Chances are you didn't pack mud pies or clay bricks for lunch, but humans - like many animals - are not above pica in their diet. In this episode, Robert and Julie discuss the practice of dirt and mineral consumption and just what impulses are at work.
Robert: Welcome to Stuff to Blow Your Mind from howstuffworks.com. Hey, welcome to Stuff to Blow Your Mind. My name is Robert Lamb.
Julie: And I'm Julie Douglas.
Robert: Julie, when you were a kid did you ever make mud pies?
Julie: All the time.
Robert: Yeah? Do you remember any of your recipes?
Julie: I just remember an ordinate amount of them because it was rural Michigan right, so there wasn't a lot to do at that time, and so I just remember making them by the side of the house. I use my hands mostly to shake them though.
Robert: Oh cool. Yeah, we did as well, me and my sisters. There was a facet behind the house, it was like a concrete slab back there for some reason, and then just dirt. So we'd add some water to the dirt, create mud, pack that mud into pie tins and also mini pie tins, and then you leave them out there on the slab. They bake, they dry, they become delicious pies.
Julie: That's when you cut a slice and you eat it right?
Robert: You know I don't know if I ever did, but I was the older of the kids, and it's entirely possible that my younger siblings ate some of the mud pies.
Julie: And you know what, that's not probably a surprise to any parents because all parents know that at some point their kid is gonna be chomping something, some non-food item that they shouldn't be, but it turns out that dirt eating, which is called pica, which is actually a lot more than dirt eating, is so much more common than anybody has ever really realized.
Robert: Also known as geophagy if you want to get a little fancier.
Julie: That's pretty fancy though. So we talked about benefits of pre-mastication and regurgitation in other podcasts, and we thought you know what why not talk about dirt eating because its kind of fascinating stuff.
Robert: Yeah, now from a very broad viewpoint, there's nothing really that weird about it. I mean there are organisms that need minerals, the mineral crunching bacteria for instance exist, and then just in any dieting what do you think you're doing when you put salt on something. You're adding a little mineral to your diet. It's not crazy. Likewise various medications that we take have some sort of mineral component to it. So there's nothing just off the wall nuts about eating dirt, eating minerals, essentially rocks.
Julie: Yeah, and you've probably even witnessed your dog or cat eating something that's null and food item?
Robert: Yeah, especially dogs.
Julie: Especially dogs. In fact, you might have even witnessed Fido chomping down on a chunk of poo before right?
Robert: Yeah, especially cat poo.
Julie: That's happened. It's called coprophagy and it actually means that your dog could have a vitamin deficiency or even a touch of OCD, and this is something we're gonna talk about more in humans later. But before we really get into the meat of this or the dirt of it, let's talk a bit about what it is, how it's characterized. Pica actually comes from the Latin word for magpie, since the magpie bird will eat just about anything.
And it's been thought of as a physiological eating disorder, and as you have noted it's also called geophagia or earth eating and in humans it's mainly pregnant women and pre-adolescent children who exhibit pica eating behavior. And again, when we talk about pica it's most associated with dirt, but it can be a whole lot of different things. It can be clay, it can be starch.
Robert: Yeah, I was looking at some words, were talking about ice, pregnant women that experiencing pica and half of them are eating ice, which is pagophagia, which is different. I mean eating a bunch of ice or just drinking a lot of water, except for the more crunch right?
Julie: Yeah, and some people say that it's a texture thing, and it can be stressing when it comes to ice.
Robert: Yeah, soothing on the tongue and all that. Now with children, obviously children, very young children will try and eat just about anything. That's why you don't give them micro machines to play with. That's why you limit things in their environment, they can go down their mouth, throughout their nose because it's just part of the testing out their environment. What can I eat, what can I not; fits up my nose what doesn't quite fit up my nose.
Julie: Yeah, but then there's this other little section that kind of veers off into the other territory, and it's more about compulsive eating, and that's where you see very unusual non-food items. So we're talking about cigarette ashes, toothpicks, athletic socks, dust, balloons, patient's hair and burnt matches.
Robert: Oh yeah, the hair one's big. Need to see that.
