All About Prions and Food

[jsolomon]

Straight from a 2005 CDC report.

http://www.cdc.gov/ncidod/dvrd/prions/reso...blic_Health.pdf

To date, no convincing evidence of CWD transmission to humans has been

reported. Because the decade-long occurrence ofCWDhad been relatively limited

to a small geographic area, it is possible that not enough human exposure with

the appropriate latency period has occurred for the agent to overcome the species

barrier and cause disease in humans. There is a concern that the level of human

exposure to CWD might increase over time with the increasing spread of CWD

to new areas. Continued surveillance for possible human CWD among high-risk

populations (e.g., persons hunting for many years in the CWD-endemic areas of

Colorado and Wyoming) and evaluation of the zoonotic potential of the CWD

agent in transgenic animal models should be conducted to monitor the possibility

that the CWD agent can cause disease in humans.

[eje]

One of the most vigorous skeptics of the prion theory has been the journalist Gary Taubes. One example of his writings on the issue can be read online on Slate in his story "Nobel Gas". Also good on this, and accessible to the layperson, is this debate on the Nova website -- it presents both sides respectfully. This recent summary on the Fox News site, while no doubt politically motivated, makes some interesting points as well.

Now that the bloom is off the Atkins diet, I guess Taubes has moved on to prions?

A lot of scientists were pissed off at him about the way he misrepresented them in his pro-Atkins articles about diet.

I expect a number more will be pissed off at the way their research is presented in this piece.

In any case, aside from Alzheimer's Disease, the odds of dying from prion disease still remain nearly non-existent in this country and there are much more dangerous food borne pathogens to worry about.

But, really, do we need to continue to feed cattle meat? C'mon, they're herbivores, for cripes sake.

edit - What is it about February?

Disclaimer: I used to work for a lab that did prion research and some of my salary at that time was paid by grants co-authored by our group with Dr. Prusiner.

Edited February 2, 2006 by eje (log)

[Fat Guy]

eje, Taubes was actually focusing on the prion issue long before he turned his attention to obesity. This really dates back to his 1987 book, Nobel Dreams, which had nothing to do with prions but established Taubes (who according to the New York Times "studied physics at Harvard, aeronautical and astronautical engineering at Stanford and journalism at Columbia") as a strong public contrarian on the conventional wisdom of the scientific research establishment. His work on Prusiner and prions dates mostly to the mid-to-late 1990s and is essentially follow-up to his earlier Nobel Prize work.

jsolomon, I'm happy to use whatever set of terminology you think is most appropriate (having written on this subject, I've been through all the debates with editors about proper use of the terms hypothesis, theory, etc.). And it's definitely the case that the prion theory gathers more support with each passing year. It would be interesting to see if that continued to happen if more funding became available for research of competing theories. Currently, where the big grants are concerned, it's prions or nothing.

[docsconz]

It is disturbing that prions have not passed Koch's test. It is also disturbing that the scientific community has jumped on board without that test. It is even more disturbing that extensive funding has been skewed toward the "sexy new phenomenon" instead of a more moderate approach to search for a more conventional possible culprit. I guess that this confirms my long held belief that the media needs to stay out of real science. But, that will never happen.

←

Why is this so disturbing? These diseases are different from conventional ones, nevertheless the only postulate they don't really fit is the second one as outlined in this Wikipedia article on Koch's postulates. Even then, the postulates have been shown not to stand up universally as amongst other things they don't allow for carrier states.

As for "more conventional" culprits, they have been searched for for years and so far haven't been found. I thought the second argument from the Nova link that Steven presented was the more persuasive of the two.

[docsconz]

And it's definitely the case that the prion theory gathers more support with each passing year. It would be interesting to see if that continued to happen if more funding became available for research of competing theories. Currently, where the big grants are concerned, it's prions or nothing.

←

That's because competing theories haven't been able to cut the mustard so to speak compared to the prion theory so far. Of course the money is going to go to the areas with greater promise as it should. The prion theory did not start out as the likely candidate. It grew into it as the evidence grew to support it.

While CWD so far hasn't been shown to infect humans and as far as I know neither has scrapie, the relatively recent emergence of BSE and Mad Cow Disease is certainly cause for concern that other strains that cross-over may have already or may yet develop. As I said earlier, i wouldn't volunteer to eat meat that is known to be infected. Would anyone here?

[Fat Guy]

I thought both were well argued, as befits a good debate. I've found that it's suprising to most people, however, that two sides even exist.

[docsconz]

...and they should exist. Just because the prion hypothesis appears to be the strongest one at this time doesn't mean that scientists shouldn't continue to try to disprove it. If they try and fail it only makes the hypothesis stronger but still leaves room for others to approach it. A good scientist should never get too emotionally involved with any theory.

