WEBVTT - Does the body replace itself? 0:00:01.440 --> 0:00:11.119 Welcome to Stuff you should know, a production of iHeartRadio. Hey, 0:00:11.160 --> 0:00:13.960 and welcome to the podcast. I'm Josh Clark with Charles W. 0:00:14.160 --> 0:00:18.880 Chuck Bryant, and guest producer Noel Noels in the house. 0:00:19.120 --> 0:00:22.160 It's the It and the New Studio. Yeah, man, this 0:00:22.280 --> 0:00:25.080 place is comfy, cozy. I like it. I wish um, 0:00:26.239 --> 0:00:28.600 you know, I wish there was a chair version of 0:00:28.640 --> 0:00:32.440 a water bed. I know this is a nappish little place. Yeah, 0:00:32.560 --> 0:00:36.800 especially today, I think I'm I'm dragging all apologies. Yeah, 0:00:36.840 --> 0:00:40.000 same here. So if we're talking kind of slow or low, 0:00:40.280 --> 0:00:42.840 or we just stopped talking for a little while, it's 0:00:43.560 --> 0:00:46.360 where its tired. Yeah. We bumped into you at the 0:00:46.400 --> 0:00:48.680 Hawks game last night. I know. Hey, how many does 0:00:48.720 --> 0:00:52.599 that you know? Yeah? Just the bumping. Yep, we were 0:00:52.640 --> 0:00:54.720 both at the Hawks. Gammy in the Hawks. One didn't 0:00:54.720 --> 0:00:57.080 even know we were going. No. Look over in the line. 0:00:57.280 --> 0:01:01.000 There's Josh and Yumi. Yeah that's great. There's Chuck and 0:01:01.120 --> 0:01:06.880 Eddie yep, each other in an arena of eighteen thousand 0:01:07.200 --> 0:01:09.679 bumping into someone. Is that it? That's all it holds. 0:01:09.959 --> 0:01:12.360 I think it's something like that. It's a good a 0:01:12.400 --> 0:01:14.280 lot of people. It's a good arena. Yeah, but you 0:01:14.319 --> 0:01:17.880 had box seats because you're special. They were free o. 0:01:18.080 --> 0:01:21.120 Mine were free to in. The nosebleeds Yeah, I like 0:01:21.280 --> 0:01:23.280 just about every seat in that place. Yeah, it's not 0:01:23.319 --> 0:01:26.399 too bad. I was. I was laughing about the nosebleeds 0:01:26.440 --> 0:01:28.800 going in, But then I got up there. I was like, 0:01:28.840 --> 0:01:31.200 this is great. Yeah you can see everything. Did your 0:01:31.319 --> 0:01:36.160 nose actually bleed just twice? Yeah, once out of a 0:01:36.280 --> 0:01:39.760 cheer excitement, and then once from the altitude and that 0:01:39.840 --> 0:01:43.280 was more of a spray, right yeah, yeah, just covering everyone. 0:01:43.440 --> 0:01:47.360 Everyone was like hawks, Boy, what a weird intro. It's 0:01:47.360 --> 0:01:49.840 a little weird, um, But I mean it kind of 0:01:50.280 --> 0:01:55.559 jibes a little bit because we're talking. Yeah, you're mentioning blood. Sure, 0:01:55.680 --> 0:01:59.240 I was shedding cells and blood. You were like blood 0:01:59.320 --> 0:02:01.680 is made up of sell and we shed tons of cells. 0:02:01.720 --> 0:02:04.080 But before we get to that, right, there's the fact 0:02:04.080 --> 0:02:08.200 of the podcast. You shed cells. Um. I want to 0:02:08.200 --> 0:02:11.640 mention this one thing I read. Yeah, it's called I 0:02:11.680 --> 0:02:14.320 think the title of the article is the Self is Moral. 0:02:14.520 --> 0:02:17.600 It's about like where we get our identity of self from, 0:02:18.040 --> 0:02:20.840 like where it's rooted. It was written by a person 0:02:20.960 --> 0:02:24.520 named Nina Stromeyer, I believe is on aon magazine. Just 0:02:24.600 --> 0:02:28.080 type in the self is moral aon It'll come up. 0:02:28.080 --> 0:02:32.639 I'll get you there. Uh and uh. It Towards the beginning, 0:02:33.560 --> 0:02:38.799 the author says, there's this very famous philosophical exercise, which 0:02:38.840 --> 0:02:41.919 you know, philosophers love to do, like mental exercises. Yeah, 0:02:41.960 --> 0:02:44.440 that's what that's all they have. So imagine you have 0:02:44.560 --> 0:02:49.000 like kind of imagine you have like a ship, right, 0:02:49.400 --> 0:02:54.000 like a boat, ye, a nice Yankee clipper okay, okay, 0:02:54.240 --> 0:02:57.800 And this Yankee clipper is slowly, over time kind of 0:02:57.919 --> 0:03:01.680 salvage for parts, okay, but rather than just being stripped, 0:03:01.720 --> 0:03:04.560 like every time a part is