Julie: Yeah, and depending on the item that's being eaten, pica could lead to health problems like led poisoning from the paint chips or constipation from clay intake.
Robert: Just everything in moderation. Don't go out and eat just a whole lot of pizza, don't go out and drink an exurban amount of water, and if you're going to eat gym socks, keep it down to like 1 or 2 pairs tops.
Julie: But see that's the problem right, if you're eating gym socks it's probably because you have a compulsion to do so.
Robert: This is psychological disorder at that point.
Julie: Yeah, so this podcast is really gonna talk about two different aspects of pica. One is more sort of cultural aspects, and the nutritive aspects, and the other's gonna be more of a psychological and sort of the compulsion aspect of it. But I did want to mention that pica has been around for a long time. The first written account of human geophagy comes from Hypocrites more than 2,000 years ago.
Robert: Yeah, so we've been eating dirt for quite some time, and I've also read accounts, and I don't know to what degree they were accurate now that I think about them, but you at least find stories in which individuals are so hungry, that to satisfy their hunger on some level, they were eating on food items. And certainly there have been plenty of times where food items have been panned out like during the second World War there were times where they would add say wood shavings, the saw dust to say flower or something you know, and it's not really a food item, but you can sort of try and make your food stretch a little further by doing that.
Julie: You're right in filling up your belly right? So if you eat a bunch of clay, then may be that can stem off your hunger for a little while.
Julie: So let's talk about the cultural aspect of this because in some cultures both inside and outside the United States it really is not uncommon for say women to consume clay or dirt during pregnancy, and that's where we most associate pica.
Robert: And it's interesting - I didn't find any sources that really are into this, but by the mere fact that you see pregnant women engaging in it, I feel like there's a huge amount of sexism in our cultural history with pica because women are the ones that are eating it. And they're doing so while they're pregnant, so in many cultures, I mean you can easily imagine it being explained a way as oh, its crazy pregnant ladies, of course they're going to do crazy things, whereas, as we're discussing, there are a number of other possibilities that work here beyond just mere madness.
Julie: Yeah, I mean sometimes it is an aspect of cultural bonding that pregnant women will eat clay or some other substance because it's what's done in that community, in their society that it can stave off symptoms of pregnancy like nausea, and then sometimes it has to do with vitamin deficiencies, which we'll talk about a little bit more.
Robert: Yeah, but certainly the cultural aspect is just one huge part there. If you're in an environment, in a culture where it is accepted that consuming clay or some sort of mineral during this time has been official and okay than obviously you're gonna go for it. Whereas in other areas it's gonna be basically a taboo, it's just gonna be who eats dirt.
Julie: It's kind of like what is that cultural norm there right? So if you're in Kenya or you've gone to dirt eating, it's not gonna be so weird because it could be used in ceremonial or religious practices.
Robert: But then path world away somebody else is bringing their own cultural bias to it, and they're saying whoa, look at these backwoods people in this backwoods country eating dirt like a moron. But because they have their cultural blinders on they don't realize that it is essentially the normal act.
Julie: Yeah, let me share this historical tidbit with you because I think it's real interesting. In psychology today, Brain Sense column, it's pointed out that clay eating and soil eating were common in the 1800s, especially among slaves in the American South. And that in the '50s and '60s the practice was so popular that clay-filled lunch bags were sold at Alabama bus stops for snacks as travelers and southerners would mail bags of hometown clay to their friends and relatives who moved north.
Some reports estimate that clay eating is a daily practice in over 200 cultures worldwide.
Robert: Well, you know there's something perhaps from a psychological and almost magical thinking level where like the earth that you are from, that you would want to engage with. Like it also reminds me of Dracula, when Dracula moved to London from Transylvania he had his native dirt shift with him because he needed that dirt to really to be, I mean that was his home. He had to bring a chunk of his home with him, and of course we all do that when we travel. We want to bring a piece, not the dirt necessarily, the grave dirt, but we bring a piece of the place we were with us.
Julie: Yeah, and depending on the area that you're in, you're gonna have a different content in terms of minerals and other things that could potentially be helpful to someone, and we'll talk more about that later.
