Talking 'Gulp' With Mary Roach

<strong>Mary Roach Interview:</strong> We all love Mary Roach, so in this episode of Stuff to Blow Your Mind Robert and Julie invite the "Stiff" author on the show to chat about her latest book "Gulp: Adventures on the Alimentary Canal." Plus she'll answer listener questions and discuss how to eat with your butt.

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Julie Douglas: Welcome to Stuff to Blow Your Mind, from

Robert Lamb: Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb.

Julie Douglas: And I'm Julie Douglas.

Robert Lamb: And we have another treat for you here as we are about interview Science Author Mary Roach, one of our favorite authors, one of our writing heroes.

Julie Douglas: And she has a fascinating new book called Gulp and it is all about the adventures of the digestive system.

Robert Lamb: Yes, you'll recognized it in stores or online because it has a big mouth on the front opening up, tongue lolling out, esophagus waiting for that food to begin this epic journey through the body and if you've never read Mary Roach before, I will remind you that she's the author of Stiff which is the book about the life of human cadavers, about how we relate to dead bodies, how scientists study dead bodies.

She also wrote Bonk which is about sex. She wrote Spook which is about scientific investigations of the afterlife and more recently she wrote Packing for Mars, which is about human space exploration and a lot about the scientific research that has gone into making it possible for humans to travel to Mars and even return.

Julie Douglas: And she brings that same level of research and humor and inquisition into this topic which I think is a wonderful topic really from mouth to sphincter.

Robert Lamb: Yeah, I mean she brings so much humor to it but not in a way that she's belittling the subject matter like she demystifies the subject matter, has a few laughs with you, but you never feel like she's exploiting the topic or anyone, I mean her books are great from start to finish.

Julie Douglas: Indeed, so let's go ahead and get into it.

Robert Lamb: Well, welcome to our podcast, Stuff to Blow Your Mind. Thanks for taking the time out of your day to chat with us about your excellent new book, Gulp.

Mary Roach: Thanks for having me.

Julie Douglas: Yeah, we are so excited. In our podcast, we try to cover a range of topics, whether or not we're talking about cloaca or the role of regurgitation with vultures so this book is right up our alley.

Mary Roach: I love the How Stuff Works series, it's really great.

Julie Douglas: Thank you. Thank you so much. It's really nice to hear that.

Mary Roach: I have the whole human body one.

Julie Douglas: Oh, you do?

Mary Roach: Yeah.

Julie Douglas: Very cool. It would be an honor to say we've been helpful with-

Mary Roach: Yes, indeed. That was my training. That's where I started. That's where I familiarized myself with because it's the whole tube. The whole tube is in [inaudible].

Julie Douglas: Well, thank you so much. Well, I guess we should just go ahead and launch into this. We're wanting to know from you, there's so much research in here and so many wonderful little nooks and crannies, was there anything that really surprised you, any sort of discovery during your research period that you had a big moment of like wow, I didn't see it in that context before or it was completely new to you?

Mary Roach: The entire trip down the food chute, every turn, I mean even just in the mouth, saliva is something that I just assumed like most people that it was moistening the food that you need to swallow to make the bolus but I was completely blown away by the fact that it's got five other functions including - I love this, the enzymes and not just in saliva but in some of the other digestive enzymes further on down the line, but these are the enzymes when you hear about a laundry detergent that says new improved Biz with stain-fighting enzymes.

These are digestive enzymes so the stuff that you spill your food, when you spill your food that is meant to be in your mouth onto your clothes, those enzymes are amylase, lipase, protease - these are digestive enzymes. I don't know. I found that kind of - the whole laundry detergent is like a digestive tract in a box. I mean there's obviously other - your basic soap type products as well, but the fact that these were salivary enzymes and that art conservators use their saliva to clean because of the enzymes. Again, they need a delicate, something to breakdown maybe the egg wash or something like that. They've been known to use their own saliva.

Robert Lamb: So obviously you're hitting up a lot of different places, talking to a lot of people about the book right now, what's your favorite part of Gulp that no one's asking you about?

Mary Roach: Well, Jon Stewart was the only one to bring up rectal alimentation, rectal feeding, so that's an interesting - I have a whole chapter on - he's the only one that's brought that up, a whole chapter on, and we didn't have time of course to get into it in any detail and I don't know if you want to get into it in any detail, but I have a chapter called Eating Backward: Is the digestive tract a two?way street?

