David (00:09)

Hello and welcome to a very special episode of Where Are We At With? I'm David Curnow. In the long history of this show, yes, all five episodes, we've always spoken to experts in their field who've spent years, decades researching and studying the specific topic. But sometimes you've just got to break the code.

Clip from “Pirates of the Caribbean” 2003, Bruckheimer and Walt Disney Corp.

“The Code is more what you might call a guideline, than actual rules.”

And that's because when we started looking at the topic of the human body and all the different ways we can repair different parts of it or replace or even downright make bits from scratch, well, the name that stood out wasn't the inventor of spray on skin or the world's most advanced lung transplant or even the latest in false teeth. It's someone who's spoken to all of those involved in every aspect of the topic and wrote the book on it.

Mary Roach is a writer, journalist, speaker, science communicator with eight New York Times bestselling books, including “Stiff, The Curious Lives of Human Cadavers”, “Gulp, Adventures of the Alimentary Canal”, and “Fuzz, When Nature Breaks the Law”. The Washington Post describes her as America's funniest science writer. Her TED Talk was named one of the top 10 ever by the organization.

Clip from TED talk by Mary Roach 2009

“Thank you very much. *applause* Thanks!”

I'd tell you the title but then our show would probably lose its “kids safe” marks in podcast apps and YouTube.

With just under 43 million plays, it's well worth Googling yourself to have a listen. Otherwise, the link is on this episode's page on our website, www.wawawpod.com. That's www.wawawpod.com. Mary Roach's new book, “Replaceable You”, explores the myriad ways we have and do repair, renovate, or even recondition every part of the human body.

It was published in America in 2025. It'll be released in Australia in early February. If you haven't read any of her books, and you really should, Mary Roach is incredibly, at times slightly disturbingly, dedicated to her research, while also quite irreverent. She joined me from California, overcoming her scheduling challenges and my computer skills challenges to give us an overview of where are we at with body rebuilding.

David (02:38)

Mary Roach, thank you so much for joining me today.

Mary (02:41)

My pleasure. Thank you.

David (02:43)

I want to start off by saying that when I read the book, I wonder how many other people in the world would watch a messy and possibly quite gory surgery, think to themselves, hmm, raspberry smoothie or lasagna. Do you know many?

Mary (03:02)

Let's be honest, no. No. I guess I'm a little unique in that way.

David (03:07)

Do you ever tell the people involved that's what you're thinking or do you keep that to yourself?

Mary (03:17)

⁓ I did not mention the raspberry smoothie to the surgeon, but that's for sure. The lasagna. I may have said, I may have said, I may have mentioned that, ⁓ to those folks.

David (03:26)

Yeah, look, it takes a fairly strong stomach then and if you're thinking of those things, I suppose it makes it a little easier. You've written quite a few books about, I suppose, the various functions and foibles of our bodies, the squishy bag of meats and assorted treats that make up humans. Do you think it's as much an interest about the people who study them as the bodies themselves?

Mary (03:53)

Yeah, very much so. ⁓ The bodies are interesting, the things that bodies do, but ⁓ I come back from a reporting trip and I'm always, it's just amazed at the people who do this work, their commitment, their curiosity, sometimes their eccentricities. So, and I never know heading into a research trip, a reporting trip, you know, I've emailed a couple of times with someone, but I've never met, I really don't know anything about them and their personality. And there is always a risk that, what if they're really boring or what if they're an asshole? know, I think that the people who say yes to me, I'm not paying them. You they're not getting anything out of this. It kind of self-selects for good people. And they just end up being ⁓ really interesting and really ⁓ often fun, sometimes weird.

David (04:53)

And let's be honest, sometimes that can be hand in hand, so to speak. And look, I know the feeling as a radio host for a while, I often would be most inspired by the people whose passion and depth of knowledge was, I suppose, as intense as their subject was niche. Quite often, particularly people like scientists or researchers, they're actually, in a sense, reluctant to speak. I just want to get on with doing my subject.

Mary (05:10)

Yes. That's right. That's right. But there are also those individuals who their research area is so niche that they don't talk about it very often. Their spouse doesn't want to hear about it. Their kids don't know anything about it. And so I come into the room and here's this researcher who spent 30 years studying the reflexes of the jaw when you're chewing and how a bolus is formed when you chew food and you have to put it back together and all of the kind of biology and physiology of chewing and swallowing. No one's ever been interested in it. So, he's just pretty excited that I've gone all flown all the way to the Netherlands to speak to him. Then I'm fascinated by this and how do you study this? You have this weird stuff that you chew on for research that's like plastic and you have to spit it out this technology for studying chewing. And I'm like, I love this guy. I love this. I'm so excited. And it's going to be so fun to write about this because it's a secret world. has a clue what this guy's been doing. And it's really interesting. And he's kind of maybe a little embarrassed about it. Maybe he thinks it's sort of trivial, but I'm like, no, pretty cool.

David (06:38)

I want to get onto the dental side of things in a minute, but I will very quickly go through my favourite list of just grabs, just I suppose phrases, just so I can put them out there and hang them on the wall for the moment while we chat. That includes “masticating in the privacy of my own room”, because that always is appealing to people. The “blood bank glory holes”, of course, has been trotted out a few times to friends. ⁓ As well as what sounds like, I suppose, the trailer for a weird sci-fi film, “this is the dawn of unlimited hair”.

Mary (06:53)

You Thank you. Thank you for appreciating those. I do. I absolutely do. And those are probably the three that, yes, gave me the most glee.