Robert: It kind of comes right back around into some of the discussions you hear involving say the consumption of local honey to deal with local pathogens. The idea that you're essentially a local being and the more you consume locally, the more in tune with the local ecosystem you're going to be.
Julie: So this is a story really about how widespread and common it is. In fact, the agency for toxic substances and disease registry decided that pica couldn't be considered abnormal because it was so widespread, and because it was associated with cultural practices as opposed to some sort of OCD behavior.
Julie: Now the question becomes well what's the deal with eating things that are non-nutritive or outside of the cultural norm that don't have anything to do with cultural practices or religious practices. For instance, like what's the teal with eating something like toilet paper. Where does that all fit into this because this is under the heading of pica right?
Robert: Isn't that the Japanese diet that Gina Maroney was on 30 Rock? She could eat all the tissue paper or just paper I think she wanted but you could only eat paper.
Julie: That's right, that's right. So other than in pregnant women, chronic pica or this kind of you know outside again the cultural norm pica is most common in people with developmental disabilities, including autism. You see this in children, and typically the children are between the ages of 2 and 3 when this begins to surface. Pica also may surface in children who have had a brain injury affecting their development, and according to kid's health, between 10 and 30 percent of kids, Ages 1 to 6 years have the eating disorder of pica, and again this is characterized by persistent and compulsive cravings that last for one month or longer to eat these non-food items.
Robert: So naturally, if you have this compulsion to eat things that are not food, it could wreak havoc under digestive system, and there's actually been an uptake in this.
Julie: Yeah, a huge one. The study by the agency for Healthcare Research and Quality found that hospitalizations for pica in a 10?year span jumped 93 percent. That is huge, so what happens is that people are hospitalized for a laundry list of problems, including obstruction of the bowel or airways from consuming or choking on stuff like hair.
High blood pressure, high levels of sodium salts in the blood and abnormal liver functions because of consuming huge quantities of something like baking powder. Again, so the list of pica items is - you'll get some lists and they're 20 items long, 30 items long, and they range anywhere from like chalk again hair, chomping on match sticks.
Robert: Trying to get into the Guinness Book. You have a certain subset of people who are always trying to do things like can I pass an entire toy train through my digestive system piece by piece. So they'll take something big, take it apart - I think people have done this with cars before, like can I consume a car piece by piece and pass it through my body.
Julie: Does it come out altogether on the other end?
Robert: Hey, I just naturally assumes it comes out whole, I don't know how they do it. But I think maybe it's sort of a sense of power in that. It's like you're not so tough, Volkswagen, I can eat you in small pieces, but I can still eat you. I don't know.
Julie: When I hear about things like that, I always think that, that's some of those things where you feel like you have a measure of control over your life right. So everything else could be spiraling out of control, and then you begin to obsess over this one thing you can control.
So it's sort of interesting in that if you look at pica, and you look at it in the OCD spectrum it very well may be related to that, especially because they've taken studies of people with pica, and they've given them the SSRIs, the serotonin uptake inhibitors right, that helps you balance out the serotonin in your brain. These aren't largely a class of antidepressants, and they have found that is really effective for people with pica. It helps to curb their behaviors or their compulsions to do that, so there is this idea that it is existing on that spectrum.
Robert: All right, well we're gonna take a quick break, and when we come back we're going to press on with dirt eating, with mineral eating and some of the vitamin deficiency elements of this situation. So speaking of control in one's life, let's talk a little bit about postage. There's no doubt that small business operations have improved over the years because of technology, and that includes mailing and shipping thanks to Stamps.com.
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Click on the microphone at the top of the home page, and type in stuff. That's Stamps.com, enter stuff, and start printing out your own postage. All right, we're back, and as I mentioned earlier eating dirt, eating things that are essentially the earth are not that crazy when you think about the fact that we put salt in our food. We use various minerals in our cooking and in our medication, so we are doing it - everyone is doing some of this anyway, perhaps just in a more elegant fashion.
Julie: Well, think about stomach upset right? Are you familiar with Kaopectate?
