Speaker 1: Hi everybody.
Speaker 2: My name is Catherine Sampson, and I met both of
Speaker 2: the Aarons and graduate school at the University of Illinois.
Speaker 2: I'm currently an ap biology teacher down in Texas, where
Speaker 2: I'm from. They asked me to share my story about
Speaker 2: my lactose intolerance throughout my life, and of course I
Speaker 2: jumped at the opportunity to be on the podcast and
Speaker 2: share my poop stories with basically the entire universe. There
Speaker 2: was one part of my life that I think was
Speaker 2: one of the most formative defication experiences I've ever had,
Speaker 2: and it goes a little something like this. My mom
Speaker 2: and I, Hi Mom. We were sitting in a restaurant
Speaker 2: eating lunch one day and I just ordered something off
Speaker 2: the menu that appealed to me. And maybe about thirty
Speaker 2: minutes later, when my mom and I were shopping at
Speaker 2: the store that is very famous for selling containers of
Speaker 2: all varieties, we were walking down the gift wrapping aisle
Speaker 2: and I felt something kind of odd in my bowels,
Speaker 2: and so I thought to myself that it's not normal,
Speaker 2: but it'll be okay. Just shake it off, just keep walking,
Speaker 2: Everything's going to be fine. And I remember thinking back
Speaker 2: about this moment, and I went, maybe that's why they
Speaker 2: called it a bowel movement, you know, because I physically
Speaker 2: felt my bowels moving inside my body.
Speaker 1: So you know, I continue walking.
Speaker 2: And I start feeling like a buildup of gas inside
Speaker 2: my body. And so for all of the people out
Speaker 2: there who ever felt that, you know what I'm talking about.
Speaker 2: And so you think, for a moment, well, maybe if
Speaker 2: I let it out and I relieve that pressure inside
Speaker 2: my body, that everything will be okay. But for me
Speaker 2: in that moment, if I can give you all, one
Speaker 2: piece of advice is to never really trust a fart.
Speaker 2: I unfortunately did trust this fart, and it ended up
Speaker 2: being very bad for both me and my pants. So
Speaker 2: I ended up defecating myself in the middle of the
Speaker 2: gift wrapping aisle in some light blue jeans, very light
Speaker 2: blue jeans, And I remember walking up to my mom
Speaker 2: going I think I just put my pants, and I
Speaker 2: remember for the rest of my life. She looked at
Speaker 2: me and laughed and went what And I said, no, Mom, really.
Speaker 3: I just I put my pants.
Speaker 2: And she looks at me and she goes, well, I'm
Speaker 2: not done shopping. Nothing's going to change it right now,
Speaker 2: right Katie, and I said, okay, yeah, And so from
Speaker 2: that moment on, I realized that, you know, I'm standing
Speaker 2: in the middle of public in Houston, Texas and I
Speaker 2: just put my pants and this was going to be
Speaker 2: my life, and so I should probably make some concerted
Speaker 2: decisions to recognize what I'm eating and telp people that
Speaker 2: I'm lactose intolerant. And so I started doing that. You know,
Speaker 2: that was when I was nineteen, so nine years ago.
Speaker 2: But nowadays, when I go to restaurants, I don't really
Speaker 2: get taken seriously a lot saying that I'm lactose intolerant
Speaker 2: by the waiters or something like that. So I usually
Speaker 2: just say I'm allergic to milk, I'm allergic to cheese,
Speaker 2: or if it's a hard day, I just tell them
Speaker 2: I'm vegan and I go with it. So, yeah, that's
Speaker 2: just that's my poop story, and I hope that everybody
Speaker 2: out there can maybe relate to that a little bit
Speaker 2: and recognize that we shouldn't be ashamed of maybe pooping
Speaker 2: or pants in public. That's my story, y'all.
Speaker 3: That was amazing as always.
Speaker 4: As always, thank you so much, Katie for your always
Speaker 4: enjoyable stories.
Speaker 1: The best, the best not only poop stories, but definitely the.
Speaker 3: Best poop stories. Definitely the best poop stories without a doubt. Hi,
Speaker 3: I'm erin.
Speaker 1: Welsh and I'm erin omen Updyke.
Speaker 3: And this is this podcast will kill you.
Speaker 1: And today we're talking about wlacktose intolerance.
Speaker 3: Or lack tase persistence, because really that's the.
Speaker 1: There's so many names for this. I love it.
Speaker 3: Oh my gosh, I think we were We're gonna have
Speaker 3: to do some sort of like a primer or briefing
Speaker 3: on the names.
Speaker 1: A lot of the articles that I read had like
Speaker 1: tables of all of the acronyms that they use, because
Speaker 1: there's so many different ways to talk about.
Speaker 3: I wish that the articles I looked at had tables
Speaker 3: because that would have made my life a lot easier.
Speaker 3: I was like, oh no, does this one stand for again?
Speaker 3: So to get us through this episode, what are we drinking?
Speaker 1: Our quarantine of the day is truth or dairy.
