Stuff You Should Know - How the Hygiene Hypothesis Works

Episode Date: June 18, 2019

In the early 90s, a new study that found that kids who are exposed to more germs early in life are less likely to develop allergies later. With the West in the grip of a full-blown immunity crisis (still going on today), this was an interesting thought. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

On the podcast, Hey Dude, the 90s called, David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're gonna use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s.

We lived it, and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass

and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. And a different hot, sexy teen crush boy bander each week to guide you through life. Tell everybody, ya everybody, about my new podcast and make sure to listen so we'll never, ever have to say. Bye, bye, bye.

Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple Podcasts, or wherever you listen to podcasts. Hello there, it's me, Josh, and I just wanted to let you know, people living in Minneapolis or with access to Minneapolis, I'm gonna be in your city doing my solo show, The End of the World, or how I learned to start worrying and love humanity.

It's a gas, and it's pretty interesting too. So on June 19th, I'll be at the Parkway Theater in Minneapolis, and the next night, I'll be at the Miracle Theater in Washington, D.C. So come see me, go to themiracletheater.com or theparkwaytheater.com for tickets. Welcome to Step You Should Know, a production of iHeartRadio's How Stuff Works.

Hey, welcome to the podcast, I'm Josh, there's Chuck, there's Jerry, Step You Should Know. You jerk. I'm a brat. Oh, Jerry's back from vacation. Hello, Jerry. Welcome back. Welcome back, Ms. Rowland.

You don't look any different. You're rolling your eyes at Josh. That means everything's normal. Everything's quite normal. I thought you might be sun-kissed, but she's nodding now. No. She just wrote down help me on the side.

I saw that. I'm sure everybody heard the paper rustle, too. I have an announcement real quick, if you don't mind. Please. The Bryant's are back in the cat game, got two kittens. Oh, congratulations. Thanks. The cat game.

Yeah. Okay. The kitty game. What are the cat's names? Luna and Levon. Oh, there's a good name. And they, you know, we've been planning this for a while, since we lost our cats, but we had the house renovation.

And it was like, that makes no sense to get two cats in a rental house and move them. So then we waited and then we were like, well, we're going out of town on vacation for Memorial Day. So let's wait until after that. And we did. And I woke up on Sunday and looked at the calendar and I said, it's cat day. It's cat day. So went to the Humane Society of Atlanta, got two eight month old kittens, siblings.

Oh, matching cats. Yeah. Boy and a girl. And she's a girl and she's black. And Levon is black and white, both short hair, which you're going to try and recreate Laurent and the wizard a little bit. You know, that whole thing. Well, rules that you have established for us.

Well, we were going to get a tabby and another Maine Coon. Gotcha. Because we really love those. But you went a different direction. I was just like, you know what? These are kittens. They're great. They need a home.

Let's take them home. Well, you know what, dude, congratulations. Thanks. It's been a lot of fun. It's been the best of a lifetime with Luna and Levon. Well, you start at my age with cats. I was like, you know, this may be one of the last bears. It's crazy.

And Emily was like, stop. I know. I think it's so weird. Just don't even go there. People say that. Stop doing math. You mean I have a friend who's a neighbor and she was like, you know, we're like, how old your dog?

And she's like, oh, she's like three. So we'll probably pass it about the same time. I was like, why, why would you say that out loud? Well, if these cats live a nice, healthy, longish life, they will see me into my mid sixties and see Ruby through high school. That's cute. That is, that part's cute. So yeah.

This mid sixties is so cute about that. So it's good that you're getting these kitties for Ruby in part for Ruby. I'm sure it's largely for you guys too. Yeah. It's for all of us. But she's going to run around growing up, being exposed to cats. Are they going to be indoor, outdoor cats? No.

No. Strictly indoor. They live longer. Still. Not judging, but. No, that's fine. Keep your cats inside. They kill fewer birds too.

Yes. But the fact that she's going to be exposed to cats is a big leg up for her. Yeah. And the fact that she was being licked in the mouth by dogs from the moment she was born. Yep. That's true too. But dogs, cats, different animals. True.

Which means. Yeah. Very, yes. Very microbes. Very spit. We're going to find out why we're saying all this stuff soon enough. Just hold your horses, everybody. But what we're talking about is the hygiene hypothesis today.

Yeah. And this is sort of the Venn diagram of several past episodes, including some really good ones on allergies, the immune system. Did we do one on the immune system? Either that or just the microbiome. We definitely did that. But they may have been three, but if not, at least those two. And the hookworms episode.

Sure. Yeah. Why not? Southerners, lazy and dumb. Right. Nope. It was hookworm. Yeah, we did do some good ones.

But this is like, yeah, the stuff you should know away is where we talk about all the stuff that has to do with the larger issue before we ever do a larger issue. Yeah. And if you listen to the show for a long time, you're getting a pretty robust education. Yeah. 11, 1200 episodes worth. Yeah. Ain't a lot of silliness.

