In response to rising concerns over the safety of genetically engineered food, the Food & Drug Administration is holding a series of three public hearings designed to ask the public whether FDA's policies for ensuring the safety of such foods should be modified and to solicit comments on whether genetically modified foods should be labeled.

The first hearing was held in Chicago on Nov. 18 and the second in Washington, D.C., on Nov. 30. The most striking revelations to come out of the Washington meeting were numerous memoranda showing that a number of FDA officials and scientists strongly disagreed with the agency's policy of regulating genetically modified food in the same way as conventional varieties. For example, in 1992, the FDA official in charge of the Center for Veterinary Medicine, Gerald B. Guest, expressed grave doubts about this policy, especially when applied to feed intended for livestock.

"Animal feed derived from genetically modified plants presents unique animal and food safety concerns," Guest wrote. These concerns arise partly because one crop-field corn-supplies 50 to 75% of the diet of most domestic animals, so small changes in nutrient levels from genetic engineering can have large effects on animal health. The antibiotic resistance marker genes contained in most crops would likely make animals resistant to some antibiotics, especially neomycin, which is used in animal feed, he added. Furthermore, he wrote, toxicant residues from transgenic crops could end up in meat and milk products and may pose human food safety problems.

At the opening of the Washington meeting, Joseph A. Levitt, director of FDA's Center for Food Safety & Applied Nutrition, described the agency's current policies for regulating genetically engineered food. The policies were finalized in 1992 as FDA's interpretation of the Food, Drug & Cosmetic Act [Fed. Regist.,57 , 22984 (1992)]. At that time, FDA decided to regulate genetically engineered food in the same way as any other food and to require no label unless the food was substantially different in terms of its nutrient or allergen content.

FDA decided not to regulate the new proteins introduced to food through genetic engineering as food additives- which are tested extensively-but as materials generally recognized as safe, Levitt said. FDA chose to utilize an approach that is "identical in principle to that applied to foods developed by traditional plant breeding," he said.

Under this policy, companies that develop a new food through recombinant DNA techniques are encouraged-but not required-to consult with FDA before marketing the food. Only if a substance added to a food as a result of gene splicing raises "questions of safety" would FDA require formal premarket review and approval, which might include toxicological tests.

"We believe our oversight has been substantive and credible," Levitt said. Even though the developers of genetically engineered foods are not required to consult with FDA before marketing a new food, they have done so in every case, he noted.

James H. Maryanski, biotechnology coordinator at FDA's Center for Food Safety & Applied Nutrition, explained that there could be circumstances in which a new genetically modified food should be tested in animals. For example, a potato developed in Europe, which contains toxic proteins called lectins, would be tested, he said. But testing in animals is not generally recommended because "feeding whole foods to animals is complicated."

At the meeting, two six-member panels critiqued FDA's policies. On each panel, some members said FDA's current regulatory regime is satisfactory, while others were highly critical.

The process FDA has established for regulating genetically engineered crops "is working very well," but it needs to be flexible to take account of new situations as they arise, said Peter R. Day, director of the Center for Agricultural Molecular Biology at Rutgers University, New Brunswick, N.J. The greatest benefit of biotech crops is their potential for helping the developing world, he said. Rice engineered with higher than normal levels of vitamin A and iron could do much to relieve malnutrition in poor countries, he explained.

Samuel B. Lehrer, research professor of medicine at Tulane University Medical Center, New Orleans, said the fear that genetically modified foods will give rise to new allergies is largely unfounded. Most allergens are proteins, and genetic engineering precisely determines which proteins are introduced, he explained. Consequently, the new proteins can be tested, and "the likelihood these proteins will be allergenic is minimal," he said.

Rebecca J. Goldburg, senior scientist at the Environmental Defense Fund, strongly disagreed with Lehrer. The biochemical characteristics of the new proteins can be screened to see if they are similar to those of known allergens, Goldburg said, but there is no predictive methodology for testing for the allergenicity of most proteins introduced to food via genetic engineering. "Our concern is that, by adding proteins to food through biotechnology, some people may become allergic to foods they previously could safely consume," she said.