Speaker 3: And appropriately it is essentially a milk punch, So it's
Speaker 3: got milk and ram and Brandy r Kognac and nutmeg.
Speaker 1: Listen, do you say milk or milk? I say milk
Speaker 1: because I got made fun of this morning, for saying milk,
Speaker 1: for saying what I guess, I say it weird milk.
Speaker 1: Oh great, so it's gonna be It's gonna be another
Speaker 1: one of those episodes where Aaron can't pronounce the thing
Speaker 1: we're talking about. That's fine, I'll just say dairy.
Speaker 3: There we go. We will post the recipe for the
Speaker 3: quarantine and the non alcoholic pluicy Brita on our website.
Speaker 3: This podcast will kill you dot com and all of
Speaker 3: our social media pages, so check it out.
Speaker 1: Yes, most definitely. Do we have any other business?
Speaker 3: No, I don't think. So let's just get started.
Speaker 1: Okay, we'll take a quick break first. I'm very excited
Speaker 1: about this episode. This is our first, the first non crossover,
Speaker 1: non disease episode. Wait a second, Like we've had crossover
Speaker 1: episodes where we talk about poisons or things, actually what
Speaker 1: you mean, But this is our first, just me and you,
Speaker 1: and we're talking about maybe not even a disease. Well
Speaker 1: it's not really, it's not it's really not spoilers. So
Speaker 1: I figured that because this is a wonky episode where
Speaker 1: we aren't talking about a disease, I would do the
Speaker 1: biology section in a bit of a wonky way. Okay, perfect, Okay,
Speaker 1: So we're gonna start off the biology section where we
Speaker 1: usually end up, and that is with the symptoms, because
Speaker 1: we usually kind of end with that. So if we're
Speaker 1: being honest, we pretty much already know the symptoms of
Speaker 1: lactose intolerance aka lactose malabsorption aka lactase non persistence aka hypolactasia.
Speaker 1: It's another term for it.
Speaker 3: I see, I've seen all of these.
Speaker 2: Good.
Speaker 3: It's nice refresher.
Speaker 1: So we know these symptoms. Eron, what are the kinds
Speaker 1: of symptoms?
Speaker 3: Bloating, rumbly tummy diarrhea?
Speaker 1: Do you want to know the Do you want to
Speaker 1: know the fancy word for grumbly tummy? I do? Borborygmy?
Speaker 3: Uh? Can I get the etymology of that? Please?
Speaker 1: Mmm? Let me google that for you. It's Greek. Great,
Speaker 1: it comes from the Greek bor borygmos meaning what meaning
Speaker 1: a rumbling or gurgling noise made by your tummy.
Speaker 4: Wow, So it really is specifically like that word has purpose.
Speaker 3: Amazing, I know.
Speaker 1: Ohymas. Yeah, that's a big one. That's the medical term
Speaker 1: for a gurgly tum abdominal pain. I think you said diarrhea.
Speaker 1: Diarrhea tends to be less common in adults, at least
Speaker 1: according to the literature. But we'll kind of talk about
Speaker 1: why you might see diarrhea even if you're an adult.
Speaker 1: Does that make sense? All right? Cool, So we all
Speaker 1: know what we're dealing with here. But to talk about
Speaker 1: lactose intolerance or lactose malabsorption, we have to actually take
Speaker 1: a step back and first talk about one of our
Speaker 1: favorite things, the gastrointestinal tract. Yeah, so your guts, because
Speaker 1: lactose malabsorption is a gut problem. We're going to talk
Speaker 1: about how it functions normally in order to understand what
Speaker 1: goes wonky in these situations.
Speaker 3: So hold on, okay, lactose malabsorption is the normal state.
Speaker 1: Okay, Yeah, this is going to get confusing. Yeah, yes,
Speaker 1: I mean yes and no. Right, Like, mammals can digest
Speaker 1: lactose for at least a portion of their lives.
Speaker 3: Yeah, yeah, so.
Speaker 1: As adults, some mammals, most mammals can no longer digest lactose.
Speaker 1: But let's talk about how your GI tract normally would
Speaker 1: handle lactose if it's able to digest it. Okay, okay,
Speaker 1: and just kind of how your GI tract handles sugars
Speaker 1: to begin with. Okay, well, like we're going back to
Speaker 1: the very beginning here, okay, okay, So the main function
Speaker 1: of your gi tract.
Speaker 3: Is what to digest food.
Speaker 1: Yeah, exactly, absorb nutrients, you know it all.
Speaker 3: Okay.
Speaker 1: So your gut has three main divisions, right. You have
Speaker 1: like your foe gut that's your mouth and maybe down
Speaker 1: to your stomach. Right then you have your midgut that's
Speaker 1: your small intestine, and then your hindgut, which is like
Speaker 1: your colon and your butt. Okay, okay. So digestion, which
Speaker 1: is that main function of your gut, starts at the
Speaker 1: very top in your mouth where you choose things and
Speaker 1: you physically and chemically start to break them down, and
Speaker 1: then it travels down to your stomach where that digestion
Speaker 1: process continues. Like physically, your stomach clenches in and out.
