SciShow Tangents - Aging

Episode Date: March 14, 2023

Every millisecond of every day, you, everyone you know, every rock on the ground, every star in the sky... they're all aging. And podcasts are no exception. In fact, Tangents is hitting a milestone in its aging as we bring season 4 to a close with this episode! You can't hear the dull roar of time lurching ever onward if you're listening to a funny show, so come listen!SciShow Tangents is on YouTube! Go to www.youtube.com/scishowtangents to check out this episode with the added bonus of seeing our faces! Head to www.patreon.com/SciShowTangents to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter!And go to https://store.dftba.com/collections/scishow-tangents to buy your very own, genuine SciShow Tangents sticker!A big thank you to Patreon subscribers Garth Riley, Mike A, and Tom Mosner for helping to make the show possible!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen[Trivia Question]Epigenetic clock of dog years vs. human yearshttps://www.smithsonianmag.com/smart-news/theres-new-better-formula-calculating-dog-years-180973575/https://pubmed.ncbi.nlm.nih.gov/32619550/[Fact Off]Brown-Séquard and using testicle injections to reverse aginghttps://archive.org/details/Brown-sequardC.-e.TheEffectProducedOnManBySubcutaneousInjectionsOfAhttps://academic.oup.com/brain/article/140/5/1525/3760152https://www.jci.org/articles/view/57089Sperm aging/senescence in toads and other vertebrateshttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050820https://www.eurekalert.org/news-releases/683429https://support.webb.uu.se/digitalAssets/52/a_52297-f_BeckyTREE.pdfhttps://pubmed.ncbi.nlm.nih.gov/21332857/[Ask the Science Couch]Causing/reversing aging in mice through epigenetics (ICE - inducible changes to epigenome)https://hms.harvard.edu/news/loss-epigenetic-information-can-drive-aging-restoration-can-reversehttps://www.cell.com/cell/fulltext/S0092-8674(22)01570-7https://www.news-medical.net/news/20230115/The-loss-of-epigenetic-information-accelerates-the-aging-process.aspxhttps://newatlas.com/biology/epigenetic-reboot-reverse-aging-extend-lifespanhttps://www.biorxiv.org/content/10.1101/2023.01.04.522507v1https://www.nature.com/articles/s41586-020-2975-4[Butt One More Thing]C. elegans rapid senescence (kind of lactation)https://www.eurekalert.org/news-releases/930463https://www.nature.com/articles/s41467-021-25821-y

Hello and welcome to SciShow Tangents, the lightly competitive science knowledge showcase. I'm your host, Hank Green, and joining me this week, as always, is science expert, Sari Riley. Yeehaw! And our resident everyman, Sam Schultz. Hi. I'm your host, Hank Green, and joining me this week, as always, is science expert, Sari Riley. Yeehaw! And our resident everyman, Sam Schultz. Hi. I wasn't prepared to do a fun one. So, I wanted to ask you two a question.

When you go to the dentist, do you get taken to a special room for people whose teeth are too big? Or did I just... or not? Which of those two things are, is it? You know we do talked about it both of you do yeah both of us go to the special big teeth person room okay you don't go existed how do you get your x-ray when they x-ray your teeth what happens to you i'm just sitting there and they put a little thing and they put a little thing and then a gun comes down and it shoots the side of the gun down like that i gotta down like that. I got to go in a different room. I got to stand by a tower. They lower something over my head and I bend forward and bite something and it goes.

And I learned apparently. Siri has this too. Right before this podcast started that that means I have gigantor teeth and no one's ever told me. Yeah. Because I recently went to the dentist and they went to go do the the the laser one as hank described and as they were putting in my mouth i was like my teeth are too big for this you'll see uh and they were like ha ha ha what is this person doing they probably get a lot of

really obnoxious people in the chair um saying this but they put it in my mouth and then they took a picture and they were like you think that that's very good can handle these teeth yeah my teeth are the alpha teeth yeah harassing the dental assistant but i was like i've been told before my teeth are too big and they took a picture and they were like you're right your roots go right off the screen your teeth are huge and then he was like let me prepare the special machine for you i'll bring you over to the special room no one ever told me it was a big teeth yeah no it's a special room me and sari both have if you've never watched us on youtube youtube.com slash sideshow tangents you won't know that me and Sarah have giant teeth. I had never thought to myself that y'all have big teeth. Now that I'm looking at them, they seem tiny or anything.

There was a comment on one of the episodes that said, that guy sure has all the teeth, doesn't he? In reference to me. Rude. They didn't even notice my teeth. They were too busy looking at yours. And my big ones. That happens. That guy sure has all the teeth. Well, we can't go any further down this road.

