SciShow Tangents - Stimulants

Episode Date: February 5, 2019

Are you one of those people who doesn’t feel awake until you have caffeine coursing through your bloodstream? Well, you can choose to ingest some chemical stimulants, but they’re also something your body makes! Just think about the adrenaline rush before a public speech. This week, we’re going to dig into what science actually says about caffeine and dehydration. Why did some people try to ban coffee, and how dangerous was the pick-me-up given to some Antarctic explorers? And why the heck did researchers think gerbils could help with airport security? Sources:[Fact Off]Gerbils:Forced March:https://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2810%2962153-8/fulltexthttps://granta.com/shackletons-medical-kit/https://www.npr.org/sections/health-shots/2012/09/27/161881513/cocaine-for-snowblindness-what-polar-explorers-packed-for-first-aidhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC1279970/[Ask the Science Couch]Dehydration:http://jpet.aspetjournals.org/content/33/2/167https://www.ncbi.nlm.nih.gov/pubmed/12187618https://pdfs.semanticscholar.org/640f/49f096f9a01e2c3ef103945a39830a12cd5c.pdfhttps://www.nytimes.com/2008/03/04/health/nutrition/04real.html?_r=2[Butt One More Thing]Civet poop coffee:https://www.businessinsider.com/kopi-luwak-cat-poop-worlds-most-expensive-coffee-taste-test-2018-11https://www.britannica.com/topic/Kopi-Luwak

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week joining me as always are Stefan Chin. Hello. How you doing? Good. What's your tagline? Ooh, mysterious peanut.

No, good. That's a weird... Also joined by Sam Schultz. Hello. How you doing? Good, how are you? I'm okay. We'll talk about it a little bit later.

Okay. What's your tagline? Big dog in a little pond. Oh, whoa. Sounds later. Okay. What's your tagline? Big dog in a little pond. Oh, sounds nice. Yeah. Sari Riley, writer for various science-y things is also here. Sari, how are you? I'm okay. Yeah. Everybody's doing okay today. Yeah. It's very cold in the studio. We're all bummed. Hank has the only blanket. I have, I got the blanket first. You can't have it. What's your tagline? New blood, new me. Ooh, whoa.

Where'd it come from? That's a mystery. Alright. You're always making new blood. It's cool. That's true. And I am Hank Green, creator of SciShow, I think it's fair to say. And my tagline is cozy little snuggle

bucket. Ooh, cute. Snuggle bucket? I don't know what the last word was. I think it might be bugget. It's a cute word. Thanks. A little bug nugget. Cozy little bug nugget.

So every week here on SciShow Tangents, we get together and try to one-up, amaze, and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding Hank bucks. We do everything we can to stay on topic, but judging from previous conversations, we will not be great at that. So if the rest of the team decides the tangent is unworthy,

we will force you to give up one of your Hank Bucks. So tangent with care. Now, as always, we introduce this week's topic with the traditional science poem. A group of drugs that invigorate the body. Some addictive, some make you go potty. Some help you focus even if you're groggy. Many are used illegally.

Catnip, nicotine, alcohol, methamphetamine, and of course, don't forget our good friend caffeine, placed in a drink that can give you wings. Here I go, up, up, and away, feeling great for most of the day until the effect starts to decay. Wait, how much do my eyelids weigh? What a nice poem.

Yeah. It's like listening to a Dr. Seuss story. Science. Yeah, so our topic for the day is is stimulants and caffeine I just finished my Coca-Cola I am nonetheless

still feeling not particularly stimulated you look very I don't know I always am really tired after shooting SciShow

yeah like I shoot and even like it doesn't really matter how many episodes I do I'm like I am ready

to go down now thanks I don't know why it's so exhausting you're throwing your all into it gotta put my all really matter how many episodes I do, I'm like, I'm ready to go down now, thanks. I don't know why it's so exhausting. You're throwing your all into it. I gotta put my all into it. Yeah. It's true. It is cognitively demanding. Yeah. Hard to read that stuff so fast, probably, right? I've never done it. You've never done it?