And this was fascinating to me that you can - the small intestine is where most of the absorption goes on, like 80 percent absorption of nutrients. But the rectum does absorb, you can absorb like I said glucose and salts and some shortchange fatty acids, there's some absorption that can go on. Also drugs, it's a very effective drug delivery system if for some reason you can't swallow them like the ancient Maya used to use the rectum because the drug goes straight into the bloodstream, doesn't have to be processed by the stomach or the liver. It's just like boom into the blood and then you don't, if it's one of those hallucinogens that would make you throw up, you don't have that problem either.

So people had some creative uses for the rectum. I don't know if that's something you want me to even be talking about but that is something nobody else - people rarely bring up that chapter.

Robert Lamb: Oh no, that's excellent. That's -

Mary Roach: Yeah, and it also gets into this - there was this huge debate historically on whether or not this was useful at all because there was a thinking that oh, well if you put it up there, you put enough in there, it could make it up to the small intestine but the valve, the ileocecal valve between the large and the small intestine, is a one?way valve and it's designed to keep stuff in the colon out of the small intestine. So you can do it if you force and people have done it with cadavers.

And there's very strange and entertaining accounts of these particular demonstrations but it is pretty hard to breach the ileocecal valve and send material past that into the small intestine so you can help someone stay alive. It's not ideal to be eating in reverse but it can to a certain extent be done.

Julie Douglas: I'm gonna ask you too, you had talked about the ick factor, especially when you were talking about bacteria therapy and which is something that is hugely helpful but has had some problems in terms of perception so I wondered with something like bacteria therapy, do you think that the human microbiome and this idea that we're trying to get a better, more nuanced understanding of our gut floor and how all of this interacts with our body, do you think that this will help to sort of make it less icky?

Mary Roach: Yes, I think that the amount of attention that's been placed on bacteria therapy or fecal transplants as they are also known, the amount of coverage that's gone on in the past couple of years I think has created a climate of acceptance which didn't exist before. When I started this book, I mean I actually went and observed a fecal transplant, bacteria therapy, and at that time I told people where I was going and they were like what? I mean it was this you're kidding, why would anybody do that, how is that legal?

They're taking one person's poop and putting it in - and now two years later when I say fecal transplant, people go oh, I've heard that's very effective in certain cases of infection, I hear that's like - so just by exposing people and breaking down the taboo, I think that that has created - this is one of those instances where media coverage has had a positive effect because people understand why it's done, they understand that it works and they're more accepting of it and it just lost its kind of novelty, ooh, what, oh.

Robert Lamb: So how long did it take you to research and then write Gulp? Obviously you mentioned the starting point was that moment in the research for your last book, Packing for Mars, about the scientists researching ways to feed humans on a long-distance space journey?

Mary Roach: Two and a half years is about what it took me to do the research and the writing. There's a lot of time spent sort of finding the right places to go and things to do that would be interesting for people so there's a fair amount of kinda waiting around and false starts. If I just could set everything up in a span of weeks back to back and then write it, I think I could be very efficient but it never happens that way so it takes a lot longer.

Robert Lamb: Now has writing Gulp changed the way you approach your own diet or the manner in which you masticate?

Mary Roach: The manner in which I what?

Julie Douglas: Masticate.

Mary Roach: Masticate. I thought that's what you said. Yeah, it's like wait a minute, are we talking about Bonk? Which book are we talking about? Well, it has this effect on me and this happened with Bonk too which is this sex lab, physiology of sexuality, and there's a period of time when you're looking into what the body does. And it's something you've never really looked into in detail like how the body is doing, what it does. It can be very distracting, whether it's you're having sex or you're eating a cracker.

I mean I remember reading this paper that had calculated the minimum number of chews of a McVitie's Digestive biscuit and it was like eight and I'm like I think I can do it in fewer than eight. I think I can do it, you know, and I was like, okay, [inaudible], I'm gonna form because there's these phases of forming the bolus in your mouth. There's like you take it apart then you moisten and reconstruct and so eating became not just eating, it was this kind of this weird science experiment in my mouth and that went on for a while but now I'm over that.