It is delightful to me that Sam didn't realize that it was a special room. He thought this happened to everybody. I don't know why they didn't think I could handle knowing that. They just looked at me and said, you're too sensitive. It's just too much. Yeah. Yeah, you're special. He looks like such a sensitive man.

But now you can feel included because we're in the majority here. I love going to stand at the big room. I hate when they put the little things in your mouth you have to like bite down. They're so sharp. I like just going in and have the thing go all the way around my head.

Good for you. I'm happy for you both. So every week on SciShow Tangents we get together to try to one-up, amaze, and delight each other with science facts while also trying to stay on topic. But the topic of the day is not teeth or big teeth, so we've already failed. Our panelists are playing for glory and for Hank Bucks, which I'll be awarding as we play. And at the end of the episode, we will have a winner. will have a winner. We will also, at the end of this episode, have the winner for this season, because this is the last episode of this season of SciShow Tangents, according to this show flow, which I found out just now. But as always, first, we have to introduce this week's topic with the traditional science poem. This week, it's from me. Life is both simple and quite complicated, but its reason for being can be easily stated. You have packed inside you a whole lot of genes that determine together a great many things. The size and quantity of

fingers and toes, how you get smells to your brain from your nose. A successful gene proliferates, and they only do that when you procreate. A gene can't live forever in a single creation. It wants to get passed to the next generation, So they keep you alive. For a while, at least. But each year, the challenge of that is increased. For the briefest of moments, life will rage. But from the moment it's born, it begins to age. Some species are great at breeding quite quick, so a very short life still does the trick. And the systems aren't there to keep them breathing, because the genes have lived on through breeding. But if your body is big and you breathe real slow, the pressure to stay alive longer will grow. But always, a balance is found from breath to breath.

We are each of us one step closer to death. Wow. A great end of the season poem. That was beautiful. Yeah, that's like an illuminated manuscript type poem. I would love for my manuscript to get illuminated. That would be the best kind. It's a great honor.

It's the best kind I have. The topic of the day is aging, which is the thing that happens from the moment you get born, I guess. Or maybe even before that. I don't know. Say what's aging? Yeah, I don't know. The thing is, it happens to us all. And we know that, and we observed that. And then we tried to define it biologically. And we were like, oh, man,

that's complicated now. That's a lot of stuff going on. If there wasn't so much stuff going on, it might be easier to deal with. But it turns out it's a lot of different things. Yeah, it's a lot of different things all at once. So it does have to do with the march of time. So it does have to do with the march of time. So it is time-related aging. And in general, we think of it as the deterioration of any sort of biological, physiological functions. And they can be for survival. They can be for reproduction.

They can just be general physical attributes like a phenotypic changes but generally it's this idea that you captured so poetically that we just over time we break down entropy entropy wins and we we slowly the order in our bodies become less ordered and we turn back into goo. I mean, that's the last step. Yeah. I mean, the weird thing is that we continue to live as we deteriorate, which is not a great frame to think of it inside of. Don't think of it that way. That's kind of what's happening. But not like who you are.

You're you. And whatever body you're in, love it, et cetera. Is there like a part of you you could point to that's the part that's getting older that's making all the rest of it be less? Is it like your DNA? Is that the ultimate thing that's messed up? It's not entirely clear. There are things you can point to that definitely have an effect,

but there is not one thing that you can point to. Yeah, and I think it's because you are so many things, which is also kind of a weird thing to think about. Not only are you breaking down constantly, but you are also a collection of so many different molecules that you're constantly introducing to yourself and not in control of. So we think there are some genetic components to aging. In all the scientific literature, you'll see the word senescence instead. And that's like the scientific term for biological aging. And so there might be genetic components. So like the way that DNA

is arranged or stable or breaking down or replicating, there might be diet related things. So like what food you eat or what environment you live in and molecules you breathe in and have around you. There could be stress components, like in the way that stress can affect your physical health, your mental health. It can also affect the rate at which you age. So like the whole gray hair caused when you're stressed because stress and psychological damage can cause physical or phenotypic effects on our bodies as well. So all these things together become aging and we have to tease out which pieces are which, and I'm not very good at that because being a human or being any animal is complicated. So if like a particular gene in a particular cell is designed to do a particular

thing, it's going to do that thing. Ideally kind of perfectly the moment you're born. And then it's just going to like, it's not going to get worse in a, in any particular way. It's just going to get less good at being that specific. It's going to be like less precise. And it's a bunch of imprecisions that add up to your skin not being as flexible and your body being less good at clearing stuff from your blood or you know things being more inflamed etc

but there's also like absolute like normal genetic things where it's like you're supposed to have these things like graying hair uh in a you know in a gorilla might be to signal that i am a more advanced member in age and so you can see that phenotypically in the same way that we have sort of adult characteristics generally like your achy knee so yeah you don't hear kids go around going saying, ah, my knee. But you hear all those old fogies like us walking around. So distinguished. His knee hurts. He's the leader of us all. But it's good, too.