Yeah. Let's stop the silliness here and now. So if you didn't realize this already, prepare to have your socks knocked off. But we in the developed and rapidly developing world, right, I'm just scanning my memory. That's the right term, correct? I think so. Okay. Our suffering, what's known as an immunity crisis, like a massive one, the likes of which

has probably never been seen before in human history, and it's happening at the snap of a finger, the blink of an eye, the pop of a spit bubble, right, like that fast in evolutionary terms. To be fair, Josh just said that because I popped a spit bubble in his mouth while he was talking. That's sort of one of my chores. I got some stats. Let's hear them.

Between 1950 and the year 2000, rates of hay fever, eczema, asthma, and type 1 diabetes, and these all have to do with immune dysfunction, sorted 300% and developed and developing countries. 300% since 1950. Yep. Between 50 and 2000, and children born in the UK in 1970 were twice as likely to get eczema than those born in 1958. And there are tons of stats we could keep reading, but all of this flies in the face of what you would think would be happening.

Which is, as we get more medically advanced and... Our world gets more sanitized. Sure. Like everything, people should be getting sick less and have more robust immune systems, and the complete opposite is happening. Yeah, and it really has been confounding people because there's a couple of factors, or there's a couple of things here that this evidence is screaming. Number one, it's happening really fast.

Number two, it's happening in a distinct part of the world, right, the developed world. But it's also happening over time, too, in the same places. Yeah, but the first one is happening so fast that rules out genetics, because genetics doesn't operate that fast. No. No. So it's clearly environmental. That's what everybody's settled on.

And again, it was confounding everybody for a very long time. And then in 1989, there were a lot of people who tried to explain this. And in 1989, there was a British epidemiologist named, I think you pronounce his last name as Strayhan. Oh, really? Strachan. Strachan. Strachan.

The Kraken. The Kraken, I think is his name. Or Michael Strayhan, one of the two. One of those. Yeah. Or Michael Shannon. Let's throw him in the mix, too. Oh, man, he's good.

So David Strachan, I'm just going with that, he and some colleagues released a very short paper in the British Medical Journal in 1989. And it said, we think we might actually have this figured out. What's going on behind this confounding immunity crisis? Why everyone's bodies are turning on themselves, why their immune systems are going haywire and crazy. We think it's because things are too clean, actually. And he didn't actually use the term, but the word hygiene was in the title of the paper.

But right after that, people said, I like the way you're thinking, we're going to call what you're talking about the hygiene hypothesis. But first, explain to us what you're talking about, Strachan. Right. I mean, basically he was saying that if you're a little baby that's born and raised up through your early, very important immunity developing years. Yeah, to about age four, the most important. Yeah, so if you were cleaning everything too much and slathering everything in hand sanitizer

and keeping your child inside in a protective clean play place, then they are not being exposed to the, they're too clean, they're not being exposed to the germs that they need to develop a robust immune system. Right. That was his interpretation of some evidence. The actual study that the paper was based on was a study he carried out of, I think, 15,000 British households. Yeah, kids in particular.

Yeah. And he found that kids born into smaller families had a higher chance of developing allergies as they grew older compared to kids born into larger families. Yeah, which has supported his theory. Right. Which is that because there's more people in a family, there are more people bringing germs into the home, exposing the little kid to the germs more frequently at an earlier age and that those germs somehow protect us from developing allergies later on.

That was the basis of, we have to say, the original hygiene hypothesis, because a lot of people don't know it, but it's changed dramatically since then. Yeah, and people got on board, it made sense, still kind of makes sense in some ways. And it made a lot of news and people really kind of got on this train of let's not have any kids or just have one and let's let them roll around in dog poop. Right. It did get translated really quickly into let's all stop washing our hands because initially the thing that was identified was infections.

That kids develop infections from infectious pathogens and that being exposed to infections early on actually trains the immune system and makes it basically bulk up, makes it gives you a beefy immune system later on and more to the point a smart one. And really we should probably talk about what the immune system does to really get home what Straychin and all of his colleagues and everybody in the world was thinking was actually going on. Yeah. Should we take a break and talk about a little do a little allergy recap?

On the podcast, Hey Dude the 90s called David Lasher and Christine Taylor, stars of the cult classic show Hey Dude bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it and now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co stars, friends and non stop references to the best decade ever. Do you remember going to blockbuster?

Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal? No, it was hair. Do you remember AOL instant messenger and the dial up sound like poltergeist? So leave a code on your best friends beeper because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy blowing

on it and popping it back in as we take you back to the 90s. Listen to Hey Dude the 90s called on the iHeart radio app, Apple podcasts or wherever you get your podcasts. Hey I'm Lance Bass host of the new iHeart podcast frosted tips with Lance Bass. The hardest thing can be knowing who to turn to when questions arise or times get tough or you're at the end of the road. Okay, I see what you're doing. You ever think to yourself, what advice would Lance Bass and my favorite boy bands give

me in this situation? If you do, you've come to the right place because I'm here to help. This I promise you. Oh God. Seriously, I swear. And you won't have to send an SOS because I'll be there for you. And so my husband, Michael, um, hey, that's me. Yep, we know that Michael and a different hot sexy teen crush boy band are each week

to guide you through life step by step. Not another one. Kids, relationships, life in general can get messy. You may be thinking this is the story of my life. Just stop now. If so, tell everybody, yeah, everybody about my new podcast and make sure to listen. So we'll never ever have to say bye, bye, bye. Listen to frosted tips with Lance Bass on the iHeart radio app, Apple podcasts or wherever

you listen to podcasts. All right. So you can refer to our allergy episode for the full picture, but, um, here's sort of an assessment, an overview, if you will. And that is, and I remember when we said this in the initial episode, an allergy is basically a mistake. It's a case of mistaken identity. Yeah.

There's nothing inherently wrong with dust. Right. Or pollen. Those things are great. They're not actually foreign invaders that are going to harm your body. No, there's nothing wrong with dust. People avoid dust because they're allergic to it, but it's not like dust has some inherent property that gets in your nose and makes you sick or allergic.

Right. Well, it makes you allergic. It does. But it doesn't make you sick. But it's not the dust's fault, I think is what you're trying to say. It's your stupid immune systems fault. No, your immune system says this is a harmful invader, even though it's really not. It's pollen or dust or something, and let's mount a defense against this.

And that is what triggers this allergic response, which is, we'll go over in that in detail, but everyone knows what that is. It's in the case of dust and pollen, it's sneezing and inflammation in the nose. Scratchy throat. Yeah, scratchy throat, redness, maybe a rash, depending on what kind of allergen you're talking about. Yep. But it's all just a big mistake.

You just made me itchy, dude. Really? I'm serious. Okay, so it is a mistake, and this is why mistakes like allergies happen, okay? The immune system, you're born with an immune system that says I'm ready to learn, I'm thirsty for knowledge. It's remarkable. Right.

It actually trains, and like we said earlier, that first four years are really important. It's basically when your immune system learns to recognize what's an actual foreign invader that I need to defend against and mount an immune response against, and what's just a normal harmless or maybe even friendly microbe in the environment, like dust or pollen or cat hair. Such a friendly microbe. Right. It really has a good personality as far as cat hair goes.

So what happens is when that immune system meets something harmful, truly harmful, it creates an antibody, and it's very customized. Like you said earlier, it's a very smart system. It's not just a one-size-fits-all deal because your body is trying to get very specific with how it's going to deal with these invaders for the rest of your life. Right. So when a foreign microbe, friendly or harmful or totally neutral, comes into your body, you have a multi-layered system, immune system.

It's actually really two layers to tell you the truth. There's the innate immune system, and then you have the adaptive immune system. And the innate immune system is basically... That's what you're born with. It's the blaster from Master Blaster. Okay. Which was blaster. I think blaster was the big crush skull guy.

Of course, and then master was the master that wrote on his shoulders. So blaster gets his meaty paws on a microbe, what seems to be a foreign invader, and it doesn't matter what it is, blaster does the same thing to it. He crushes them up and eats them and digests them, and then poops out the parts of that invader, that microbe, that make that microbe, that microbe, the proteins on the outside of the microbe called antigens. Yeah. Okay.

And it says, look at this, and it shows the adaptive immune system what it's got. Yeah. So that innate immunity, you're born with it, and it's sort of like a mom is going to pass on some Cobra coverage almost. You get this temporary insurance that mom is kind enough to pass on, and that covers you for a little while, while your body is sort of learning how to do it on its own with master, I'm sorry, blaster, sort of leading the way at first. So where you left off was it presents it to master and says, here, do with this what

you will. Start learning. Right. What is this that I just chewed up? That's two Jontra voltas in one episode. No, that was Vitti Barberino, and what's the other one? I just regular Jontra voltas. Okay.

Why are you so weird? So when blaster spits out these antigens, it says, what is this? Check it out. Yeah. Master's job, now master is the adaptive immune system. Right. The second part. This is a more nuanced, smarter, selective, or supposedly selective part of your immune

system, where it looks at this stuff, and somehow, some way, I don't understand exactly how it does it. Maybe we touched upon it in our immunity episode. But the adaptive immune system master says, okay, this is actually not harmful at all. Don't worry about building an antibody. You can forget about that. And as a matter of fact, don't forget about it. But the next time you see this thing, just let them on through.