David (07:08)

You obviously get a bit of glee writing those.

Mary

The satisfaction as they fly off the fingertips as we type them in.

David

Let's go back to dental because again that's something that spoke to me recently with I had a walk in a remote part of Australia in which we came across a number of lighthouses and the tale was related to us of the fact that for a long time if you were a lighthouse keeper you and all of your family had to have all your teeth removed effectively because there's no way people could get to you in time for any serious dental infection. This was the one thing they could do to prevent serious health complications for lighthouse keepers and you write about removing your teeth all of them in the book tell me a bit about that.

Mary (07:59)

First of all, David, you're killing me that I didn't know that and I wasn't able to put it in the chapter. This always happens. Your book comes out, you talk to people and you find like five things that were so great that should have been in the book. But anyway, yeah, this was the thing all the way up there in the United States and Canada, up through the, and I think Australia as well. are people up through the sixties even, but I think more so in like the forties and fifties, people at a young age in their 20s, say 30s, 40s, having all of their teeth pulled on the assumption that it'll save them bother and money to just have it done in one go rather than going back over and over. And for a certain span of years when dental care, particularly in remote areas, wasn't available at or readily available. could sort of see the appeal, but this was being done in cities. I mean, Paul McCartney, his dad was saying, you know, you just have them all pulled and get dentures. It was a thing. was just, yeah, yeah. Just to get some nice shiny white ones. I mean, there was this sense that, well, that'll be better. You know, the technology had invented a new and improved set of teeth that you could just pop in there and you'd be good to go and you'd look like a movie star. Yeah.

David (09:02)

Just whip ‘em out. What are you gonna do? Given the fact that we've gone from using, I suppose, foreign objects, metals, variety of metals and things like that, other people's teeth as chewing implements, I suppose there is an argument to say, well, look, the idea of these days removing them all and screwing them into our jaw and putting false ones in, I suppose there's a certain logic to it, even if it's a bit traumatic.

Mary (09:20)

Kind of amazing. Well, now, yes, now, like you said, they're being screwed into the jaw, into the bone, and then the plate can kind of click in so you don't have the slipping and the gapping and the food getting caught underneath. was up through implants, implant technology. It was an inferior set of teeth, was something like 20 % of your chewing ability would be retained.

You were always nervous they were slipping. was just, dentures were kind of awful. But now, yeah, I mean, I think there's a desire to retain as many real teeth as you can and maybe do one or two individual teeth rather than pulling the whole lot. Yeah.

David (10:29)

Yeah. And of course, the poster child for a lot of the dental work and dentures that you write about is the American hero, George Washington.

Mary (10:38)

George. Yeah, George Washington. That was an interesting, you you see, I used to see, you know, as an American, his portrait, it's on money, it's on walls. You see George Washington a lot and he also looks very grim and a little, still strangeness around the mouth and the upper lip. And, and as it turns out, he had a pair of spring loaded dentures, which was a fairly common way of doing it back then where there were springs, the upper, between the lower and the upper plates, there was this very sort of tight coil pushing them up against the palate and using the lower jaw as the, bracing it on the lower jaw. But what would happen, and this was what he wrote to one of his, he had several dentists, that it would also push it, had the effect of pushing the upper teeth out as well as up. So he was constantly holding, using his upper lip to hold them back. Yes, exactly, like that. So you look at pictures. Yeah, he was just doing battle with his upper teeth. And you see photographs. I mean, I can't say for certain that that's what's going on, but it certainly looks like that.

David (11:40)

The threat of escape from your mouth. He is always pictured with a very, I suppose, grim or at least austere look. And we suppose that's just because he was a serious guy. I know he's just seriously trying to stop his teeth from jumping out and grabbing you separately to himself. Do you look at your own body and like the various components of it differently, having done all this research?

Mary (12:01)

Yeah. Exactly. Yeah, I frequently do. Yeah, mean, whatever the book is. when I wrote Bonk, which is about people who studied sexual physiology, the physiology of arousal and orgasm, you know, and you read Masters and Johnson's Human Sexual Response, which goes like, you know, minute by minute, what's happening? Like the earlobes start to engorge and all these things you weren't aware of. And so now you're aware of that and you're like, hmm. Are the earlobes engorging for you? And the chewing guy, I came back from the Netherlands and I just would be chewing and thinking, I'm forming a bolus now. It's disgusting. What I'm doing with the saliva mixing with the bits and I have to put it back together and now I'm swallowing the bolus. And I'd go to a restaurant and I'd look around and I'd go, people should be doing that in private. It's disgusting. So yes, I'm definitely hyper aware of these things whenever I do a book.

David (13:13)

Indeed, masticating the privacy of your own room. What are you doing in a restaurant doing it?

Mary (13:16)

Exactly.

David (13:21)

You mentioned this, the fact that you get involved in some of these things. mean, the research that you do is fairly hands-on, if not other parts on, whether it's from other books getting into the vomit comet or ⁓ the body farm for decomposition and things like that. In this particular case, like an iron lung. How on earth did you even find someone who had an iron lung?

Mary (13:30)

Yes. I'll tell you, is, there was a, there's a woman named Norma Brown who is a historian of negative pressure breathing and the iron lung is an example of negative pressure. It's not the same as you go in an ICU with that kind of medical leaf blower that's just blowing air into your lungs. The iron lung works by, ⁓ you know, your rib cage expands, pulls in air. So it's quite a natural way to breathe artificially.

