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Prions are concerning. We know very little about them and have no cures. There are forms for common animals that we eat, like cows. Our processing of these anim

Prions are concerning. We know very little about them and have no cures. There are forms for common animals that we eat, like cows. Our processing of these animals leads to 100s or 1000s of unique DNA being identified in a single package of ground beef. They do not test for BSE unless the cows are symptomatic, but it's unlikely they would be symptomatic when they have a typical market time of only 18 months. BSE is thought to be a potential cause of CFJ in humans. In my opinion, our industrialization of the food supply will lead to mass prion distribution/infection at some point.

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jajag 3y ago
It already has with the BSE crisis, and I'm not sure if we 100% understand how close to a much greater crises we came. I remember there was period in the UK back in the nineties where there was the grim prospect of hundreds of thousands of cases - thankfully it never came close to that. And there are European countries where I still can't donate blood, because I lived in the UK during the outbreak.
- giantg2 3y ago
  "I'm not sure if we 100% understand how close to a much greater crises we came." That's basically my point. It doesn't seem like we changed our practices that much. I would have thought we'd test the animals, process them separately, etc.
  - gustavus 3y ago
    My understanding is that one of the changes we made is we stopped feeding cow brains to other cows, which was the root cause of the problem.
    - consumer451 3y ago
      My personal pet theory was that prions are an evolutionary mechanism which prevents cannibalism in mammals. I know nothing about evolutionary biology, and I wonder if there is any chance that this is true.
      - kaikai 3y ago
        One of the first thing you learn in evolutionary biology is that evolution doesn’t have intent.
        consumer451 3y ago
        Yeah, I guess even I know better than that and should have chosen my words more carefully.
      - nrdvana 3y ago
        Also not a biologist, but as I understand it: Every living creature synthesizes proteins. Every time you synthesize a protein, there is a tiny tiny chance that it synthesizes "backward". Backward proteins are physically incompatible with "forward" proteins, and also increase the risk that more proteins synthesize backward. It leads to a cascade of errors where lots of proteins synthesize backward and the cells and internal structures can no longer function. It's like you fall apart due to half your Lego bricks being upside-down. And, this is all a statistical probability that could occur in any moment to any living organism. The evolutionary defenses are to break apart all incoming proteins and reassemble them yourself, and have a cycle of life that starts new organisms from scratch. Large carnivores can't hope to break apart every incoming protein, though. So, basically our lifespans and reproduction method of growing up from a single cell are the evolutionary defenses against the natural phenomenon of prions. But yes, prion disease is probably what forces all higher foodchain animals to avoid cannibalism.
        gustavus 3y ago
        So that has raised an interesting question in my mind. But as far as I know the only significant case of prion disease amongst human beings, excluding CJD which seems to be generically determined, was the instance of Kuru among the Papau New Guinea tribes; however we know other societies practiced cannibalism at a certain scale such as the Aztecs in which people were eating other people all over the place, yet we don't have widespread evidence of Kuru. Is there something distinct about Brian tissue which puts it at a higher risk for prion disease formation?
  - sigmoid10 3y ago
    There were lots of changes that permeated far beyond Britain. There was a time when every cow was tested in Germany if it was merely alive during the time when contaminated animal-based feed was going around, even if it wasn't fed anything like that. The EU only lifted general testing like 10 years ago - 20 years after the original outbreak. People have also completely stopped using the kind of feed ingredients that allow transmission of the disease to livestock intended for human consumption in most parts of the world. It was a shitty situation, especially in Britain, and many people there probably still carry the disease without knowing it because it can take up to 50 years to show symptoms. That's also the reason why many countries still won't allow you to donate blood if you lived in Britain at the time as the other comment mentioned. So saying that we didn't learn from it or changed nothing is just wrong. Another outbreak like the original one is basically impossible in the western world.
Mordisquitos 3y ago
Prions are indeed very concerning on a concrete per-instance basis, but —unlike viruses— not that concerning in the abstract as a generic threat. Prions as a phenomenon do not exploit an essential feature of our metabolism, and cannot 'evolve' per se, but are limited to the specific cases in which a) a given protein sequence can stably misfold rendering it ineffective, b) exposure of already functionally 'eufolded' proteins to the misfolded one can trigger subsequent misfolding, and c) misfolded versions of the protein can and do consistently come in contact with non-misfolded functional ones. I'm not trying to downplay the threat and incredible difficulty of preventing known prion diseases, particularly with regards to destroying the infectious prions. However, to illustrate the rarity of the phenomenon on a per-protein basis, consider how the processes involved in cooking have themselves been denaturing (i.e. mifolding) an unimaginable number of all kinds of proteins in a myriad of ways all since human prehistory, and yet we have no known examples nor even hints of new prions having been created in the process.
- lumost 3y ago
  The mass processing of food could be the additional mechanism allowing mass distribution of prions, no? Through processed foods, an apex predator like humanity comes into contact with proteins from several orders magnitude more animals than our ancient hunter gatherers or farmers. This problem is compounded as our livestock eat processed foods themselves. Perhaps prions were not as dangerous for most of evolutionary history as they simply lacked a distribution vector?
  - consumer451 3y ago
    > The mass processing of food could be the additional mechanism allowing mass distribution of prions, no? My grandmother was from "the old country" and would never allow us to buy ground meat in a package. She made us ask the deli to grind her selected cuts, in front of her. Back then, I wrote this off as some kind of old world silliness. I remember being embarrassed about the whole kerfuffle. I know she wasn't thinking of prions, just contamination in general. Now I realize that I was the silly one, and she was very wise.

