Thanks
to the Brits, Mad Cow Won't Claim U.S. Victims
By Dennis Avery of
the Center for Global Food Issues
Despite the headlines,
"mad cow disease" is unlikely to claim a single
human victim in this country.
The reason is simple. The
British have already paid the human price for learning
about this apparently new and fatal disease, with nearly
140 deaths and years of lurking fear for millions of
consumers. Thanks to the UK's dearly-bought experience,
America now knows what causes "mad cow," why
it was epidemic in Britain-and how to keep it from attacking
humans.
First, we know that "mad
cow" is not very contagious. More than 180,000
British cattle have been officially diagnosed with "mad
cow," and millions of British consumers may have
eaten meat from affected animals. But the UK has less
than 150 cases of the human disease thought to be caused
by the cattle disease (new variant Cruetzfeldt-Jakob
disease).
The rate of contagion is
not much higher than a million to one.
Today, Britain, the U.
S., and most other countries have banned the feeding
of ruminant animals with meat and bone meal from other
ruminant animals. That prevents spread of the disease
among both animals-and humans.
Secondly, we know now that
"mad cow" offers virtually no risk to humans
unless we eat the brain or nerve tissue of affected
animals. There has been no human transmission through
the muscle meat or milk. Thankfully.
When the dairy cow in Washington
State was reported ill at the slaughter house, the brain
and nerve tissue were held out of the marketing chain.
But throughout most of the their epidemic, the British
were routinely eating the brain and nerve tissue of
their "mad cows," ground up in their cherished
meat pies and sausages.
It all began in 1986, when
the British found an epidemic was ravaging their cattle
herds, making cows act drunk before they died. The disease
was eventually named bovine spongiform encephalopathy
(BSE).
At first, British authorities
assured the public that "mad cow" presented
no danger to beef consumers. Then came horrifying news
that a few people had become infected with a new form
of a brain-wasting ailment that could take years to
incubate, and was always fatal.
One government science
advisor estimated there might be as many as 800,000
human deaths. Everyone in Britain who'd eaten beef in
the previous ten years feared the disease was already
riddling their brain tissues.
The British eventually
found that "mad cow" is caused by a previously
unknown tiny "thing" called a prion, a sort
of warped natural protein. Prions spread in Britain
because the government had mandated a milder process
for rendering dead animal carcasses into meat and bone
meal. (They did it to lower energy costs and reduce
solvent risks to rendering plant workers.) Every country
renders livestock carcasses because they contain valuable
nutrients-and because it would create a huge, expensive
mess if we didn't.
But the Brits didn't know
that the high rendering temperatures and harsh solvents
had been protecting them and their animals from prions-which
we didn't know existed.
A human prion disease in
humans, Cruetzfeldt-Jakob Disease (CJD), occurs spontaneously
in about one in a million humans. The BSE rate may be
similar in cattle; we don't yet know. We don't know
whether the Washington State cow and/or the Canadian
animal diagnosed with "mad cow" earlier this
year somehow got contaminated feed or were spontaneous
cases. (They were born before the ban on feeding ruminant
meat and bone meal to ruminants.)
The British now ban all
ruminant nerve tissue, including spinal cords and brains-and
even bone-in cuts of meat-from both human food and animal
feed. That forces gourmets to give up eating brains
as a delicacy, and would force a lot of Americans to
give up T-bone steaks.
If we want to go that far,
we could reduce the risk of new variant CJD from one
in a million to perhaps one in 1.25 million. It's our
choice.
But let's be thankful that
science and the suffering of British consumers have
already defused virtually all of the danger from the
new disease. Or more likely, have nearly eliminated
most of the risk from a very old disease that never
threatened enough cows or humans to be noticed-until
our well-meant effort to cut rendering energy costs
gave "mad cow" its big chance to become an
epidemic.
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