taken out, it's replaced 0:03:05.400 --> 0:03:08.160 and then over the course of like fifty one hundred years, 0:03:08.160 --> 0:03:12.560 as each plank, as each bolt, as each like masked head, 0:03:13.080 --> 0:03:17.000 even the thing the carved lady in front, yeah, eventually 0:03:17.160 --> 0:03:20.000 just gets replaced with something else. Yeah, a new carved 0:03:20.040 --> 0:03:23.400 lady that speaks of the time, right, you know? Is 0:03:23.400 --> 0:03:27.160 it still though, after every single part has been replaced, 0:03:27.400 --> 0:03:30.839 the same ship that it was before? Yeah, I see 0:03:30.880 --> 0:03:33.920 what you mean. I don't think that can be possible. 0:03:35.800 --> 0:03:38.680 Why not, especially if it has the same name and 0:03:38.720 --> 0:03:41.120 it's the same ship in the same place as before. 0:03:41.200 --> 0:03:46.000 It was just slowly, over time moved out. True, where 0:03:46.040 --> 0:03:49.440 does the self lie? Yeah, that's a good point, man, 0:03:49.600 --> 0:03:52.240 Like redoing a house, same thing, Yeah, I mean all 0:03:52.280 --> 0:03:54.480 the floors and the walls and the windows, Like when 0:03:54.480 --> 0:03:57.840 does it cease to become that same house that was 0:03:57.880 --> 0:04:00.920 built in nineteen thirty exactly? Isn't that cool? Yeah? It 0:04:01.000 --> 0:04:02.760 is really cool. And the reason that it applies to 0:04:02.800 --> 0:04:05.720 this episode is because over the course of your lifetime, 0:04:06.280 --> 0:04:11.000 a significant portion pretty much all of the cells in 0:04:11.040 --> 0:04:16.120 your body are going to like be replaced. Yeah, so 0:04:16.160 --> 0:04:21.560 that the the person even after you reach your adult self. Yeah, physically, 0:04:23.000 --> 0:04:26.640 by the time you die, assuming you're gonna die much later, 0:04:27.520 --> 0:04:30.760 you're you are essentially a different person, at least on 0:04:30.800 --> 0:04:36.680 the cellular level. Yeah. Thirty seven trillion cells ish, that's 0:04:36.680 --> 0:04:39.719 how many we have. Yeah, that's what they estimate. And 0:04:39.800 --> 0:04:43.000 I did a little looking into lifespans. Sounds like an 0:04:43.160 --> 0:04:46.800 estimate thirty seven trillions. Yeah, what do you want, like 0:04:46.800 --> 0:04:50.200 like give or take? Yeah, I did a little research 0:04:50.240 --> 0:04:53.240 into lifespans just because this all sort of comes back to, 0:04:54.640 --> 0:04:57.880 like your death basically, because that's all death is is 0:04:57.920 --> 0:05:04.279 your your cells, you know, dying little by little. Well, yeah, 0:05:04.320 --> 0:05:05.920 I mean if you think about it, chuck, one of 0:05:05.960 --> 0:05:08.160 the things that like why do we die? If our 0:05:09.120 --> 0:05:11.719 we'll get to all that, but it's intriguing, you know, 0:05:11.839 --> 0:05:16.320 it started, you know, questions started popping up. So apparently 0:05:16.320 --> 0:05:19.599 we gain about three months every three months of life 0:05:19.720 --> 0:05:26.200 humanity every year that we progress, Like the average lifespans 0:05:26.520 --> 0:05:28.880 spans by three months. Yeah, Like if you were born 0:05:28.880 --> 0:05:31.680 in twenty twelve, the average lifespan is now and this 0:05:31.800 --> 0:05:34.760 is the United States, is seventy eight point eight. If 0:05:34.760 --> 0:05:36.719 you were born in nineteen oh one, it was about 0:05:36.800 --> 0:05:40.200 forty seven and fifty years for men and women respectively. 0:05:40.720 --> 0:05:42.920 But if you look at the ratio, it's still about 0:05:43.000 --> 0:05:48.520 three months. Despite all our technologies, three months a year, 0:05:49.000 --> 0:05:52.359 every year, every year, just slowly creeping along. Yeah, Because 0:05:52.560 --> 0:05:54.560 I think the article it was like when we're going 0:05:54.600 --> 0:05:56.560 to live to be one hundred by average, and they 0:05:56.600 --> 0:05:59.040 say by the year twenty one hundred, if things hold, 0:05:59.600 --> 0:06:02.839 then the average human or American will be about one 0:06:02.920 --> 0:06:05.160 hundred years old. I thought that, so I guess that 0:06:06.040 --> 0:06:08.640 