David (13:45)

good.

Mary (14:13)

So, and I don't remember how I found Norma Brown, but anyway, said, do you know anyone who is still, you know, because she treats patients who have chronic pulmonary issues. I said, do you know anyone who still uses an iron lung? And she said, yeah, there was a woman who just died this year and her husband still has the iron lung. And here's his email address. So I just wrote an email out of the blue to this guy Mark and said, this is what I'm doing and could I come spend the night in your iron lung, which is kind of a strange thing to say to a stranger. But he, a little strange. Fortunately, he was familiar with one or more of my books. So that helps, it always helps ⁓ diffuse the weirdness. And he's like, okay, I get it. I understand what you're doing. And yes, you can come in. ⁓ it's you.

David (14:51)

A little “Oh it's that person. Right. Yeah. Okay. Yeah. Yeah.”

Mary (15:11)

That sounds like you. Yes, you can come take a spin in my deceased wife's iron lung.

David (15:18)

recently deceased wife's iron lung. What was the experience like? Because very few of us have experienced this.

Mary (15:20)

Yes. Yeah, ⁓ it is a very natural feeling. If you've ever, I don't know if somebody has had a CPAP machine, that's a kind of low grade positive pressure where it's just giving you, people don't like having a machine blowing air through their nose or down through their mouth. It's a very uncomfortable intrusive feeling, but the iron lung, first of all, it's comfortable, it's big, it's like a giant water heater on its side and the bed rolls out like in an MRI machine and you get on board and they put you in and then your head goes through this opening. So your head's outside. It's not as claustrophobic as you would imagine. And the breathing is very luxuriant. It's kind of, I think it was turned up a little too high for me actually.

She needed that. I did not. I was, but, it, it's, it's very, it feels very normal. That's how you breathe. Your rib cage expands, but you're not doing it and you're not controlling the timing. So if you try to speak with somebody and the machine is inhaling at that moment, it'll cut you off. It's just, just cut you off. Also it's very dangerous to try to eat when you're in an iron lung, because if you're about to swallow at the moment that the machine decides to inhale, you could inhale the food. So they wouldn't let me, I wanted to eat dinner in the iron lung and they wouldn't let me because it's too dangerous. Because you inhale food, you can choke, you get bacteria down in your lungs. It's bad. It's a bad situation. So, ⁓ not designed for food. I...

David (17:09)

Yeah, lungs not designed for food.

Mary (17:17)

I thought I would last longer, but there were a couple of things going on. One, you're on your back. I don't sleep well on my back. You can't just roll over. You've got this very tight collar, because it's got to be sealed. There can't be air leaking ⁓ in and out of the lung. The air going in and out has to come through you, your nose and mouth. the neck thing is uncomfortable. You can't roll over. also Mark Randolph, the man whose iron lung it was, has on his wall, one of those, I don't know if you have this in Australia, one of those clocks where each hour is another bird call. So I'm like, I'm not going to make it through the whippoorwill that's coming in 10 minutes.

David (18:02)

Yeah, it was the birds

Mary (18:10)

It was really part, yeah, the bird calls. I, know, it's here after 10 minutes. I'm like, I get it.

Clip of the call of a whippoorwill

*tweets

David (18:09)

Look, the lung was fine. I’m just not an ornithologist. Couldn't deal with the bird calls.

Mary (18:22)

I get it. I don't think I need to sleep here. Yeah.

David (18:25)

I think a lot of people are even just surprised that iron lungs still exist. We tend to think of them as something mid-20th century or even early 20th century.

Mary (18:34)

Yeah, and for the most part, they don't exist. They're in store rooms, they're in museums. There are very, very few, at least in this country, in the US. ⁓ This was one of the very few that was still in use. ⁓ There are, though, a number of negative pressure breathing devices that are worn around the chest, the torso. So it's the same kind of thing. It's a very physiological way of breathing more comfortable and relaxing than a tube. I mean, you can talk, you can eat, your arms are free. It's sort of an assist. It's not, know, an iron lung is taking over for you. You are not breathing on your own. It is completely in control of when you inhale and when you exhale. But these devices, they're just sort of an assist for somebody who has chronic breathing problems. So they can wear it, say if they're home watching TV, reading, you know, it's not something you're going to go out on a hike with because it's a big, you know, kind of like the size of a, yeah, it's, it's, it's a battery, you know, there's a electrical or is it, I guess it's battery. Anyway, there's a component on the floor next to you, but it's, it's, it's certainly better than those positive pressure, those tubes, you know.

David (19:42)

Yeah. And I imagine that the people who need it, it is a game changer. It really makes a difference.

Mary (19:59)

Yeah, exactly. Exactly. Exo-Vent is one that's a charity that's trying to, and it's also for say a rural community or a place that doesn't have a ventilation system like most intensive care units, you know, it could be a lifesaver. know, it's a less expensive. They can be made quite cheaply and they're very helpful. So yeah, you don't see the whole Emerson iron lung. I think those are, I don't know if anybody still ⁓ is sleeping in one or using one now. I'm the last. ⁓

David (20:34)

Mary Roach is our guest. The last indeed to use an iron lung, even if it was just for research purposes and in a stranger's house. She's our guest on “Where Are We At With…?” today. We're looking at where are we at with our own bodies, perhaps building them or rebuilding them as is needed. One of the things that you looked at was replacing things like hair, follicles. Now I'm somebody who has been blessed, cursed with the fact that that's never going to happen, the need for replacements, although I could probably donate to lots of different areas.

