How Your Blood Type Protects and Hurts You

You already know that your blood type is important. If you’ve lost a lot of blood, getting a
transfusion of the wrong stuff can be deadly. But did you know that whether you’re A,
B, AB, or O can also put you at higher risk for things like malaria, cholera, and heart
disease? The blood type you have is the result of a
specific kind of antigen — in this case, a type of sugar — on the surface of your
red blood cells. If you have the A antigen, you’re type A;
if you have the B antigen, you’re B. If you have both, you’re AB, and if you
have neither, you’re O. But here’s the thing: There’s more to your
blood’s alphabet soup than just those three letters. You also have another kind of antigen — one
you’ve probably never heard of: The H antigen. The A and B that you always hear about are
really extra sugars that get added to antigen H. And what’s more, all of these sugars aren’t
just on your red blood cells. They also appear in your guts, and in other
compounds that are swimming around in your blood, where they interact with pathogens
and toxins and even parts of your own immune system, to make you either more or less vulnerable
to certain infectious diseases. For example, it turns out that having type
O blood can help you, if you contract malaria. One of the big dangers of malaria is when
your red blood cells begin to clump together, forming characteristic flower-shaped patterns
known as rosettes. They form when an infected red blood cell
sticks to uninfected red blood cells — a process that’s helped along by A and B antigens. As a result, people with A, B or AB blood
tend to develop more and bigger rosettes if they get malaria. These cell clusters can get lodged in tiny
blood vessels — often in your brain — and block blood flow. Which is bad enough. But when rosettes get tucked away like this,
it also prevents the infected cells from being cleaned up by your body’s natural defenses. All of this means that people with A or B
or AB blood are at higher risk for a severe case of malaria than people with type O. But, type O blood has its downsides, too. You may fare better with malaria if you’re
an O, but you’ll probably do worse against certain strains of the bacteria that cause
cholera. During an outbreak of cholera in Peru in the
early ‘90s, people with type O blood were 8 times more likely to be hospitalized. And it turns out that type O blood is least
common in places like the Ganges River Delta, where cholera has been making people sick
for centuries. While scientists still don’t fully understand
what’s going on here, one idea is that having A or B antigens might help prevent the cholera
toxin from binding as firmly to some of your cells. But this protection doesn’t take place in
your blood. Instead, it’s the result of antigens on
the cells that line your intestines. That’s where the cholera toxin does its
work, making your cells pump out water and electrolytes, and causing the diarrhea that
makes cholera such a fast killer. For people who have A’s and B’s on these
cells, the cholera toxin can still bind to them. But it binds even more strongly to the H antigen. And since H is the antigen that Type O people
have, O’s are at greater risk for a more severe case of cholera. Finally, the antigens that determine your
blood type can also affect your risk for heart disease. Here, it is the antigens in your blood
that call the shots. But not the ones on your red blood cells. Instead, the key is the antigens on something
called your von Willebrand factor. It sounds like the name of a German techno-pop
band. But von Willebrand factor is a protein that
helps your blood form clots. Obviously, you want to have enough von Willebrand
factor in your blood to stop bleeding in case of an injury. But having too much of it in your circulation
can create clots in places you don’t want… and trigger a heart attack, or a stroke. Thankfully, your body routinely sweeps out
some of this factor. Scientists haven’t quite figured it out yet
but for some reason if your von Willebrand factor has either the A or B antigens on them,
that clearance is harder to do. As a result, people with type A, B or AB blood
have about 25 percent more of this clotting factor in their blood. This may explain why researchers have consistently
found higher rates of heart disease, heart attack, and stroke in people with A, B, or
AB blood, compared to those with O. Now, in the grand scheme of things, your blood
type is only a bit player when it comes to what diseases you might get. Eating too many hamburgers and not working
out, for instance, are almost certainly more damaging to your heart than having A or B
antigens on your blood cells. But scientists hope to figure out why certain
blood types help protect you from some conditions, while making others worse. The hope is that, one day, everyone will be
able benefit, whether you’re an A, B, AB, or an O. Thanks for watching this episode of SciShow,
which was brought to you by our patrons on Patreon. If you want to help support this show, just
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100 thoughts on “How Your Blood Type Protects and Hurts You”

  1. I may be worse off if I get malaria and more vulnerable to heart disease, heart attack and stroke, but at least if I'm like bleeding to death I can get a blood transfusion from any blood type. I have AB+ blood which is basically opposite to O-. O- can donate to any type, AB+ can receive donation from any type

  2. I love how there are references in the video description! Not all "scientific channels" do that. Congratulations for the excellent and informative job!