Speaker 1: Plus you've got all that acid in there. Right. Then,
Speaker 1: as your food moves into the small intestine, your small
Speaker 1: intestine has two main goals finishing up that digestive process,
Speaker 1: and this one's important absorbing all those nutrients that you
Speaker 1: unlocked during that digestion process.
Speaker 3: Okay.
Speaker 1: So to do that, your small intestine has a bunch
Speaker 1: of different enzymes which are responsible for breaking down all
Speaker 1: these nutrients into the smallest possible particles so that they
Speaker 1: can pass through the intestine wall and make it into
Speaker 1: our bloodstream. Okay. So some of these enzymes come from
Speaker 1: the pancreas and some of them come from cells in
Speaker 1: the wall of the intestines themselves. But these enzymes are
Speaker 1: all really important because your intestine basically acts as a
Speaker 1: filter and large particles can't make it through your intestine
Speaker 1: wall into your bloodstream, so everything has to be broken
Speaker 1: down into really small molecules. In the case of sugars,
Speaker 1: it has to be broken down into monosaccharides. That means
Speaker 1: one piece of sugar.
Speaker 3: Cool cool.
Speaker 1: Okay. So anything that can't be digested or can't be
Speaker 1: broken down small enough will stay in your small intestine
Speaker 1: and keep traveling down to your colon. Your colon is
Speaker 1: the last part of your gi tract, and it's basically
Speaker 1: responsible for sucking all the water out of the junk
Speaker 1: that's left in there so that you don't lose too much.
Speaker 3: Water oh aka diarrhea.
Speaker 1: Aka diarrhea, And then you have a whole bunch of
Speaker 1: bacteria in your colon which helped break down any last
Speaker 1: particles that might have nutrients in there that you want,
Speaker 1: so that you can absorb absolutely everything possible and then
Speaker 1: what's left is poop and you poop it out.
Speaker 3: Ok. Excellent.
Speaker 1: So that's your GI tract in a nutshell. So what
Speaker 1: happens in lactose malabsorption or lactose intolerance? So lactose is
Speaker 1: a sugar, it's a die saccharide. So that means two
Speaker 1: sugars bound together. It's galactose and glucose. If you care
Speaker 1: about that sort of thing.
Speaker 3: Oh, I mean, I didn't think I did, and I
Speaker 3: don't think that I do. But still interesting.
Speaker 1: You're good to know. Yeah, okay, And lactose is found
Speaker 1: in milk, of course, milk dairy products. I don't hear.
Speaker 3: I don't hear milk and milk, but thank you.
Speaker 1: I appreciate that because I really got made fun of.
Speaker 1: And so, since lactose is a die saccharide, we know
Speaker 1: that it has to be broken down into monosaccharides, the
Speaker 1: two that it's made up of, galactose and glucose, in
Speaker 1: order to be absorbed by the small intestine. It turns
Speaker 1: out that this happens in our small intestine by a
Speaker 1: specific enzyme called lactase. So what happens right off the
Speaker 1: bat is that if lactase isn't able to break down
Speaker 1: lactose into its two component parts, then you will have
Speaker 1: undigested lactose, a die saccharide that's left in your small
Speaker 1: intestines to travel down to the colon. Okay, that's the
Speaker 1: main thing that happens in lactose intolerance or lactose malabsorption.
Speaker 1: So the function of the colon is to absorb the
Speaker 1: water that's left and leave your behind. When you have
Speaker 1: undigested sugars like lactose, they serve as a really great
Speaker 1: food source for bacteria. So the bacteria in your colon
Speaker 1: gets super stoked and they will go nuts eating this sugar,
Speaker 1: this lactose, and they convert this sugar via biokin We're
Speaker 1: not going to get into into fatty acids and hydrogen gas.
Speaker 3: Uhah.
Speaker 1: So guess what it feels like when you're intestinal bacteria
Speaker 1: start producing a bunch of gas.
Speaker 3: I mean, whatever the Greek word you said, borberygmy, barberigmy.
Speaker 1: Exactly, You're literally going to have a bunch of gas
Speaker 1: in your colon. Okay, And that is why you have
Speaker 1: these symptoms. If you have a bunch of lactose, that
Speaker 1: makes it all the way from your small intestine down
Speaker 1: into your colon. Now, the other thing that can happen
Speaker 1: if you have undigested disachrides like lactose in your colon
Speaker 1: is that it turns out that this sugar, this disacharide,
Speaker 1: it's what we call osmodically active, which means that it's
Speaker 1: going to draw water towards it. So if you have
Speaker 1: sugar left in the lumin of your gut, you're not
Speaker 1: going to be able to absorb water through the walls
Speaker 1: of your colon. Rather, water is going to stay in
Speaker 1: your colon because in your body there has to be
Speaker 1: a balance between the solutes and water. Right, Okay, so
Speaker 1: what does that mean arin If you've got a bunch
Speaker 1: of water left in your colon.