[eje]

While CWD so far hasn't been shown to infect humans and as far as I know neither has scrapie, the relatively recent emergence of BSE and Mad Cow Disease is certainly cause for concern that other strains that cross-over may have already or may yet develop. As I said earlier, i wouldn't volunteer to eat meat that is known to be infected. Would anyone here?

←

To me the real concern with CWD is just how transmissable and nearly ineradicable (word?) it is.

It is my understanding that they have done everything short of drop a nuclear bomb on the deer station where CWD was first identified and yet new deer put in the same pens still come down with CWD.

Having listened to and read a bunch about BSE and CWD, it also is very clear that the method of infection for transmissible spongiform encephalopathies between peer animals is not well understood at all.

[Jason Perlow]

Prions have something to do with food? I thought they were a secret society that protected the secrets of the Merovingian linkage to Jesus.

Oh what, thats the Priory of Sion.

[docsconz]

Prions have something to do with food? I thought they were a secret society that protected the secrets of the Merovingian linkage to Jesus.

Oh what, thats the Priory of Sion.

←

I knew there was a conspiracy in here somewhere

[Syre]

I knew there was a conspiracy in here somewhere

←

If you want to get really paranoid, think about this:

Prions are not destroyed by cooking or by detergents. It takes a temperature of well over 1000 degrees F to make them inactive.

There are documented cases of people being infected from surgical instruments which were autoclaved but not sufficiently cleaned.

So if you go to a place that serves venison, and if the venison has prions and if it is communicable to humans (okay, 3 big ifs), you could be infected even if you don't order any venison, from prions which were on the frying pans or other cookware used to prepare your meal.

Does that keep me away from restaurants that serve venison? Not necessarily. But I'm paranoid enough to think of it and take it into consideration...

[annecros]

Well, you can still color me skeptical.

No, I would not knowingly eat a sick animal. That's just common sense, isn't it?

But, on the other hand, this all smacks of the Avian Flu hype and such. I guess it wouldn't be too difficult for some unethical person to slip a sick animal into the food supply.

I guess I am from the there is nothing new under the sun school of thought. Can disease cross species? Of course. Will I lay awake at night worrying that I am going to contract Chroic Wasting Disease? Nope.

Seems like it has been nearly two years since I have eaten Venison anyway. I eat fresh produce every day, and E Coli can kill. So can hepititis. So can just plain old food poisoning. So can high cholesterol, stroke, heart disease, morbid obesity, etc. etc.

You pay your money and take your chances.

[Mallet]

I thought both were well argued, as befits a good debate. I've found that it's suprising to most people, however, that two sides even exist.

←

I certainly had no idea that there was disagreement on the issue, and like docsconz I found the pro-prion argument on the NOVA website much more convincing. I can't say I fully understand the conceptual hangups about proteins not being able to self-replicate and/or not being able to "transmit information". Firstly, to the best of my knowledge no-one is claiming prions self-replicate; I have only seen the claim that they can convert other (pre-existing) proteins into prions. Secondly, we already know that proteins do almost all of the work in living cells, including literally thousands of known examples of one protein inducing a change in the shape of another. I fail to see a controversy at the conceptual level, although to be sure we are free to argue about the results.

[JohnL]

I knew there was a conspiracy in here somewhere

←

If you want to get really paranoid, think about this:

Prions are not destroyed by cooking or by detergents. It takes a temperature of well over 1000 degrees F to make them inactive.

There are documented cases of people being infected from surgical instruments which were autoclaved but not sufficiently cleaned.

So if you go to a place that serves venison, and if the venison has prions and if it is communicable to humans (okay, 3 big ifs), you could be infected even if you don't order any venison, from prions which were on the frying pans or other cookware used to prepare your meal.

Does that keep me away from restaurants that serve venison? Not necessarily. But I'm paranoid enough to think of it and take it into consideration...

←

You are more likely to be seriously injured sick or die:

1--taking a shower that AM

2--walking or driving to the restaurant

3--eating those oysters as a first course

4--eating the salad with sprouts

than you are encountering prions in you venison getting sick and dying.

prions have been around for quite a while--so have deer. we have been eating deer for a long time. where are all the deaths?

per the CDC there is no cause and effect here only a suspicion.

It is a good thing that the prion issue is being studied and that the CDC has cautioned hunters and people who eat wild game (most of us eat farmed).

and yes there is a conspiracy (of sorts).

Special interest groups conspiring with media outlets to frighten the public.