Mary (20:41)

Yes, yes exactly.

David (21:04)

I can tell you that when I told my teenage daughters that you tried to have hair transplanted to your legs for a luscious lock of leg hair, the eye rolls and the shudders were about equal from the teenage girls.

Mary (21:17)

Well, you see, I had an educational purpose. I wanted to demonstrate, uh-huh, I know it's true. I did. I wanted to be able to visually demonstrate a concept called donor dominance. And that is the principle by which a hair transplant works. You can take follicles from the sides or the back of the head where they don't fall out. They don't react to testosterone the same way as you could put those follicles up on the top of the head, the hairline in front and they won't fall out, which is kind of amazing. So you can mix and match body hair, pubic hair, underarm hair could go on the head or the eyebrows. And this is done every now and then. and you know, it's not, it's not a terrific look. The one, there's a clinic in, I think it was San Diego. The guy published a paper, uh, and he, about transplanting body hair to the head. And one of the issues, this is a quote, it was difficult to style because it's pubic hair, chest hair. It's short, it's wiry. Anyway, so I thought, okay, because I should say, should preface this by saying I was donating some follicles to research. So was in there anyway, they were messing around on my head, taking these follicles. And I said, while you're at it, can you take a follicle or two, a follicular unit, and put it on my calf, my lower leg, so that when it comes time for book tour in a few months, I'll have this, six inch long, luxuriant hair growing down my leg, which is freakish, but also really interesting. ⁓ sadly, it didn't take. They did it. The guy reluctantly agreed. They agreed to do it, and...

David (23:07)

they agreed to do it.

Mary (23:12)

he was sceptical that it would work because the blood supply to the calf is a lot smaller than to the head. The scalp gets a really robust blood supply. So, and in fact, it did not take, I was so disappointed. So disappointed.

David (23:27)

Yeah, look, I could understand if you go into that trouble, you want it to actually work in the end, make book sales just even that little bit better. I'd surprised that they weren't already pretty good. They were also going into mice, I understand. Like now I've seen mammoth mice, but not Mary mice. You had your hair transplanted to a mouse?

Mary (23:36)

Yeah, exactly. no, not quite. ⁓ Well, that was the plan. That was the plan. It's kind of complicated, but this is place, StemSyn Therapeutics, sadly, the next round of funding fell short and they don't exist anymore. But what they were trying to do, they were trying to figure out what are, can we take stem cells, can we take blood cells, somebody's adult cells, regress them to pluripotency, which is their infancy when they can be convinced to turn into whatever you want them to be. So, regress somebody's cells ⁓ and then instruct them to become the building blocks of follicles. There's two different kinds, ⁓ keratinocytes and dermal papillae cells. And they were able to do that, which is amazing. They figured out the formula, like get them to that state. And then the two would come together, which was also amazing. These two types of cells were coming together under the skin, but then they were not making their way up through the skin. So they had on these mice, these black patches, and they called it disorganized hair. There was hair material, but it wasn't growing up out of the skin. they built little tubes to try to encourage them to grow. It was a really ⁓ amazing and extravagant and complicated undertaking being executed in order to help balding men grow hair. ⁓

David (25:23)

and incredible to think that they managed to get what we lay people, or at least I lay people, would imagine to be the hardest part, the building block, the encourage to join, to do the thing that they wanted it to do. And then just the last little hurdle, you know where you got to go, you got to go up.

Mary (25:37)

Yes. Yeah. Yeah, exactly. Exactly. I mean, saw pictures of, the mice with this sort of black stuff under the skin and it was like, it's hair. just isn't behaving like hair. And you could imagine they're like, we're so close. Yeah. It's like a, yeah, exactly. It was like a really messy ingrown hair. And you could imagine the frustration. Like we've got them to, you we've created this primitive follicle and it's doing, it's creating.

David (25:49)

Lots of ingrown hairs?

Mary (26:06)

Hair-like material, it's just not coming up like hair. And they built little, yeah, little combs. They called them Barbie combs with little tubes to train the hair. I thought it was really sad that they had to quit. You could imagine your investors coming and go, see these mice, they're growing blobs of hair material beneath their skin. And they're like, yeah, okay, that's not very exciting.

David (26:32)

Hmm. That's what balding men want.

Mary (26:35)

Yeah.

David (26:36)

And I think it speaks a little bit to the purpose of this podcast. “Where are we at with” so many things that we hear about, scientists are doing, cultural researchers are doing. This is going to be the way things are done in the future once we get this right. And so often they will do these incredibly difficult things and then just reach a hurdle that no one ever saw coming. And if not fizzle out, have to wait until the technology catches up.

Mary (26:59)

Yeah, was the visit to somebody said at one of my events, why did you cover dead ends like Stemson? I said, because I just found it fascinating the amount of commitment and money and expertise that went into figuring out, you know, how do we create a follicle? they got, you know, just, just they, they got as far as they got, tried, they backed off, they tried a different technique and in the end they just couldn't make it happen. And I just felt that they, Stemson, were kind of emblematic of what happens in biotech all the time. You know, before you start, you're like, this is what we're going to do. We're really confident we can regress these blood cells to pluripotency. We can instruct them to become the material to grow a follicle.

David (27:38)

Yeah.

Mary (27:51)

and it's going to work and look, and look, this is how far we are. And then, you know, there's so many things that come up that nobody anticipated, you know, the unknown unknowns. So.