Speaker 3: I think we both know where this is going. It's
Speaker 3: rather bashroom for some loose stool.
Speaker 1: Exactly dirhea. As a fun side note, this is how
Speaker 1: osmotic laxatives work. So if you've ever taken merr lax
Speaker 1: or lactulose, lots of kids take it because kids are
Speaker 1: always constipated. That's exactly how they work. It's basically just
Speaker 1: big molecules that can't be broken down by our enzymes
Speaker 1: or our gut bacteria. So then it draws a bunch
Speaker 1: of water into your colon.
Speaker 3: Wow, that sounds uncomfortable.
Speaker 1: Yeah, I mean it just cleans you out. It's what
Speaker 1: you use if you're having a colony. Yeah. Okay, So
Speaker 1: that is how lactose intolerance or lactose malabsorption happens, why
Speaker 1: it causes the symptoms that it causes. So now we
Speaker 1: have to get back to the beginning where we mentioned
Speaker 1: this isn't really a disease state. So why is it
Speaker 1: that some people have this and some people don't. Wow,
Speaker 1: turns out there's a few different ways. Let's talk about
Speaker 1: the least common first. Okay, First, you could be born
Speaker 1: with very low levels of this lactase enzyme function that
Speaker 1: is called congenital lactase deficiency. You can imagine that because
Speaker 1: mammal's main food source is breast milk, which has lactose,
Speaker 1: that would be pretty bad.
Speaker 3: So this is pretty rare, okay.
Speaker 1: And those good question. Actually I never did find I
Speaker 1: have starstar EPI numbers, and I never found good EPI
Speaker 1: numbers on this it's most common in the Finish population.
Speaker 3: Really yeah, I know, you know, Okay, this is jumping
Speaker 3: the gun a little bit. But in Northern European countries
Speaker 3: and Northern European populations, lactase persistence, so the ability to
Speaker 3: digest lactose is pretty high across the board. Yes, but
Speaker 3: when I was living in Finland, I saw so many
Speaker 3: like lactose free or low lactose milks and yogurt and
Speaker 3: blah blah blah blah blah, we'll talk about it. Okay, great, Yeah,
Speaker 3: I was like, wait a second, but I thought, yeah, okay.
Speaker 1: M mmm. So yeah, this congenital lactase deficiency. You can
Speaker 1: imagine you would recognize this pretty early on when a
Speaker 1: baby is an infant, because they would have some pretty
Speaker 1: severe symptoms from breast milk. This is an autosomal recessive disorder.
Speaker 1: So this is a genetic disorder. Okay, uh, but again
Speaker 1: it's pretty rare. I don't have exact numbers, but that's
Speaker 1: one way that you could end up with lactose malabsorption.
Speaker 1: Another way is if you are a very premature baby.
Speaker 1: Sometimes premature babies have what's called developmental lactase deficiency because
Speaker 1: their GI tract just isn't quite developed enough, and it
Speaker 1: for some reason turns out that lactase is one of
Speaker 1: the last genes to get properly turned on during development.
Speaker 1: But this is something that would be rather transient.
Speaker 3: Okay, it's interesting that it's one of the last genes.
Speaker 1: I know, you'd think it'd be an important one. But
Speaker 1: also like so is surfactant production, and that's like essential
Speaker 1: for life. That's what allows your lungs to stay open.
Speaker 3: That's pretty crue.
Speaker 1: Yeah, it doesn't happen till like after thirty five weeks
Speaker 1: of gestation anyways.
Speaker 3: Huh.
Speaker 1: Another way that you could end up with being not
Speaker 1: able to absorb lactose very well is if you get
Speaker 1: a GI tract infection, for example, giardia.
Speaker 3: Wow.
Speaker 1: Okay, that kind of GI tract infection can cause damage
Speaker 1: to your small intestine where this enzyme is located, so
Speaker 1: that even after clearance of that infection, you don't have
Speaker 1: proper function of that lactase enzyme. So it basically just
Speaker 1: causes damage to the cells of your small intestine.
Speaker 3: Okay, So in theory, you could still produce lactase, but
Speaker 3: the cells are so damaged exactly, there's no way to
Speaker 3: write blackchase, okay, precisely.
Speaker 1: But finally, number four, the most common way that you
Speaker 1: can have lack toast malabsorption.
Speaker 3: I feel like people are gonna get angry with us
Speaker 3: because we're describing the normal state of things.
Speaker 1: Well, then let me say this, Aaron. The fourth option
Speaker 1: is you can be a normal human adult Okay, okay,
Speaker 1: in most humans, in fact, in most adult mammals, it
Speaker 1: is totally normal for the activity of the lactase enzyme
Speaker 1: to downregulate as we age. What does that mean. It
Speaker 1: means that this enzyme works really well when we're babies
Speaker 1: in infants, and literally by the time we're like six
Speaker 1: years old, the action of this enzyme is substantially less
Speaker 1: than it was when we were babies.
