Seafood 'can be toxic to kidneys'

SINGAPORE - A chemical that can accumulate in seafood and known to cause brain damage is also toxic to the kidneys, and at much lower concentrations, say researchers.

Certain algae in oceans produce harmful chemicals, many of which are considered neurotoxins because they cause brain damage.

One of these is domoic acid, a very stable, heat-resistant toxin which can cause "amnesic shellfish poisoning".

It can accumulate in mussels, clams, scallops, and fish, and the US Food and Drug Administration (FDA) has set a legal limit of domoic acid in seafood based primarily on its adverse neurological effects, said the American Society of Nephrology in a statement.

Researchers from the Medical University of South Carolina who gave mice varying doses of domoic acid found that the kidney was much more sensitive to this toxin than the brain.

"We have found that domoic acid damages kidneys at concentrations that are 100 times lower than what causes neurological effects," said Professor Darwin Bell, one of the scientists involved.

"This means that humans who consume seafood may be at an increased risk of kidney damage possibly leading to kidney failure and dialysis."

While the findings need to be repeated in people, the researchers said increased awareness and monitoring of domoic acid levels in all seafood was needed, and that the FDA might need to reconsider the legal limit of domoic acid in food due to its kidney toxicity.

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