The Science of Tattoos - Human Body Theme

Tanner 0:01

how does that even work? How do you get the ink from your skin into your bowels?

Sups 0:06

You're telling me they didn't teach you this in med

Tanner 0:09

I Oh, how could it be a lie?

Sups 0:13

Hmm.

Andi 0:15

So now let's say you have some remorse

Tanner 0:18

Yeah. you wanna

Andi 0:18

get your tattoo

Sups 0:19

Yeah.

Tanner 0:20

No regrets.

Andi 0:21

No, you have regrets. You want it removed. Okay, I love how Tanner giggles every time you mention poop

Tanner 0:27

Yeah, every time.

Andi 0:29

Hello and welcome to this episode of I Should have known the Trivia Game Show that Can't be Trusted. Each week, one of our quiz masters will present you with four facts about a topic, but one of them is a lie This month we are celebrating the human body. its abilities, how it looks, how it changes, how it works, all kinds of things. So for this week, I'm your quiz master. I'm Andy, and I'm doing an episode on the science of tattoos., this topic was fan suggested. Oh If you would like to suggest ideas, get in touch with us, either on social media, leave a comment if you are watching on YouTube or listening on Spotify,

Tanner 1:08

Yeah, So shout out to Josh for this special request.

Andi 1:11

Yeah, So, yes this is going to be about the science of tattoos and we're not gonna talk about any of like the cultural significance, just the science. I will present you with four facts about the science of tattoos, but one of them is a lie. So join our other hosts, soups and Tanner in figuring out which one it's,

Sups 1:29

Mm-hmm.

Andi 1:30

so to start it off, we have our P Q Q, our pub quiz question. Alright. Okay. So what is the medical term for the deep, or true layer of skin? Now, I'll give you an extra

Sups 1:42

hint. Okay. Is

Andi 1:42

It's where the name for doctors for the skin comes from.

Sups 1:45

Okay. A dermatologist. Uhhuh. Yeah. So Dermis

Andi 1:48

Dermis. It's the dermis. Yes, exactly. So yeah, your skin has Dr. Tander, I'm gonna tell you

Tanner 1:55

this. Tell me please.

Andi 1:56

The skin has two main layers. The dermis is also called the true skin. and then the epidermis, which is the outer layer. So we're gonna talk about both of those today. They're very relevant to how tattoos work.

Tanner 2:09

Okay. So we're going a little deeper

Andi 2:12

It's deeper than skin. Deep ha. We Are you ready for some facts? Yeah. All right. Just remember one's lie.

Tanner 2:20

All right.

Andi 2:20

Fact number one, having more tattoos is highly correlated with reduced immune response.

Sups 2:27

Mm.

Tanner 2:27

having more tattoos. Lower immune response. So you get sicker more often? Potentially.

Andi 2:33

Potentially, yes. It was just simply by, studies measuring the number of immune cells in people's blood. So

Sups 2:40

mm-hmm.

Andi 2:41

Mm-hmm.

Sups 2:41

But why

Andi 2:42

So it has to do with how tattoos work, So a tattoo, gun or needle injects the ink into the dermis.

Tanner 2:51

Mm-hmm.

Andi 2:51

Now ink is a foreign invader, and when our bodies sends a foreign invader, they send immune cells to the location and get rid of it. Yeah. Right. That's how your body works. So the ink triggers that response. Mm. Your immune cells arrive and they try to grab the ink and run away with them. Yeah. Particularly, we're talking about macrophages.

Tanner 3:11

So these are the cells that go in and eat the

Andi 3:14

Yeah. They wrap their bodies around it. So you could call it eat and then what they do once it's inside the macrophage, it releases enzymes that are supposed to break it down, and then it can be released into the rest of the lymph system or the blood system. But the ink molecules cannot be broken down by these enzymes, and so they remain in the body of the macrophages. So actually the tattoo Ink is not technically stored in the dermis. It's not technically in your skin. It's not the skin cells, it is the immune cells inside your skin that are actually holding the ink.

Tanner 3:50

Really? That's kind of mind

Sups 3:52

blowing. My mind is blown. Yeah. Yes. Yeah. I'm flower gusted.

Andi 3:57

Yeah.

Tanner 3:58

So what happens to these immune cells? Why do some people have lower

Andi 4:03

So they aren't a hundred percent sure of why, but they did these studies and they looked at people who have more tattoos,

Tanner 4:10

mm-hmm.