deleted 3y ago

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jajag 3y ago

It already has with the BSE crisis, and I'm not sure if we 100% understand how close to a much greater crises we came. I remember there was period in the UK back in the nineties where there was the grim prospect of hundreds of thousands of cases - thankfully it never came close to that. And there are European countries where I still can't donate blood, because I lived in the UK during the outbreak.

giantg2 3y ago
"I'm not sure if we 100% understand how close to a much greater crises we came." That's basically my point. It doesn't seem like we changed our practices that much. I would have thought we'd test the animals, process them separately, etc.
- gustavus 3y ago
  My understanding is that one of the changes we made is we stopped feeding cow brains to other cows, which was the root cause of the problem.
  - consumer451 3y ago
    My personal pet theory was that prions are an evolutionary mechanism which prevents cannibalism in mammals. I know nothing about evolutionary biology, and I wonder if there is any chance that this is true.
    - kaikai 3y ago
      One of the first thing you learn in evolutionary biology is that evolution doesn’t have intent.
      - consumer451 3y ago
        Yeah, I guess even I know better than that and should have chosen my words more carefully.
    - nrdvana 3y ago
      Also not a biologist, but as I understand it: Every living creature synthesizes proteins. Every time you synthesize a protein, there is a tiny tiny chance that it synthesizes "backward". Backward proteins are physically incompatible with "forward" proteins, and also increase the risk that more proteins synthesize backward. It leads to a cascade of errors where lots of proteins synthesize backward and the cells and internal structures can no longer function. It's like you fall apart due to half your Lego bricks being upside-down. And, this is all a statistical probability that could occur in any moment to any living organism. The evolutionary defenses are to break apart all incoming proteins and reassemble them yourself, and have a cycle of life that starts new organisms from scratch. Large carnivores can't hope to break apart every incoming protein, though. So, basically our lifespans and reproduction method of growing up from a single cell are the evolutionary defenses against the natural phenomenon of prions. But yes, prion disease is probably what forces all higher foodchain animals to avoid cannibalism.
      - gustavus 3y ago
        So that has raised an interesting question in my mind. But as far as I know the only significant case of prion disease amongst human beings, excluding CJD which seems to be generically determined, was the instance of Kuru among the Papau New Guinea tribes; however we know other societies practiced cannibalism at a certain scale such as the Aztecs in which people were eating other people all over the place, yet we don't have widespread evidence of Kuru. Is there something distinct about Brian tissue which puts it at a higher risk for prion disease formation?
- sigmoid10 3y ago
  There were lots of changes that permeated far beyond Britain. There was a time when every cow was tested in Germany if it was merely alive during the time when contaminated animal-based feed was going around, even if it wasn't fed anything like that. The EU only lifted general testing like 10 years ago - 20 years after the original outbreak. People have also completely stopped using the kind of feed ingredients that allow transmission of the disease to livestock intended for human consumption in most parts of the world. It was a shitty situation, especially in Britain, and many people there probably still carry the disease without knowing it because it can take up to 50 years to show symptoms. That's also the reason why many countries still won't allow you to donate blood if you lived in Britain at the time as the other comment mentioned. So saying that we didn't learn from it or changed nothing is just wrong. Another outbreak like the original one is basically impossible in the western world.

Mordisquitos 3y ago

Prions are indeed very concerning on a concrete per-instance basis, but —unlike viruses— not that concerning in the abstract as a generic threat. Prions as a phenomenon do not exploit an essential feature of our metabolism, and cannot 'evolve' per se, but are limited to the specific cases in which a) a given protein sequence can stably misfold rendering it ineffective, b) exposure of already functionally 'eufolded' proteins to the misfolded one can trigger subsequent misfolding, and c) misfolded versions of the protein can and do consistently come in contact with non-misfolded functional ones. I'm not trying to downplay the threat and incredible difficulty of preventing known prion diseases, particularly with regards to destroying the infectious prions. However, to illustrate the rarity of the phenomenon on a per-protein basis, consider how the processes involved in cooking have themselves been denaturing (i.e. mifolding) an unimaginable number of all kinds of proteins in a myriad of ways all since human prehistory, and yet we have no known examples nor even hints of new prions having been created in the process.

lumost 3y ago
The mass processing of food could be the additional mechanism allowing mass distribution of prions, no? Through processed foods, an apex predator like humanity comes into contact with proteins from several orders magnitude more animals than our ancient hunter gatherers or farmers. This problem is compounded as our livestock eat processed foods themselves. Perhaps prions were not as dangerous for most of evolutionary history as they simply lacked a distribution vector?
- consumer451 3y ago
  > The mass processing of food could be the additional mechanism allowing mass distribution of prions, no? My grandmother was from "the old country" and would never allow us to buy ground meat in a package. She made us ask the deli to grind her selected cuts, in front of her. Back then, I wrote this off as some kind of old world silliness. I remember being embarrassed about the whole kerfuffle. I know she wasn't thinking of prions, just contamination in general. Now I realize that I was the silly one, and she was very wise.