The friendliest cat hair you're ever going to meet, don't kill them next time. Or if it's an actual foreign invader, and everything's going smoothly and correctly, then the adaptive immune system is going to say, whoa, whoa, whoa. This is a really dangerous thing you've just presented me with. We're going to study its weaknesses, and we're going to build a molecule that is designed to kill this thing with extreme prejudice. Yeah. It turns into Clint Eastwood all of a sudden.

Yes. While this is going on in the background, we should mention that Blaster has already set off the, he's basically walled things off with an inflammatory response. And not like something mean that he said to master. Not that kind of inflammatory response. Right. Why are you so short? But regular, a regular inflammatory response is sort of the big dumb guy's way to deal

with something. It's like, all right, while you figure this out, just let me puff up, and let me cause a rash or give you a fever. Or there's all sorts of inflammatory responses. Yeah. Blaster's responsible for what you think of when you think of an infection that you're fighting on. Like me last week when I had that weird virus.

Yeah. It's gone. It's gone. It's great. That is weird. It is weird. But I had, Emily and I both had all sorts of things, weird bumps and lumps and rashes and fever.

Like you're getting those lately. Yeah. It was not good. But so that's the inflammatory response that's going on while master is working on his plan. You're right. It's sort of like a first line of defense almost. So we have to, so Julia Layton put this one together, like we have to go over the four key components of the inflammation response.

Okay. Okay. You've got calor, dolor, rhubor and tumor. Sounds like Game of Thrones or something. It does. It's heat, pain, redness and swelling. Yeah. And when you put them all together, you're like, yeah, of course, it's an allergy.

That's an infection. That's what happens when something tries to get in my body, blaster goes and brings this on, right? Yeah. And man, every time we study the immune system, it just blows me away. I love it. It's just amazing that humans can do this. Yeah.

You know? So yeah, we're not even trying. No. We're just sitting around watching, well, I'm not watching Game of Thrones, but do you watch that? No, did you? I did the first few seasons and dropped off. Yeah.

Apparently you pulled out just in time. According to Reddit. Well, I don't know. Everyone said one through seven was great. Okay. So you didn't ever saw seven? No, I saw like one through three. Oh, okay.

And then just got confused and went to sleep. It was confusing? Oh yeah. There's a lot going on. Yeah. You had to keep up with? Yeah. Characters and storylines and it just got too much.

I was just like, yeah, I'm going to go back and watch a... Deadwood? I can't wait for you again. Right. Oh, I can't wait for that. I watched... Barry? Have you been watching Barry?

No. I watched a few episodes on a plane. That's where I started to. Yeah. I need to get Emily on the Barry train. It is very good. It is good. Yeah.

That's a good show. And Veep, of course. I need to watch the last season of Veep. I'm not on that one. Same here. Yeah. Same here. Okay.

So anyway. Slight digression. Caller, Dolor, Rubor, and two more. And Blaster, the innate immune system, is basically creating... Creating this to keep the infection localized while the adaptive system master is figuring out what to do and building the antibody. Right. So once all this happens, the antibody is released, it goes in and destroys the whatever

remaining microbes of that foreign invader are still around, and the body is saved. And even better, somehow your immune system remembers this. Yeah. That's the important part. Right. Blaster comes along and comes back with that same microbe, the same kind of microbe. Master says, I know just the thing for this guy, we've met him before, we're going to get this antibody over here, and it's going to destroy him.

And the body will just keep humming along with the immune system mounting normal appropriate responses. Right. And your body, all your cells are just screaming, two men enter, one man leave the whole time. Yeah. It's kind of disturbing, actually, under a microscope. Should we talk about T cells? Yeah.

Didn't you say we were quickly going to go over the immune system? No. I mean, we don't have to talk about T cells. No, no. I'm just saying. We've talked about... We've talked about them a lot in the past. Yeah.

But not to this degree. And they actually are pretty important in this. All right. Well, so remember that Blaster, the innate immunity dude. Remember, any microbe it gets its hands on, it does the same thing too. Yes. Every time. It gets pretty bad for the microbe.

So he's going to present that microbe's antigens to these T helper cells, TH cells that we've talked about before. Mm-hmm. And they are part of Master's Smarter system. Right. And like earlier when you said he presents it, what he's really doing is presenting to those T helper cells. Right.

So there's T helper cells that are undifferentiated. There's kind of floating along, waiting to be told what to become. And then Master says, you turn into some TH1 cells because this is a bacterial or a viral infection. Yes. And TH1 cells are specialized to combat that kind of microbe. Or if say it's a hookworm infection, they would turn into TH2 cells. Or if it's an allergy, an allergic response, it means TH2 cells are involved too.

And this is here the key to the original interpretation of the hygiene hypothesis. Yeah. And the TH1, it's sort of a, they do a lot of things, but TH1 generally work on the inside of cells and TH2 generally work on the outside of cells. Right. They sort of split up and they sort of balance each other out too. That's a big, big key too. Yeah.