Speaker 2: Right.
Speaker 1: So, lactase persistence, which means that your lactase enzyme is
Speaker 1: on at high levels throughout your life, is actually the
Speaker 1: mutant state, and that is what is present in some
Speaker 1: populations and erin I'm pretty sure you're going to talk
Speaker 1: about why and where this mutation came from. Definitely awesome,
Speaker 1: But yeah, the bottom line is if you can drink
Speaker 1: milk as an adult human and not have borborygmy and
Speaker 1: tons of gas and abdominal cramping and possibly diarrhea. You're
Speaker 1: the mutant, we're the mutants. So I think that's really fun.
Speaker 1: So I don't know this episode is lactose intolerance, but
Speaker 1: it's really like weird lactase persistence. Yeah mutants.
Speaker 3: Maybe we'll just milk mutants, milk milk mutants.
Speaker 1: Milk mutants. But arin what you mentioned about in Finland
Speaker 1: having really high levels of seeing a lot of like
Speaker 1: lactaid type.
Speaker 3: Yeah LA products, low lactose products.
Speaker 1: It turns out that people are actually really bad at
Speaker 1: knowing if their symptoms are associated with lactose intolerance or not. Right,
Speaker 1: So when they've done studies to look at, like what
Speaker 1: your tolerance levels actually are, it turns out that even
Speaker 1: people with lactose intolerance or lactase non persistence can actually
Speaker 1: tolerate about a cup or a little more than a cup,
Speaker 1: like twelve ounces of milk a day.
Speaker 3: I was gonna make that point or like bring bring
Speaker 3: that up, that lactose intolerance and lactase non persistence are
Speaker 3: different things, Like you can also have different levels of
Speaker 3: lactose intolerance exactly even if you don't produce lactase into adulthood.
Speaker 1: Exactly, because lactose intolerance is essentially you having symptoms from
Speaker 1: after you drink milk, but most because your colon bacteria
Speaker 1: can actually digest lactose. As long as you're not drinking
Speaker 1: or eating so much lactose that you become symptomatic, then
Speaker 1: it's no problem, right, So the only problem is if
Speaker 1: you have so much that basically your whatever whatever your
Speaker 1: individual colon bacteria can handle, after that point is when
Speaker 1: you're going to become symptomatic. So for some people that
Speaker 1: might be like one piece of cheese, and for other people,
Speaker 1: even if their lactase enzyme is very low activity or
Speaker 1: no activity, they might still be able to drink like
Speaker 1: a full glass of milk and not have any problems.
Speaker 3: So the microbiome, the gut microbiome, and lactose, yes, the
Speaker 3: bacterial species that feed on the lactose. Like, is there
Speaker 3: have there been any studies that look at maybe like
Speaker 3: different amounts of that type of bacteria or anything like
Speaker 3: that in association with symptoms or tolerance or whatever else.
Speaker 1: Like whether you could give somebody probiotics and lessen their symptoms. Yeah, yeah,
Speaker 1: there have been studies of it to my knowledge, they're
Speaker 1: not like, we don't have a pill, a probiotic pill
Speaker 1: that you can take to be able to digest lactose
Speaker 1: with no problem at this point, but there are definitely
Speaker 1: people looking into it because for sure, differences in colon
Speaker 1: bacteria would lead to differences in symptoms. And there have
Speaker 1: been a number of studies that have shown that if
Speaker 1: you kind of train your colon bacteria over time, then
Speaker 1: you might actually be able to tolerate greater levels of lactose,
Speaker 1: although other studies have said maybe that's just a placebo effect.
Speaker 3: So in any case, if you don't have the allele
Speaker 3: that allows you to produce lactase, you're not digesting.
Speaker 1: On your own. You're not digesting it.
Speaker 3: Yeah, so tell me about lactase and the little pills,
Speaker 3: the little helper pills. What do those do?
Speaker 1: So the lactase pills that you take are lactase enzyme.
Speaker 3: Oh okay, So.
Speaker 1: That's literally just going to break down the lactose before
Speaker 1: it makes it to your colon. Okay. There are other
Speaker 1: things that you can put, like in your milk, like droppers.
Speaker 1: I don't know if it's a liquid or not, but
Speaker 1: that is yeast or bacteria that you can let sit
Speaker 1: in your milk and it'll digest the lactose for you.
Speaker 1: I think, wasn't it?
Speaker 3: I am hearing milk?
Speaker 1: I can't help it.
Speaker 3: I mean, you do you? There's that whole like, what
Speaker 3: part of the country dialect test are you from? I
Speaker 3: wonder what isn't milk a Midwest Midwestern thing?
Speaker 1: I don't know. Brett and I are from the same place,
Speaker 1: and he makes fun of me, So I mean, maybe.
Speaker 3: You've picked it up since living in Illinois.
Speaker 1: You know, milk milk. I just don't hear a difference.
Speaker 3: Quite honestly, this episode is just going to be forty
Speaker 3: five minutes of us saying ill.