David (28:00)

Yeah. And it speaks a lot to blue sky funding, I think too, in the idea of, sometimes you do the science for the sake of doing the science. And while we'd like to get to this particular outcome, even if we don't, it may be an often great discoveries or inventions piggyback on the discovery of someone else who's, who stopped it there because well, I can't go any further with what I was trying to do, but someone else can take, pick it up and use it for a different purpose. Yeah.

Mary (28:27)

Yeah, exactly. I remember speaking to a woman in a bioprinting lab at Carnegie Mellon University. And I said, do you, don't you get frustrated when something fails? And she just looked at me like, said, no, these aren't failures. We learned something and now we know how to apply that. And we move forward. That's how science happens. It wasn't a failure. It's an educational moment. Like, okay, that doesn't work, but we can take what we learned there and go in a different direction if our funding holds out.

David (29:03)

Yes, failure is effectively not doing the experiment properly, not coming up with a result that you didn't want because that still is, still has information. Let's get some skin in the game, so to speak, because it is something we've discussed here on the podcast before, particularly frog skin and its wonderful benefits. But over the years, so many different other species skin has stood in for hours, not necessarily a replacement, more like Oscar-night seat-warmers, waiting for the real stars. Tell me about some of the different animals that have been tried.

Mary (29:35)

Well, ⁓ my favorite era was ⁓ the pedicle, the era of the pedicle graft. Now that's a graft and it typically was ⁓ coming from animals. Pigs and dogs were the two examples in the book. ⁓ But there was this belief that, and it makes sense because a pedicle graft, those are sometimes still used in caring for burn patients. But the idea is that you, you lift a portion of skin from the animal, let's say a dog, you would apply it to the patient's burned area, but you'd leave it attached at one point so it still has a blood supply. So that meant the pig or the dog and the person were in bed together for like a couple of weeks waiting for this graft to grow in. Not successful. Charles Sédillot in the...

David (30:35)

willingly just lying there beside you.

Mary (30:39)

Well, the problem, Charles Sédillot, who was quite a renowned ⁓ French surgeon, tried this with a dog. And he, in his paper, and I read a little French from high school, it said, en chien d'enois, which is a Danish dog breed. And I was imagining it to be something fairly small. It was a great dame. This person was tethered by a little isthmus of skin to a great dame. It didn't work because of the mouvement excessifund et continuelle. Like, okay, what did you expect? This dog is like, get me out of here.

David (31:11)

You've cut a patch of its skin nearly off and then asked it just lie still. “Just breathe normally”

Mary (31:19)

Just a couple of weeks, just a couple of weeks while it takes. But the thing is, ⁓ as it turns out, all of these animal grafts and cadaver grafts, all of them are essentially bio-dressings. So when they do start to take, it's partly because of the severe burn. Is this how it was explained to me by the burn surgeon, with a severe burn, the immune system is kind of knocked out and infection is a huge risk. So, but because the immune system is not up to snuff, it's allowing a patch of skin from another species or another human to kind of take for a while. And then when the immune system starts to get back on track, it's rejected and it sloughs off, but that's okay. For the time that it's there, provides, it keeps moisture in and it protects it. So it works fairly well, but it's not ever being permanently incorporated. There were newspaper accounts that would say that this young boy is now part frog. It's like, no, no, he's not. Maybe for a couple of weeks he was, but they're going to pull it off and they're going to install a graft from somewhere on his own body.

David (32:31)

And of course, parochially Australia has a bit of a role to play the invention of the spray on skin, at least internally in Australia is quite famous as being something done by two wonderful Australian women ⁓ invented. Even that is sort of being passed at the moment or superseded by new technology.

Mary (32:38)

Yeah! Yeah. Yes, there are now, ⁓ I love the spray on skin. TM, spray on skin. It just sounds like you just go to the drug store and you get, yes, exactly. First the skin, then the tan. Yeah, spray on skin. that was, ⁓ but that was very, it's very cool because it's made from using biopsy from the patient's own skin. So it's unlike the frog skin, you know, it's going to take and it's going to grow ⁓ in place. ⁓

David (32:54)

Sort of reverse spray on tan.

Mary (33:21)

It was used a lot. Now there's some company, Cutis, that claims to have a full thickness graft and that's grown from the biopsy of the patient's own skin. At Mass General, when I was there, there was a little boy who'd been burned, I would want to say 80 % of his body, horrific burn. He was going to get Cutis grafts, I think it's a Swiss company. And it was an FDA compassionate use exemption. So isn't FDA approved yet, but in certain extreme cases, they're allowing the company to try it out. And it seemed to be working well, which is impressive because up to that point, it was either the spray on skin or that very, very thin, you know, couple cells thick layer.

David

I want to talk about that reading, particularly the skin section, but then it cropped up in a few others where there'd be times where, say a particular technique, a particular medical item, for instance, the gold standard. This is best, but it's too expensive and the patient can't afford it, so we will do this. How much of a difference did you notice in healthcare systems around the world in the developments and use of some of these technologies?

Mary (35:03)

Well, I didn't really investigate other countries, but ⁓ I can tell you that here ⁓ it's frustrating for people to read about a new development, which is just now in clinical trial. Say it's a phase three clinical trial and it's going to be, you know, the trial's probably going to take a year, phase three trial, and then you have to wait till the insurance companies are going to agree to cover it. And for somebody who's, you know, got late stage Parkinson's say, and they read about these new developments, stem cell therapies and things that sound very exciting, but the reality is that we've got to wait for the study to go through. And then you got to wait for the insurance company to agree to cover it. And often they don't, you know, insurance companies want to cover the cheapest possible option. And I don't know if that's the case elsewhere. mean, some of these things are incredibly expensive. mean, when you talk about ⁓ taking someone's blood, regressing it to pluripotency, and then instructing it to become another kind of cell, that's a bespoke process. One person sells and it takes time. It's very expensive. And so it's not the kind of thing an insurance company anytime soon is going to go, yeah, we'll cover that. You know, unless it's a

David (36:30)

Yeah.