No. Throw it out. Stefan, what do you think? Do you get tired afterward? Not if it's just a couple scripts. Yeah. But if I have to do any more than that yeah it's more that like my mouth stops working yeah it's weird my tongue gets sore yeah i'm like that's not supposed to happen why is my tongue tired yeah and everything dries out everything dries out mostly my mouth yeah so the topic is stimulants. Sari, do you know what those are? Yeah, they're like a very broad category of things, which I don't know if that was interesting. We don't have one key example of a stimulant, but basically they're chemicals that interact with

the biology in your body, usually some sort of receptor that binds to a neurotransmitter normally and causes you to be more active or awake or alert or any number of those. Yeah, and those are good things. We would all like to be more active, awake, and alert. So they make your brain be something, but they all do it in different ways? Yes.

They don't all do it in the same way. Yeah. So they really aren't. It's like a weird umbrella term. Yeah. Like caffeine, for example, acts differently than a lot of other stimulants i think a lot of stimulants interact with i want to say dopamine

pathways um and like the reward systems in your brain so that's why they're addictive is because they reinforce they like give you energy and then reinforce that behavior because it's whatever neurotransmitters are involved in feeling good and feeling pleasure in addition to feeling alert. And everything is super interconnected, so it's hard to untangle these things. But caffeine specifically interacts with adenosine receptors and adenosine is a neurotransmitter that affects like how drowsy you feel. And so caffeine is an antagonist to that. So it binds to the receptor in some way, which blocks the binding of adenosine. And so it keeps you awake that way.

So it doesn't so much stimulate me as prevent me from feeling drowsy. Yeah. It's failing at the moment. The adenosine already got there. We'll see what happens. Yeah, the adenosine was already bound. Yeah. It's already competed the caffeine out of the way.

Aren't coffee naps a thing? Is that a thing? thing yeah coffee naps are better than coffee or naps alone so i think it's when you have some some caffeine and then you go to sleep immediately then you sleep for 20 minutes or less and then you wake up feeling real good so if you guys are cool with it you just do the rest of the podcast for 20 minutes i'll be back i'm just gonna just lean over get my pizza john blanket up to my chin we should have nap pods but is it a coca-cola nap or is it just just do the rest of the podcast for 20 minutes. I'll be back. I'm just gonna lean over, get my pizza-jump blanket up to my chin. We should have nap pods here. But is it a Coca-Cola nap or is it just a coffee nap? It's probably too late.

It's too late. I finished it like 15 minutes ago. I wonder if the sugar would mess up your nap too somehow. Yeah. Seems like an impure coffee nap. That's good sugar though. Yeah. Takes about 20 minutes for caffeine to hit your brain that's pretty fast oh I think that seems

like a long time I feel like when I drink coffee I must just have been drinking it for so long that I'm just like I'll feel better soon so I feel better now is that a real

that's a real thing right it's also possible that smelling the coffee has some of the effect of drinking the coffee yeah you've got you've got sort of like Pavlov'd

into into getting stimulated. It's like, you know, you rang the bell and I'm drooling. I smell the coffee and I'm awake. Coffee has a wonderful smell. I hate it. Really? I've never had a cup of coffee in my life. You never even tasted it?

Well, if you don't like the smell of coffee, you definitely don't like the taste. I don't think it tastes like how it smells. It smells better than it tastes by a long shot. But maybe if you don't like the smell, you would like the taste. So one time I ordered a hot chocolate from Starbucks and they gave me a mocha instead and it tasted bad. Oh, you didn't like a mocha. Good though. Wow.

She didn't like a mocha. There is no help for you. Mochas are coffee for people who like coffee but don't like to drink coffee. I think it's a no for me. Coffee's the best. And now, my friends, it's time for Truth or Fail. One of our panelists has prepared three science facts for

our education and enjoyment, but only one of those facts is real. And the rest of us have to figure out by wild guess or deduction which fact is true. And if you do, you get a Hank Buck. If you don't, then Sam, who was our presenter this week, will get the Hank Buck. Sam, hit us with three caffeine-slash-stimulant-related science facts. Okay.

Here in America, we are living in a time when coffee is viewed by some to be the vital lifeblood of our nation. Oh. Coffee is viewed by some to be the vital lifeblood of our nation, keeping our country's overworked employees working through their double shifts and their overtime. But that has not always been the case. Throughout history, there have been times when people have tried to ban coffee because they thought it was bad for the brain and other things. Sure, it does give you headaches. Which of these pseudoscientific attempts to destroy coffee's good name are real?