Speaker 1: Anyways, Aaron, that's it. It's what I got. That's a biology Wow.
Speaker 3: Okay, very interesting.
Speaker 1: That was also some of the EPI.
Speaker 3: So are you ready to hear about the history of
Speaker 3: blacktase persistence.
Speaker 1: That's what I'm here for.
Speaker 3: Okay, excellent. Let's take a quick break, all right. So
Speaker 3: I want to start off by talking a bit about
Speaker 3: milk and then about lactase persistence, and so for this part,
Speaker 3: just a clear things up because most of the time
Speaker 3: when I'm talking about the history of lactose intolerance, or
Speaker 3: lactase persistence. I'm talking about the specific allele and not
Speaker 3: necessarily the disease itself, and so I'll say lactase persistence,
Speaker 3: and that refers to people who have the allele that
Speaker 3: allows them to digest lactase throughout or lactose throughout their lifetimes. Right, Okay.
Speaker 3: Milk is a pretty revered liquid if the myths and
Speaker 3: folklore surrounding it are any indication. The Greek word for
Speaker 3: milk is gala, which forms the basis of the word galaxy,
Speaker 3: and ours is called the milky Way. So, yeah, isn't
Speaker 3: that cool? Because according to Greek mythology, yes, the milky
Speaker 3: Way was formed when Hera spilled milk while breastfeeding Heracles
Speaker 3: aka Hercules, with each drop of milk forming a star.
Speaker 1: Huh.
Speaker 3: Yeah. And the ancient Greeks weren't the only ones to
Speaker 3: have creation myths with milk playing a central role. So,
Speaker 3: for example, in the Thalani people of West Africa, there's
Speaker 3: a myth that the entire world began from one huge
Speaker 3: drop of milk, And in Norse mythology, a frost ogre
Speaker 3: named Emir was kept alive by the milk of a
Speaker 3: cow made from thawing frost.
Speaker 1: Wait wait, wait, the cow was thawing. The cow was
Speaker 1: made from thawing frost.
Speaker 3: The cow was made from thawing frost.
Speaker 1: And then the milk made.
Speaker 3: The milk from that cow of thawing frost. Okay, weird,
Speaker 3: that's my understanding. And milk was believed to be a
Speaker 3: type of blood for a really long time, and so
Speaker 3: that also, as we have talked about in the hepatitis episode,
Speaker 3: also carried a bunch of weight and it was used
Speaker 3: as the blood of Christ for a long period in
Speaker 3: the Catholic Church until being replaced by one.
Speaker 1: I gotta tell you that my brain can't keep flipping
Speaker 1: between like cow milk and human breast milk, and it's
Speaker 1: it's grossing me out both ways either time.
Speaker 3: Well, so, yeah, and that's the thing is that like
Speaker 3: milk holds a lot of meaning for many human cultures,
Speaker 3: and a lot of that is human breast milk. Yeah,
Speaker 3: but with some of these, as with the cow made
Speaker 3: from thawing frost, it also shows that animal milk had
Speaker 3: significance as well. Right, Okay, So let's see. A refrigerator
Speaker 3: was built in the US in eighteen oh three, Like
Speaker 3: the first time for the purpose of keeping butter butter butter.
Speaker 3: The Cia once tried to poison Castro by slipping like
Speaker 3: a poison pill in his ice cream. He was a
Speaker 3: huge fan of ice cream, apparently, who isn't pints. There
Speaker 3: was a lot of power in milk, so in breast milk,
Speaker 3: it was believed often that picking a wet nurse with
Speaker 3: the right temperament was incredibly important in the baby's personality.
Speaker 3: And also goat's milk or sheep's milk or cow's milk
Speaker 3: was seen as nourishment and was also used as a
Speaker 3: sacrifice as well. And milk wasn't universally hailed as of
Speaker 3: wonder liquid though so For instance, for millennia, fresh milk
Speaker 3: could pretty much only be consumed on farms, and so
Speaker 3: it was held in low status as like a peasant beverage.
Speaker 3: Oh interesting, yeah, And this created cultural tensions or conflicts.
Speaker 3: So in southern Europe, the Romans looked down upon those
Speaker 3: in Northern Europe who drank more fresh milk because it
Speaker 3: was colder there and the milk kept better. And in
Speaker 3: addition to making people more quote barbaric milk was also
Speaker 3: thought to be bad for you healthwise and fresh milk
Speaker 3: wasn't the only thing that got labeled with this like
Speaker 3: as a suspect. Food cheese and other dairy products also
Speaker 3: got the stamp. But as you mentioned, milk is crucial
Speaker 3: for humans in infancy, just as it is for all
Speaker 3: mammal species, and here comes like this is just going
Speaker 3: to be an influx of trivia. Not all mammal milk
Speaker 3: is created equally, so some are loads fattier than others,
Speaker 3: like northern seals at fifty three point two percent fat.
Speaker 3: Oh my humans for reference four point five percent?
Speaker 1: Whoa I mean?