if things are steadily progressing, I had heard that like 0:06:08.800 --> 0:06:13.320 our generation would be either the last or the first, 0:06:13.360 --> 0:06:16.719 the last two to not hit triple digits or the 0:06:16.800 --> 0:06:20.799 first two on average. Yeah. Yeah, again these are all guesses, 0:06:20.839 --> 0:06:24.280 you know, so who knows. Plus if you believe in like, 0:06:24.480 --> 0:06:29.400 uh things, speeding science, speeding up? Yeah, what is that? 0:06:29.440 --> 0:06:33.000 Moore's law? Yea is at it? Yeah, applied to computer 0:06:33.080 --> 0:06:35.080 or though in that case right right, but I mean 0:06:35.520 --> 0:06:38.440 you can send it to other stuff. Yeah, then you 0:06:38.520 --> 0:06:41.160 might think, you know, it's it's but you know, they 0:06:41.160 --> 0:06:44.320 say it's not increasing like that. No, at least not 0:06:44.360 --> 0:06:47.479 so far. Moore's law is exponential growth just adding three 0:06:47.520 --> 0:06:52.480 months every years, non exponentials geometric. I think we're still 0:06:52.520 --> 0:06:57.640 at non exponential growth definitely. Yeah, we're just adding three months. Yeah, 0:06:57.680 --> 0:07:00.760 it's not bad though. That's pretty good average every four years. 0:07:00.760 --> 0:07:03.279 That's an extra year. Yeah. Well, and it's interesting to 0:07:03.320 --> 0:07:06.000 think about, you know, people that were born you know 0:07:06.040 --> 0:07:09.320 a lot of our colleagues like eight years behind us. 0:07:10.080 --> 0:07:15.280 We're going to live an average of two years longer. Yeah, 0:07:15.320 --> 0:07:17.720 that seems unfair, sad. Yeah, I know, what did they do? 0:07:18.440 --> 0:07:23.000 Just observe that we're thinking about our own deaths today. Yeah, 0:07:24.520 --> 0:07:30.960 and chuck that there's this rumor theory legend maybe okay, 0:07:31.360 --> 0:07:36.640 that your body regenerates itself, of your body regenerates itself 0:07:36.680 --> 0:07:40.360 every year. Yeah, that's not true. No, it's not true, 0:07:40.400 --> 0:07:42.320 but it was a very long standing rumor, and it 0:07:42.360 --> 0:07:45.400 was actually based on science. Yeah, you know, not just 0:07:45.440 --> 0:07:48.800 the idea that, oh, yeah, ourselves regenerate. So back of 0:07:48.880 --> 0:07:52.360 the envelope estimate is that, you know, we regenerate ninety 0:07:52.400 --> 0:07:55.120 five or ninety eight percent of ourselves every year. It 0:07:55.200 --> 0:08:01.280 was early experimentation by injecting radio act of isotopes into 0:08:01.400 --> 0:08:04.679 human beings and then following their course and then making 0:08:04.800 --> 0:08:08.040 estimates based on that led to this idea. It's called 0:08:08.040 --> 0:08:11.000 pulse labeling, is it. Yeah. It's like tagging an animal 0:08:11.040 --> 0:08:14.280 in the wild basically, right, but you're just tagging a cell, yeah, 0:08:14.320 --> 0:08:16.360 for specific types of cell. Yeah. They don't do that 0:08:16.400 --> 0:08:19.280 to humans anymore. No, it's very animals anything. It's a 0:08:19.360 --> 0:08:23.880 very dumb thing to do. Sure, ejecting radiation exactly, Yeah, unless, 0:08:23.880 --> 0:08:28.040 of course you know it's radiation treatment. That's true, which 0:08:28.080 --> 0:08:29.920 is still a really weird thing if you think about it. 0:08:29.920 --> 0:08:31.720 It's Yeah, I have a feeling it's gonna be like 0:08:31.720 --> 0:08:33.800 one of those things we look back on as like 0:08:33.800 --> 0:08:37.240 a primitive treatment. Yeah, yeah, yeah, I hope so. Um, 0:08:38.000 --> 0:08:41.040 but there there was this long standing science for decades 0:08:41.160 --> 0:08:47.640 or this idea, scientific idea that we regenerated ourselves by finally, 0:08:47.760 --> 0:08:53.320 and I think two thousand five, Um, there was a 0:08:53.320 --> 0:08:59.440 a researcher named doctor Jonas Freezing. He was Swedish. Dude's awesome. 