Wow. French wine dealers in the 1700s, afraid of the toll coffee consumption was taking on their businesses, spread a questionable study that coffee consumption suppressed sexual urges. Number two. In the 1700s, the king of Sweden read a report that coffee was potentially a deadly poison, so he had it banned from the kingdom and began testing the effects of coffee on his prisoners. And number three. And they were like, actually?

And he just had a Starbucks installed in the basement. In the 16th century, dogs were given coffee as part of a study put on by the Catholic Church to show that it made them paranoid, violent, and conspiratorial. And this was used as evidence that there should be a ban on coffee because it was a potential catalyst for social unrest. Well, I mean, the Catholic Church in the 15th century was very worried about social unrest. So that's legitimate.

I don't know if we had coffee then, 15th century, do you say? You can't look at me while you're saying this stuff. Can anybody describe a conspiratorial dog to me? I feel like it's if you took a pack of hunting dogs and then instead of following you,

they like huddled up together and like barked at each other and then hit around corners or ran away from you. That's cute. I like it. Very good Looney Tunes episode. Yeah.

Put a bunch of coffee in their dishes and they're just like, and then they turn into people who hate the Catholic Church. Okay. I like that one because I know that that's something the Catholic Church would do. Yeah, it sounds the most real to me. Yeah.

For that time period. I'm like, of course they would think dogs are like creating social unrest in some way. The French wine one also sounds real, though, because if you wanted to scare people away from drinking something, impotence is the way to do it historically. And I'm sure that like French wine people were very, very interested in exerting their dominance over the drink market. I'm just not sure if studies were a thing. Right. Studies is a little bit of a weird word. But I think, you know, like using, like obviously science didn't exist as a thing back then.

But one of these is true. Yeah. But one of them doesn't have the word studies. It has the word rumors. Right? Well, what was this Swedish king one? It was. Oh, he was just testing it on his basement people.

Yeah. On his prisoners. But he didn't do a basement study. He read a report. He read a report. I bet. Well, I don't know. We didn't have isolated caffeine.

Isolated caffeine would possibly kill someone. I don't think you can just die from drinking the amount that would be in. Right. You couldn't fit enough coffee inside of you to overdose on caffeine. Yeah. So I don't think someone would be poisoned. No, but he didn't say that they were. He just said they were testing.

No, because he was afraid that it was poisonous. Oh, everybody's afraid of things. They're afraid of non-dangerous things all the time. That's true. And we have science now and we're still afraid of everything true true yeah it's true we're afraid of lots of things that science is like that's okay people are still like no i don't think it is um i'm gonna go i feel i'm feeling actually pretty good about giving coffee to your prisoners i like that one because i'm wondering if they also got biscottis. And discussed philosophy.

Yeah, they just thought they were down there and they suddenly became very sophisticated. I'm going to go with the dogs. Conspiratorial dogs. I'm in on the prisoners too. Oh, double prisoners. You ready? You two get Hank books. So, King Gustav III of Sweden read a French doctor's paper that said that coffee could shorten a man's life. And he kind of overreacted and he banned coffee.

He banned like coffee pots and everything from Sweden. Coffee pots? I thought you said coffee pods for a second and I was like, they have curry? Is curry a Swedish word? They probably have been sitting on that pods for a second, and I was like, they have Keurig? Is Keurig a Swedish word? They probably have been sitting on that technology for a long time. I have a tangent about Keurigs, though. The guy who invented them almost died of caffeine poisoning because he was drinking between 25 to 30 cups a day. And he went into the doctors because he was having heart palpitations and weird headaches.

And the doctors did all these tests and eventually they just started asking him questions about his life. Like, are you getting enough sleep? How many cups of coffee are you drinking per day? This idiot was drinking so many. I appreciate his commitment to ensuring the quality of his products.

You know, I also, if anybody's going to drink 30 cups of coffee a day, it should be that guy. But that's the first thing you say when you get to the hospital. Hello, my name is Mr. Keurig, and I drink 20 or 30 cups of coffee a day. I don't feel good. Do you want to hear the end of my story? Yeah, I'm so sorry. So Jover reacted about this.