Like if there are more TH1 cells, there will be less TH2 and the other way around. Right. They can regulate one another or more light, more to the point, T regulator cells regulate TH1 and TH2 cells. Yeah. The Tregs, which we didn't find out about until like the 2000s, right? Right. But if there are, this is the point here.

If there are a lot of TH2 cells, there's not going to be very many TH1 cells. And vice versa. And so the original interpretation of the hygiene hypothesis was that kids who are not exposed to bacterial or viral infections early on in life do not have a chance for their immune system to learn what's good, what's bad. And since their TH1 cells aren't activated because they're not exposed to pathogens, their TH2 cells, the ones that are responsible for allergic reactions, get to go into hyperdrive. That's right.

If they're not responsible for allergic reaction, TH2 cells kind of like a hammer. And to a hammer, everything looks like a nail. Yes. So to the TH2 cells, everything looks like a foreign invader. And so an allergic response is mounted. So because the kids, TH1 cells weren't active enough, the TH2 cells were overactive. They weren't exposed to infections. They developed allergies later in life.

That's what they thought was the crux to the hygiene hypothesis and that it was all because we were living in a world that is far too clean for our own good. Yeah. And there are more studies that they did that really seem to support this in the 90s. One really interesting one in the Germanies in the early 90s, they did a study of allergy rates of East and West German kids, pre-unification obviously. And this was a really great idea because what you had was two populations that were genetically identical basically, just living in two drastically different environments.

Obviously, East Germany was very polluted, was generally more poor, much more industrialized. And in the West, it was cleaner probably and well. Safer water. Not cleaner, but cleaner air. Cleaner for sure. And kind of all the way around. And so they hypothesized, there was a researcher named Ericka von Mutius. That's good enough.

I think that's exactly right. And she basically said, well clearly the children from the West will be healthier and less allergic. And she found the exact opposite again. So it was just another sort of some more compelling evidence that this hygiene hypothesis kind of carried a lot of weight. Yeah. And the fact that she was expecting the opposite was kind of interesting too. But she was like, whoa, I just accidentally proved this hygiene hypothesis.

It doesn't, again, it makes zero sense that the cleaner the environment, the more likely your immune system is to malfunction later in life. Yeah. Right? Should we take a break? Yeah, we should. All right. We'll take a break and we'll talk about sort of where this is now in the new understanding

that hasn't gotten nearly enough press. Right. All right. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it.

And now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co-stars, friends, and nonstop references to the best decade ever. Do you remember going to Blockbuster? Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal? No, it was hair.

Do you remember AOL instant messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy, blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass.

The hardest thing can be knowing who to turn to when questions arise or times get tough or you're at the end of the road. Ah, okay, I see what you're doing. You ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. This I promise you. Oh, God.

Seriously, I swear. And you won't have to send an SOS because I'll be there for you. Oh, man. And so will my husband, Michael. Um, hey, that's me. Yep, we know that, Michael. And a different hot, sexy teen crush boy bander each week to guide you through life, step by step.

Oh, not another one. Uh-huh. Life in relationships, life in general can get messy. You may be thinking, this is the story of my life. Just stop now. If so, tell everybody, yeah, everybody about my new podcast and make sure to listen so we'll never, ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple podcast or wherever

you listen to podcasts. Okay. So the, the world really clamped on to the hygiene hypothesis because I mean, it makes a lot of sense. Like it's very appealing. It's like, yeah, just go be dirty. You don't have to worry about all this stuff and yeah, pesticides are, are terrible for us.

Like antibacterial soap and, you know, just everything you can think of. The idea of it was, was really, really just kind of appealing to the world, especially in the nineties because that's when people started caring about like herbs and supplements and like organic food and stuff like that. So the timing was really good. Sure. And the idea of looking at all these chemicals we were using to sanitize our world is actually harmful rather than beneficial, appealed to a lot of people.

But it also appealed to people in the sense that now we had an explanation for this mysterious massive explosion in, in allergic reactions and immuno messed up function. Right? Sure. Did you know type one diabetes is, is a, an immuno deficiency? Just from this. Yeah, me too. I had no idea.

I was like, why do they keep talking about diabetes? And then I realized your body has, you know, a lot of, a lot of, a lot of, a lot of things that I realized, your body has mistaken the beta cells that produce insulin in your pancreas as a foreign invader and attacks them. Yeah. That's why you don't have insulin or enough insulin because your body's turned on it. Yeah. Very interesting.

Same with like Crohn's and any kind of autoimmune disorder really. Yeah. Your body's mistaking the cells of your own body as a foreign invader. But again, these, the incidents of these, these kinds of disease just exploded over, you know, a handful of decades and by the nineties and about 2000 people had said, it was because we're overly clean. We're killing off the pathogens that we actually need to infect our kids so that their bodies can recognize a good invader from a bad invader and they won't develop allergic reactions

later on. Right. Well, today we now know that the hygiene hypothesis wasn't quite right. It's been, it's not like they threw it all out, but it's been revised and, and it's a lot smarter now and they're, the basic theory now is, is that what's missing. It's not necessarily a hygiene thing, but it's nature and they, they have a name for it, which is very cute. The old friends theory, right?