Speaker 3: And you know that one of my favorite bits of
Speaker 3: trivia is that the breast milk of some whales has
Speaker 3: the consistency of toothpaste.
Speaker 1: Toothpaste. I'm imagining that in my frit Like, we have
Speaker 1: a lot of milk in our fridge right now, and
Speaker 1: you can see the fat as it rises to the
Speaker 1: top when it gets cold, you know, And knowing that
Speaker 1: that's only four percent, imagine and imagine seal milk in
Speaker 1: your fridge.
Speaker 3: Fifty three point two percent.
Speaker 1: Yeah, imagine that butter oh.
Speaker 3: I mean just toothpaste consistency stock. I mean, it makes
Speaker 3: a lot of sense because if you're in the water.
Speaker 3: You wouldn't want it to just immediately diffuse or whatever. Yeah,
Speaker 3: so get wouldn't want.
Speaker 1: You want that toothpaste milk.
Speaker 3: Did you know also that some pinnipeds like sea lions
Speaker 3: and walrus's lactose isn't present.
Speaker 1: Really, Yeah, so what's their main carb?
Speaker 3: I don't know. I didn't. If we look it up,
Speaker 3: it's okay, I saw it. It's like I was like, oh,
Speaker 3: cool bit of information. That's not reading any further. But
Speaker 3: humans are the only mammal that consume the milk of
Speaker 3: other species and continue to do so throughout their lives,
Speaker 3: and in retrospect, it's kind of easy to see why
Speaker 3: this practice would have been popular. Milk of various ruminants
Speaker 3: like cows and reindeer could be used to make yogurts
Speaker 3: or butters or cheeses that would keep for a decent
Speaker 3: period of time, and that could be especially important when
Speaker 3: other food was scarce. Side note, Did you know that
Speaker 3: unsalted butter was a recent invention because basically refrigeration was
Speaker 3: the only way to keep unsalted butter fresh.
Speaker 1: That makes so much sense because salt is a preservative,
Speaker 1: so you'd have to have salted.
Speaker 3: Yeah, I hope that you go to trivia night, you
Speaker 3: and anyone who is listening, and you get asked a
Speaker 3: question about milk, that this episode a key question.
Speaker 1: The question is going to be what carbohydrate do you
Speaker 1: pinnipeds have.
Speaker 3: Instead of lactose? Well, sorry, guys, there's only so much
Speaker 3: I can do. Okay, But of course the majority of
Speaker 3: humans can't actually digest lactose into adulthood. And this feature
Speaker 3: or this whatever, this pattern has been recognized for millennia.
Speaker 3: Hippocrates in the fifth century BCE said quote, cheese does
Speaker 3: not harm all people alike, and there are some people
Speaker 3: who can eat as much of it as they like
Speaker 3: without the slightest adverse effects. Indeed, it is a wonderfully
Speaker 3: nourishing food for the people with whom it agrees, but
Speaker 3: others suffer dreadfully.
Speaker 1: Which is as you heard in Katie's Katie Can the test.
Speaker 3: And Galen, who lived in the second century CE, observed
Speaker 3: and described lactose intolerance. And there were many ancient writings
Speaker 3: that advise against the consumption of milk after weaning. So
Speaker 3: why can some of us digest lactose? Approximately thirty five
Speaker 3: percent of us? Okay, So, first to answer that. Let's
Speaker 3: look at the global pattern of lactase persistence to see
Speaker 3: if that gives us any clues. So these are the
Speaker 3: proportion of people who can continue to digest lactose into adulthood.
Speaker 3: Eastern Europe the frequency of lactase persistence is between fifteen
Speaker 3: and fifty four percent, whereas in the British Isles. In
Speaker 3: Scandinavia that ranges from eighty nine to ninety six percent.
Speaker 1: WHOA, yeah, that's even higher than I thought.
Speaker 3: And in northern India around sixty three percent of people
Speaker 3: have lactase persistence compared to twenty three percent in the
Speaker 3: South or the East.
Speaker 1: Aarin, that makes so much sense for something that I
Speaker 1: was reading where I went lots weird.
Speaker 3: And in some pastoralist populations in Sudan, lactase persistence is
Speaker 3: around sixty four percent, but in a nearby non pastoralist
Speaker 3: group that number is around twenty percent. So there's a
Speaker 3: common thread here, and that thread is that lactase persistence
Speaker 3: might have something to do with pastoralism or dairy farming
Speaker 3: as a way of life. So what came first milking
Speaker 3: or lactase persistence? So one hypothesis, which is kind of
Speaker 3: like a chicken and egg scenario is whether pastoralism only
Speaker 3: developed in those populations where lactase persistence was already high.