0:09:00.200 --> 0:09:04.080 He said, this whole urban legend is really bringing me down. 0:09:04.520 --> 0:09:08.520 I want to figure out a way to really track 0:09:09.080 --> 0:09:13.120 how often the human body regenerates itself. Yeah, and the 0:09:13.360 --> 0:09:19.800 biggest question has been the brain, specifically the cerebral cortex 0:09:20.360 --> 0:09:23.120 and the heart and the heart muscles. I mean, they 0:09:23.120 --> 0:09:24.920 want to know all this stuff, but those were the 0:09:24.920 --> 0:09:27.800 two biggest mysteries. I think. Right, there's still the mysteries. 0:09:27.840 --> 0:09:30.280 But if you went back to prior to two thousand 0:09:30.280 --> 0:09:33.400 and five, in doctor Freeson's research, it was all a mystery. Yeah, 0:09:33.600 --> 0:09:37.880 he figured out he basically put a very accurate time 0:09:37.920 --> 0:09:42.959 stamp on how often human tissue and human cells regenerate themselves. Right, 0:09:43.360 --> 0:09:47.880 So the way he did this is very clever. For 0:09:47.920 --> 0:09:52.840 a long time, botanists knew that the trees around the 0:09:52.840 --> 0:09:59.000 world contained a spike of carbon fourteen radiation, Yes, thanks 0:09:59.000 --> 0:10:02.800 to humans and nuclear bombs. Exactly from nineteen fifty four 0:10:02.880 --> 0:10:07.640 to nineteen sixty three, tree rings for tree growth around 0:10:07.640 --> 0:10:11.040 the world show a big spike in carbon fourteen. Carbon 0:10:11.080 --> 0:10:15.880 fourteen is naturally occurring too, So like just cosmic rays 0:10:15.960 --> 0:10:21.800 from the Sun bombard Earth's atmosphere and create radioactive isotopes 0:10:21.840 --> 0:10:26.560 by knocking electrons from particles in our atmosphere, right, those 0:10:26.880 --> 0:10:32.360 radioactive particles become carbon fourteen, which is radioactive, and in 0:10:32.400 --> 0:10:38.040 the atmosphere, carbon fourteen binds to oxygen and creates carbon dioxide, 0:10:38.400 --> 0:10:42.840 which comes to Earth. Every living thing breathes this stuff in, 0:10:43.000 --> 0:10:45.800 whether it's a plant, whether it's a human, Like we 0:10:45.920 --> 0:10:49.760 just have C fourteen in our bodies. We also eat 0:10:49.880 --> 0:10:53.160 plants exactly contain the C fourteen bids breathing it in, 0:10:53.200 --> 0:10:55.320 and we also eat the animals that eat the plants 0:10:55.360 --> 0:10:59.280 that in just C fourteen. Right, Yeah, so like we 0:10:59.400 --> 0:11:05.160 got CAR fourteen in our bodies, that's right. But because 0:11:05.200 --> 0:11:08.040 of the spike in carbon fourteen that was introduced to 0:11:08.160 --> 0:11:14.840 the atmosphere from nuclear testing there there is a spike 0:11:14.920 --> 0:11:17.960 in humans as well. So you can roughly age like 0:11:18.000 --> 0:11:22.240 a human compared to another human if they were born 0:11:22.520 --> 0:11:25.680 in say nineteen fifty nine, and one who was born 0:11:25.720 --> 0:11:29.440 in nineteen seventy after there was that spike of carbon 0:11:29.480 --> 0:11:32.760 fourteen had gone away, right, right, that's pretty cool. But 0:11:32.840 --> 0:11:36.520 what doctor Freezen did is even cooler. He basically went 0:11:36.559 --> 0:11:39.320 back to those tree trunks, those tree rings that show 0:11:39.320 --> 0:11:45.400 a spike in carbon fourteen, and created a calendar of 0:11:46.080 --> 0:11:51.679 carbon fourteen to Kay and basically said, Okay, on this date, 0:11:52.200 --> 0:11:56.520 this is how much carbon fourteen was on Earth. And 0:11:56.679 --> 0:11:59.600 if I take this cell and compare it, knowing that 0:11:59.640 --> 0:12:03.240 carbon fourteen decays at a constant rate, yeah, I can 0:12:03.280 --> 0:12:07.199 tell you exactly how old this cell is exactly. And 0:12:07.400 --> 0:12:10.559 he used it to date cells and tissues and all 0:12:10.559 --> 0:12:13.120 sorts of cool stuff. Yeah. He he went looking for 0:12:13.160 --> 0:12:17.280 a marker and he found one due to our atomic 0:12:17.320 --> 0:12:21.440 testing program. Yeah, which is pretty weird. Just released all 0:12:21.480 --> 0:12:24.400 that junk in the atmosphere, and now all these years 0:12:24.480 --> 0:12:27.440 later it has a nice use. Yeah, you know it does. 0:12:28.080 --> 0:12:31.480 So we now know when we're gonna die, right, And 0:12:31.520 --> 0:12:34.000 the reason he was able to use this as a marker, Chuckers, 0:12:34.120 --> 0:12:37.959 is that, um, when you when you