And this is introduced by a fellow named Graham Rook and his colleagues in 2003. And this basically theorizes that exposure to these harmless microbes, not the pathogens are what's going to protect you from allergy sensitization. So kids playing in the dirt and kids getting licked in the face by a dog in the years one through three and four is actually a really good thing. Doesn't mean you shouldn't wash your hands after you poop or just let that chicken pull that raw chicken off the counter and don't sweat it. You should still practice basic hygenes, but kids being inside all the time and not being

exposed to nature like they were for hundreds of thousands of years is the, the sort of the problem. Right. And it's part of the problem why this is why it was easy before and not now is because they're saying yes, do wash your hands, but not all the time. So what they've identified is those pathogens that they originally thought we were killing and it was having a detrimental effect on us. The opposite is true.

They found that we really should keep washing our hands and killing off things like the stuff you get from chicken juice, raw chicken and poop and like infectious disease. We need to keep fighting that like we are. That's actually a huge benefit. We need to keep like getting vaccinated. We need to defend against colds and the flu and all this stuff. Like that is something we want to keep at bay, not expose kids to that. We found the opposite is true.

Actually exposure to things like colds and flus and measles in childhood actually increases the likelihood of developing allergies later in life, which is the opposite of the original hygiene hypothesis. But what they found is, so we need to keep defending against those infectious pathogens, but we need to up our exposure to those friendly microbes. The old friends that our bodies co-evolved with over these hundreds of thousands or millions of years and that we've realized now, just beginning to realize, make up a symbiotic relationship with us or at the very least some sort of relationship.

We depend on them and by not being exposed to as many microbes as we were in decades past before everybody got obsessed with being clean, our immune systems are not functioning properly, whether they're not being trained early on enough or they're just not being exposed to the right kind of microbes that form colonies like in our gut or on our bodies somewhere. Yeah. And what's really sort of the newest concern is the rise in food allergies. It's really like you grew up in the 70s and 80s, do you ever remember peanut allergies

being a thing? Zero. I knew zero kids who had peanut allergies. Yeah. They slathered ourselves in peanut butter growing up constantly. Yeah. There was a trend. Yeah.

It exploded in the West in the 90s and it continues to rise. They're calling it the second wave of allergy, the second epidemic basically. One in 10 kids in the developed world have food allergies. That is nuts and that's just in the developed world. I think in America, in America it's 20%, one in five has a food allergy in America. Yeah. And like serious allergy sometimes, like I have a friend whose sister's son is, I mean this kid's allergic to everything you could imagine and it's not like that's the outlier.

Like you hear about more and more cases like that. Right. Yeah. One in five kids has a food allergy and like again in the 80s, there was no such thing as a peanut allergy basically. I mean there were but it was just vanishingly rare. Yeah. And it's not like, we just didn't know what to call it back then.

A kid would eat a peanut and drop dead. We call the balloon-faced syndrome. Oh God. That's terrible. It is pretty bad, isn't it? But yeah, it's a real thing that's happening. Food allergies are just off the charts now compared to how they used to be. Yeah.

So like you said, that's the second wave of this and what they're thinking is going on is kids are less exposed to the microbes that we used to be more exposed to because we're spending more time inside because we're using way more disinfectants and it's good we're using the disinfectants because they do kill the pathogens that we do want to keep at bay, but they kill indiscriminately. So they also kill all the friendly microbes that actually perform wonderful benefits like the healthy functioning of our immune system. Yeah.

The harmless bacteria that children need to be exposed to. Right. And adults. So they do think that when you are exposing kids to microbes or when you are being exposed to microbes like you and I, it's probably not doing a lot for us because our immune systems are already developed. It really counts for kids like from birth up to about four years of age because again, that's when your immune system is being trained.

And if it's being trained by a bunch of friendly microbes saying, that's okay, Blaster, you can kill me. I'm sure you don't kill anyone else like me because I'm fine, I'm not going to do anything to you. Then that is what's creating the healthier immune system and lowering the risk of allergies later on. Yeah. So they recommend getting your kids out in nature, let them play in the dirt.