He had coffee banned in Sweden in 1715 and then he began trials on his prisoners who were imprisoned for life. He gave them three pots of coffee a day. He had his doctors give them three cups of, three pots of coffee a day.

Oh, that's a lot. Until they died. Oh, geez. But, the doctors doing the experiment died of natural causes before the prisoners died. Oh.

Then, the king got assassinated before the prisoners died. And he got assassinated in like the 1780s or something like that. So these prisoners were just drinking coffee and they were feeling fine down there. But coffee was banned in Sweden until 1820. Oh my God.

From that same ban. So nobody just had to overturn it, I guess. But they also banned coffee pots like this is coffee paraphernalia. Yeah, exactly what it's like. It's like when the cops see a bong and they're like, no, I just smoked tobacco out of that. Tobacco pipe. It's fine.

I was making tea. They weren't allowed to have tea either. That was also part of the test. What a boring place. What did they drink? Beer, probably. So it's probably kind of cool. Which is kind of part of,

okay, so the French wine thing, totally wrong. French wine dealers didn't really like that coffee was cutting into their business but the french like aristocracy freaking loved coffee so they didn't right right um and then the conspiratorial dog one is in like there were certain places where coffee was banned because people would get together and drink coffee so it was a tool of the revolution in some governments' minds, and that was the reason that they would ban it. And then one other thing is that the king of Prussia banned coffee

because he thought that beer just made you stronger and cooler. Coffee is for wimps, but beer is for real men. But I don't usually drink beer at times when I would be drinking coffee. But I guess maybe that's... He wanted his soldiers, he literally said that everybody should wake up and drink a beer every morning. Because that's how he was raised and he was cool and strong. Oh, man. And that everybody should be like him.

Yeah, everybody should have diarrhea like him. Whoa. Wait. I just feel like you wake up in the morning, you have a beer. Yeah, eventually you wouldn't feel so great probably. Yeah, I feel like my stomach would be upset by that. Yeah. All right.

Well, so we got some Hank Bucks, Sari. It's time for us to go make some real bucks. Welcome back. Here's our totals for Hank Bucks. I'm just going to do it real quick because it made it easy for me. Everybody's got one. Oh, yeah. Now it is time for the fact off. Two panelists bring science facts to present to the others in an attempt to blow their minds.

You, the present-ees, each have a Hank Buck to award the fact you like the most. And who's going to go first? Let's just say it's the person who most recently had a cup of coffee, I guess. Was it you? Right. Yeah, I guess. As previously discussed. Yeah.

Okay. Let's go by the person who slept the most last night. The person who least needs stimulants. Ooh. Who slept the most last night? The person who least needs stimulants. I went to bed at around 11 and I got up at 6.30. What? So I slept 7.30 hours. I went to bed at around 1 and got up around 7. So 6 hours.

Everyone wakes up so early. How are you functioning right now? What did you do until 1? I just couldn't sleep. I've been having a really hard time sleep falling asleep lately it's not because you're drinking too much coffee no i don't drink any caffeine i haven't drank caffeine not even soda pops no i don't like i've like tried to stop like cut out soda i used to drink a lot in high school no yeah now i only do it if i have to pull

an all-nighter which has not happened since college, which is good. Yay. Well, that's good. I'm glad for that. All right. Well, it's my turn to go first, you guys. How about this one for a science fact? What if you could protect your country from terrorists, from drug smugglers, from hijackers and thieves? What if you could do it with your innate natural senses? What if you could do it with your innate natural senses? What if you could keep your fellow citizens safe? This could have all been true if you are a gerbil. Whoa. In the 1970s, scientists in Canada were testing different animals

to see what they were good at sensing. And gerbils, it turns out, are great at sensing epinephrine, a stimulant and stress hormone that people produce when they're a little bit freaked out. And Canadians share this information with other intelligence agencies. And the British spy organization, MI5, created a protocol for a small little setup that would blow air across a passenger's hands as they're like passing their documents over toward a gerbil cage that I think was supposed to be hidden.