take a breath 0:12:37.960 --> 0:12:41.360 of life, your first breath of life. That's right, and 0:12:41.520 --> 0:12:44.560 you get some you get some of that C fourteen 0:12:44.800 --> 0:12:48.440 into your DNA um and a steady amount stays in there, 0:12:48.520 --> 0:12:51.560 like you don't keep ingesting C fourteen as far as 0:12:51.600 --> 0:12:54.680 I understand, as far as your DNA goes, Oh okay, 0:12:54.840 --> 0:12:58.760 once it's in your DNA, as your cells divide, yeah, 0:12:59.200 --> 0:13:04.360 that original amount becomes divided evenly. Right, So the less 0:13:04.400 --> 0:13:09.160 C fourteen that's in tissue, the older those that cell line, 0:13:09.280 --> 0:13:12.560 is right, or the younger the actual cells are, right? 0:13:13.480 --> 0:13:15.360 Is that right? I think so? Which would mean the 0:13:15.440 --> 0:13:19.480 new cell the marker would be a fresh batch of 0:13:19.520 --> 0:13:23.440 the C fourteen. No, it have less C fourteen? Oh really? Yeah, 0:13:23.520 --> 0:13:26.360 let's say you have because the cell divided, Yes, exactly, Yeah, 0:13:26.679 --> 0:13:30.120 like you have ten grams of C fourteen, which you don't. 0:13:31.080 --> 0:13:33.719 I can't imagine that would be Like let's say you're 0:13:33.960 --> 0:13:37.040 you're one cell that's never divided has ten Yeah, when 0:13:37.040 --> 0:13:39.640 it divides into two, it's each of those two cells 0:13:39.679 --> 0:13:42.360 is going to have five grants, and then two and 0:13:42.400 --> 0:13:44.440 a half and then one point seven five and so 0:13:44.480 --> 0:13:47.320 on and so on. Um, So, since you know that 0:13:47.400 --> 0:13:50.199 C fourteen is generated at a constell rate, you know 0:13:50.320 --> 0:13:52.560 that it decays that a half life of fifty seven 0:13:52.679 --> 0:13:57.440 hundred and thirty years. You can look at the amount 0:13:57.559 --> 0:14:02.240 of C fourteen and then also the decay of it 0:14:02.240 --> 0:14:04.120 as well. Yeah, you can date things that are no 0:14:04.200 --> 0:14:07.640 longer living too, to see when when they ingested that 0:14:07.720 --> 0:14:10.880 C fourteen was. Yeah, he's a little like a bingo card. 0:14:10.920 --> 0:14:13.000 He just from the calendar that he made with the 0:14:13.040 --> 0:14:15.360 trees and he holds it up in the light and 0:14:15.480 --> 0:14:18.560 that's how he determines it. It's not true. But what 0:14:18.559 --> 0:14:21.760 he did determine though, was which is really cool. And 0:14:21.800 --> 0:14:23.800 this is sort of what we've been building toward, is 0:14:23.880 --> 0:14:29.680 that most of your cells are about seven to ten 0:14:29.760 --> 0:14:32.800 years old, yes, in the body, and there are variances, 0:14:32.840 --> 0:14:34.240 and of course we're going to talk about all that, 0:14:34.400 --> 0:14:37.880 and right after this break, we're going to give you 0:14:37.880 --> 0:14:40.160 a little primer on cells. So you know what all 0:14:40.200 --> 0:15:03.160 this means, right, all right, Josh, we were promised to 0:15:03.200 --> 0:15:06.920 sell primer and we like to deliver on those promises. 0:15:07.240 --> 0:15:11.480 Here stuff you should know. So I guess we started 0:15:11.520 --> 0:15:15.440 off by saying they're thirty seven trillion cells about in 0:15:15.480 --> 0:15:20.080 the human body, give or take, and water makes up 0:15:20.120 --> 0:15:23.640 about two thirds the weight of those cells. Oh yeah, 0:15:23.680 --> 0:15:27.160 that's right. They're tiny. You need a microscope to seum 0:15:27.760 --> 0:15:31.680 and it's like it's the tiniest thing that can still reproduce. Yeah. 0:15:31.680 --> 0:15:34.200 And even though we have many different kinds of cells, 0:15:34.360 --> 0:15:38.920 I think two hundred types, and within those cells there 0:15:38.920 --> 0:15:41.720 are differences, but there are a lot of similarities with 0:15:41.800 --> 0:15:45.640 all cells in their structure. Um. Namely, they have a 0:15:45.680 --> 0:15:48.240 cell membrane, they have a nucleus. They have a nucleus. 