when taken at high concentrations. The toxin is analogous to
glutamate, a neurotransmitter in the brain. Toxicity leads to the condition
known as amnesic
. The Food and Drug Administration
(FDA) imposes limits in the amount that can be safely consumed by humans.
The 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
Experiments in mice showed that domoic acid rapidly damaged the
, 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
in blood low.
It lowers the risk of
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
fat in sea foods are also known to boost brain power; it may also benefit
patients with depression.
Journal of the American Society of Nephrology