Julie Douglas: Did you feel like you were sort of subconsciously Fletcherizing?

Mary Roach: I did try Fletcherizing. I don't have the patience for it. It's one thing to chew your food thoroughly but, you know, 700 chews for a piece of a spring onion, you would literally spend your entire day chewing. And that's fine if you're like Horace Fletcher who didn't have to work but those of us that have a job to do, Fletcherizing is a serious commitment with very little payoff.

Robert Lamb: Now whether you're writing about Fletcherizing or the possibility that people were pooping live slugs and lizards, in your work I always enjoy the journey of the erroneous idea or even possible idea being presented and there's always a moment there before you've really gotten into the disproving of it and the science behind why it's not happening that way, where I begin to think like what if this is right? What if this is the way the world works?

Mary Roach: Well, yeah, I start out at the same place. And I would love to find out that in fact it is possible for a frog to live for years inside somebody, I mean I can't think of anything more fun than to find an actual case of that. Of course, that has not happened. But a frog would be a good candidate because a frog can absorb - if you swallowed a frog with a lot of water, the frog can take oxygen from the water and then you could - you can keep that thing alive certainly long enough for your regurgitating circus act to be over. Yeah, the frog would come up alive but not taking up permanent residence anytime soon. I just took that in a totally different - you asked about a completely different -

Robert Lamb: No, no, that's great. You took it -

Mary Roach: And I got sidetracked by frogs -

Robert Lamb: In a much better direction.

Mary Roach: And whether they could live in stomachs.

Robert Lamb: All right, we're gonna take a quick break from our conversation with Mary Roach and when we return, we will talk to her even more.

Hey, well, I know everyone out there loves to stream some content and if you're listening to this podcast, you're probably really into Mary Roach; you probably really enjoy her books. I highly recommend you also check out TEDTalks: Sex, Secrets and Love and you can find that on Netflix Streaming. As a new member and a Stuff to Blow Your Mind listener, you can get a free 30?day trial membership at Netflix.

Just go to and sign up today. Be sure to use that URL so they'll know that we sent you and remember that selection is subject to change but as of right now, you can definitely find that Mary Roach TEDTalk. It's on there. It's enlightening. It's hilarious. It's wonderful. Check that out and then check out all sorts of guts and glory movies as well.

Julie Douglas: All right, we're back. Let's go ahead and listen a little bit more about what Mary Roach has to say.

You had talked about some of the research or rather Robert had asked about some of the research changing the way you think about things and I wondered about in terms of animals and pets, A, do you own any pets and B, did your research into the pet food industry change the way that you view their sensory worlds?

Mary Roach: I don't have any pets right now. So I'm a cat person and my husband is a dog person and we essentially cancel each other out but I used to have cats and I've been around a lot of - I had a dog when I was kid so yeah, you're right, I spent some time - it's a company that makes palletins which are the coatings for kibble that make it more appealing and it's a totally different process for dogs and cats. I was kind of amazed to see them side by side.

Like a dog, it's all about smell so if you've got a product that smells great, the dog is gonna appear very enthusiastic even if it doesn't ultimately taste that good, the owner's gonna go wow, my dog really loved that because the smell is what gets the dog. If you can get the dog to the bowl, the dog will start eating whereas a cat, a cat will - and I saw a test like they had pans of different kibble and they had a bunch of cats and they were looking at their preferences.

It was a preference test like market researchers would do with humans in a room giving them different things to eat and the cats will be like oh, will take one little piece of kibble partway into their mouth and drop it and go to the other bowl. I mean they're very careful eaters compared to dogs. It's not as smell driven as it is with dogs.

Julie Douglas: Yeah, I just had one other question and then we're gonna move onto a couple of fan questions that came up, but I did wonder is there anything there on the horizon, a topic, book, article, anything that sort of captures your fancy?

Mary Roach: Well, what tends to happen is that when I've done a book on a broad topic like the eating, like the alimentary canal, then I'll get calls from magazine editors. For example, one of my editors called me about ambergris which is this product that comes out of whales. It's not poop. It's a little unclear exactly what ambergris is but it's used. It's very, very valuable and it's a base for perfume but it's a product of the whale's digestive tract so naturally they thought of me so that's an example of something that I may be covering in the future that came from the fact that I have a book on this topic.