It's like also like you start as a baby and you don't even have everything fully grown. So they get a little looser, but they also get a little bit better. It would suck to be a baby forever. Yeah. better. It would suck to be a baby forever. Yeah. So you don't want to be a baby forever. You don't want to be a teenager forever, definitely. Like that would suck even more than being a baby forever. If I could have paused like four years ago, I think that would have been just about right for me.

Yeah. Yeah, I guess I've sort of been thinking about just the senescence portion of aging, but just going from a baby to a teenager is also aging. It's the whole process. There's so many different things that are aging. This is wild. All right. We can't talk about it forever though. So do we know anything about this etymologically? Yeah. So age has just been a word. It's been a noun and then a verb for a very long time and has generally meant the same thing, uh, throughout history of like a time period, a long period, a lifespan,

a lifetime. And then from that noun came the verb of you just, you exist throughout time. Um, and it comes from the Proto Indo European route, AIW. And I'm not sure how you say that. A,

a, uh, which is vital force life or eternity oh wow um but then senescent i wanted to look into that because it's just such a nice word and such a weird word that comes from the latin senescentumum from the root word sen which means old and that you can see in things like senior or sir or senile or all kinds of like

grumpy old people surly but also in senate which I thought was funny like it's a council of elders and so you've got that. Stroking their big beards. Senescence. Yeah, everyone's rubbing their bald heads.

Yeah, bald heads, achy knees, telling people what to do. Yeah, it does kind of suck that old people can just keep getting older, but we never invent any younger young people, you know? There's always going to be more older people. That's not good. Yeah. you know there's always going to be more older people that's not good yeah yeah now there's all these people getting 114 years old but we're not we don't have any negative two-year-olds exactly that's uncool now it's time to move on to the quiz portion of our show we're going to be playing a version of truth or fail today because gettinging is Truth or Fail. Because getting older is, of course, a gift. But aging comes with strange changes in physiology and behavior across the animal kingdom, some of which might seem particularly relatable to us humans.

So the following are three stories of animal aging, but only one of these is true. Which one is it? Can I add something real quick? Yes, my dear. That we are tied sari and i are tied neck and neck for the winner of this portion of the show so whoever wins this part will have won the most of this particular part of the show for the whole the whole year that's all right i yeah i can't i can't influence the outcome here. We'll just have to see what happens.

Because I think this is Sam's only chance to win anything. Yeah. No. Well, we'll see at the end, won't we, Hank? We'll see at the end, won't we, Sam? Crunch some numbers. So it might be story number one. The small, shaggy Brant's bat loves to eat insects and moths and as they get older the bat shifts its meal times earlier so they can return to caves and sleep earlier as well hell

yeah they get that uh what's that called the early bird special yeah they might be literally eating birds i don't know or it could be the second story as prairie dogs get older they develop a bit of a crafting habit. They gather rocks from their surroundings and use them to build structures in their burrows that appear to make their homes a bit cozier, at least to us humans. We don't necessarily know what they're doing, but they look cozier to us. So maybe they're crafting as they get older. But it could also be story number three.

They're crafting as they get older. But it could also be story number three. Scientists monitoring a community of macaques found that as female macaques got older, they got more exclusive about who they hung out with, restricting their social circle to just those they were closest with as they aged. So is it our story of an aging Brant's bat eating the early bat special so they can get to sleep earlier, the story of the older prairie dog spending their times doing crafts, or story number three, older female macaques become pickier about their social circles. These are so good.

Because your icon was a bat for so long, Sam, I think it still is on Twitter. I think you know things about bats. Does it matter when bats eat? That's kind of what I was going to say. I don't know anything about bats, really. I just think they're cool. But I feel like there's like a very specific window that's based entirely on when the thing that they're trying to eat is out. So it doesn't seem like it would work for them to go out earlier, to me at least.

You got to go to Denny's while it's open. You got to go to the bug buffet while it's open. While the bugs are there, yeah. Exactly. Sam over here not knowing anything about bats but still knowing things about bats. That's like a thing. These are vibes about bats. I don't know if they're true.

The secret is Hank and I just operate entirely on vibes too. Science is all vibes. I mean, it is all wiggles. We've been there. Yeah, and balls. Literally just vibrations. Wiggles and balls.