Mary (36:33)

if it's certain very rare diseases and certain, you know, certain cases where I hate to conjecture that I imagine sometimes the goodwill and publicity generated by, you know, by saying, know, this stem cell therapy, it worked. And it's like, well, but it's very, I don't know, it's a very rare disease. You're not going to use it very often. And maybe you cover it like the early face transplants, hand transplants, sometimes the hospital itself would cover those because it was like, was exciting, it was a first, it was gonna get a lot of publicity. And not to be dismissive of the money that went into those, that the hospitals donated to those procedures, but in the end, they didn't work out that well. A lot of complications have turned up, people are having hands removed, people are needing second faces on top of the face they had. That's just never going to be covered and it's not an option for anybody who's ... I mean, that's a $100,000 plus procedure.

David (37:43)

And I guess I'm thinking as somebody who's in a health system, which sadly does have a little bit of private insurance these days, but ideally still has universal healthcare. You can't imagine those universal health cares, either the NHS in Britain or Medicare in Australia funding experimental things left, right and centre, just for the sake of it.

Mary (38:04)

No, that's right. mean, the realities of it are, it's just too much. It's just too much money. The money isn't there to do it on a national scale. and I think, you know, because the coverage in this country anyway, the coverage in the health and technology sections of newspapers and magazines, it tends to be very premature. it's not even to clinical trials yet or, you know, it's maybe phase one or it's still in a preclinical or animal phase. And yeah, it seems exciting, but let's temper our excitement here because so many of these things don't make it all the way. people, you know, people get very excited about it and they email things, look, this is like this woman that I, who's an amputee. said, I can't tell you the number of times somebody well-meaning friend

David (38:49)

Indeed.

Mary (39:02)

or family member sends me some link to a story saying, look, there are 3D printing prostheses that are just as good and you never need to go to a prosthetist and it's 25 bucks. She's like, no, that's just never gonna happen.

David (39:17)

Let's talk amputees because you went to the amputee national as a coalition conference or something like this at an amputee conference. As a non-amputee, how did you feel talking to people, striking the conversations? How did it go?

Mary (39:22)

Yes.

People were great. People are happy to talk about their prosthetic, their experience. mean, it's normal to them. It was being held at a kind of a fancy, was like desert hot springs or some kind of originally anyway, fancy hotel that in the off season is apparently cheaper to rent, anyway, you go, it's, you know, lot of it's usually business conferences. And so you walk into the lobby of this kind of fancy chain hotel and you look around and like everybody in the lobby has one leg, you know, it's like a Monty Python sketch or something. But, it was just utterly fascinating. Just talking to people about, ⁓ their experiences and, and what they're using and the limitations on certain things and what they're excited about. It was a real education.

David (40:32)

Other than the phrase terminal device, I know we all, anyone who reads it has to read it in a Schwarzenegger voice, “Ze terminal device”. ⁓ One of the ironies, of course, is the fact that for a lot of people, we hear about these incredibly complicated prosthesis, the fact that they have the ability to bio do this and control it with your brain and do these things. And yet for so many people, they prefer the simplest, easiest ones.

Mary (40:59)

Yeah, that's right. Again, it's the kind of thing, it's very Arnold Schwarzenegger Terminator, know, the hand with the individually articulating fingers. And I was there with a woman who's a lower leg amputee and we walked by, first of all, there were very few upper limb prosthesis on display there. And I didn't see a single person using one of those bionic looking myoelectric arms. And they were, but there was one booth and they had a photograph of this, you know, hand holding a raspberry, which is of course a very delicate thing to pick up. And she laughed and she said, yeah, are you going to spend 15 seconds adjusting your grip, you know, mentally doing that? No, you're going to reach over with your other hand and pick it up and eat it. And the people, there was, there was one seminar about life hacks, like ways, you know, for a people with upper limb, either amputations or they're limb different. Using a shoulder, body-powered harness, the things that you're able to do, or just with your residual limb and one arm and your mouth or your knees or a piece of the wall, you're able to do a lot. It was fascinating to see how adept people were, how they'd compensated, majority of them don't even use any kind of, certainly not a myoelectric. They're expensive, they're heavy, you need to charge them, insurance doesn't cover them, so they're exhausting to use. They're exciting in a CNN clip. Wow, look at that. With your mind, you're making it move, but the reality, is not there yet. mean, it may well be there in five years, but-

David (42:30)

Yeah. Not just yet. And it's interesting because it's almost like the way the brain works in that it can, in many cases, adapt and alter what it was doing to do something else. We're nobody's suggesting, well, don't make prosthesis, but quite often people can just end up training parts of their body to do the bit that that part used to do.

Mary (43:13)

Yeah, yeah. People, mean, I've watched, I was sitting behind a man with a body powered shoulder, you know, the harness and the graspers and he was gesturing with his hands. He was reaching up and adjusting his COVID mask. And it was as though it was a part of him, know, and relatively lightweight compared to some of the more expensive computerized prostheses. Yeah. Of course.