So they didn't even know it was there. And then if the gerbil smelled a higher than average level of epinephrine, they'd hit a little lever and flag that person for extra screening. This was never done in Britain. But for a little while, Israeli security forces did do this. They flagged travelers using gerbils. Wow. Oh, my God.

That's amazing. Thanks. I love it. I'd like to imagine. It was a short pilot study that they did to see if it was going to be effective. Were the gerbils hidden? I think that they didn't know the gerbils were there. It blew it into a box with a mesh on the side.

Just little squeaks coming out of it. Don't worry about it. Don't worry about my box. I feel like if you saw the gerbil, you would be less freaked out, and it would ruin it. Yeah, I'm calm now. I've been calmed by this cute gerbil.

Yeah. So it turns out that it's not a great way of doing things, though. Why? Oh. Why would you think it might not be great? I feel like people are always stressed out. Because people are always stressed out.

When they're traveling, especially. Speaking from personal experience. So people who were, like, afraid of flying, for example, were the ones who got, like, a lot of false flags. And those people are probably not the ones that you want to like put through extra screening. It's just like, let's pull out all the people who are having the worst days and make their day worse. So it just wasn't as good as other systems. Sort of like lie detectors that way. Yeah, they're like little living lie detectors.

But like, because dogs can smell certain things and are used in airports for security. And so it sort of makes sense that you would like try to find other animals that can smell other things. Right. But the nice thing about a gerbil is one, in some ways easier to train, especially for like a one cent thing. Second, very inexpensive. Like they're basically free. You know, you just need to purchase gerbil food. I'm sure you need a lot of gerbil handlers, though.

You need a lot of gerbil handlers and gerbil teachers. Yeah. Though the question is, can you automate teaching a gerbil? Like, you can't really automate teaching a dog. But if you've got a gerbil in a case, you just you just like puff epinephrine out the minute they hit the thing, you give them a reward. You do it over and over again. You could have like a whole factory of gerbil modification. Why do gerbils, do we know why they sniff epinephrine and can sense that? So this came out as a declassification. So the British MI5 released that they had been looking into this in the 70s and that it came from Canadian researchers.

But the Canadian research was, as far as I can tell, never declassified. So I was not able to figure out anything about how they identified the gerbils were good, epinephrine sniffers. And maybe it's out there and I just couldn't find it. Maybe the Canadians perfected it. And it's still classified. Yeah, maybe that's why Canadians are so nice because they've taken all the stressed out Canadians and fed them to the gerbils. Or they all have a little personal gerbil

that sniffs everything, everybody around them so they know who to trust and who not to trust. Or whenever they're getting stressed out, the gerbil's like, I smelled that you were stressed out and I just wanted to say, I think you're doing great. Oh, my goodness. That's probably the one. That's why Canada's so good.

They've all got a personal de-stressing gerbil. All right. Sarah, what do you got for us? I don't know if I can compete with the gerbils, but I'll do my best. So the second biggest charitable foundation in the world is the Wellcome Trust. It's known for funding science and medical research and things like co-founding the Human Genome Project. So it's like a pretty big deal. But before it was a foundation, it was a pharmaceutical company called Burroughs Wellcome & Co.

Founded in London in 1880 by a pair of American pharmacists who were, as far as I can tell, really savvy businessmen who advertised their products to their medical community, which makes them sound kind of sleazy, but they also seemed to have pretty high ethical standards for the time. So they actually wanted to make medicine to help people. In 1884, they coined and trademarked the word tabloid to help market their pharmaceutical products because their goal was to compress them into smaller forms, which apparently covered like medicine, but also things like tea and first aid kits. And that's like weird and cool because now tabloid is used in journalism

to refer to any sort of compressed thing. And the point of this is, even with their good intentions, one of their popular, I think, tabloid products was called Forced March and contained a mixture of cocaine and caffeine. And you were supposed to take these tablets once an hour, quote, when undergoing continued mental strain or physical exertion because it reduces your hunger and increases your endurance and forced march it's appropriate it's accurate um and i guess that sounded like the perfect addition to a medical kit for extreme adventures like um expeditions to the south pole including the 1907 expedition that just barely fell short of it. Okay. And a 1910 expedition that ended up kind of tragically. But they packed these

in the official medical kits. And they were just popping these energy pills because old medicine was fucking weird. They killed a bunch of explorers. The pills didn't. No.

