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  • Hi this is David from MinuteEarth.

  • Throughout history, the biggest threat to humans has been physical harm either through

  • injury or infection.

  • So it's not surprising that our bodies have developed a bunch of internal systems that

  • respond once our external defenses have been breached.

  • One of those systems is led by a special enzyme called COX that lives in tissues throughout

  • our bodies.

  • When we get injured, the nearby COX makes a chemical that triggers the production of

  • lots of extra sticky platelets, which rush to stop the bleeding by clotting the wounds.

  • And when we get an infection, the nearby COX makes a different chemical that helps dilate

  • our blood vessels, so that a rush of fluid brings our tough immune cells to fight the

  • intruders.

  • But the world has changed; not only are pathogens and violence no longer our biggest threats,

  • but we also have other - sometimes better - ways to deal with them.

  • Our COX enzymes don't know that, though.

  • And in an ironic twist, we may be more likely to be harmed by our COX's response to perceived

  • threats than we are from the actual injuries and infections it's supposed to protect

  • us from.

  • That's because in the modern world, COX is often triggered into action unnecessarily,

  • and the ensuing response can have disastrous results.

  • For example, compared to our ancestors, modern humans - with our sedentary lifestyles and

  • fatty diets - are far more likely to build up cholesterol deposits in our blood vessels

  • - including the ones in our hearts and in our brains.

  • If one of the globs happens to break open, COX gets confused and initiates the same sticky

  • platelet response that it does when you actually rupture a blood vessel.

  • Except that this time the resulting clot can stop blood flow altogether.

  • If this happens near the heart, you get a heart attack.

  • And when this happens in the brain, the clot can cause a stroke.

  • And to make things even worse, those same sedentary lifestyles, fatty diets and other

  • modern behaviors seem to make our bodies think that we have infections in certain places

  • when we don't.

  • But COX helps flood our system with fluid and immune cells anyway.

  • And with no actual infection to fight, some of those excited immune cells start attacking

  • the body instead, which can result in autoimmune disease, depression, and even certain types

  • of cancers.

  • As a result, even as our chance of dying from injuries and infections has decreased, our

  • chances of dying from COX-related problems has actually increased.

  • We don't want to totally eliminate COX - we still want it around in case we do get a serious

  • injury or infection, and because it also helps protect our stomach lining.

  • But for certain parts of the population - like older folks with more cholesterol deposits

  • - it makes sense to deliberately lower COX's ability to react to any threats, real or perceived.

  • And it turns out that Aspirin - yep, that little pain pill in your cupboard - actually

  • ties up any COX it comes across, thus decreasing your chances of getting certain COX-related

  • problems.

  • Taking Aspirin regularly has some risks: by blocking COX, we're more prone to internal

  • bleeding and stomach ulcers.

  • But even so, studies show that when people over 50 with high risk of heart problems regularly

  • take low-dose Aspirin, they on average have reduced health care costs and longer lifespans.

  • For modern humans, it seems, one of the best ways to save lives is to deliberately stop

  • our bodies from trying to save their own lives.

  • This video was sponsored by the University of Minnesota, where students, faculty and

  • staff across all fields of study are working to solve the Grand Challenges facing society.

  • One of these challenges is advancing health through tailored solutions, which includes

  • improving our understanding of the risks and benefits of the COX enzyme.

  • Dr. Jeffrey Chipman, of the Department of Surgery, was part of the team that discovered

  • a second form of COX and changed its story.

  • And Dr. Russell Luepker leads the Minnesota Heart Health Program and its "Ask About Aspirin"

  • campaign.

  • Thanks University of Minnesota!

Hi this is David from MinuteEarth.

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How The Modern World Tricks Our Bodies Into Hurting Themselves

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    林宜悉   に公開 2019 年 11 月 09 日
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