The prairie dog thing, that seems so frivolous for a prairie dog. They seem like they have too much going on to be worried about that. They got black-footed ferrets to worry about, birds. They got to be on their toes. You know a lot about prairie dogs. I work on SciShow Kids, where we You know a lot about prairie dogs. I work on SciShow Kids, where we've done a lot about prairie dogs. I think it could be a status symbol, though, of like, look how long I've lived that I have so many rocks.

That's like an old person thing. Like, look at my tchotchke collection. I'm so proud that I have gathered this junk that is now all meaningful to me. Yeah, it's going to be a huge problem when I'm not here anymore to deal with this. Yeah. I would love that one to be true because it's so cute. That's kind of the one I'm rooting for, but I just don't think they do it. What about the macaques becoming picky? This one seems the most practical of all animals of all the thing other things this

one seems like the thing that just like a natural decision be like that guy's too annoying that guy is always late to everything that guy uh he said something mean about me 15 years ago and i just can't handle that anymore that kind of even if you're a monkey you remember especially if you're a monkey sari what do you think you know the answer you're tricking me somehow i feel like no i don't know the answer and i just am i think i want the prairie dogs one to be true i'm gonna pick prairie dogs because i want it to be true but i don't know i think i'm gonna go with the macaques i think i gotta that's just what my gut says. Well, Deboki has written in the document on prairie dogs,

this was based solely on me wanting to imagine a prairie dog with knitting needles. No! That one. You got me again, Deboki. Congratulations. Now, as humans get older, we tend to be more selective about our social relationships scientists wanted to understand whether this behavior was like just like a human thing and so they started to look at macaques and found that as female rhesus macaques get older

the size of their social networks went down and the proportion of their social networks that consisted of their family members went up and they were able to determine that this effect wasn't due to them getting shunned or to the deaths of partners or other macaques around them that may have been their friends. It seems to be the result of choices made by the macaques. And there are some potential advantages to this. They might be less likely to get injured or risk illness by hanging out with a bunch of others. But researchers note that there could be other explanations. It could be a thing that older macaques are just less likely to participate in things that require a lot of energy.

Or on the opposite end, their experience could make them better at just being on their own. They don't need that social support as much. So that is the true fact, which means that Sam is the winner of this weezin... Weezins? This season's fact this is why i can never do this professionally right not not fact off but quiz whatever quiz portion everybody knows what i mean uh but in the bat fact actually is based on some truth so bats live a really long time for their size the branch branched bat can live up to 41 years. Holy cow.

And they think that sleep actually helps with this because it seems like they have studied epigenetic markers on bat DNA and found that hibernation puts a pause

on aging during their dormant state and that helps extend their lifespan. And that also goes for some non-bat species. It looks like Turkish hamsters also benefit in the aging department state and that helps extend their lifespan and that also goes for some non-bat species like uh looks like turkish hamsters also uh benefit in the aging department from their hibernations

wow so it's happening you guys we got like life extensions right around the corner all we need is to figure out how to do torpor like bats and hamsters do and they're not that different from us the world economy would just be really fucked if we did torpor though that wouldn't work with capitalism and we'd roll it we'd roll it i'd like everybody do three months and then yeah that'd be fun waking up being like what happened you have to really mow the shit out of your lawn you gotta alternate that's how you gotta plan it out you have a lawn mowing schedule with all your neighbors of like okay i'm going in torpor seat well no it's just like it's it becomes a vrbo you don't need your house you just like where do you go to the basement you get in your torpor chamber and then your house down there your torpor chamber that's a great Torpor chamber is not a good vibe. Don't use that.

No. Too close to torture chamber, I think. And like dungeonous vibes. I definitely would have my torpor chamber in the basement for sure. Or maybe even below the basement. Like just get somebody to dig out a little. A dungeon? Like a grave kind of? Yeah.

Yeah. Like a long long skinny chest freezer we could put a lot of those all together maybe and then we could hang out as friends and they already made that building it's a mortuary if hank was a if hank was a vampire he would absolutely sleep in a chest freezer. I can picture that perfectly. Some dirt. It's just cozy. It's practical.

It's cheaper. It was on sale at Costco. Yeah. It came with the house. That's a good idea. All right. Now we're going to take a little break and then we will be back for the fact off All right, welcome back, everybody.

It's time for the Fact Graph. Our panelists have brought science facts to present to me in an attempt to blow my mind. After they have presented their facts, I will judge them, and I will award Hank Bucks to any way I see fit. It doesn't matter. Who knows what comes next?

