By Steven Reinberg
THURSDAY, Sept. 18 (HealthDay News) -- The prospect of foods and other products from so-called genetically engineered animals moved a step closer to reality Thursday, as U.S. regulators said producers of such animals will have to prove they are safe to eat.
The U.S. Food and Drug Administration said it was proposing new guidelines for genetically engineered animals. These guidelines lay out the agency's position on its authority to regulate the burgeoning industry of genetically engineered animals and spell out requirements and recommendations to producers of these animals.
"Genetic engineering is no longer a new technology. It has been widely used in agriculture to make crops resistant to certain pests or herbicides or with improved nutritional qualities," Randall Lutter, deputy commissioner for policy at the FDA, said during a morning teleconference.
"Many kinds of genetically engineered animals are in development, but none has yet been approved by the agency for marketing," he said.
Genetic engineering in animals refers to the use of what scientists call recombinant DNA techniques to introduce new characteristics or traits, often adding a genetic trait from one animal to another.
Proponents say the practice will lead to animals that can grow faster, produce healthier foods such as heart-healthy eggs, or be resistant to certain diseases, such as mad cow disease.
Opponents say the practice could unleash unintended consequences by altering the traditional genetic structures of animals.
Lutter said that "in food production, genetically engineered yeast is used in baking and brewing, and other products from genetically engineered microbes are used in cheese-making." Genetically engineered microbes are also widely used in medicine to produce drugs, he added.
Some of the genetically engineered animals in development, called biofarm animals, are designed to grow faster to reach market more quickly. Others are being developed to make food healthier, Lutter said. "For example, some pigs have been genetically engineered to contain high levels of omega-3 fatty acids," he said.
Still others are intended to produce drugs. Certain animals are being genetically altered to be used in human transplantations -- for instance, providing cells or tissues or organs that are less likely to be rejected by the human immune system, Lutter said.
"These include islet cells to help diabetics, skin grafts for burn victims, and liver or kidney or heart replacements for the critically ill," he said.
Other genetically engineered traits could help animals resist diseases such as mad cow disease. And some animals are being developed to decrease their environmental impact by decreasing harmful substances in their manure.
Lutter said the U.S. Food, Drug and Cosmetics Act gives the FDA the authority to regulate genetically engineered animals.
"Genetically engineered animals that contain a recombinant DNA segment that is intended to alter the structure or function of the animal are considered to contain a new animal drug," he said. "Genetically engineered animals will, therefore, require premarket approval by FDA prior to their introduction into the marketplace."
Dr. Larisa Rudenko, senior adviser for biotechnology at the FDA's Center for Veterinary Medicine, said the safety of genetically engineered animals intended for use as food will be decided on a case-by-case basis.
"Attention will be paid to particular risks posed by each line of animal, although the basic test will be the same for all animals," Rudenko said during the teleconference. "If the animal is intended to be used for food or feed, we will have to do a full evaluation of food and feed safety. We will also perform an environmental assessment."
Producers of these animals will have to provide proof demonstrating that the new genetic traits perform as claimed, Rudenko said. "We will also ask producers to provide a plan for how they will monitor these animals to ensure that the genetically engineered animals entering commerce in the future are equivalent to those we have approved," she said.