Tuesday, June 16, 2009

Farm Raised Fish and the Possibility of Mad Cow Disease

Recently a University of Louisville neurologist, Dr. Robert P. Friedland, questioned the safety of eating farmed fish. His article in today’s Journal of Alzheimer’s Disease adds a new worry to concerns about the nation’s food supply.

Friedland's concern is that farmed fish could transmit Creutzfeldt Jakob disease--commonly known as mad cow disease--if they are fed byproducts rendered from cows. He and his colleagues urge government regulators to ban feeding cow meat or bone meal to fish until the safety of this common practice can be confirmed.

When you think about it, this is an extraordinarily bizarre fish farming practice -- feeding them cattle. "Fish do very well in the seas without eating cows," said the author.

The scientific team has not proven that it’s possible for fish to transmit the disease to humans. Still, out of reasonable caution for public health, they believe the practice of feeding rendered cows to fish should be prohibited. I would agree.

Mad cow 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. Now, rendered cow material is being fed to farmed fish. What a terrific idea that was, eh?

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 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, say the authors.


1 comment:

Anonymous said...

This problem also exists with poultry farming. Chickens and fish are not susceptible to prion diseases, but can accumulate mutant prions in
their tissues; the prions act as a toxin in this way. Infected cattle scraps are fed to chicken and fish, which are then harvested for human consumption. Chicken and fish meal is also fed to cattle, causing the mutated prions to build up in the food chain

The best way to deal with prions is to treat them as a toxin like mercury. Just like mercury, prions build up in the food chain. The only way to prevent prion buildup is to ensure that all animals destined for human consumption are fed a vegetarian diet.
Slaughterhouse refuse is a much cheaper protein source than soybeans and corn, but it is toxic and should be prohibited.