[docsconz]

I knew there was a conspiracy in here somewhere

←

If you want to get really paranoid, think about this:

Prions are not destroyed by cooking or by detergents. It takes a temperature of well over 1000 degrees F to make them inactive.

There are documented cases of people being infected from surgical instruments which were autoclaved but not sufficiently cleaned.

So if you go to a place that serves venison, and if the venison has prions and if it is communicable to humans (okay, 3 big ifs), you could be infected even if you don't order any venison, from prions which were on the frying pans or other cookware used to prepare your meal.

Does that keep me away from restaurants that serve venison? Not necessarily. But I'm paranoid enough to think of it and take it into consideration...

←

You are more likely to be seriously injured sick or die:

1--taking a shower that AM

2--walking or driving to the restaurant

3--eating those oysters as a first course

4--eating the salad with sprouts

than you are encountering prions in you venison getting sick and dying.

prions have been around for quite a while--so have deer. we have been eating deer for a long time. where are all the deaths?

per the CDC there is no cause and effect here only a suspicion.

It is a good thing that the prion issue is being studied and that the CDC has cautioned hunters and people who eat wild game (most of us eat farmed).

and yes there is a conspiracy (of sorts).

Special interest groups conspiring with media outlets to frighten the public.

←

Objectively and rationally, you are correct, but few risks are so viscerally horrifying. I will never forget a young woman architect dying from CJD when I was in Medical School. It seemed a particularly awful way to go.

As for farmed vs. wild with deer, so far so good, but given the history fo Mad Cow that is only reassuring to a degree. Personally, I will not avoid eating venison at a restaurant. I probably wouldn't be so keen to eat hunted venison from effected areas though, just like I prefer not eating raw shellfish from questionable areas or unknown origens.

[JohnL]

Well, you can still color me skeptical.

No, I would not knowingly eat a sick animal. That's just common sense, isn't it?

But, on the other hand, this all smacks of the Avian Flu hype and such. I guess it wouldn't be too difficult for some unethical person to slip a sick animal into the food supply.

I guess I am from the there is nothing new under the sun school of thought. Can disease cross species? Of course. Will I lay awake at night worrying that I am going to contract Chroic Wasting Disease? Nope.

Seems like it has been nearly two years since I have eaten Venison anyway. I eat fresh produce every day, and E Coli can kill. So can hepititis. So can just plain old food poisoning. So can high cholesterol, stroke, heart disease, morbid obesity, etc. etc.

You pay your money and take your chances.

←

You are making too much sense.

here's my "beef"--

If one goes to the web site referenced (linked) in the original post on this topic: "news@nature.com"

One sees a web page listing articles.

titles and verbage like:

Surgery Risk from prions

..prion clusters are catching

Did human remains spawn the infection...?

A wolf in sheeps clothing

Latest worrying research.

Lab case sparks fears

..survey causes spectre..."

secrets of a past prion epidemic...

Wow--this is pretty serious. I better read these so I can protect myself and my family!

Only--when attempting to read the actual story behind these urgent headlines--I find that I must sign up and spend seven bucks! (a month).

See what I am getting at here?

This stuff is the same as the dire warnings like: "your non stick pan may be killing you and your loved ones--tune in to twenty twenty at ten!"

I am not sure who is more guilty--me for not shelling out seven bucks to save my family or the folks at news at nature dot com for charging people for information they obviously feel would save lives!?

Seriously, maybe the articles present a sane and balanced perspective on a troubling topic. But forgive me for being just a bit skeptical of things.

Yes there is a link to a paper on prions that is only a part of an ongoing review by the scientific community that is important and has and will continue to yield some conclusions that will help all of us understand the prion issue better and make informed decisions.

It is important to keep some basic facts in mind and to apply common sense and perspective.

I would recommend that people go to the CDC web site where one will get good information (all of it for free).

Also the posts by PatrickS in this and other threads (mad cow, teflon etc) which are loaded with facts and rational thinking.

It is good to be concerned and even better to be informed.

most of all-healthy skepticism is important especially when dealing with the media.

It is a shame when a place like eGullet provides better factual information and more rational debate and resultant insight on a food/health related topic than ABC News given their resources and huge audience).

(probably the reason--I bet-- eGullet and other internet based locales are growing faster than ABC News).

Anyway--that's my "beef"--which reminds me--I am going to enjoy a rack of venison this weekend which I am doing because Morgan Spurlock showed what happens when you eat too much of one thing and I had beef twice this week already.

Don't worry--the other four days-I am having pasta and vegetables and lots of salads and fish.

I wish I knew who said: "Too much of a good thing...."

Now there's something that makes sense!