The explorers... If it's once an hour, it had to have been a kind of low dose. Right? Yeah. Yeah. Yeah, I like the

sustained approach. Yeah. Like, I want, I don't want five-hour energy. I want one-hour energy. Is that available? Because, like, five hours,

that's a long time. I want to be, five hours from now, I want to be not-energied. Yeah, then every hour you get to decide, do I want to extend this forced march

or not. Do you think we could be like get super rich right now with one hour energy? You could just drink one fifth

of your five hour energy drink. I don't think that would work. I think that would give me five hour not very much energy. Is that the same

as one hour energy because like half lives and whatever? Branding. It's all about branding. It's great. One hour energy because like half lives and whatever. Branding. It's all about branding. It's great. One hour energy.

A plus. Thanks, everybody. It's really important to me that you don't question any of my ideas. So these were pills. These are pills. Dissolvable like tablets.

They're tabloids. So the word tabloid comes from the tabs? Yeah. Yeah, it comes from taking something medicinal and then compressing it into a very small thing. And they advertise them in little magazines? The tabloid magazine form came way after the fact. That came after the fact.

Where tabloid, as they coined it, meant just like a compression of something. So taking a teabag, making it smaller. Taking a medical kit, turning it into a first aid kit. Oh, okay. Taking a medicine that you do. I thought they were distributing a tabloid magazine to advertise their products. Oh. That's also what I got.

I'm sorry. I explained that poorly. Well, no. I think that that's just a much stranger jump than that they were advertising. Yeah. Yeah. Like, why would you call's just a much stranger jump than that they were advertised like, why would you call your magazine a tabloid? That seems weird. I think the etymology of tabloid, I tried to look this up too, it just came from

so, like, the proper newspapers were printed on really big paper and so those were seen as legitimate journalism and then the tabloids were compressed versions of newspapers so they're printed on smaller pieces of paper, they did more sensational stories. And then the tabloids were compressed versions of newspapers. So they're printed on smaller pieces of paper. They did more sensational stories. And then they used a vice

into a small pill and then you would look at it and be like, I can't read this at all. No, you eat it and then you absorb the information that way. I didn't know all of the news

about soap operas. I can't fit that whole thing in my mouth. Oh, well, you could. All right. What do you think, guys? I think I gotta give it to the germals. I can't fit that whole thing in my mouth. I want you to. All right. What do you think, guys? I think I got to give it to the gerbils.

I'll get the gerbils. I would give it to the gerbils. They're animals with a job. That's one of my favorite things. I'm going to give it to the gerbils, too.

I did. I like forced march a lot. Yeah. I can't compete with gerbils. I love that it's called forced march. Why would they name it that?

I feel like it's that it was for a designed purpose. Endurance, no hunger, forced march. I guess so. And now it's time for Ask the Science Couch, where we ask listener questions to our couch of finely honed scientific minds. Really just one at this point. No, this is chemistry.

Okay, so Stefan, you have a question for us. Yeah, Patrick Kelly asks, to what degree does caffeine actually dehydrate you? I have heard that caffeine does have a dehydrating effect and that it is less than the liquid you are consuming. So it's not like drinking a cup of coffee dehydrates you. It's not like drinking a cup of salt water, for example. Well, if you drink salt water, you're getting less water than you would just not drinking at all. When things dehydrate you, is that always because there's sort of a diuretic effect or is there? Usually it's because it's kicking your kidneys up a bit and putting more of your liquid into your bladder.