Robert Lamb: All right, well, our first bit of listener mail here, a listener question for you comes from Deborah and Deborah says, "I'm reading Stiff right now. I wonder if examining death with such intensity has changed the way Mary experiences life and if so, has that been a lasting change for her?"

Mary Roach: Oh, great question. When I was working on Stiff, I have to say I'm not a very philosophical person, but when you look at a dead body whether it's in a science lab or out in a field of a decomposition facility or in a funeral home, there is the sense of that just at a glance you know that this is a hull, like this is not a person, something has departed so you have this sudden sort of - you grapple rather instantly with this like where did it go.

Where did that person go so it made me a little - and I don't have the answer to where did that person go. But it's a very visceral, sudden confrontation with like the matters of life and death. I can't say it's something that stayed with me day by day but it was a fairly just profound kind of thingy like wow that is not a human, that some shell, you know. It's like a shell. It's very weird. I'm not really explaining this very well, but -

Robert Lamb: No, no, but it does make - it's been a while since I've read Spook so you may have addressed this in the intro and I'm just not remembering it but it sounds to me like then Spook was very much a product of having written Stiff.

Mary Roach: Oh, yes, very much. It grew out of that sense and also there was a chapter that had to do with scientists and anatomists searching for the soul in the actual physical remains of the body, thinking well okay, if we look hard enough maybe we'll find the core processor basically like they would - [inaudible] is it the heart, is it the brain, it's probably in the brain, probably in the brain, is it this thing, no, there's two of those, it's probably something in the middle, maybe it's something, there's only one of them and there were all kinds of nominees for the seed of the soul so that was also part of where the interest came from. But yeah, Stiff definitely prompted Spook.

Julie Douglas: Okay. And our last question comes from Sarah. She says, "Packing for Mars is one of my go?to reads. The international space station captivates my children. They are tickled pink to know that there are humans in space. When I was little, space was never a part of my childhood apart from sci?fi programs from the '90s but my dad says his childhood was full of space-related things. Now given the success of Voyager I and the mission to Mars, does Mary see a resurgence of interest in investment in space with the next generation?"

Mary Roach: Yes, I do. I mean a lot of people talk about oh, when the Obama administration came in, they cut Constellation which was a program to send humans to a base on the moon and onto Mars. When that got cut, there was a tremendous amount of kind of bemoaning the death of the space program but I don't see it that way at all because of the role of some of the private industries like SpaceX. I mean I just was following the Dragon capsule which just was successfully launched and docked with the ISS and very soon that capsule will be carrying astronauts back and forth.

And this is a private company that's gotten up to speed very fast, this is Elon Musk's SpaceX and there are three or four others, Bigelow's has got an operation going, Bezos has a company as well, Jeff Bezos. So there's so much excitement and activity going on in the private sector that I think there'll be this synergy between the private sector and global space agencies. You know what I'm saying? I think we will be seeing a mission to Mars soon.

I mean there's talk about the flyby of Mars coming up, I don't know, what are they saying, 2018, not a landing but like a human mission to Mars where they would just go and come back which is what we did with the moon originally as well. So I see it as a time of great excitement in fact and I'm hopeful that that will be the case for years to come.

Robert Lamb: All right, well, Mary thanks again for chatting with us and once again, we have really enjoyed Gulp as we have enjoyed your previous books as well. And we look forward to sharing it with everyone.

Mary Roach: Thank you so much you guys. I really enjoyed talking to you and I love what you do.

Robert Lamb: So there you have it. Once again, we'd like to thank Mary Roach for taking the time to speak with us about her new book Gulp. Gulp, along with her other books Stiff, Packing for Mars, Bonk and Spook are available wherever you get books these days whether physically or virtually. It's all out there and we cannot recommend it highly enough.

Julie Douglas: So thanks for listening guys and you can always find us on Facebook.

Robert Lamb: Yes, and Tumblr. We are Stuff to Blow Your Mind on both of those feeds. You can also find us on Twitter where we are Blow the Mind and we have a new website, and hey, if you really enjoyed this interview, let us know who else you would like for us to interview and we'll see if we can work something out.

Julie Douglas: Yeah, drop us a line at

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Duration: 22 minutes

Topics in this Podcast: mary roach, STBYM Interview, digestion