sampling and testing recommendations can be found at http://www.usda.gov/gipsa/biotech/starlink/cry9cdetection.htm.

Jan. 23, 2001. Farmers whose non-transgenic crops were found to contain the StarLink Cry9C protein will be compensated for losses they may incur, under an agreement signed by Aventis and the attorneys general for 17 corn-producing states. The signatory states, Iowa, Alabama, Illinois, Indiana, Kansas, Kentucky, Maine, Maryland, Minnesota, Mississippi, Nebraska, New Mexico, North Dakota, Ohio, Oklahoma, South Dakota, and Wisconsin, include nearly all of the areas in which StarLink corn was planted. The agreement lends legal enforceability to Aventis's previously announced StarLink Enhanced Stewardship program for compensating farmers. An announcement by the Iowa attorney general is available at http://www.state.ia.us/government/ag/StarLink_binding_agt_rel.htm. Details of the StarLink Enhanced Stewardship program are available at http://www.starlinkcorn.com.

February 2001: The president, general counsel, and vice president for market development of the U.S. crop sciences division of Aventis CropScience have been fired. A spokesperson for Aventis said it was fair to link the firings to the StarLink fiasco. A story on the dismissal of the three executives is available at http://www.guardianunlimited.co.uk/gmdebate/Story/0,2763,437347,00.html.

On March 1, 2001, the American Seed Trade Association presented the USDA with an estimate of the percent of corn seed contaminated by the StarLink Cry9C protein. The tainted seed was found in inventories slated to be sold to corn farmers this spring. There is concern that U.S. corn exports will suffer again this year if the crop contains traces of the Cry9C protein. Stories on the estimates are available at http://www.washingtonpost.com/wp-dyn/articles/A10054-2001Mar1.html and http://biz.yahoo.com/rf/010302/n02476803_2.html. The USDA and farmers' organizations have been calling for seed sellers to test their supplies and for farmers to insist on StarLink-free seeds in an effort to avoid perpetuation of the Cry9C gene in the corn supply. The National Corn Growers Association is urging farmers who planted StarLink corn last year to rotate to another crop or to plant herbicide-tolerant corn this year. Both options would allow growers to find and kill "volunteer" StarLink corn that grows from kernals left in the field at harvest last year. The NCGA's recommendation is available at http://www.ncga.com/01hot_off_the_cob/dtn/2001/021301.html.

On March 7, 2001, the USDA announced that it would buy Cry9C-tainted corn seed from small seed companies that are not affiliated with Aventis and were not licensed to sell StarLink corn last year. Major seed companies and companies licensed to sell StarLink will not be compensated. The USDA said less than 1 percent of the corn seed supply is affected and the buyback will not affect the price or availability of seed. The USDA expects to buy between 300,000 and 400,000 bags of seed, at up to $50 per bag, for a potential cost of up to $20 million. The USDA announcement is available at http://www.usda.gov/news/releases/2001/03/0042.htm. A Washington Post story on this development is available at http://washingtonpost.com/wp-dyn/articles/A37085-2001Mar7.html.

On March 18, 2001, an Aventis executive estimated the amount of corn contaminated with the StarLink Cry9C protein to be 430 million bushels, far more than the amount of contaminated corn seed that will be bought by the U.S. government to prevent its being planted this spring. About 20 million bushels of corn in fields neighboring on licensed StarLink fields were contaminated in 2000. Aventis general manager John Wichtrich said most of the 430 million contaminated bushels were stored in grain elevators after the 1999 harvest. Wichtrich suggested that Aventis will set up testing stations at grain mills to ensure that the Cry9C protein does not appear in milled corn. A Washington Post news story on this subject is available at http://washingtonpost.com/wp-dyn/articles/A20105-2001Mar17.html.

On March 19, 2001, the FDA was reported to be nearly ready to administer allergenicity blood tests to people who have reported suspected allergic reactions after eating StarLink corn. A news story is available at http://news.excite.com/news/ap/010319/13/biotech-corn.

On April 23, 2001, Aventis CropScience asked the EPA to set a legal limit of 20 parts per billion of StarLink corn in grain loads delivered to mills. The request marks a reversal from last fall, when the company asked that StarLink be accepted without limit in grain destined for human consumption. StarLink is currently not allowed in human food because of its potential for causing allergic reactions. Stories on this development are available at http://www.nytimes.com/2001/04/24/business/24CORN.html and http://www.washingtonpost.com/wp-dyn/articles/A53988-2001Apr23.html. The Aventis request and several volumes of data from tests commissioned by Aventis are available on the EPA's web site at http://www.epa.gov/pesticides/biopesticides/otherdocs/stlink/stlinkdata.htm.