But to decide who goes first, I have a trivia question. People commonly translate dog years into human years by saying that one dog year is equivalent to seven human years. Now, this is probably just based on the fact that the average human lifespan is around 70 years and the average dog lifespan is around 10 years, meaning that it's not really a useful formula, but I guess it's better than nothing. However, a group of geneticists studying DNA methylation have come up with an intriguing alternative. As mammals age, our DNA accumulates methyl groups that stick to it, forming a way for scientists to track aging through what they call the epigenetic clock. These scientists

decided to compare the epigenetic clocks of dogs and humans because we live in similar environments, and both of those things receive a lot of medical care. Based on their results, a dog that is two years old is equivalent to a human in what years? 21. It's party time. That's exactly what I was going to say. I think they get to that age, and then they freeze there for a long time, and then they turn 80 instantly and die. That's my interpretation of what a dog does. I think a dog that is two years old is 25. Well, Sam, aren't you feeling smarty pants today?

Because the answer is 42.1. Holy moly. What the hell? You get old quick as a dog and then you just stay there, I guess. What the heck's going on? So the specific formula here is human age is equal to 16 times the natural

log of the dog age plus 31. You know, the classy, the the easy quick mental math i saw i saw ln and i was like i couldn't even remember what that was for a second the loon of the dog age yeah so they studied 104 labrador retrievers between the ages of four weeks and 16 years and compared the methylation profiles to that of humans between one and 103 years old. And they found that while the epigenetic clocks of a puppy and a baby lined up pretty well for a bit, once dogs get past early puppyhood, they mature much faster. And after early puppyhood, the dog epigenetic clock sped up for about a year

until they reached sexual maturity. And then it started to slow back down again to match more up with a human's clock. I don't buy it. Two-year-old dog is not 41 in human years. All right. So that means that Sam gets to decide who goes first. I will go first. For as long as humans have existed, we've been getting older.

And for as long as we've been getting older, we've been trying to figure out how to stop getting older and maybe even get younger. Emperors, alchemists, and explorers of the ancient world hunted for elixirs or fountains of youth. At some point, we started to figure out more science stuff and stopped looking for magical solutions to our problem. Instead, we looked for usually equally as unlikely scientific solutions to our problems. And that brings us to Charles Edward Brown-Saquar, a French physiologist in the late 1800s. Brown-Saquar studied the nervous system, and from what I can

tell, he made some important observations regarding the spine's relationship with the nervous system, how the nervous system regulates blood flow, and that blood seemed to contain chemicals that caused changes in the body. But he was also a fucking weirdo. He was notorious for operating on unanesthetized animals, the screams of which echoed through the various college buildings he worked in during his career. A fellow professor has accounts of Brown-Saquard at dinner parties trying to regurgitate and re-chew his food like a cud.

And the same professor who wrote that also found... Y'all have never done that! Not at a dinner party. Just in the privacy of my own home. And then the same guy who wrote about the dinner party also has a story about Brian Seward. He found him in his lab covered in varnish and suffocating. And then the professor had to help him sandpaper off his breathing holes

so that he wouldn't die. I don't think he knows why he was covered in varnish, but that happens. So this combination of half pretty smart scientist, half extremely weird, freaky old man made Brown-Saquard the perfect type of guy to think of a really messed up way to reverse aging. So from his animal experiments and observations of humans, he concluded correctly that people got old because the various systems of their bodies were breaking down. But he also concluded that old people were so tired because they had used up all the juice in their spermatic glands and they had lost their pep. And he also figured that the spermatic glands must be in the balls. So when he was 72, he was sick of being old and tired all the time, so he used his scientific expertise

to come up with his own anti-aging regimen. One part testicle blood, one part semen, and one part juice extracted from crushed dog and guinea pig testicles injected subcutaneously into his own body so after one day of these injections he reported feeling several years younger able to climb stairs better

and even his urine stream was stronger uh when he skipped his injections the classic definition of yeah of anti-aging how hard Exactly. When he skipped his injections, he said his frailty returned. And he was so happy with the results of his own experiments that he did experiments on some other human test subjects and reported the same finding in them. He ultimately claimed that this

routine made him feel 30 years younger, but he died five years after he made that claim, either at the ripe old age of 75 or the much too young age of 45, depending on how you look at it. So from a modern lens, it's unlikely that these subcutaneous injections actually did anything but provide a placebo effect because testicles don't store hormones. But I mean, I give dog balls, reverse aging. I think the world would be a much different place than it is. His research and the research that other people did based on his research is said to have helped in the discovery of hormones and their function.

And he's apparently regarded by some as inspiring the whole field of endocrinology. So he wasn't just smushing up dog balls. Well, yeah, but he was also smushing up dog balls. He did a lot of that. Yeah.