Edited February 2, 2006 by JohnL (log)

[JohnL]

Doc

makes sense to me.

the disease is horrible--as manifested in humans also the version in animals.

I am not an animal rights person but I hate to see suffering of any kind.

Hopefully, good preventative measures will be developed and a cure will be found--

It makes a lot of sense to always consider the sources of one's food. Especially, items like shellfish. Luckily I have only "encountered" a bad oyster once--the memory of that is seared into my brain!!! Yeeeow!!!

[jsolomon]

In affected areas, game deer legally hunted must all be inspected for CWD.

I've been eating inspected hunted deer for shockingly close to 3 decades, and I'm no crazier, saner, smarter, or dumber than when I began to eat Nebraska wild deer.

I'm still more likely to be made a vegetable by my insistence on riding my bicycle in traffic.

I'm also more likely to be made a vegetable by working with the bacteria that I work with.

I refuse to be made afraid of my food supply. The US's is still so amazingly safe that we are even being protected from having a good time. In the words of Private Fong at basic training, "Fuck that." I've gotta go of something, and it's sure as hell not going to be stressing over how many zeptograms of prions are in my diet.

[annecros]

Well, you can still color me skeptical.

No, I would not knowingly eat a sick animal. That's just common sense, isn't it?

But, on the other hand, this all smacks of the Avian Flu hype and such. I guess it wouldn't be too difficult for some unethical person to slip a sick animal into the food supply.

I guess I am from the there is nothing new under the sun school of thought. Can disease cross species? Of course. Will I lay awake at night worrying that I am going to contract Chroic Wasting Disease? Nope.

Seems like it has been nearly two years since I have eaten Venison anyway. I eat fresh produce every day, and E Coli can kill. So can hepititis. So can just plain old food poisoning. So can high cholesterol, stroke, heart disease, morbid obesity, etc. etc.

You pay your money and take your chances.

←

You are making too much sense.

here's my "beef"--

If one goes to the web site referenced (linked) in the original post on this topic: "news@nature.com"

One sees a web page listing articles.

titles and verbage like:

Surgery Risk from prions

..prion clusters are catching

Did human remains spawn the infection...?

A wolf in sheeps clothing

Latest worrying research.

Lab case sparks fears

..survey causes spectre..."

secrets of a past prion epidemic...

Wow--this is pretty serious. I better read these so I can protect myself and my family!

Only--when attempting to read the actual story behind these urgent headlines--I find that I must sign up and spend seven bucks! (a month).

See what I am getting at here?

This stuff is the same as the dire warnings like: "your non stick pan may be killing you and your loved ones--tune in to twenty twenty at ten!"

I am not sure who is more guilty--me for not shelling out seven bucks to save my family or the folks at news at nature dot com for charging people for information they obviously feel would save lives!?

Seriously, maybe the articles present a sane and balanced perspective on a troubling topic. But forgive me for being just a bit skeptical of things.

Yes there is a link to a paper on prions that is only a part of an ongoing review by the scientific community that is important and has and will continue to yield some conclusions that will help all of us understand the prion issue better and make informed decisions.

It is important to keep some basic facts in mind and to apply common sense and perspective.

I would recommend that people go to the CDC web site where one will get good information (all of it for free).

Also the posts by PatrickS in this and other threads (mad cow, teflon etc) which are loaded with facts and rational thinking.

It is good to be concerned and even better to be informed.

most of all-healthy skepticism is important especially when dealing with the media.

It is a shame when a place like eGullet provides better factual information and more rational debate and resultant insight on a food/health related topic than ABC News given their resources and huge audience).

(probably the reason--I bet-- eGullet and other internet based locales are growing faster than ABC News).

Anyway--that's my "beef"--which reminds me--I am going to enjoy a rack of venison this weekend which I am doing because Morgan Spurlock showed what happens when you eat too much of one thing and I had beef twice this week already.

Don't worry--the other four days-I am having pasta and vegetables and lots of salads and fish.

I wish I knew who said: "Too much of a good thing...."

Now there's something that makes sense!

←

My favorite is:

"Everything in moderation. Including moderation."

[Fat Guy]

At the height of the mad-cow scare, or at least one of the mad-cow scares, I had a really big steak in London. I figured it was probably the safest place in the world to have a steak, given that they were incinerating whole herds if one animal anywhere near it was suspected of having mad-cow. The steak was actually from some part of Scotland where, according to the somewhat defensive server, there were no recorded instances of mad-cow. It was delicious.