Julie: Okay, well that has something called kaolin in it and kaolin is really helpful, it's in clay and it can combat diarrhea because it forms a protective coating in the lining of the intestine and binds bacteria there. So in some parts of Nigeria you see people eating this kaolinite, this kind of clay.
Robert: Yeah, the idea that you're eating this to ramp up the protection in your gut against something that you just ate, you see various animals that do this after they have consumed a toxic plant or semi-toxic plant. Something that if they just ate it by itself, it would just become an increasingly more of a problem, it cause diarrhea etcetera.
And I've read some explanations of this where they essentially say that it's us refusing to be bossed around by plants because plants ultimately have it figured out. I mean there are plants that grow everywhere now because they have, and I hate to personify evolution too much, but or personify plants, but they've essentially figured it out. They know people need potatoes, they know people need illicit substances that they produce, and they gain the system to their advantage.
So vegetation that has a fruit that is toxic or slightly toxic, they're telling us where we can eat them, when we can eat them, how much we can eat them and who can eat them. And so the ability to consume clay or some other substance is essentially our way of saying actually I'm going to decide when I'm gonna eat you and how much of you I'm going to eat.
Julie: Hmm-hmm, right because I figure out of way, you're gaming me and I've figured out a way to game you so that I can still get some sort of food resource.
Robert: Yes, that's the whole evolutionary battle in essence.
Julie: Now pica is thought to be associated with low levels of iron. In some people calcium, zinc and Vitamin C and pica may appear in as many as half of those with iron deficiency and has been reported in about 20 percent of pregnant women. A study in France found that among 79 patients with iron deficiency anemia, 44 percent reported the regular ingestion of non-food items, while only 9 percent of the non-anemic subjects in the control report of this behavior.
So already you're seeing here that there's a pretty good amount of data that is saying that people are sometimes seeking it out, and sometimes not even announce themselves right?
Robert: Right. Because the body is saying we need this. We need an intake of this substance o this substance, we need more iron. Go find it, and distinctively we know where iron occurs.
Julie: Right. And that's when you think about pica you tend to think again back to pregnant women or children who there are studies that show that they do have a low level of these vitamins and/or perhaps seeking it out.
Robert: Yeah, children are growing, they need more vitamins to grow. You see that in the animal kingdom as well. For instance, deer; during antler growth period, there's a lot of tissue growth going on pretty rapidly, so you'll see them eat calcium or magnesium rich soils during that time.
Julie: Yeah, and if you think that pregnant women and children are just sort of you know anomaly or one off, this is really interesting. There's a study that was published in the 2011 quarterly review for biology, and again it looked at pica and pregnant women and preadolescent children and it found that they are also the most sensitive to parasites and pathogens. So Cornell University Researcher, Sara Young, who is also the study's lead author, she put together a database of more than 480 cultural accounts of geophagy, and the database includes as many details as possible about the circumstances under which the dirt was consumed and by whom.
And then they found again that not only was it pregnant women and kids who engaged in the dirt eating, it was far more prevalent in tropical climates because this is where you have many more food borne microbes that are very abundant and they found that these two groups of people tend to eat the dirt during a gastrointestinal distress. So the story that's painted here is that this dirt eating is helping to keep those pathogens and those parasites at bay in those different cultures in protecting against these two groups that are so sensitive to them, and I thought this was interesting, Young who said in her study we hope readers agree that it's time to stop regarding geophagy as a bizarre non-adaptive gustatory mistake.
So in this realm you see it not as you know something that's a compulsion or perhaps part of the CD spectrum, but more again lining up with what the body is needing or trying to guard itself against. Or as you say, gaining what's around you, gaining those parasites or pathogens.
Robert: As we discussed before I mean it also comes back to understanding the mind/body connection, realizing that there's more going on in our body's that our body's not just a magic throne that our brain rides in, but it is part in partial to who we are, and the more we understand about its cravings and its needs and its desires, in this case in terms of minerals and clays and what not, the more we understand how we work. And we know that this kind of behavior is not something that stands outside of ourselves, but is a part of the experience.
