fish that eat rendered animals could pose risk of mad cow disease
of Article: http://www.examiner.com/x-7160-Sacramento-Nutrition-Examiner~y2009m6d22-Are-mad-cow-disease-prions-turning-up-in-farmed-fish
June 22, 10:20 AM
Farmed fish are being fed too high on the food chain.
Instead of fish eating fish and seaweed, farmed fish commonly are being
fed rendered cows and bone meal from animals that never lived in the
Some cows may be born with a gene variation
that gives them a higher risk of later developing mad cow disease or
of being carriers without being infected. The solution to this dilemma is
for government regulators to ban the feeding of cow meat
byproducts or bone meal to farmed fish until the safety of this
common practice can be ascertained. The basic problem is that farmed fish
are not being fed what they normally would eat.
When restaurants buy farmed fish, or when you buy farmed
fish from supermarkets, are there prions in the farmed fish
that could cause mad cow disease in humans? According to a Science News article, published June 17, 2009,
"Farmed Fish May Pose Risk For Mad Cow Disease,"
University of Louisville neurologist Robert P. Friedland, M.D., questions the safety of
eating farmed fish in Journal
of Alzheimer’s Disease, adding a new worry to concerns about the
nation’s food supply.
For those people anywhere in the world that have been
diagnosed with fatal mad cow disease, did they get it from previous
farmed fish meals or from beef? Are other prion-caused diseases of the
brain, including Creutzfeldt Jakob disease caused by eating
meat from infected animals?
Most consumers know it's not safe to eat fish that ate
bonemeal. How long will it take to prove it? And is Alzheimer's also
linked to what people eat? Who's studying prions in the brain related
possibly to diet?
A press release on neurologist Robert P. Friedland's research results,
titled, "Farmed Fish May Pose Risk for Mad Cow Disease," appeared
in the Journal of Alzheimer's Disease on June 16,
2009. Based on his research, he and his team question the safety of
eating farmed fish that are fed byproducts rendered from cows.
Recently, Dr. Friedland also has been working on the patterns
of disease occurrence, including risk and protective factors, with
studies of the Kikuku in Kenya, Jews and Arabs in Israel, and Caucasian
and African-American subjects in Cleveland. Friedland and his
co-authors suggest farmed fish could transmit Creutzfeldt Jakob
disease--commonly known as mad cow disease--if the farmed fish are
fed byproducts rendered from cows. The scientists researching the
question of whether there are prions in farmed fish 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. There's a food safety problem with feeding animal
by-products that contain mad cow disease prions in meat and bone meal.
Yet rendered cow meat and bone meal is routinely fed to farmed fish. A
few years ago people even fertilized vegetable gardens and
fruit trees with bovine bone meal.
You'll still see calcium or mineral supplements containing
bone meal from animals. How do you know the animals didn't carry a
gene for mad cow disease or had been infected with it or some other
disease fatal to humans? You've seen flu jump species from bird and pig
to human, why not mad cow disease prions from cows to humans? Of
course the mad cow prions jumped species from cow to human.
Can they jump from cow to fish to human? Prions for
mad cow disease can't be killed by cooking. Research will eventually
confirm or deny whether fish can pass along mad cow disease based on whether
the fish ate rendered meat or bone meal from cows infected with mad cow
disease. Meanwhile, the nation's food supply is at risk as evidence
How do farmed fish get the prions in their
flesh that are then eaten by humans so that the fish and the human
comes down with mad cow disease? It's a genetic mutation within a gene
called the Prion Protein Gene that causes mad cow disease.
Prion proteins are proteins expressed abundantly in the
brain and immune cells of mammals. The questions researchers are trying
to answer is whether prions are found in farmed fish after the fish
consume meat or bone meal containing prions from cows that are carriers
but not infected themselves.
Another issue being researched is whether the meals that
the fish are fed contain prions that the fish pass on to human
consumers. And is it possible or not that humans can get mad cow disease
from consuming farmed fish? If mad cow disease actually is a
genetic mutation in the cow, can a cow that doesn't become infected
with mad cow disease act as a carrrier, and still pass on the prions to
humans to cause mad cow disease in people or other animals--from farmed
fish to chickens?
It's not only the ongoing research
on whether farmed fish are transmitting diseases to
humans--diseases that range from mad cow disease to possibly
Alzheimer's or other brain diseases theoretically caused by prions.
Think of commercial pet food also made up largely of meat by-products.