The general media representation of mad-cow is as follows: 1) mad-cow is caused by cows eating other cows; 2) there are these things called prions that are unlike any other infectious agent and are responsible for transmission of mad-cow; 3) people who eat mad-cow tainted beef get new variant Creutzfeld-Jakob disease. Each of these points is stated as incontrovertible fact, so much so that they're often run together, for example, "If you eat beef you'll get mad-cow disease!"

Needless to say, people don't get mad-cow disease. Cows get mad-cow disease. There is some good evidence to suggest that some cases of Creutzfeld-Jakob disease in humans are related to some cases of mad-cow (Bovine Spongiform Encephalopathy aka BSE) in cows. It has not actually been proven that any of these cases were due to eating beef. The cases of nvCJD in vegetarians, the possibility that pharmaceutical gels, the water supply or surgical supplies are to blame, and the disconnect between the scare and the actual epidemiological information (there should be an epidemic but there have only been a few hundred human cases since the beginning of the mad-cow scare) all raise serious questions. Likewise, there is some information that there's a genetic predisposition, in that all victims of nvCJD (last time I checked -- it has been a few years since I wrote an article on this) had a certain genetic marker and that nobody without that marker has every gotten the disease.

I wouldn't be so quick to accept the whole chain of causation that is presented so often in the media and by funding-dependent scientists in soundbites. It all may turn out to be true. Then again, some day some researcher in Australia may say "Hey, I was just looking at a totally unrelated thing and I found the virus that causes nvCJD. Yep, it was a virus all along!" Just as we learned a few years ago that the cure for ulcers is antibiotics -- a reality that escaped us for decades as an entire branch of medicine proceeded based on totally false assumptions about the nature of ulcers. Just as, currently, extraordinary steps are being taken to combat mad-cown -- steps costing billions of dollars and affecting the livelihoods of many -- based on assumptions that are hardly as certain as the literature makes them out to be.

[docsconz]

Steven, they may not be certain, but a of now they do represent the best evidence available and what appears to be the least risky course.

By the way, antibiotics represent the cure for perhaps most, but not all ulcers.

Nothing is ever as simple as it appears.

[jsolomon]

Likewise, there is some information that there's a genetic predisposition, in that all victims of nvCJD (last time I checked -- it has been a few years since I wrote an article on this) had a certain genetic marker and that nobody without that marker has every gotten the disease.

←

I'm not sure of the total fact of that statement, but there is a relation between prions and an open reading frame on Chromosome 20 in humans. Your last clause I can't vouch for.

My understanding of how at least one of the pathologies is supposed to work is that somewhere between translation and post-translational modification of the protein in this open reading frame, the pathogenic prion interacts with the incompletely folded/modified protein and causes it to fold into the pathogenic form.

But, I don't support genetic tests before being allowed to purchase beef. The simple fact is, we all got a life sentence when we were conceived. Whenever I see a patient now as a medic in the Army, or later as a medical student, or even later as a physician, I am always going to remind them to make the most of it, because the last laugh will always be on them. And my last laugh will be on me. It's a simple fact.

Why can't we deal with it?

Repeat after me: eat, drink, and be merry, dammit!

Reason for above statement: statistically, less than one member of eG will die of a prion disease.

[Fat Guy]

the best evidence available and what appears to be the least risky course

←

This is where science and policy meet, and "the best evidence" and "least risky course," while often easy to determine scientifically (as in, "the least bad evidence" and "if we never do anything, there will be no risk"), are not as easily translated into public policy, especially when that policy involves coercion and great economic cost. The near decimation of the British beef industry led to much loss of quality of life -- maybe even a few suicides and the like -- and it's certainly possible that the billions in costs could have been better spent some other way to save more lives in a less speculative manner.

[Fat Guy]

I'm not sure of the total fact of that statement, but there is a relation between prions and an open reading frame on Chromosome 20 in humans.  Your last clause I can't vouch for.

←

I believe the information, which I saw in Science maybe two or three years ago, pertained to the MM genetic profile.

[docsconz]

the best evidence available and what appears to be the least risky course

←

This is where science and policy meet, and "the best evidence" and "least risky course," while often easy to determine scientifically (as in, "the least bad evidence" and "if we never do anything, there will be no risk"), are not as easily translated into public policy, especially when that policy involves coercion and great economic cost. The near decimation of the British beef industry led to much loss of quality of life -- maybe even a few suicides and the like -- and it's certainly possible that the billions in costs could have been better spent some other way to save more lives in a less speculative manner.

←

Perhaps, but the I believe the best evidence at that time justified the action. It may also be true that the actions taken were in the best interest of not only the British beef industry, but also beef in the EU as well. This is not just a scientific issue (though that should be predominate). It is also a very strong emotional issue. There are few things more emotionally charged than food-related health issues - especially such powerful ones as this.