Andi 4:11

When they checked their blood, they had fewer immune cells. And so the theory is that because their immune cells are holding this ink, They can't be running around fighting off bacteria or whatever, and this is why you don't see as much of a response in a situation where you should see them.

Tanner 4:28

Okay. So they're like already responding to an infection sort of via tattoo. Mm-hmm. And you can't just make more, you could to replace them, but they don't need to be replaced. They're still

Andi 4:40

Yeah. That's what they think is the reason.

Tanner 4:43

Interesting.

Sups 4:44

Wow. Okay. But that's so cool. I never thought about like how tattoos work and to learn that, you know, I'm, I'm, she's really fascinated by it, that's super

Tanner 4:54

cool, but I've never heard of this, But does the rest of your body react to that by making more so then you don't have lower levels? Or is it really like, You used up all your macrophages. Sorry, we, we don't have any more for you.

Sups 5:08

Are there limited number of macrophages in the human

Tanner 5:11

body? I don't think so. I mean, it's just what your body comes to a natural balance with. Mm-hmm. You know, if they're already employed somewhere else, it's not like, oh, we went over the certain quota and now we're sick. You know, like, mm-hmm. I don't know. If this is so true or not,

Sups 5:26

Yeah. As she started explaining, there are things which, yeah, one plus one is not two, that kind of feeling. But we've got three more facts to go, so we'll find out more about tattoos.

Andi 5:39

Okay. So, Fact number two, light colored ink often shows poorly on darker skin, so like white ink or pastel colors.

Sups 5:50

Yes.

Tanner 5:50

Yes. So this is talking about the science of ink and light and skin.

Sups 5:55

Ah, I mean, do we have to do some physics here? Let's understand some color theory, maybe,

Andi 6:00

that's what this fact is playing on. Right? Is that in color theory, the contrast? You should be able to see it better.

Sups 6:06

Yeah.

Tanner 6:07

Yeah. I mean, light colored ink often doesn't show up well on any skin tone. Right? I don't know about the validity of this. I don't know.

Andi 6:16

probably important to note because there are some misconceptions, but any skin tone, any skin color can be tattooed, right? You are a human, you can be tattooed, pending medical issues.. but If you used white ink or light colored ink, it would show up very well on dark skin It's just contrast in the same way that black ink would show up very well on light skin. But the reason for this about light colors and many other colors in general, has to do with how tattoos heal.

Tanner 6:45

Oh.

Andi 6:46

so now we are talking about the epidermis. Okay.

Sups 6:49

Okay.

Andi 6:49

So the tattoo doesn't only go into the dermis, it also tattoos the epidermis as well.

Tanner 6:55

Right. 'cause it has to get

Andi 6:56

because it has to go all the way down. at first the tattoo might look great. So if you don't have tattoos, maybe you don't know this, but when they heal, they peel. Oh, and they come off in flakes The color of the ink. Yeah. Mm-hmm. So I have a blue tattoo on my wrist and it flaked blue. Yeah. This is your epidermis. Mm-hmm. Once all of the epidermal layers have healed and produced new ones, now you won't have flakes anymore. But this is the window through which you're seeing that. tattooed dermis. Right? How the tattoo will appear after it heals, does depend on your skin color. So your epidermis. On top of your dermis. It is not transparent. Melanin, which is the pigment in your skin that causes it to be darker. you can think of it kind of like a tinted window, The more melanin in your skin, in your epidermis, the darker it is, the harder it is to see down into the dermis,

Sups 7:51

Okay.

Tanner 7:52

but it is still a window. You can still kind of see what's

Andi 7:55

Yeah, exactly. You can still see through it, but it is a bit harder to see through the darker your skin is. Mm-hmm. So that's the mechanism behind it.

Tanner 8:05

and the idea behind your fact is then the more melanin in these epidermal cells in darker skin people makes that lighter color tattoo harder to see. Mm-hmm.

Andi 8:16

Yeah.

Sups 8:16

Okay.

Tanner 8:17

I mean, if you're talking about layers of something that light has to penetrate and then you see color, I'm thinking of like the ocean, like, it's about absorbing the colors. It's about how the wavelengths are bounced back to us, right? So, It checks out to me. Checks out.

Sups 8:34

out. Yeah. So far, yeah.