So it was crushed up dog balls injected under the skin what else did he do test so he mixed together testicle blood uh-huh semen uh-huh i don't it doesn't say actually where he got those two things from whom i don't know okay maybe his own the youth no he can't put more old stuff back he's got old balls you're right he's got old balls absolutely not he's gotta find someone who's p-streaming meyers and then be like sir can i please have yeah he's like sitting in the stall for p-streams i need your i need your testicle blood

but yeah the his his paper will be in the show notes. And it's a wacky old paper where he's just like, I was so tired and now I'm running up the stairs. Now I'm peeing really hard. It's great. Yeah. That's how I feel when I have a Dr. Pepper. So take that. Well, they got a lot of crushed up dog balls in Dr. Pepper.

So that explains that. That's the main flavoring. People don't talk about it. It's vanilla, prunes, and crushed up dog balls. dr pepper so that explains that's the main flavoring people don't talk about it it's uh vanilla prunes and crushed up dog balls three main flavors sari what do you have for us and the spirit of things also balls um as we've been talking about it's actually about balls actually about balls it's like some balls bookended by aging so one way scientists have defined exactly what aging is biologically throughout history is to focus on sex baby in other words an organism is born it reaches sexual maturity and can reproduce

and then there's a point where it can no longer do that successfully and it's on its way to death. It has no more fucks to give, quite literally. Oh, sorry. Thank you. And modern day researchers have started looking at much more specific questions like, is aged sperm worse at doing the do? Specifically, they're usually interested in questions of motility or how well the sperm can move around and eventually mesh with an egg during fertilization. One way to answer this question is to look at pre-meiotic sperm senescence, which is a jargony way of saying how old are the cells that

are making the sperm and what effect does that have? And in general, we found in mammals and other vertebrates that sperm made from older organisms has more DNA damage and has worse motility. But another way to answer this question is to look at post-myotic sperm senescence, which is a fancy way of saying, how do sperm cells age after they've been made and are just hanging around? For decades, as far as I can tell, our main way of studying this was to make mice or rats or humans or whatever ejaculate and then see what's going on with the sperm as time passes. From these kinds of experiments, we learned that reactive oxygen species damage sperm in many ways, including motility, and there might be protective

chemicals in the seminal fluid or other stuff. But those are all artificial lab conditions. So in 2008, a group of Hungarian researchers wanted to study how sperm ages post-meiotically in the wild as it's meant to be. So they went out and caught 100 male common toads in the mountains, and then they released 52 of them because they had their pick of sizes and wanted a good range of them. Okay, great, great, great. So 52 toads didn't have the time of their lives. They did not go on this scientific adventure. And they chose toads for this particular experiment because they all stop hibernating and start making sperm at the beginning of their mating season, so their sperm was all around the same age, like a great equalizer. They divided their male toads

into three groups of 16, one group that they put in the cold and dark to make them re-hibernate, one group that they kept completely isolated from females, and one group that they let mate with new females as many times as they wanted, which ranged from one to four times. natural mating peak, they did lots of sperm science. And to skip past the testicle smashing to the results, there was frog testicle smashing involved, they found that the re-hibernated males had the most sperm motility. So after their body made sperm, shutting everything down again helped prevent sperm aging and kept the cells really fresh. So something about hibernation slows the biological process of aging, even in specific cell populations. And what was also kind of surprising was that of the non-hibernating groups, the toads that made it had better sperm motility than the ones that didn't. So something about females being around or getting to blow their load helped with the overall quality

of aging sperm. They said the implication of this is that more frequent ejaculation may help remove the old stuff or reduce age-related damage, but in general, it opens up a lot more questions than it provides answers. And we obviously can't extrapolate these conclusions directly to humans, but they may help add to other knowledge related to sperm banks or other forms of reproductive science and aging gametes because there's just so much to learn about aging and different types of cells. You can't treat any of them the same. So I thought all 52 frogs were going to have, or 48 frogs were going to have the time of their lives, but only a third of them did.

Yeah. Well, a third of them got to take a nap, which is pretty sweet. A third of them had the time of their lives. Now what's better? I've heard about sex, but have you tried a little nap a little cozy nap a big old long map where you get to and it turns out it's great for you it's great for your uh your whole situation did that did they all get their balls smashed though i think like a select number from each population got their balls smashed okay then the last few frogs were walking out the door and the scientists closed it and said not you

excuse me not you we have a little bit more business to attend to so i think here what we have is is maybe a little bit more useful information in the near term uh that that like like a little bit of fresher science with sari's fact but but ultimately we do have a man who who may be created into chronology and also injected crushed up dog balls under his skin so sam's gonna come out the winner on this one, which means Sam is also the winner of this episode of SciShow Tangents. But is he the winner of this season of SciShow Tangents? You're going to find out soon, but not quite yet. Because first, we have to ask the science couch where we have a listener question for our couch of finely honed scientific minds.