If you can breastfeed, then that helps. If you can have a vaginal birth, that helps. Although I saw a study that showed children born from C-section were swabbed in vaginal fluid from their mother's birth canal to give them this coating of microbes like they would have gotten from a vaginal birth. Oh, they do that. They did it to like four kids in this one study and the results were mixed. And then another study found six weeks after birth, this study didn't find any difference

in microbial makeup between kids who were born vaginally and kids who were born through C-section. Interesting. So we might not be as big of an issue as we thought. Well they definitely say to practice what they call targeted hygiene, which like you were saying, it's not like you don't clean up after the raw chickens on the counter or wash your hands after you poop. But get rid of the snotty tissues and wash your hands after you do those things and blow

your nose. Right. Wash your hands after you use the bathroom. Yeah, like start washing your hands again, everybody is the key. But get out there and play in the dirt too and it's like a kid should be in nature. Okay, so yes, play in the dirt, go out in the woods, go for a hike, get your kid a dog or a cat. Yeah, and let them hug and kiss.

Take them to a petting zoo, like this is the point. You don't have to like attack your kid with the antibacterial spray on their hands after they pet a goat at the petting zoo. It's actually what they're finding is that it's healthy for the kid to pet the goat and then eat a sandwich afterward. Seriously. No, I know. It's all making sense now because we have 10 goats that live across the street.

Always had two dogs and two cats in the house except for the brief period where we didn't have the cats and we were very lazy parents and still don't bathe our daughter with much regularity. Right. Like every week or three? No, but she's been like, take her to the doctor sick four times. Yeah, well, and then hopefully it will also mean that as she gets older, she's going to be far less likely to have allergies because her immune system trained like Dwayne Wade

and Gabrielle Union put together. That's a super couple. Yeah. Yeah. You seen their kid, their oldest son that's about to start playing basketball with the Brani, they're transferring to the same high school. So LeBron son and Dwayne Wade son are going to play basketball together and he looks just like Dwayne Wade.

Does he really? Yeah. Has their sleepy eyes. Yeah. It's like no mistaking whose kid that is. That's very cool. It's not the milkman. No, it's Dwayne Wade.

Unless the milkman had sleepy eyes. Who was the basketball player that was the mailman, Clyde Drexler? Carl Malone. No. Carl Malone was a mailman. Clyde Drexler was the glide. That's right. Yeah.

You're right. It was for men commercials. You watching the finals? Oh yeah. Pulling for Toronto pretty hard. Who's not? Did you see that map of the US and who's pulling for Golden State and who's pulling for Toronto? It was just like the Bay Area and nowhere else.

It was California and Hawaii and then the rest of the country was pulling for Toronto. For Toronto. Pulling for another country. Yeah, exactly. Wow. So go Raptors. That's what I say. If you want to know more about the hygiene hypothesis, go back and listen to this episode

again because there's real nuance there and I hope we got it all. Maybe we should re-record this again. Yeah. Like now. Okay. Okay. Anyway, we'll see what version comes out and in the meantime, it's time for what, Chuck? Administrative details.

So if you don't know what this segment is, if you're new to the show, this is the time every few months, let's say quarterly. Where we give thanks. Where we give thanks. To people who have sent us kind gifts over the past few months and for some reason we named it administrative details. I don't even remember any longer, but that's a pretty good assessment of what we're doing right now.

Yes, it's a very cold name for a very warm segment. So you want to start, Chuck? Sure. I'll start it off with a gift of wine, Jeremiah Nelson sent us wine from Baronmore. Very nice. Speaking of wine, big ups to our buddy Addison Rex. Dude. This is the wine.

He once gave me homemade olive oil too. Yeah. So Addison and Kat live in California and Emily and I went and had a very personal wine tour experience. Yes. You're a lot about your life, your fears. Yeah. And I sent a lot about wine and how it's made.

And then not only that, but when we went to the next wineries, they went with us and we ended up hanging out all day and they're just great. They're awesome and we have new pals and we're going to see him again. And then he went after a long day of that. Drove into town. Drove into town to see you do End of the World Live. Yep. And we hung out for a little while after.

Didn't go in any wine or anything, but he is now a friend too. Good dude. Kat's great too. And if you want to find out, he's got, I didn't meet Kat, but I'm going to take your word for it. Yes. But if you want to find out about the wines we're talking about, his label is Jurassic Wines because his name is Addison Rex, so he sounds like a dinosaur, but Jurassic like

the movie. Yes. Minus the park plus wine. That's right. Jurassic wines. Thanks guys. Yep. You're the best.

Can't wait to see you again. So Julie Mullins from the Onion. Remember back in the day we had our OG Onion pals? We used to be big time at the onion. We did. They moved to Chicago and we have new Onion pals now. That's so great. Julie Mullins sent us the Onion Daily Counter.

Counter? Counter. Right. And she is an MGFX artist at the onion. Yeah. Thanks a lot. How about this? This one is a long time coming.

Do you remember our Phoenix show like 50 years ago? I quite enjoyed that. Or October, maybe one of the two? Yeah. Well, at that show, or maybe the Salt Lake City show. Okay. I think it was Salt Lake. One of those two shows, our friend Kathy, Kathy with K, Tosh, gave us each a lasso.

