A panel of experts that advises the US Food and Drug Administration (FDA) decided on Monday more research was needed before it could vote on whether to recommend approval to allow genetically modified salmon to be bred for human consumption in the US.
An analysis by FDA staff that was released prior to the meeting had concluded that the AquAdvantage salmon from AquaBounty Technologies of Waltham, Massachusetts, was as safe to eat as conventional Atlantic salmon and posed little risk to the environment, reports the Wall Street Journal.
However on reviewing the available evidence, the FDA’s Veterinary Medicine Advisory Committee did not vote on the issue but instead offered a series of recommendations calling for more evidence, for instance on whether the genetically altered fish might provoke allergic reactions and other health problems in consumers, said a report in the Los Angeles Times.
If approved, the AquAdvantage salmon would be the first genetically altered food animal to be consumed in the US.
Panel member Dr James McKean, a veterinarian and professor at Iowa State University told the LA Times that there were “questions that have not been answered by the data that has been presented”.
Other panel members were of the opinion there was essentially no difference between the genetically engineered salmon and the conventional type.
A professor and fish researcher at Washington State University, Dr Gary Thorgaard, told the paper that he would “not feel alarmed about eating this kind of fish”.
The FDA has been considering the case of this particular salmon for over a decade: scientists starting producing the modified fish in the lab nearly 13 years ago.
According to AquaBounty, one of the advantages of the genetically engineered AquAdvantage salmon is that it grows twice as fast as conventional salmon, but is in other respects indistinguishable from Atlantic salmon: it just reaches the same size faster.
To make the genetically modified Atlantic salmon, they take the growth gene from the Pacific chinook salmon and insert it into the DNA of newly fertilized Atlantic salmon eggs. However, this of itself is not enough to keep the salmon growing all year round: to keep the growth gene permanently “switched on”, the AquaBounty scientists also add a small piece of DNA from another fish called the ocean pout.
In the wild, Atlantic salmon differs from Pacific salmon in many ways, including appearance, habitat, and ability to survive in different environments.
One of the main differences between Atlantic salmon and Pacific salmon is that Atlantic salmon do not die after returning to spawn in the streams in which they hatch: they can go back to the sea. Mature Pacific salmon, however, generally die within a few days or weeks of spawning.
AquaBounty says its genetically modified Atlantic salmon, which would be bred exclusively on inland fish farms, is reproductively sterile (all the fish would be sterile females), which “eliminates the threat of interbreeding amongst themselves or with native populations, a major recent concern in dealing with fish escaping from salmon farms”.
Curiously, the FDA’s powers to regulate genetically modified animals for human consumption (under the provisions of the Federal Food, Drug, and Cosmetic Act, FFDCA) require them to consider the “new product” as if it is a drug. In this case, the “drug” is the piece of DNA that is added to the Atlantic fish eggs to change its characteristics.
Under the FFDCA provisions, the agency must assess the health of the affected animal, examine the characteristics of the food products derived from it (such as milk, cheese, meat), consider the risk of a toxic reaction to these products in humans, and also assess the impact on the environment.
To date, the FDA has approved one application related to a genetically engineered animal: this was for a genetically altered goat that produces a human pharmaceutical compound in its milk. The pharmaceutical, recombinant human antithrombin III, for use in individuals with clotting disorders, has also been approved in Europe.
The FDA panel meets again on Tuesday in open session and will consider comments from the public, for instance on what should appear on the consumer product label, if the salmon is approved.
Sources: FDA, AquaBounty Technologies, Sacramento Bee, LA Times, Wall Street Journal.
Written by: Catharine Paddock, PhD