Julie: Yeah, and I like this topic too because you do start to look at it in these very different ways, the cultural aspect way that the body in just what it can do and game for itself, and how nature can game you as well. And then of course, the psychological element to it where you see it with kids and autism and so on and so forth.
Robert: Yeah, now we'd be remiss if we did not mention some of the dirt aficionados out there, in particularly in the wine tasting world. Julie: That's right.
Robert: Now this is the French term, and your French is better than mine. It is -
Julie: Actually I was thinking - I'm not quite sure if I know - it's T-E-R-R-O-I-R, which of course means earth.
Robert: Yeah, and this is the idea that for someone who really knows their wine. They get a sense of the earth in which the grapes were grown. So it's kind of the Dracula thing again. The earth that the grapes came from that were transformed into this elegant wine. There's a sense of that, and certainly I mean it makes sense to a lot of - because the actual components of earth vary from one location to the next. Anyone's who ever engaged in some serious planting of trees.
My wife and I are currently having a few fruit trees put in our back yard. Did a trade with somebody, and we're learning, yeah there are certain trees that grow in Georgia in the soil, and then you have to also think about acidity levels and what not. I mean there's a lot that goes into dirt, not all dirt is just dirt, there are many different types, so it makes sense.
I've also heard Milwar mentioned? And this is the idea that the ocean, the body of water from which salt water from which something is harvested, seafood. That also plays into its taste, and that it's part of the reason that the people are so into the different sea salts. You can go to the grocery store and just buy straight-up sea salt, but you can also buy a wide variety of sea salts from various parts of the world. The idea being that the salt of that ocean, of that particular corner of the ocean has a distinctive impact on taste.
Julie: So the next time you're at a dinner party I dare you as you are coughing your wine to say that you think the soil came from a low acidity grape grown under the tendrils of the sun. You can say tendrils of the sun.
Robert: Tendrils of the sun.
Julie: And perhaps even note that the meat was salted with something from the Pacific Northwest, from the winds of the Pacific Northwest.
Robert: I like it.
Julie: You do? All right.
Robert: All right. You know we're kind of pressed for time today, so I'm gonna skip calling the robot over here with its listener mail. We will get back to that because I know we have a lot of disgusting snail mail. Not snail mail in the terms that it came in to the post office, but rather snail and it's about slugs and snails and [inaudible] disgusting and I know you want to hear me read it and gag, so we will get to that. I will real quick mention, address a couple of things that my wife who is a regular listener brought up.
First of all, in a previous episode, I may have - sometimes I make these - obviously I'm really into certain T.V. shows, and in this episode I made a 30 Rock reference earlier, and I at least explained it. In a previous episode I use the term reaganing, and I need to remind everyone that I'm not dragging any kind of politics in to the episode, but in a particular episode of 30 Rock, the conservative character Jack Donaghey uses reaganing to describe a day in which everything is going right, and he's nailing every task before him.
So in case anyone of you were wondering what in the heck I was talking about, I did owe you an explanation, and that is the explanation. And likewise, multitasking; a classic example of multitasking that I did not bring up is the use of an electric toothbrush. I regularly fight this particular temptation, and so does my wife to grab the electric toothbrush, start using it, and then do other things like go check email or do some other morning task while brushing, and if you do that of course you end up not really brushing all that well. You're just kind of holding the brush in your mouth and it's just kind of an empty procedure, and likewise you're probably not doing a great job of the other thing either so.
Julie: And you're gonna get cavities.
Julie: That's the moral of that story.
Robert: It's a cautionary tale for everyone out there. So if you have some insights on any of these topics, particularly dirt, the consumption of dirt, the tasting of a foreign soil in the wine or perhaps you're a vampire, and you like to have your native soil shipped in so you may sleep in it. Everything's open for conversation, so let us know. You can find us on Facebook, you can find us on Tumblir. We have stuff to blow your mind on both of those, and on Twitter we go by the handle blowthemind.
Julie: And you can always drop us a line at firstname.lastname@example.org. For more on this and thousands of other topics, visit howstuffworks.com.
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Duration: 27 minutes