A panel of U.S. scientists says there is no evidence that food from genetically engineered animals is unsafe to eat. Nevertheless, it says uncertainties remain that should be addressed before such food reaches the market. The scientists also express concern that genes from genetically modified animals might escape into the wild with unknown consequences.
Just as they have done with plants, biotechnology firms are developing genetically modified animals to be hardier, produce more meat or milk with less fat, resist disease, or produce pharmaceuticals that having nothing to do with the animals themselves.
They do this is by introducing genes from other species that give these traits. Offspring can carry these features on either by natural reproduction or cloning.
The report from the U.S. National Academy of Sciences amounts to a cautious endorsement of this technology, noting that it has benefits, but that it also raises potential worries.
"New technologies such as biotechnology are often characterized by a variety of uncertainties resulting in unexpected outcomes," said zoologist John Vandenbergh of North Carolina State University, who also chaired the scientific panel. He pointed out that genetic engineering has increased the variety of farm goods, drugs, and other products that promote human health. But he added that his panel identified several concerns that regulatory authorities should address.
Chief among them is the potential ability of certain organisms whose genes have been changed to escape into the natural environment. "These could result in the transgene spread through reproduction with wild individuals of the same species," said Mr. Vandenbergh. "Our greatest concerns were with species that become feral [wild] easily, are highly mobile, and have a history of causing extensive community damage."
As an example, the panel warned that if farm-raised salmon that have had their genes altered to speed growth were released into the wild, they could compete more successfully for food and mates than wild salmon.
Another potential risk is that food from genetically modified animals might cause allergic reactions in some people, although the panel considers the probability low.
Scientists say there are grounds to worry that animals designed to produce products other than food, could end up in the food supply.
Mr. Vandenbergh said they found that in one instance, meat from the carcasses of animals genetically altered to produce drugs, wound up in a food product.
"The safety of food products that are derived from animals engineered for non-food purposes might present a concern if the non-food product is found in parts of the animal that may be sold," he explained.
But the National Academy of Sciences group says food from cloned animals, such as Dolly the sheep, pose few threats to food safety.
These are animals grown from an egg into which the genes from one parent are inserted so that the offspring are exact genetic copies of that parent.
Experts on both sides of the genetic engineering debate find support in the panel's review. The Center for Food Safety is a Washington organization that has criticized genetically modified food. Its legal director, Joseph Mendelson, emphasized the report should alert government regulators to potential problems with the technology.
"I can't see how the findings of this report will go unnoticed by our government," he said. "In fact, the report is really a call to arms for our government to establish mandatory pre-market safety review and environmental review of these products before they come on the market."
Biotechnology companies, meanwhile, are relieved that the report is largely speculative about the potential risks genetically altered food presents and that it finds no reason to fear food from cloned animals.
At the Biotech Industry Organization, a trade group, spokeswoman Lisa Dry said the industry is aware of its responsibilities in producing genetically engineered products from animals.
"For instance, one of our members works with the transgenic salmon," she pointed out. "They have chosen to grow the salmon in containers or pens to reduce the risk of them getting into the wild and also to select only female salmon and to render them sterile."
The new study will be closely examined by the U.S. government agency that regulates products from genetically altered animals, the Food and Drug Administration. It had requested the report as it prepares to rule on the safety of such products.