Tanner 8:36

I'm thinking about this and I'm like, where could this be a lie? Checks out. So, well the science,

Sups 8:42

I mean, first thing, first I want to check, like, is my skin transparent? Is that the reason why we see like these blood vessels, And so that's what is, so this skin is not transparent, you said.

Andi 8:53

not perfectly transparent. Right. It's not clear like a window.

Tanner 8:57

It's also not fully opaque, so you can see some under your skin.

Sups 9:02

Hmm.

Andi 9:02

I love that. Listeners, it's very funny. Both of the boys are like looking at their hands and their arms being like, oh, how does my skin work?

Tanner 9:09

Look at my skin. Examine my tattoos. I have a very light colored tattoo on my ankle. It's orangeish.

Sups 9:15

It's Okay.

Tanner 9:17

Pretty hard to tell against my

Andi 9:19

skin Yeah. You can't really see his tattoo.

Sups 9:22

Yeah. Right. Okay.

Andi 9:23

close too, actually.

Sups 9:24

Yeah, yeah, yeah, yeah. Like, I feel like it, it doesn't look like a tattoo. It looks more like a highlighter, like, you know, someone just draw a light, that

Andi 9:30

It It, is bright orange. Yeah.

Tanner 9:32

So this checks out to me. Yeah. So if my skin color was darker, of course these would look different and the lighter colors would be harder to see.

Sups 9:41

Yeah.

Tanner 9:41

Oh, how could it be a lie?

Sups 9:44

Hmm. So should we do fact number three? Yeah. Fact number three. Medical tattooing dates back to at least the second century ce.

Tanner 9:54

That's a long time.

Andi 9:56

it's

Sups 9:56

how

Andi 9:56

2000 years

Tanner 9:57

Well,

Sups 9:58

What is a medical tattoo?

Andi 10:00

So a medical tattoo. it's not exactly a clear thing Really anything that's not purely aesthetic. Sometimes it is actually therapeutic. Mm-hmm. And Also you can have tattoos that help with imaging.

Tanner 10:15

Right. 'cause you mark a part of your body with a tattoo and then you can just easily check that part of your body Exactly the same spot every

Andi 10:23

time. Yeah. And then in the same way where some people wear medical bracelets to, show that they have medical conditions. That paramedics should know about, but they maybe won't be able to vocalize people. Get those

Tanner 10:35

tattoos as well. right? EpiPen? Just right across your

Andi 10:37

Yeah. Yeah. there are many different kinds, therapeutic and also reconstructive. the oldest one that can be really like, strongly corroborated is from one 50 ad. Okay. Or CE done by your boy Galen.

Sups 10:53

Mm.

Tanner 10:53

classic anatomist.

Andi 10:54

Yeah. So the Greek physician if you've taken any history of medicine, you've heard of Galen. He wrote about a. Process called corneal

Tanner 11:05

Oh God. Oh

Andi 11:06

no.

Tanner 11:07

That's in your eyes. Oh, Don, shove needles in your eyes please.

Andi 11:10

So the cornea is the clear part of your eye in the case that Galen was describing, it was in order to cover leuk mattus opacities, which are milky white spots in front of your eye. So if you have like a milky eye and you feel like it looks weird, you can have it. Tattooed over so that you look like you have a normal iris. Oh, some people do get corneal tattoos aesthetically, but it's very, very rare. It's almost always done by a medical professional. Mm-hmm. And the process of tattooing your cornea is very different from your skin? Yeah. Yeah. But it works because your cornea has no blood vessels or lymph vessels. Okay. It's clear. Mm-hmm. So because of that, there's nothing to take the ink away. Right. It does slowly degrade and so sometimes you might need to get it again. Mm-hmm. Yeah. So it's very different from your skin.

Sups 12:04

What was the year again? You said

Andi 12:05

1 50 ce. Second century.

Sups 12:09

Wow.

Tanner 12:10

How did, Dang it. Geez. That's gross. I don't want to know how they did it.

Andi 12:14

Oh, yeah, I he describes it very clearly. Yeah. Lemme tell you. Mm-hmm. Um, it's, I do love about that

Sups 12:20

a second, but yeah,

Tanner 12:21

it needle. Oh,

Andi 12:22

gross. Oh,

Tanner 12:23

oh no.

Andi 12:24

no.

Sups 12:25

this sounds way too old. No.

