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Speaker 1: Welcome to Brainstuff, a production of I Heart Radio, Hey

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Speaker 1: brain Stuff Lauren Bolga bomb here. A thorough inspection of

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Speaker 1: an old Viking latrine in Denmark has confirmed what we've

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Speaker 1: all sort of suspected. The lives of early Scandinavians were

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Speaker 1: not especially sanitary. These otherwise hardy people were crawling with

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Speaker 1: intestinal parasites, mostly due to the food they ate and

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Speaker 1: because they lived in close quarters with their livestock. The

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Speaker 1: outpousing question was active a thousand years ago, but recent studies,

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Speaker 1: including one published in twenty six and the journal Nature

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Speaker 1: Scientific Reports, show that the genes of some modern people

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Speaker 1: are still haunted by the ghosts of those Viking parasites.

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Speaker 1: They may even contribute to the reason why lung diseases

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Speaker 1: like chronic obstructive pulmonary disease and emphysema are so prevalent worldwide,

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Speaker 1: affecting around three hundred million people, nearly five percent of

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Speaker 1: the global population. Of course, these types of diseases are

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Speaker 1: most common in smokers, but there is one heritable risk factor.

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Speaker 1: It's genetic. It leads to your body having a deficiency

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Speaker 1: of this protein called alpha one ant trips in or

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Speaker 1: A one a T that deficiency is caused when your

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Speaker 1: body makes slightly different forms of A one A T

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Speaker 1: than normal. These deviant forms of A one A T

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Speaker 1: are particularly common in Scandinavian populations, and for years researchers

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Speaker 1: have been stumped as to why the deviant forms exist

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Speaker 1: at all. But these new studies show that they can

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Speaker 1: be traced back to the way vikings adapted over generations

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Speaker 1: to being completely overrun by parasites. It's a weird answer,

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Speaker 1: for sure, and it's a big deal because in your body,

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Speaker 1: A one AT normally protects your lungs and your liver

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Speaker 1: from these enzymes called proteases. Basically, proteases are enzymes that

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Speaker 1: break stuff down. Your immune system produces them as part

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Speaker 1: of its normal functioning, But in your lungs and liver,

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Speaker 1: your immune systems proteases can break down healthy tissue, leading

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Speaker 1: to diseases like emphysema, and those alternate forms of A

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Speaker 1: one A T don't help protect you like they should.

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Speaker 1: It turns out that what they do help with is

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Speaker 1: protecting you against parasitic worms. Okay, in your body, when

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Speaker 1: something like a parasitic worms sets up shop, your immune

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Speaker 1: system creates antibodies to try and kick them out, but

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Speaker 1: the worms have counterattacks. They produce proteases that break down

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Speaker 1: those antibodies. And it turns out that those alternate forms

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Speaker 1: of A one A T are really good at teaming

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Speaker 1: up with, or more specifically, binding to, your antibodies and

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Speaker 1: preventing them from being broken down so your body can

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Speaker 1: clear the parasites. Useless for protecting your lungs, great for

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Speaker 1: protecting you from parasites. And because Viking didn't smoke tobacco

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Speaker 1: and lived relatively short lives anyway, your average Viking would

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Speaker 1: have been unbelievably fortunate to make it to the age

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Speaker 1: of fifty. The fact that the deviant forms of A

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Speaker 1: one A T didn't protect them as effectively from lung

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Speaker 1: disease wasn't as important as the fact that they helped

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Speaker 1: them deal with their worms. These days, however, things are different.

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Speaker 1: Some people do smoke tobacco, We've got a decent grasp

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Speaker 1: on food safety, better practices for animal handling. We regularly

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Speaker 1: live past the age of fifty. We need A one

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Speaker 1: A T to prevent proteases from corroding our lung tissue.

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Speaker 1: Yet some of our bodies are still living in the

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Speaker 1: Viking age. Today's episode is based on the article Viking

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Speaker 1: toilet worm investigation that finds genetic clues to emphasemas. Origins

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Speaker 1: on how stuff works dot com, written by Deslin Shields.

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Speaker 1: Brain Stuff is production by Heart Radio and partnership with

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Speaker 1: how stuff works dot Com, and it's produced by Tyler Klang,

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