Laughing Mom Fish on Discord asks, I've read several articles about the recently announced gene therapy that can reverse aging, and I have many questions. But just now, I was wondering, if you did this treatment on someone and, quote, turned back the clock on their body, how many times could you do that? I have heard of the bare minimum about this, and I'm kind of bad about longevity stuff because it's so hard not to see it in the historical context of every single generation of rich guys has been obsessed with this since the beginning of time and i and so it's like and and they've always been wrong you know ponce de leon

was not going to find the fountain of youth because it didn't exist. But look, it'd be great to deal with aging in a lot of ways. It'd be great. Be very good for human health. It'd be very good for health outcomes to be in more control over its senescence. But I don't keep up on it. I don't keep up on it either. So I don't think it's bad of you i

think i i was trying to search this and the problem is is i have already a level of like bullshit filter on my the way that i search things and so i did not see the most click-baity articles about it. But the big thing is on January 12th this year, 2023, in Cell, the magazine, the digest, the journal. I couldn't remember the word for it. You know, the comic book. The periodical. The periodical Cell. the periodical the periodical cell uh there was a a study published about how epigenetics and how epigenetic information can both drive aging and reverse it so this study specifically what they did and what i think is not making the headlines as as boldly is that they broke the mice before they fixed them uh so they

they took normal mice and then used a technique that they called ice uh which is inducible changes to the epigenome and they just made a bunch of cuts in dna messed it up messed up the dna in these mice um and found that the epigenetic information on on the dna the way that it was methylated the way that it was bound up and packaged started getting weird when they made enough cuts to it so like this damage led to weird packaging so they were inducing epigenetic weirdness by doing a bunch of cuts on the DNA. Yeah, by messing with the DNA. And then these mice that had a bunch of weirdness introduced to their epigenetics displayed signs of aging. They ran slower on treadmills. Their grip strength weakened.

Their hair changed texture. And cells started losing their identity a little bit. How was their P-stream? Was their P-stream real strong probably weak organs failed so i'm guessing the p stream was weak i'm guessing they couldn't climb stairs all the problems that this man and instead of injecting dog balls into them they injected a uh a combination of genes that are generally known to be active in stem cells and and stem cells are these cells that are like in your bone marrow and can differentiate into a lot of different types they're generally like they keep generating new cells that are healthy

as opposed to being cells that are frozen in time and get old or die so they injected this gene cocktail into these broken mice and then after that the problems the epigenetic weirdness that they introduced seemed to reverse itself whatever this gene therapy did helped reboot their cells in some way the scientists compare it to rebooting a malfunctioning computer where it gave the template again for healthy cells and helped restore organ function and restore some tissue function and restore some mobility their Their P-streams were stronger probably. And that is the reversal of aging. So they like induced symptoms of aging and then reversed it. And they don't know why or how it happened. They just kind of were like messing around in mice.

I mean, that seems still like a pretty big deal. Yeah, it's not nothing. And so there's something to it and that's cool like there's this idea that we can we can improve quality of life or like health healthfulness um potentially if we know which genes to help amplify to like help our systems as they're breaking down keep doing good But it's not this, like the way this question, like turning back the clock,

it's not a Benjamin button situation. It's not an injecting dog balls into you situation. It's not going to be like a magic fix unless you were broken in, in the way that these researchers broke you. Like we are not anywhere near that yet. It'll be like a little boost of of vim and vigor just like uh i don't know having a good day my stream is a little bit better it's great what it sounds like to me honestly is i need to pay more attention to this stuff because

like at this at this point it seems like the research is going to start to matter probably sometime during my life then we can have a forever hank uh well you're gonna get that anyway he's gonna be made out of artificial intelligence it's gonna be great which hairstyle do you want just pick and the goatee definitely can we pick the goatee that's it immediately because it's the correct choice if you want to ask the Science Couch your questions, you can follow us on Twitter at SciShowTangents, where we'll tweet out topics for upcoming episodes,

or you can join the SciShowTangents Patreon and ask us on our Discord. Thank you to Ike on Discord and at WitchHouseKey and everybody else who asked us your questions for this episode. And now, the results of this season of tangents. The panelist who won the most first half games, that was Sam. As of this episode, Sari came in with 10.