On June 11, 2001, the Centers for Disease Control released its finding that the transgenic protein in StarLink corn probably was not the cause of the apparent allergic reactions that have been attributed to it by people who suffered symptoms shortly after eating corn products. StarLink corn, containing the Bt Cry9c transgene, had been approved for animal feed but not for human consumption because of concerns that it might cause allergic reactions. Allergenicity was not demonstrated before approval of StarLink for release, but the Cry9c protein exhibited several properties of known food allergens. Despite the ban on use of StarLink for food, the transgene was detected in commercial food products and 51 people complained that their allergy symptoms were caused by eating StarLink-laced food. Using an IgE-specific ELISA test, the CDC did not find any reactivity in serum samples from the 17 people who participated in the testing. A story in the Washington Post is available at http://washingtonpost.com/wp-dyn/articles/A62890- 2001Jun13.html. The CDC's report is available at http://www.cdc.gov/nceh/ehhe/Cry9cReport/.

On July 3, 2001, stores removed from their shelves a brand of tortilla chips made from white corn because traces of StarLink corn were found in it. Makers of tortilla chips have been switching to white corn as a precaution because the Bt Cry9c transgene was incorporated only into a yellow corn variety. Avoidance of yellow corn was believed to eliminate the presence of the StarLink protein, which has been found widely, at low levels, in stores of corn destined for human consumption. A story in the Washington Post is available at http://washingtonpost.com/wp-dyn/articles/A16045-2001Jul3.html.

On July 19, 2001, the Associated Press reported that scientists in Japan had conducted tests on the safety of animal feed containing StarLink corn and had found no problems in pigs raised on the feed. Twenty pigs were fed a diet of 70% StarLink corn. After slaughter, the meat, organs, and blood of the pigs was examined. Neither the StarLink DNA nor the StarLink protein was detected in the samples.

On July 27, 2001, the panel of scientists who have been advising the EPA on the safety of StarLink corn declined to recommend lifting the ban on human consumption of the corn, saying they were not yet satisfied that the transgenic product is safe. Data provided by Aventis, the company that developed StarLink, were insufficient to determine the maximum safe level of exposure, the panel said. Aventis maintained that StarLink protein was degraded by wetting and heating, so that commercially processed foods and foods prepared in the home by mixing and baking would contain only low levels of the intact protein. The advisory panel suggested that higher levels of the protein might still be present and capable of causing allergic reactions, but might be undetectable via current tests, if wetting and heating changed the shape of the molecule. Although the Centers for Disease Control and Prevention did not find evidence that the StarLink protein had caused allergic reactions in people who reported adverse health effects from eating corn-based products, the scientists on the panel said the CDC's test might not be sufficiently sensitive. The government should pursue further research on the allergenicity of StarLink, including encouraging physicians to report possible reactions to the protein, they said. The panel noted that the government's estimate last winter of about 0.4% StarLink in the nation's human food supply was probably an overestimate and that aggressive actions by the government and by Aventis had reduced the amount to less than 0.125%. The scientific panel's full report is available at http://www.epa.gov/scipoly/sap/2001/july/julyfinal.pdf. A story on this development is available on the Washington Post web site at http://www.washingtonpost.com/wp-dyn/articles/A62091-2001Jul27.html.

In December 2002, Japan's Agriculture Ministry reported that it had found traces of StarLink corn in a shipment of U.S. corn that docked at Nagoya harbor. USDA officials say they believe the last stocks of StarLink corn were destroyed last year. News reports on the reported discovery are available at FINDS,'S STARLINK, CONTINUE, FIRM CLUELESS and BEEFS.

In September 2003, a coalition of groups from several regions of Mexico reported that the GM gene from StarLink corn, along with the GM genes from other types of GM corn, had entered the native corn populations of Mexico. The samples from nine Mexican states contained

  • Bt-Cry1ab/1ac, the gene commonly used in insect-resistant corn,
  • Bt-Cry9c, the gene used in StarLink corn, which is banned for human consumption in the United States and which was taken off the market in 2000 after tests revealed that it was present in supermarket foods, and
  • CP4 EPSPS, the gene that provided resistance to glyphosate herbicides such as RoundUp.

The samples showing the presence of GM genes came from the states of Chihuahua, Morelos, Durango, Mexico State, Puebla, Oaxaca, San Luis Potosi, Tlaxcala, and Veracruz. The commercial cultivation of any kind of GM corn is prohibited in Mexico because of concerns about gene flow to Mexico's indigenous corn varieties, but GM corn kernels can be imported for use as food. A press release on this discovery is available at

In November 2003, scientists reported that additional tests had failed to demonstrate the presence of an allergy in a person who had complained of allergic reactions to StarLink corn. The person was fed StarLink corn, non-StarLink corn, and a placebo on different days under conditions in which neither he nor the technicians who provided the food knew which kind he was receiving. The person did not experience allergic reactions on any of the days of testing. A report on the tests is available at http://www.nytimes.com/2003/11/10/business/10cornxx.html.

Page last updated : March 11, 2004

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