Tuesday, June 16, 2009
University of Louisville neurologist
Robert P. Friedland, M.D., questions the safety of eating farmed fish in the
June issue of the Journal of Alzheimer's Disease, adding a new worry to concerns
about the nation's food supply.
Friedland and his co-authors suggest
farmed fish could transmit Creutzfeldt Jakob disease--commonly known as mad cow
disease--if they are fed byproducts rendered from cows. The scientists urge
government regulators to ban feeding cow meat or bone meal to fish until the
safety of this common practice can be confirmed.
"We have not proven
that it's possible for fish to transmit the disease to humans. Still, we believe
that out of reasonable caution for public health, the practice of feeding
rendered cows to fish should be prohibited," Friedland said. "Fish do very well
in the seas without eating cows," he added.
Creutzfeldt Jakob disease is
an untreatable, universally-fatal disease that can be contracted by eating parts
of an animal infected with bovine spongiform encephalopathy (BSE or mad cow
disease). An outbreak in England attributed to infected beef prompted most
countries to outlaw feeding rendered cow material to other cattle because the
disease is so easily spread within the same species.
The risk of
transmission of BSE to humans who eat farmed fish would appear to be low because
of perceived barriers between species. But, according to the authors, it is
possible for a disease to be spread by eating a carrier that is not infected
itself. It's also possible that eating diseased cow parts could cause fish to
experience a pathological change that allows the infection to be passed between
the two species.
"The fact that no cases of Creutzfeldt Jakob disease
have been linked to eating farmed fish does not assure that feeding rendered cow
parts to fish is safe. The incubation period of these diseases may last for
decades, which makes the association between feeding practices and infection
difficult. Enhanced safeguards need to be put in place to protect the public,"
Friedland said.
There have been 163 deaths from Creutzfeldt Jakob
disease in the United Kingdom attributed to eating infected beef. Bovine
spongiform encephalopathy has been identified in nine Canadian and three U.S.
cattle.
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IOS Press