Okay. But that's not what's happening with salt water? It is what's happening with salt water. Oh, okay. Makes you pee it out because you got way too much minerals in yourself and you need to get rid of those minerals. Okay. Whereas caffeine, I think, is a diuretic because of its biochemical action that it takes on

your body. But you would not die if you only drink coffee because you are getting more water in the form of the water in the coffee than the caffeine is causing you to pee out. Am I right? Yeah, that's pretty much it. I think a lot of the conversation around this seems to be confusion about the definition of diuretic and dehydration and implications about what those terms mean, I think. So diuretic is any product that increases your production of urine. Dehydration in its broadest sense is just anything that causes you to lose water. And there's like medically significant dehydration where you're actually,

I don't know, dehydrated and you don't have enough water for your body to do all the normal functions. So you get dizzy and everything. And so I think people automatically equate any sort of diuretic with the dangerous level of dehydration instead of just like drinking water is technically a diuretic because you have more water in your body

and you have to pee it out. So like water, if you want to get technical about it, is a diuretic because it's going to make you pee. Is there something else in coffee that would maybe dehydrate you? Besides water? We think caffeine may inhibit the release of

a hormone called vasopressin or antidiuretic hormone which results in less water reabsorption by the kidneys. And so basically it messes with the kidneys operation of introducing water back into your body so that more gets excreted, if that makes sense. So could you be in trouble if

all you drank was coffee? No, there have been studies. And I think a couple of scientists point to a 1928 study as causing this misconception. They had three people. So it was very small sample size. They had those three people abstain from caffeine for a little over two months. And then they gave them about half a coffee cup's worth of caffeine. It was 0.5 milligrams per kilogram of body mass. And they peed more than they had. But after four to five days of regular caffeine, they started building up tolerance and like peeing a more normal amount. So the discovery was if you don't drink caffeine and then you do all of a sudden,

there is like you do pee more and you do pee out more water. So like if I started drinking coffee right now. You'd be peeing all the time. Yeah. And from that people extrapolated like the extremeness of the diuretic effect of coffee. But in other studies,

like there've been a bunch of review papers these days and people who studied this in more depth with more people, like there's one with 59 participants and they really regularly gave them caffeine pills or placebo and they measured a bunch of different factors like their body mass, their urine volume, their color of their pee, a bunch of different electrolytes in there.

Oh man. Like they measured everything you could their pee, a bunch of different electrolytes in there. Oh, man. Like, they measured everything you could about pee, it seems like, and found no evidence of dehydration. Of dehydration? Of dehydration. It was, like, basically the same as water, I think. So no diuretic effect at all? I don't think so.

I'm done with water then. Water's over. All right. If you want to ask the science couch your questions, you can tweet it to us using the hashtag Ask SciShow. Thank you to Cephalopod's Rule and Jen Marker and everybody else who tweeted us your questions. Hank Buck final scores. Let's just get it over with.

I won. Oh, I got three. I got three. You guys all got one. It's the damn gerbil fact. Yeah, your gerbils were very good. Oh, thanks. I was very excited You guys all got one. Yeah. Damn gerbil fact. Yeah. Your gerbils were very good. Oh, thanks.

I was very excited when I found my gerbils. I was like, oh, good. I was like in bed, feverishly typing. And I was like, oh,

thank goodness. And Catherine was like, what, what? And I was like, I found my fact. Like, oh,

this is what it's like to be married to you. I guess. If you like this show and you want to help us out, it's really easy to do that. First, you can leave us a review wherever you listen. Katie didn't and Yona L did. Thank you to them.

Super helpful. And let us know what you like about the show. Second, you can tweet out your favorite moment from this episode. We want to see them. And finally, if you want to show your love for Tangents, you can just tell people about the show.

Thank you for joining us. I have been Hank Green. I've been Sari Riley. I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and WNYC Studios. It's produced by all of us. And Caitlin Hoffmeister.

Our art is by Hiroko Matsushima. And our sound design is by Joseph Tuna-Medish. Our social media organizer is Victoria Bongiorno. And we couldn't make any of this stuff without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. You probably heard of civet coffee, the so-called most expensive coffee beans in the world. They go through the digestive system of civets, which are like little cat weasel type animals. And the resulting pooped out beans are supposed to taste really, really good when they're brewed into coffee.

So you might think it's kind of weird that people would drink poop coffee. brewed into coffee. So you might think it's kind of weird that people would drink poop coffee, but there was a story in National Geographic that had a kind of interesting possible origin story for the coffee beans. So the Dutch plantation owners who were growing coffee in Indonesia would not let the workers who were picking their coffee drink the coffee, which sucks. So eventually the workers figured out that the civets were eating and pooping out these beans and that they could take and use those to make coffee and apparently it tasted really good.