0:15:48.240 --> 0:15:51.560 I have more than one. And these membranes are what 0:15:51.640 --> 0:15:54.440 allows nutrients to pass in and out, ways to pass 0:15:54.480 --> 0:16:04.640 out water through osmosis travels in reverse, osmosis travels out. Yeah. 0:16:04.680 --> 0:16:08.000 And what else you got your mitochondrian as well. That's 0:16:08.000 --> 0:16:11.000 where this is the important, really important thing, which is 0:16:11.240 --> 0:16:14.240 basically what keeps your cells alive. That's the power center, 0:16:14.360 --> 0:16:17.120 right yeah, and that's um. You know, your cells need 0:16:17.320 --> 0:16:20.400 food to live just like your body does. But you 0:16:20.400 --> 0:16:24.480 can't pass that that hamburger straight into your cell. It 0:16:24.480 --> 0:16:26.400 needs to be broken down so your cell can use 0:16:26.440 --> 0:16:32.040 it exactly into what adnosine triphosphate ATP is like the 0:16:32.040 --> 0:16:38.080 the universal cell fuel, right. Yeah. So there's a lot 0:16:38.120 --> 0:16:40.160 of stuff that the body does make I think you 0:16:40.200 --> 0:16:44.600 need like twenty three. I think you need twenty three 0:16:44.800 --> 0:16:47.800 amino acids, and like nine of them your body doesn't 0:16:47.800 --> 0:16:51.440 really manufacture. So those are the nine non essential amino acids. Right, 0:16:51.640 --> 0:16:54.680 And you use amino acids to build proteins, and use 0:16:54.720 --> 0:16:59.000 proteins for everything from making muscles to making red blood 0:16:59.040 --> 0:17:04.080 cells to um, you're mounting an immune response. Proteins are very, 0:17:04.160 --> 0:17:07.680 very vital, and some of them you have to build 0:17:07.720 --> 0:17:11.000 by eating stuff from your environment. Right. Yeah, So you 0:17:11.040 --> 0:17:13.119 go out and you find yourself a nice pig and 0:17:13.160 --> 0:17:15.600 you cut off its back leg. You say, sorry, pig, 0:17:16.119 --> 0:17:19.160 here's a peg leg for you. But I need this leg. 0:17:19.480 --> 0:17:21.360 I'm going to eat this leg. And what I'm really 0:17:21.400 --> 0:17:23.560 eating is the muscle, and what I'm really really eating 0:17:24.080 --> 0:17:26.919 is the glutamine. Yeah, and my body is going to 0:17:26.960 --> 0:17:29.199 take this glutamine. It can make it itself, but it 0:17:29.240 --> 0:17:31.640 doesn't hurt to have an extra little bit of glutamine. Yeah, 0:17:31.640 --> 0:17:33.480 it doesn't hurt to have that pig leg. And you're 0:17:33.520 --> 0:17:38.800 exactly right, So I'm chomping on the pig legs, like right, 0:17:38.880 --> 0:17:42.360 just use your imagination for a second, sure, um, And yes, 0:17:42.440 --> 0:17:45.640 I'm sorry too, uh, so you're eating the pig leg 0:17:45.760 --> 0:17:48.680 and you're gaining this glutamine as a result, and your 0:17:48.680 --> 0:17:52.240 body's metabolizing the glutamine and then reusing it, right, Yeah, 0:17:52.320 --> 0:17:56.040 And it can be glutamine, it can be um anything. 0:17:56.160 --> 0:17:59.760 We if we're ingesting a protein, if we're ingesting amino acids, 0:17:59.760 --> 0:18:03.680 before eating any kind of food, sugars, whatever, our bodies 0:18:03.800 --> 0:18:07.199 break it down into its constituent parts, and then a 0:18:07.240 --> 0:18:12.560 lot of those constituent parts become part of our bodies. Yeah. 0:18:12.600 --> 0:18:15.000 So if you think about it in this sense, when 0:18:15.040 --> 0:18:18.959 we eat, when we breathe, we're taking in stuff we 0:18:19.000 --> 0:18:22.159 need from the environment. Yeah, and that stuff that we 0:18:22.280 --> 0:18:24.520 take in from the environment becomes a part of us 0:18:24.600 --> 0:18:28.240 literally physically on the molecular level. It becomes a part 0:18:28.240 --> 0:18:30.320 of us, for better or worse, depending on what it is. 0:18:30.320 --> 0:18:32.600 Of course. Yeah, that's a that's a great I think 0:18:32.640 --> 0:18:35.280 that's ultimately one of the side lessons of this whole 0:18:35.280 --> 0:18:38.720 thing is we should take care of our environment because 0:18:38.760 --> 0:18:41.960 that environment becomes us and we either suffer or thrive 0:18:42.000 --> 0:18:43.960 as a result of it. You ever heard the expression 0:18:44.000 --> 0:18:46.560 you are what you eat exactly? You know, you literally 0:18:46.560 --> 0:18:49.680 