Sidebar: Hearing addresses four questions

Steven M. Druker, executive director of the Alliance for Bio-Integrity, an advocacy group based in Iowa City, Iowa, presented the most striking testimony. His organization, along with the Washington, D.C.-based International Center for Technology Assessment, has sued FDA, claiming that its current regulatory policies violate provisions of the Food, Drug & Cosmetic Act. The suit demands rigorous testing and labeling of genetically modified foods. During the discovery procedure for this lawsuit, FDA memoranda came to light that revealed internal dissent within the agency when the policies were under development in 1991 and 1992.

In his testimony, Druker read from several of these memos. They show that a number of FDA scientists repeatedly cautioned that foods produced through DNA technology present different risks than do their conventional counterparts. Memorandum after memorandum warns about the unique hazards of genetically engineered food.

In one 1992 memo that comments on the agency's proposed Federal Registernotice, FDA microbiologist Louis J. Pribyl wrote: "There is a profound difference between the types of unexpected effects from traditional breeding and genetic engineering, which is just glanced over in [FDA's policy] document." Several aspects of gene splicing may in some cases be more hazardous than traditional breeding, he continued. The document "reads very pro-industry, especially in the area of unintended effects," he wrote. "What has happened to the scientific elements of the document?" he asked.

In another memo, Edwin J. Matthews, an FDA pharmacologist, warned that genetically modified plants could contain unexpectedly high concentrations of plant toxicants, which could be "uniquely different" from the chemicals that are "usually expressed in unrelated plants."

A 1992 memo from FDA compliance officer Linda Kahl states: "The processes of genetic engineering and traditional breeding are different and, according to the technical experts in the agency, they lead to different risks."

In light of these risks, a number of FDA divisions and individual scientists advised in late 1991 and early 1992 that genetically engineered foods should undergo special testing. FDA's Division of Food Chemistry & Technology warned: "Every transformant [transgenic food] should be evaluated," with toxicological tests before it enters the marketplace.

The memos reveal that, at that time, FDA officials were well aware of uncertainties and warnings emanating from agency scientists and from the broader scientific community. Maryanski, who was coordinating biotechnology policy, wrote in a letter to a Canadian official in late 1991 that there was no scientific consensus concerning the need for toxicology tests on genetically engineered food and that it was "particularly difficult to predict" whether some substances in these foods would cause allergic reactions.

Prior to the FDA hearing in Washington, these memos were not available to the general public, even though several environmental activists had obtained some-but not all-of them. FDA refuses to comment on the memos because they are the subject of litigation in the D.C. district court.

The panelists at the Washington, D.C., meeting were also sharply divided over whether genetically engineered food should be labeled, and whether the labeling should be mandatory or voluntary.

Carol Tucker Foreman, director of the Food Policy Institute of the Consumer Federation of America, said mandatory labeling of transgenic food would increase public confidence in these foods. Goldburg said that FDA's current policy concerning labeling "may not adequately protect public health." If some genetically engineered foods do indeed cause allergies, and they are not labeled, consumers will not be able to distinguish between the foods that cause allergic reactions and other nonallergenic foods, Goldburg maintained.

The industry representatives on the panel favored voluntary labeling. Richard Frank, vice president of Food Distributors International (FDI), said he opposed mandatory labeling requirements. "But FDI does support voluntary labeling provided the statement is truthful and the label does not imply that nonbiotech foods are superior," he said. "Consumer education along with a voluntary label will help people better understand what genetically modified organisms are," he said.

Kendal Keith, president of the National Grain & Feed Association, also warned against a mandatory labeling regime, but said he "does not oppose voluntary labeling." However, Mario Teisl, assistant professor of economics at the University of Maine, Orono, said that labeling may not be the best way to convey information about transgenic food. It may only increase uncertainty, he said.

Observers expect that FDA will wait until next year to decide on policy changes for genetically engineered foods. Michael Hansen, a research associate at the Consumer Policy Institute, the research arm of Consumers Union, predicts that FDA will decide to make industry consultations mandatory, rather than voluntary. In other words, industry will be required to consult with FDA before marketing a new transgenic food. He also predicts that FDA will decide to encourage the voluntary labeling of foods that contain genetically modified ingredients. Many industry groups now favor voluntary labeling because they fear they will not be able to sell transgenic foods or their traditional counterparts to Europe unless the transgenic foods are labeled.

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