Sam had 11. You somehow tied 14 times. That's crazy. So you're both either bad or good at this. That's great. That's huge. The panelist who got the most trivia answers right, that was Sam with 20 wins to Sari's great. That's huge. The panelist who got the most trivia answers right. That was Sam with 20 wins to Sari's 15.

I'm on a roll, baby. I'm going to sweep the rest of them. You'll see. The most frequent winner of Fact Off was Sari with 18 to Sam's 13. You also tied four times somehow. It's just hard to make up my mind sometimes. We also posted a poll on Twitter so that our audience could decide on their favorite fact-offs.

And the winner of the most Twitter polls, the Audience Choice Award, that's going to go to Sari with 14 wins. But we haven't told for this episode yet, so it might end up tied because Sam has 13 and you tied one time.

Even on the Audience Choice, you tied once, which is amazing. Oh, that's sweet. Thank you. They were both equally loved. I'm just loving one little tiny, tiny bit less. And the panelist with the most overall episode wins was Sari with 18 versus Sam's 16 with one tie. So you were very, very close. I did not too bad this time.

You guys are always saying, you're so stupid, Sam. And I'm always like, no, but I'm doing good. That's the inside of your brain that's doing that. Oh, okay. So that's the end of season four of SciShow Tangents. Congratulations to Sari on her win. Next week we'll have a rerun.

Then on March 28th, we'll be back with the beginning of season five. But we are changing things up. We're going to change our upload schedule from weekly to every other week. There's a bunch of reasons for this. Ideally, we'd like for a season five to have some bigger and better facts off,

some wild new games, some more guests. We want to do a little bit more of that. So we want to devote more time to that. We also are just adjusting our stuff generally because while our audience has continued to grow, and we love that, and that's because you've been telling people about us,

it's because of other reasons. I don't know. It is continues to grow, which is fantastic. Tweeting about us, which I guess is telling about us. You've been tweeting about it. You've been, you've been continuing to listen and watch. But the ad,

the ad people have not been buying more ads. So there's that problem. So we're moving to every other week. We think it'll help make the show a little bit more ambitious, more sustainable, hopefully more fun. And if you need more tangents in your life, you can consider supporting us on Patreon. There you'll get some monthly bonus episodes.

You'll get access to our Discord. You can talk to us, ask us questions, talk to other people who love the show. And finally, our normal outro. If you like the show and you want to help us out, it's very easy to do that. You can go to patreon.com slash scishowtangents. You can get things like our newsletter and our

bonus episodes thanks to patrons John Pollock and Les Aker, especially. Second, you can leave us a review wherever you listen. That's super helpful and it helps us know what you like about the show. And finally,

if you want to show your love for SciShowTangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. And I've been Sam Schultz. SciShowTangents is created by all of us and produced by the fantastic Sam Schultz.

Our wonderful associate producer is Faith Schmidt. Our editor is the one and only Seth Glicksman. Our story editor is Alex Billow. Our social media organizer is Julia Buzz-Bazio. Our editorial assistant is Deboki Chakrabarty. Our sound design is by Joseph Tuna-Medish. Our executive producers are Caitlin Hoffmeister and me, Hank Green. We couldn't make any of this, of course,

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. For a while, we didn't understand why C. elegans worms seemed to self-destruct in old age after they couldn't reproduce anymore. Towards the end of its lifespan, one of these worms will basically dissolve its internal organs into a goopy protein liquid and poop out more than its own body weight in unfertilized eggs for a while we assumed that this was some sort of age-related disease or senescence causing problems but a 2021 study

concluded that this process is actually more like a primitive kind of lactation a way for sea elegans to use up every last ounce of energy to make worm milk and eggs to feed any offspring around. So we may be able to study these worms more to understand what genetic triggers cause their cells to age all at once after reproduction or what holds off this wormy milk process during the rest of their life. I mean, I've heard some things in my time. Worm milk. A new milk to try. Worm lactation cannibalism isn't one of them.

That's new. It's wild that we would have found out about this so late in the game. Yeah. Yeah, we just didn't pay attention. We were like, they're old and feeble. Their pee stream's weak and they're old and feeble their p-streams weak and they're just popping out all these eggs look at this loser disintegrating that's what we said and yeah yeah and then do they just die yeah i think they die after it my god this is what i'm

saying the genes don't want to keep us alive they want to keep themselves alive and they'll make you shoot out your body weight and eggs and leave the rest of you an empty husk to just die so that you can keep the genes alive. It's a great story, though. Sarah, we need to write this book. I don't know what it is, but. Oh, it's a new book. Is this a new book? Yeah, this one's about this one's about. Milk.

Milk. Milk. It's a great title for a book.