It's easy for pet food to get into the human food chain by handling pet
food and touching one's mouth, nose, or eyes, or handling human food in
the same room, dishes, or dishwasher, or transfering fluids or dust
from canned or dry pet foods to human foods.
For now, the question is whether farmed
fish contain mad cow disease prions. That's what Dr. Friedland and his co-authors want consumers to
know about as the research continues. The goal is to see whether
it's safe or not to feed farmed fish rendered cows. The research team so
far thinks it's not safe but will continue researching to confirm or
not confirm safety beyond a doubt.
Dr. Friedland wants consumers to know that
scientists have not proven that it’s possible for fish to transmit the
disease to humans. But researchers want consumers to be cautious. The
warning is out of reasonable caution for public health. Friedland
believes rendered cows should not be fed to fish. Friedland
explained, "feeding rendered cows to fish should be
His group also is using animal models to better define the
pathophysiology of Alzheimer’s disease and develop new treatments. Dr. Friedland has documented a series of
important determinants of the disease, including physical and mental
inactivity, smoking and diet. This work has focused on interactions of
genetic and environmental lifestyle elements.
Who's studying the health of the rendered cows that are
currently fed to farmed fish? 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). According to "Farmed Fish May Pose Risk For Mad Cow Disease,"
the mosts recent 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
Now people eating farmed fish have to worry not only about
the hormones and antibiotics given to the farmed fish to make them grow
faster, or the pollutants and insecticides in the farmed fish. Now
consumers have to worry about the rendered cows, those meat byproducts
fed to the fish that might be full of mad cow disease prions.
The barriers between species could be breaking down. But
scientists will have to study how a disease jumps from one species to
another. Rather than rely on a prion mutating, a person could get
infected from a fish even if barriers between species are perceived as
Maybe the infection barrier between species is
no longer low if the fish eats the sick mammal or infected cow as
ground meal byproducts, and then the human eats the sick farmed
fish? If a disease infects a fish that once infected a cow, could
that disease also infect a human? It's easy for a disease to jump between
a cow and a human. Mad cow disease spread to humans through infected cows
that might even have a gene variant that makes them susceptable to mad
The risk of transmission of mad cow disease, also known as
BSE to humans who eat farmed fish could be higher than most people
thought. According to the authors of the research, "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."
According to the press release, Friedland notes, "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."
Scientists know it takes decades, sometimes up to 30
years, for certain brain diseases similar to mad cow disease
infections to incubate in a human. Most people don't make the
association between what meat they ate and what that animal or fish ate
before it was cooked or sold in the market. When you go out to
a restaurant for a fish sandwich, do you think that the farmed fish in
the sandwich contains mad cow disease prions or similar infections?
Dr. Friedland and the authors of the research
studies would like consumers to know that "enhanced
safeguards need to be put in place to protect the public.” People in
Europe that came down with mad cow disease after eating infected beef
never had to wait very long. Certainly not for decades.
Those people that caught mad cow disease in
Europe didn't have to wait 30 years between the time they
ate the beef and the time they came down with Creutzfeld Jakob, the
human form of Bovine spongiform encephalopathy (mad cow disease). In
recent years, mad cow disease, always fatal in humans and cows, also has
been identified in nine Canadian and three U.S. cattle.
The moral compass of this finding is that farmed fish need
to be fed safer foods, and in the meantime, eat wild-caught fish from
some ocean areas that are relatively cleaner than others.
Even wild-caught fish can be bought in cans, without added
salt, because they are canned from the overrun of wild-caught fish. Worse
yet, some commercial chicken ranches feed their chickens rendered cow
meat and bone meal. When you buy organic chicken, do you know what they
were fed? All you know is that they weren't given hormones or
anti-biotics if the label says so.
What are turkeys fed? You are told that they're not
getting hormones. But what else is in the food animals eat if you're
eating the animals? Think about whether cows were fed grass or grain.
They should have been grazing on grass. Cows shouldn't be feeding on bone
meal and rendered other cows. And dogs/cats shouldn't be eating meat
byproducts that have been genetically altered and then injected with
all types of chemicals, hormones, or antibiotics.
Be aware of what the animal ate and what hormones,
antibiotics, and insecticides that animal absorbed before you ate
it. If you're a vegetarian, ask what herbicides, genetic
alterations, or insecticides went into the plants you eat. At least
you'll know what's going into your body. And the research continues
on whether farmed fish present a mad cow disease problem.