A new study in mice finds that domoic acid, a natural toxin found in seafood, damages the kidney. This damage was caused by concentrations much lower than the prescribed safe limits for humans. It is time, hence, for officials to reconsider the safety levels of chemical toxins in seafood.
Domoic acid has already been known as a neurotoxin that damages the human brain when taken at high concentrations. The toxin is analogous to glutamate, a neurotransmitter in the brain. Toxicity leads to the condition known as amnesic shellfish poisoning. The Food and Drug Administration (FDA) imposes limits in the amount that can be safely consumed by humans.
AdvertisementThe natural toxin is a product of algae; it accumulates in marine organisms such as shellfish, anchovy, and sardines. While bottom feeders acted as usual store houses of the toxin, it has now become more prominent in coastal regions.
Experiments in mice showed that domoic acid rapidly damaged the rodents' kidneys, even at low concentrations. "We looked further at lower and lower concentrations of domoic acid, and it actually caused kidney damage at a hundred times lower than what causes injury in the brain," says the study author P. Darwin Bell. "The FDA sets the limit of domoic acid that can be consumed by humans at 20 parts per million (ppm)... The government says below this it doesn't cause any neurologic affects, but the kidney is affected at a hundred times lower than this concentration."
"The kidney is actually what helps to eliminate domoic acid," Bell said. "So when you take it in, the kidney is responsible for getting rid of it. The kidney actually accumulates domoic acid, and the receptors bind to [it], and they get overwhelmed."
It is indeed premature to reach a proper consensus at this point of time since human studies are yet to be performed. "Although we have not looked at this directly, it's quite possible that individuals who have chronic kidney disease, very young children or the elderly may be more sensitive to domoic acid than healthy individuals," Bell said.
The compound is heat stable and cannot be eliminated from food by cooking. Maintaining strict regulation in the levels found in sea foods may be the only practical solution.
The new study published in the Journal of the American Society of Nephrology, should in no way avert the public away from seafood, for the health benefits surpass any level of suspicion. Here's a short list of the many advantages offered by a regular intake of seafood:
Health Benefits of Seafood
• Eating fish and shell-fish protects the heart and keeps the cholesterol levels in blood low.
• It lowers the risk of thrombosis that arises from faulty clotting of blood
• It eases the symptoms of joint diseases such as rheumatoid arthritis and osteoarthritis.
• Sea foods are good for healthy eyes; they help maintain skin tone and protect skin from the ills of UV damage
• Omega-3 fat in sea foods are also known to boost brain power; it may also benefit patients with depression.
Reference: Journal of the American Society of Nephrology