Tanner 12:27

Yeah, it's a long Time ago. But I also think, who would say this is a good idea? You have to be like 2000 years old to do this, you know? I mean it, there's a medical reason to do it. Okay. Yeah, that makes sense. Is it that old

Sups 12:41

I mean, she had a lot of facts to back her point up, but also she was describing more, not so much about the age, but actually like the process or more like, you know,

Tanner 12:51

Right. I really have nothing to go off of. I think it, it's either that old or it isn't because it's still done.

Sups 12:57

Or do you think it's even older?

Tanner 12:59

Oh, good point. Could be. Hmm. I'm inclined to believe this one. Maybe just because I think that the Greeks and Romans did all kinds of stuff like this, and so I wouldn't put it past them.

Sups 13:12

Yeah. I mean, when you have like a really absurd, and you drop the G word. Yeah. Yes. Nine out of 10 times because they've done so outlandish things. It might just make sense. Or it might just happen.

Tanner 13:28

Yeah. Yeah. I mean, yeah, outlandish medical treatments, like drilling holes in your skull was also commonplace at one time, so like I believe

Sups 13:37

that, Yeah. Okay. We've got one more.

Tanner 13:40

Yeah.

Andi 13:40

one more. So now let's say you have some remorse

Tanner 13:44

Yeah. you wanna

Andi 13:44

get your tattoo

Sups 13:45

Yeah.

Tanner 13:45

No regrets.

Andi 13:47

No, you have regrets. You want it removed. Okay, so fact number four, after laser tattoo removal, you poop out the tattoo ink.

Sups 13:56

Mm

Tanner 13:57

Really? poop. I'm

Sups 13:59

I'm

Tanner 13:59

so sure it's poop. how does that even work? How do you get the ink from your skin into your bowels?

Sups 14:06

You're telling me they didn't teach you this in med

Tanner 14:08

I skipped that day of dermatology, I guess.

Andi 14:11

All right, so going back to how tattoos work, remember the ink is stored in your immune cells. So what a laser does is it breaks down the ink molecules small enough so that they can be taken away by those cells. Okay. so now Your immune cells have this ink and they're carting it through the lymphatic system, now they can be filtered out. So typically it's through sweat. So you can sweat it out. If it gets into your blood, then it can be filtered out by your kidneys and you can pee it out. Sure. Through your urinary system, or especially if it's a metal based ink. It will go to your liver. Mm-hmm. And your liver will filter it out and then that will be sent to your digestive system. And then you will poo out the inks

Tanner 14:59

Okay, So if you've got a bright blue tattoo and you got it lasered off, do you get bright blue poop?

Andi 15:05

That's a very good question, Tanner. No, because the particles are so small. That we can't see them. They're microscopic. Okay. So don't go looking in the toilet to see if your tattoo is in there. Okay.

Tanner 15:17

Okay. And you're not sweating it out like bright blue sweat

Andi 15:20

right? Yeah., it's been broken down small enough so that you can't see

Tanner 15:23

it. Okay. That makes sense with your explanation.

Sups 15:25

Okay. Yeah. Alright. So first things first, laser tattoo removal I've

Tanner 15:31

mm-hmm. Oh, well, so are

Sups 15:34

in my experience, yes. and expensive. And so now the question is sweat pee or poop can be anything.

Andi 15:43

yeah. It's likely a combination of all of them.

Sups 15:45

her explanation sounds pretty good. Mm-hmm. But maybe that's where the problem is

Tanner 15:50

again, like how could it be a lie? How else could they come out?

Sups 15:55

It's laser brew. You're just burning

Tanner 15:57

You're just,

Sups 15:58

Yeah,

Tanner 15:58

it's gone. You

Sups 15:59

It's just gone. Exactly. I

Tanner 16:00

know if you can do that. This ink. has to go Somewhere. I think It might come out your poop. You Sure. Don't like cough it up. So I mean, yeah, it's gotta go out somewhere. never thought of that

Sups 16:12

Yeah. I, yeah. Where does it go? Where does it go? Maybe it's only sweat and it doesn't go to

Tanner 16:18

the Digestive system. Mm-hmm.

Sups 16:20

Yes.

Tanner 16:21

Possible.

Sups 16:21

yes.

Tanner 16:22

Hmm. That's a good point. I think it might be along those lines, but I'm also like, huh? Checks out could be true.

Sups 16:29

I doubt This is like the first thing that laser guy will tell you when he goes, they say, do you know what I'm gonna do? I'm gonna

Tanner 16:34

remove the tattoo.