David (43:38)

Let's talk, can we talk pigs? If we could, I would like to have a porcine update on this because one of the things I was fascinated by was not just the fact that there are organs of pigs that are very close to human-type size workings, but also the fact that quite a lot of the pig which we use is just because we've just always used pigs and they're not necessarily the best, but hey, that's what we use.

Mary (44:03)

Yeah, they may well be the best, nobody knows because we got started with pigs and it's pigs that we're going to use. And I got curious about that. pigs? Poor pigs, we eat them all. Now we're going to start using them for organs. Why are we picking on pigs? And one of the things that happened, it was a collaboration between the Mayo Clinic Foundation and the Hormel Institute. So you had the Mayo people ⁓ who needed animals for research and the Hormel. I don't know if folks there are familiar, Hormel is well known for ham products, pork, Hormel is, Hormel hams and you name it, pig products. They're the kings of pig

Clip of Hormel advertisement (USA)

“Hormel Black Label microwave-ready bacon. Live for it.”

David (44:50)

⁓ right.

Mary (44:59)

So Hormel is like, can create a pig for you. They created, they bred pigs to be ⁓ smaller so that, because they wanted to find a lab animal that would be a little more convenient to have around a lab. ⁓ The organs are a close match in terms of their size and surprisingly their function as the Hormel Institute ⁓ showed in many, papers. They needed to be a little smaller because a pig is a big, active, very loud creature to have ⁓ in a laboratory setting. So they bred these miniature pigs for use in laboratories. They were volume after volume ⁓ of this collaboration between the Mayo Clinic and Hormel, ⁓ the cardiovascular function of the pig versus the human, the kidney output in the pig and the human, just sort of documenting what a good match they are. And they are a pretty good match in many cases, ⁓ including there was one where it was an orthodontia paper. They just poor pig had braces. A pig with braces. They had a photograph. I'm like, ⁓ God, poor pigs. I think at a certain point we should just make a deal with pigs. look, it seems like we're going to start using you for organs. So maybe we'll stop eating you. And maybe when you're like, it's too much. The poor pigs. Anyway.

David (46:15)

Mm. I mean, a lot of people imagine when they think of pigs, they think of "Babe" And “Babe” is a very different creature to a fully grown boar or sow when you come across one and realize it's like three times your size.

Mary (46:37)

They are big and they are loud. Yes. Yes. That's what they, found a quote by, um, Oh God, who's the, um, Pavlov talking about, uh, why he uses dogs in the laboratory. He had, I think the quote was something like all pigs are hysterical. Like just, you just don't want to work with pigs. They're full sized anyway. Yeah.

David (47:00)

Yeah, try and find the smallest creature you can and the most amenable to what you're doing if you're going to do it. ⁓ Quickly, I don't want to ⁓ dwell too long on it because the prurient will do that anyway. Genitals, given the number of options on the markets, apparently, I'm told, not that appear in my emails, for replacements that are supposedly better, I found it interesting that most of the repair, replace or create.

Mary (47:07)

Yeah.

David (47:28)

surgery is using our own body parts.

Mary (47:33)

Are we talking, are we going down penis or vagina lane? Yeah, sorry.

David (47:35)

So we, look, I'm happy to ⁓ take a detour into either. I was certainly in the neighbourhood of both ⁓ and sometimes turning one into the other.

Mary (47:43)

Okay. Yeah. Yes. Well, ⁓ yeah, the, ⁓ I had dinner with, the director of, transgender surgery and health at Cedar Sinai hospital in Los Angeles. Cause I was intrigued by a paper he had written about, using a length of the intestine, the patient's own intestine to create a vagina, neo vagina. It's not the typical technique is to kind of turn the penis inside out. But if that doesn't work, if there's complications or it's just not, it was a fail, you can actually take a length of intestine. ⁓ You pull it down, you're going to reconnect where you took it from, obviously, so you have an intact intestine, but you can keep it attached to its blood supply and swing it down and make a vagina. you think about it, it's kind of like it's moist, it's tubular, it's pink, it's stretchy, it has mucus. It's kind of brilliant. And it's been, it wasn't invented by him. This goes back to the 1800s, women who'd had cancer. ⁓ Those were the first efforts to do so and it can be done and it works fairly well, which is kind of amazing. You've got this organ that evolved for one purpose, eating, digesting, absorbing, ⁓ and you can persuade it. It's like, Okay, we're gonna ask you to do something different now. The intestines like, okay, I can do that boss.

David (49:16)

I think in the modern world, in the modern workplace, that's re-skilling, isn't it?

Mary (49:20)

It's re-skilling, yes. Yeah, exactly. You can re-skill that piece of intestine. And I thought that was fascinating. Yeah.

David (49:24)

But you also travelled, Yeah, you also travelled to find out more about taking a finger and turning that into a penis.

Mary (49:36)

Yeah, again, not a common technique. In fact, no one else other than the surgeon to my mind has ever done this and will ever do it, but he does it or he's done it about five times. He wasn't there when I got there. This is a surgeon in Tbilisi, Georgia. And I had written in English, in Russian, in Georgian with the help of Google Translate, never got a reply, just decided I'm just going to show up. ⁓ And ⁓ he was on vacation. ⁓ But the woman who runs the office took pity on me and said, yeah, I can show you slides. We can go in his office. Apparently, he doesn't lock his office when he's on vacation. So we went in and she turned on his computer and ⁓ showed me these some slides. ⁓ yeah, that what it wasn't the case. He didn't just take the finger as is and like stitch it in place, which was my original kind of image when I heard.

