NFI: Shellfish chemical study ‘ very flawed’

The National Fisheries Institute (NFI) is says a new study linking a chemical in shellfish to brain neurotoxicity and calling for the Food and Drug Administration (FDA) to review the toxin, is very flawed.

In an upcoming “Journal of the American Society of Nephrology” (JASN) study, researchers from the Medical University of South Carolina and their colleagues said that officials may need to re-consider the levels of domoic acid (DA) that are safe for human consumption.

“We have found that domoic acid damages kidneys at concentrations that are 100 times lower than what causes neurological effects,” said the study’s author, P. Darwin Bell, PhD, in a statement. “This means that humans who consume seafood may be at an increased risk of kidney damage possibly leading to kidney failure and dialysis.”

The researchers reviewed the effects of DA, from algae, because it is becoming more prominent in coastal regions, likely due to environmental changes. “It can accumulate in mussels, clams, scallops, and fish, and the FDA has set a legal limit of domoic acid in seafood based primarily on its adverse neurological effects,” according to the statement.

However, the steady measured the effects of DA concentrations on mice and has numerous flaws, according to the NFI. The study has received some consumer media attention, and the NFI doesn’t want Americans to get the wrong idea about seafood safety. “The FDA and state shellfish authorities closely monitor DA levels in shellfish to ensure that DA does not accumulate in shellfish,” Gavin Gibbons, spokesman for NFI, told Seafood Source.

The main problem was that the study conducted on mice not humans. “Results from animal studies cannot necessarily be extrapolated to results on humans,” Gibbons said. “Also, researchers injected DA into the rats. Injections of DA cannot be extrapolated to consuming varying amounts of DA in food, which contains other components and nutrients.”

In addition, because water restriction may accelerate DA transport, the mice were dehydrated prior to receiving DA injections. This is not necessarily representative of the state a human would be exposed to DA in foods, according to Gibbons.

The researchers acknowledged that the findings need to be verified in humans. However, they said they would like to see increased awareness and monitoring of DA levels in all seafood and that the FDA may also need to reconsider the legal limit of DA in food due to its kidney toxicity.