  3. I have O blood, and my Celiac disease makes my digestive system very stupid, so I better not get cholera or I shall Surely Die

  4. k so first you add that other guy to this show but hank remains now this lady? why? hank is the one we want i literally get so excited by episode titles and then when its not hank hosting i just get mad and click off they’re ruining my experience #teamhank

  5. Have they accounted for the fact that over 50% of Hispanic people have O blood? Maybe that's why the Peru thing happened

  6. What if I get malaria and my type AB blood identifies as type O? According to modern day liberal logic this should help me. If you think anything else you're a racist, sexist, homophobic, islamophobic bigot.

  7. I enjoy the content. I don't focus on who's hosting or providing the information, because that really doesn't matter. As long as I'm learning something new I'm open to listen to anyone talk.

  8. Well it's scientifically proven that mosquitoes are more likely to bite a person with O+be blood group as compared to others. Although the blood groups saves us from the fatal effects of malaria but it makes us more susceptible to be infected by it and other mosquitoes borne diseases. I'm O+ve and i know the pain of being bitten my mosquitoes even if 10 more people are present in the same room. It's a miracle I haven't been infected by any mosquitoes borne infections.

  9. @4:13 Not if you removed the carbs off those hamburgers it's not. Because it's high fat or high carb that keeps you healthy but NOT both!!

  10. …What blood type am I? I hope I'm O, since I've heard that means you can have more than one antipoison/venom of one type.

  11. I love how anytime I've donated blood they always say "You're A positive person HAHAHAHA" I wonder how many times I've heard that lol…..

  12. Olivia, you're an amazing host. I'm a creature of habit, and without your glasses on, it feels weird to me. Keep up the good work educating us all!

  13. Glad it says who is hosting. Not too interested watching someone have a stroke in front of the camera.

  14. This comment section:
    90% about Olivia
    5% about blood type
    4.99% about everything else
    0.01% about comment section

  15. Am i the only one bothered by her not wearing her glasses? Wear did they go? Like dont you need them to read the script?

  16. I'm O and while my Malaria was bad….it wasn't as bad as my AB brother who nearly died from it twice.
    Nice to know why.

  17. All hail blood the "type O" people [the master race] we are the life givers of universal blood donations, and are immune to malaria, obesity, and diabetes 😎😎😎

  18. In Latinamerica over 70% of the population is Group O Rh (+), The type of blood found from the outbreak in Peru is a coincidence. By example the type O is found in about 8 of every 10 patients i've seen in the labor area.

  19. Everyone complaining about her hand movements surprisingly say nothing about LITERALLY EVERY OTHER HOST WHO DOES THE SAME!

  20. You make it seem like A,B or AB suck. I'm not gonna say your wrong because I don't have enough medical knowledge but I don't want those blood types right now

  21. Tbh the main reason i wanted to donate blood last year was so i could find out my blood type. A+, here!

  22. Idk, Im Blood Type O
    Im Very Underweight
    I Rarely Get Sick
    I Have Way More Physical Strenth For my Weight
    Is it my Blood Type that Prevents me from Getting Sick tho im Underweight?

  23. 2:06 Oh, yes, I believe you. Cholera caused many thousands of deaths among Basques (like me, O-) at the beginning of the XX century. Full small villages disappeared as if it was a modern bubonic plague. I remember how my grandfather showed me the ruines of a village close to the French border in which almost all its inhabitants died and the rest emigrated in order to scape from a more than probable dead. During that era almost all houses had their own stable downstairs, with cows, lambs, pigs… and the hygiene was not good. This was a typical Basque house back then: But now all is clean and modern, without animal "poo" everywhere

  24. I’ve been watching these videos for years, and I’ve noticed throughout that each host has their own quirks, and she’s super bouncy when talking lol

  25. you are kinda just making your way through the words – open your mouth to pronounce/project what you are saying

  26. I know more people with O postive blood have caught malaria more so than other blood types. I'm sorry but I don't agree with this. I know more people with O has had many heart surgeries too, along with strokes. It's all in the gut.. if and what we contract of various diseases.

  27. I was always concerned about saying my blood-type in public because of human trafficking for organs and people's blood type being useful.

  28. All this information, which in very intrinsic, SHOULD make people question how all this complexity "just happened due to a piece of rock falling into the ocean and creating EVERYTHING on this planet. Huh?

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