David (50:32)

Yeah.

Mary (50:34)

That this surgeon had used a middle finger to reconstruct a penis. It was supplying the rigidity. It was inside and then there was skin taken probably from the forearm, which is often a place that's used to rebuild a penis or to build one from scratch, depending on what you need. and it was kind of like, do know, do you have that pigs in blanket where you wrap bacon around a sausage? Anyway, was, the skin goes around the finger. And so, I mean, it looked, it was a very realistic looking penis, I have to say, in the end. And it could bend.

David (51:12)

It's not crazy if it works, I think is the saying.

Mary (51:15)

It apparently worked, apparently worked, and it could bend in the middle, which was a unique talent for a penis.

David (51:22)

And possibly in the market for some people who want that sort of thing. There are a lot of people who did agree to speak to you for this book, as you said, quite often you just send out an email, you shoot for the stars and that's how you end up in the moon. Who surprised you most by both agreeing and perhaps by then what they revealed once you did speak to them?

Mary (51:44)

Let's see who surprised me most. I think I, ⁓ the candour of a lot of the people at the, ostomy 5k run, ⁓ their enthusiasm for, you know, the, there's so many different systems that you can use. If you're an ostomate, if you're using a pouch and they were welcoming, they were willing to kind of show me how it works and they were just, ⁓ and the gratitude that they felt for the surgery and the freedom that it had returned to them. you know, because you hear about ostomy, which is, know, basically pooping into a bag because you either have cancer, you have a blockage, you have bad colitis, you're now ⁓ excreting further up the intestinal tract into a pouch. And people just assume that that is just the most unthinkably horrible fate that could befall a human being. And in fact, you have to compare it with what was their life like before. They were kind of afraid to to be far away from a toilet. They were worried all the time. They felt like they couldn't participate in life in the same way. And now that now they're in control. So that, you know, that was, that was all surprising. And ⁓ I guess I didn't know what to expect. And they, they were all just incredibly welcoming. And it was just a fun afternoon at the.

David (53:30)

I have to say reading through the book that that theme tend to come up a bit as I mentioned with the iron lung or other aspects where effectively while those of us who haven't yet had to have those sorts of things done and as you point out, we will all be disabled should we live long enough. But if it's an alternative between the absolute horror of toileting versus “Hey, it's really, really easy and fairly clean comparatively now”. Yeah, you know what you'd take.

Mary (53:58)

Yeah, yeah, exactly. And the woman that I went to the amputee coalition conference, when I met her, kind of what got me interested in this topic was her talking about how badly she wanted her foot cut off. She had an underperforming foot. It was twisted. She couldn't run. She couldn't hike. She's like, I want this off. I see people with prosthetic lower limbs playing sports, running around, winning Paralympic medals. Why can't I have this? And this attitude with the surgeons that she consulted with, was like, well, this is a healthy foot. We're not going to take it off. And she's like, no, but I want that. Yeah.

David (54:36)

Yeah, healthy is a fairly loose term and it's very relative. Yes, you do encounter that a lot with different people. It's interesting. I'll bring it to an end here. I know you've got many things pressing on your time. I'd like to finish though with a quote from a great book that I read recently. You may know it. “The body's all day, everyday achievements, the architectural brilliance of cartilage or tooth enamel, the effortless autofocus of the eye, a heartbeat so committed it persists outside a body. These are the real miracles.”

Mary (54:39)

Yeah.

David (55:04)

“That's where the gee-whiz belongs.” After several years of researching this, which of your body parts would you be most comfortable replacing in current technology?

Mary (55:15)

⁓ I'm heading towards contact, not contacts, your lenses. I'm pretty comfortable with the idea that within five years, I'll probably, they'll be popping those out and putting new ones in. And as somebody who is pretty near sighted, ⁓ I can pick, you know, I can pick where my focus is going to be. You know, that's kind of cool. ⁓ So uh, yeah, that, that I'm comfortable with that. I'm not yet comfortable with the idea of replacing a hip or a knee, even though that's probably down the road and I hear it works really great. I've seen it and I've, I've heard the hammers and the saws I'm like, ah, not quite there yet. I guess when the pain, if I, you if you're in pain, you know, again, it depends on what you're living with that, that alternative because it can become very appealing. Yeah.

David (56:08)

It does indeed. And for anyone who wants to know more about pretty much all of those topics, you can read the book, Replaceable You by Mary Roach. It's available in Australia from February, 2026. Those of us in far flung parts of the world have to wait so long for these things. Mary Roach, thank you so much for your time today.

Mary (56:23)

thank you, David. I really enjoyed it.

David (56:33)

And once again, a huge thanks to Mary for taking the time to join me on the show. Over the years, she's appeared on The Daily Show in the US, as well as The Colbert Report and Neil deGrasse Tyson's podcast Star Talk. So obviously talking to me was a bit of a step up. You can pre-order Replaceable You with a number of book retailers in Australia, or you can head down to a large South American rainforest where you can buy it online from anywhere in the world. The transcript for this show is on our website, www.www.wawapod.com, that's www.wawawpod.com as well as links to Mary Roach's website and the TED Talk she gave. Music for the show is by Michael Willimott, production assistance from Clare Macmillan, Julie Newton and Annie Pappalardo. I'm David Curnow goodbye.

Where Are We At With Body (re)Building?

With Mary Roach

Transcript
Episode published 12/01/2026