are what you eat, quite literally, and then also chuck 0:18:49.680 --> 0:18:51.960 it goes. It goes the other way as well. When 0:18:52.000 --> 0:18:57.240 we excrete waste, when we exhale CO two that's taken 0:18:57.320 --> 0:18:59.760 up by other things in the environment, is deposited into 0:18:59.800 --> 0:19:03.440 the environment and it becomes part of the environment itself. Yeah. 0:19:03.480 --> 0:19:08.360 So not only do we regenerate our cells, regenerate tissue 0:19:09.359 --> 0:19:14.480 every on average seven to ten years, become almost wholly 0:19:14.680 --> 0:19:20.120 a new version of ourselves. Yea, we are also the 0:19:20.160 --> 0:19:26.760 boundary between us and the surrounding environment is really nonexistent 0:19:26.920 --> 0:19:31.880 because there's a constant exchange of molecules. Yeah, we lose 0:19:32.080 --> 0:19:35.639 on average, they say nine average adult male loses ninety 0:19:35.720 --> 0:19:43.840 six million cells per minute, but we also replace those 0:19:43.920 --> 0:19:48.000 at the rate of ninety six million per minute, yeah, roughly. Yeah. Yeah, 0:19:48.480 --> 0:19:50.520 so that's the good news. So we've got all these 0:19:50.600 --> 0:19:52.600 cells that we're losing, we've got all these new cells 0:19:52.600 --> 0:19:54.680 that are replacing them. And I think, like you said 0:19:54.720 --> 0:19:59.600 earlier before the break, that these the different types of 0:19:59.640 --> 0:20:04.960 cell and then hence different tissues regenerate at a different rate, right, Yeah, 0:20:05.000 --> 0:20:08.200 And they all have specialized jobs, and the cells are 0:20:08.240 --> 0:20:13.520 often built in such a way to aid that job physically, 0:20:13.600 --> 0:20:15.800 you know, different to make that job easier, which is 0:20:15.840 --> 0:20:20.119 really cool too. Shows how versatile they are. Yes, you know, 0:20:20.359 --> 0:20:24.320 like stem cells are very versatile. Super. So let's say 0:20:24.600 --> 0:20:29.960 your skin. Yeah, your skin regenerates every two to four weeks. 0:20:30.000 --> 0:20:33.560 I think, ye, so exactly, you get a new healthy 0:20:33.920 --> 0:20:36.560 coating of skin every two to four weeks because your 0:20:36.840 --> 0:20:42.240 epithelial cells are particularly good at regenerating themselves. That's right, 0:20:42.320 --> 0:20:46.159 and that is well. I guess that would fall on 0:20:46.200 --> 0:20:49.840 the low side obviously, if we're talking seven to ten years. 0:20:49.880 --> 0:20:52.560 On the super low side, you have the cells that 0:20:52.680 --> 0:20:56.560 line like you're intestine and your gut, and those things 0:20:56.600 --> 0:20:59.600 don't last long at all because it's such a harsh environment. 0:20:59.640 --> 0:21:01.719 You know, you would expect him to last like weeks 0:21:01.720 --> 0:21:04.399 and months and years, but I think, how long is it? 0:21:04.600 --> 0:21:08.200 Five days? Yeah, that's nothing. But the structure of your guts, 0:21:08.440 --> 0:21:12.520 they that are beneath that membrane lining that turns over 0:21:12.640 --> 0:21:18.040 five days, they last about fifteen years. Yeah, it's it's 0:21:18.080 --> 0:21:22.439 such a like a beautiful, elegant system. Yeah, that we 0:21:22.520 --> 0:21:25.800 have to keep us alive. Red blood cells last about 0:21:25.800 --> 0:21:28.760 one hundred and twenty days. But then you have things 0:21:28.800 --> 0:21:32.920 like cells in your bone which actually regenerate as well, 0:21:33.200 --> 0:21:36.480 so your bones are over time, over a much longer 0:21:36.480 --> 0:21:39.520 period of time, actually becoming I mean, I hate to 0:21:39.560 --> 0:21:44.080 call them new bones, but they kind of are, you know, well, yeah, 0:21:44.119 --> 0:21:49.120 I mean compared if you took your femur and somehow 0:21:49.160 --> 0:21:53.000 compared it to your femur when you were fifteen years old, Like, 0:21:53.040 --> 0:21:56.840 they are two totally different bones, even though they're your bones. Yeah, 0:21:56.880 --> 0:21:58.480 they were in the same place, growing in the same 0:21:58.480 --> 0:22:02.320 person with the same DNA. There's still different bones because 0:22:02.520 --> 0:22:06.080 they're made of different cells. Ten years or so for 0:22:06.200 --> 0:22:08.280 the bones, yeah, something like that. For the human skeleton, 0:22:09.440 --> 0:22:12.520 three hundred to five hundred days. For the liver, very 0:22:12.520 --> 0:22:14.920 important organ it is. And one of the other cool 0:22:14.960 --> 0:22:19.440 things about the liver is it's just gangbusters that regenerating itself. Yeah. 0:22:19.800 --> 0:22:22.520 You can apparently cut out ninety five percent of a 0:22:22.600 --> 0:22:26.000 person's liver and it will grow back, and you won't 0:22:26.000 --> 0:22:29.040 have full function, but it will function and you'll survive 0:22:29.200 --> 0:22:33.480 with just five percent of your liver. That's pretty amazing actually, yeah, 0:22:33.560 --> 0:22:35.800 because it will just grow right back, kind of like 0:22:35.880 --> 0:22:41.880 a hornet's nest. Uh. Interestingly, the inner lens cells of 0:22:41.880 --> 0:22:48.480 your eye um form in your embryo and basically don't change. Yeah, Now, 0:22:48.560 --> 0:22:51.960 is that why you have suffer from degeneration and vision? 0:22:52.040 --> 0:22:53.880 That's what I would guess. Is that the reason? Yeah, 0:22:53.960 --> 0:22:57.520 So with the corneo lens Chuck, when you're when you're born, 0:22:57.760 --> 0:23:03.880 when you're conceived, right, you are a cell that divides. Finally, 0:23:04.200 --> 0:23:08.600 once that first division takes place, those corneal cells, they're 0:23:08.680 --> 0:23:11.640 set in stone. Like your corneal cells are as old 0:23:11.680 --> 0:23:15.760 as you are, the same age as you. Other cells 0:23:15.760 --> 0:23:18.360 that make up different parts of the eyes they're far newer. 0:23:18.640 --> 0:23:24.440 But your corneal cells, your cerebral cortex cells, they think, Yeah, 0:23:24.440 --> 0:23:26.879 that's the one I mentioned. The brain and the heart muscles, 0:23:26.880 --> 0:23:30.120 those are the two big ones. Because obviously the reason 0:23:30.200 --> 0:23:34.840 we have diseases like Alzheimer's and dementia are because the 0:23:34.880 --> 0:23:39.520 cerebral cortex has long thought to not to regenerate cells 0:23:39.600 --> 0:23:44.760 at all. Now I think they believe that they do 0:23:45.280 --> 0:23:48.600 in a very small number or different regions, like the 0:23:48.600 --> 0:23:52.280 olfactory bulb supposedly does. Yeah, in the hippocampus, so we 0:23:52.320 --> 0:23:55.040 can learn new things. Our sense of smell can be 0:23:55.080 --> 0:23:57.560 refined over time. Yeah, And I think isn't that also 0:23:57.600 --> 0:24:02.320 the reason the smell is very much tied to your memory, 0:24:02.640 --> 0:24:08.119 probably like a smell can conjure up a memory more clearly. Yeah, 0:24:08.160 --> 0:24:12.919 but the cerebral quartex itself, they don't think. Who was 0:24:12.920 --> 0:24:16.520 her name? Elizabeth Gould Princeton did a lot of work 0:24:16.520 --> 0:24:20.119 on this because it was just basically set in stone 0:24:20.119 --> 0:24:22.960 for years like, no, it doesn't happen. And she did 0:24:22.960 --> 0:24:24.720 a lot of work over the years trying to prove 0:24:25.720 --> 0:24:29.639 that it did using tracer studies. And I think that 0:24:29.760 --> 0:24:31.600 where they are now as they think it does some 0:24:32.320 --> 0:24:35.520 yeah here there, here there, But obviously we still have 0:24:35.560 --> 0:24:38.520 to mention Alzheimer, so it's not it doesn't regenerate like 0:24:38.560 --> 0:24:41.280 the rest of the body. Name close. Yeah, Alzheimer's also 0:24:41.359 --> 0:24:45.480 maybe produced I guess by plaques rember plaque build up. 0:24:45.520 --> 0:24:47.800 Oh yeah, in between your neurons that keep them from 0:24:47.800 --> 0:24:50.679 firing as well. Yeah, that's it seems like we're so 0:24:50.720 --> 0:24:55.119 close to figuring out the secret, you know. Yeah, to uh, 0:24:55.400 --> 0:24:59.480 I don't know about not dying ever, I'm not talking immortality, 0:25:00.040 --> 0:25:04.600 but um, living much longer lives. Well, let's talk about that, 0:25:04.640 --> 0:25:07.679 because all of this stuff kind of leads to that 0:25:07.760 --> 0:25:11.000