Andi 16:34

is gonna

Sups 16:35

come out of your poop?

Tanner 16:36

I

Sups 16:36

I'm

Tanner 16:37

would lose some customers then.

Sups 16:38

I don't think that's the kind of conversation they're having there. Wow. Very interesting. And Alright. We are gonna guess which one is not a permanent tattoo.

Andi 16:47

Yeah.

Sups 16:47

But could you remind us the facts, please?

Andi 16:49

Of course. Fact number one. Having more tattoos is highly correlated with reduced immune response. Fact number two, light colored ink often shows poorly on darker skin. Fact number three, medical tattooing dates back to at least the second century CE and fact number four. After laser tattoo removal, You poop out the tattoo ink.

Tanner 17:23

Okay. One is a lie.

Andi 17:25

I love how Tanner giggles every time you mention poop

Tanner 17:27

Yeah, every time. But I don't think it's the poop one. That's a lie. I think that

Sups 17:31

one Yeah.

Tanner 17:33

think number one is

Sups 17:34

oh, I'm thinking number two. The color theory one. Oh. Mm.. Why do you think number one is fake?

Tanner 17:40

I think number one is fake. I think it's a misconception. I think people worry about this like, oh, we looked into it and macrophages hold the ink, but oh no, if I use up all my macrophages with tattoos, won't I get sick more? And I think maybe the science works out that it's not an issue.

Sups 17:56

Like it's not related or, yeah, you make more. Okay. I think number two is, Fake is because the whole explanation of how tattoo works. Yeah, I don't know if the color of the, the skin is the skin. Like, you know, I mean like, okay, melanin, That determines like the shade of the skin, but the structure, but the structure is the same. Right. So, All tattoos should have like the same effect.

Tanner 18:21

right? Yeah.

Sups 18:21

Yeah.

Tanner 18:22

I'm gonna go with the immune one.

Sups 18:23

Okay. Yeah, I, I, I can see why that could be. Yeah, it's one of those that this is a myth or this was believed yeah. Okay. I'm gonna stick with the color one 'cause something seems off about it.

Andi 18:35

Okay. The lie is fact number one,

Tanner 18:38

Aha.

Andi 18:39

but you didn't go far enough Tan.

Tanner 18:41

Oh, deeper.

Andi 18:42

You Gotta go deeper. the truth is that having more tattoos is correlated with having an

Tanner 18:48

Oh. You know, that ran through my head and I was like, no way. That can't be. Yeah,

Andi 18:53

Mm-hmm. So right after you get a tattoo, there's a high immune response. Yeah. Because it's the same as getting an infection or a wound. Yeah. Your cells are like, gimme, gimme, get rid of this. Okay. Yeah. again, it's not exactly clear why, but they think it's a vaccine like response. Oh. I see. You're basically training your immune system to be

Tanner 19:13

Yeah. You're training it. Yeah. So over time you build up,

Andi 19:17

Yeah. I think it's a misconception. You don't run out of cells. Your body will make more cells, and if it feels we don't have enough because they're being used on tattoos, it'll make more. idea

Tanner 19:28

behind how Some illnesses, you have a buildup of too many of these

Sups 19:32

cells.

Andi 19:33

So yeah, that's not a reduced

Sups 19:35

response Okay. actually Okay.

Tanner 19:37

Wow. I wonder

Sups 19:38

why this isn't like a tagline or like a spiel of the tattoo artist that you don't like

Andi 19:44

yeah,

Sups 19:44

But, wow. Okay. Well,

Andi 19:46

Do you wanna go out and get inked now?

Tanner 19:48

Yeah.

Andi 19:50

Yeah,

Sups 19:50

wow. I think I should start considering a tattoo now. I should have known.

Tanner 19:55

I should have known.

Andi 19:56

Thanks for listening to this episode of I Should Have Known. If you are watching slash Listening on YouTube, be sure to like, comment, and subscribe if you are listening on a traditional podcast platform. We would like it very much if you could leave us a review and yeah, let us know if there were more facts about the science of tattoos that you were interested in, if you got the fact right or found any of it interesting or surprising we're going to be continuing our exploration of the human body. we are going to have an episode on rare diseases, but one of them will be fake. So join us for that next week And as always, thanks for listening.

Sups 20:34

Did Mr J have any tattoos?

Tanner 20:37

Jesus,