Oh yeah, that's right. Like a real bonafide, get over here, cow. That was Phoenix. Tight lasso. I'm pretty sure. I think it was Salt Lake City. Was it? I can't remember for the life of me.

Anyway, Kathy, write in and let us know how you're doing and what show it was. But thank you for the lassoes. She also said, yeah, just go on to YouTube and you can learn how to do it, which I've yet to do. I haven't either, but it's hanging in my closet. It looks very cool there, doesn't it? It does look very cool. Yeah.

Thanks, Kathy with the K. Okay, so our friend Joe Barrett sent us his book and it's called The Managed Care. I haven't been able to read it yet, but it's on the stack on the desk. So check out The Managed Care by Joe Barrett. Speaking of books, there's a guy named Thomas Ramge. Ramge, great last name, looks wise, but I'm not quite sure how to pronounce it. He wrote a book called Who's Afraid of AI, which I cannot wait to read. Write up your alley.

Yes, it is. And it's like. You open it up and it just says Josh. It says you. Yeah. It's got just a picture of a robot holding my head. But thanks a lot. Thomas Ramge's book, Who's Afraid of AI?

Go check it out. Our old pal Dustin Bowen sent us a 3D printing of our Stuff You Should Know logo, which sits atop my desk right now. Very awesome. Yeah, it's very cool. Yeah. Huge, huge thanks to our old pal Don Cubie for the floral photography canvases. Cubes.

And yeah, Cubes photography is just out of this world. Yeah, she's really talented. Yep. Like almost exactly as good as Aaron Cooper's photography. And she sells her stuff on her site, Don Cubie, K-U-D-A-W-N-K-U-B-I-E dot com. You know, before I did the We Know's Parenting Live in Brooklyn recently and Emily and I both went for a little quickie New York trip. We went to the Brooklyn Botanical Gardens and the Frida Kahlo exhibit at the museum.

Oh, no. We were walking around the Botanical Gardens. Who wanders up but Don Cubie? Oh, really? Yep. She's like, oh, I just happened to be following. I mean, I just happened to be here as well. No, we had a nice little chat.

She was taking photos and she came to the We Know show. That's why she was there. She's great. She's very easy to talk to. Yeah, serendipity. Who else? Sheena and Ben sent us a wedding invitation. Their wedding in Burbank.

We've gotten a few of these lately along with invitations to officiate, but they've all lined up against either live shows, butted up against live shows or other travel plans. Right. So I've not been able to do that. No. Plus, we'd have to get ordained. Are you ordained? No.

Okay. But I'll do that in five minutes. We can do that. All right, there you go. Brad Topliff sent us a box of runes, R-O-O-N-S, which is short for Mac Runes, which his wife makes, Runes is his wife's company, and they're amazing, I can attest, and you can get them at eatrunes.com, E-A-T-R-O-O-N-S.com. All right, our old pal Steven Breitman sent us poopy pockets for our dogs.

This cool little invention, it's a 2-in-1 poop bag dispenser and poop a pocket for the poop. Yes. And it's a veteran-owned business, so big thanks to Steven Breitman for the poopy pockets. Nice going, Steven. Mark Kicks sent us the Simpson-themed journals, hand-drawn Simpsons journals. Those are from Mark Kicks, and thank you very much, Mark, because I think we forgot to thank him last time, and he wrote in and was like, dude, I was like, I'm sorry.

Our old pal Ian Newton from the Baltimore Spirits Company sent us their Shot Tower barrel gin and their Bat Lamarro, which is, what does that explain with it? Zeshwan Lamarro. Yeah, peppercorn infused. The Italian bitter liqueur, oh man, so good. Is it good? Yes. Got a little heat to it?

Everything that they make is really, really good. Yeah. I can't remember the name of it. He's also sent us like mezcal made from smoked apples. It's just the bomb. What kind of black magic are they doing in Baltimore? They're doing some good stuff up there. All right, support the Baltimore Spirits Company and Ian Newton, everyone.

They're getting creative with their spirits. We're going to leave it at that, and we'll do the rest next episode. How about that? That sounds great. Well, thanks a lot for joining us. If you want to send us something, we're always down with that. You can find us on social. Just go to StuffYouShouldKnow.com, and you'll find all of our links there.

You can also send us an email to StuffPodcast at iHeartRadio.com. Stuff You Should Know is a production of iHeartRadio's How Stuff Works. For more podcasts from iHeartRadio, visit the iHeartRadio app. Apple podcasts are wherever you listen to your favorite shows. On the podcast, Hey Dude, the 90s called, David Lasher and Christine Taylor, stars of the cult classic show Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and

dive back into the decade of the 90s. We lived it, and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeartRadio app, Apple podcasts or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help and a different hot

sexy teen crush boy bander each week to guide you through life. Tell everybody, everybody about my new podcast and make sure to listen so we'll never ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeartRadio app, Apple podcast or wherever you listen to podcasts.