Speaker 3: This is called the reverse cause hypothesis, and this view
Speaker 3: kind of says that lactase persistence wasn't selected for necessarily
Speaker 3: and the explanation for variation in rates is just random
Speaker 3: through like genetic drift. But another hypothesis, and this one
Speaker 3: is the one that has more support, is the culture
Speaker 3: historical hypothesis, which states that lactase persistence emerged and was
Speaker 3: selected for after pastoralism was adopted, meaning that being able
Speaker 3: to digest lactose into adulthood made you more likely to
Speaker 3: survive and reproduce. And one piece of support for this
Speaker 3: is that archaeologists have found organic residue and pottery from
Speaker 3: around sixty five hundred BCE in western Turkey, where lactase
Speaker 3: persistence is low to and so this suggests that milking
Speaker 3: that animals were milked before lactase persistence arose. So when
Speaker 3: did milking begin? Then milking animals probably began in the
Speaker 3: Middle East, possibly Iraq or Iran, around eight to ten
Speaker 3: thousand years ago, so like Neolithic Revolution.
Speaker 1: Times, Yeah, it's a long time.
Speaker 3: A long time, but also not that long for the
Speaker 3: like in terms of thinking about human evolution, which is
Speaker 3: so there was a long held belief or viewpoint that
Speaker 3: humans had basically stopped evolving fifty thousand years ago, but
Speaker 3: of course we know that that's not the case now,
Speaker 3: especially as like genomic technology has really shown that like
Speaker 3: evolution is happening on many different time skills and anyway,
Speaker 3: lacktase persistence is a great example of how humans have
Speaker 3: continued to evolve.
Speaker 1: Yeah, especially considering how widespread that a wheel now is
Speaker 1: in some populations that it was that relatively recent.
Speaker 3: Yeah. Okay, So there's a depiction of people milking cows
Speaker 3: on the wall of a temple dating back five thousand
Speaker 3: years in ancient Sumeria, but milking probably began long before that,
Speaker 3: and cows weren't the first. Goats and sheep were actually
Speaker 3: the first livestock to be domesticated around eleven thousand years ago,
Speaker 3: followed by pigs and cattle around five hundred years after that,
Speaker 3: And so people may have first tried milking goats or
Speaker 3: sheep or maybe even a camel. So the Bedouins, for instance,
Speaker 3: relied heavily on camel milk for their survival, Bedouin means
Speaker 3: desert dwellers. Also, Bedowin is a really amazing musical artist.
Speaker 3: Her Tidy Desk concert is incredible. And Bedouins were traditionally
Speaker 3: nomadic and many still are, but that traditional way of
Speaker 3: life has declined. While on the move. Camels played a
Speaker 3: major role in every aspect of life, shelter, transport, warmth,
Speaker 3: and of course, food production and the milk produced by
Speaker 3: a camel is pretty incredible. Camels themselves are pretty incredible.
Speaker 3: Camels feed on the spiky salt bush, which gives their
Speaker 3: milk a salty taste. At times of food scarcity, camels
Speaker 3: will dilute their milk to make it last longer, and
Speaker 3: in times of plenty that milk can be incredibly fatty
Speaker 3: and rich in protein. Huh so yeah, more milk facts
Speaker 3: for you. I read a book literally titled milk.
Speaker 1: So Also, I looked it up and pinnipeds and cetaceans
Speaker 1: just have the lowest amount of carbohydrates. Oh, it's why
Speaker 1: they don't have lactose.
Speaker 3: Okay, yeah, cool, go fig go fig.
Speaker 2: So.
Speaker 3: At some point after the advent of agriculture and domestication
Speaker 3: of livestock, a mutation emerged that allowed humans to continue
Speaker 3: to produce lactase into adulthood. So this was probably around
Speaker 3: eight or nine thousand years ago in Central Europe. There
Speaker 3: are different models that kind of show a variation of
Speaker 3: ranges from like six thousand to ten thousand years ago,
Speaker 3: but that seems to be like the central accepted range. Okay,
Speaker 3: And clearly this mutation had some benefits because it's spread
Speaker 3: rapidly and widely throughout Europe in parts of Africa as well,
Speaker 3: reaching frequencies as I said, of over ninety five percent
Speaker 3: in some places. And so why would being able to
Speaker 3: consume lactose as an adult be advantageous? And there seem
Speaker 3: to be three main hypotheses for why continued milk consumption
Speaker 3: could be selected for. And the first is that in
Speaker 3: pastoralist society, so ones that keep cattle for milking and
Speaker 3: meat consumption, drinking milk would have meant more nutrition. If
Speaker 3: milk is a constant part of your diet, but you
Speaker 3: have diarrhea and horrible stomach pains whenever you drink milk,
Speaker 3: it's easy to see how your health could be negatively impacted.
Speaker 3: And that people who had the ability to digest lactose
Speaker 3: into adulthood might have slightly higher fitness if you're relying
Speaker 3: that heavily on milk. Another hypothesis is that drinking fresh
Speaker 3: milk could have been super beneficial to people in high
Speaker 3: latitudes like in northern Europe where lactase persistence is high,
Speaker 3: because it would have allowed them to get vitamin D
Speaker 3: during the long winter months and that would have prevented
Speaker 3: things like rickets and also helped calcium absorption. And it's
Speaker 3: true that you see more lactase persistence and fresh milk
Speaker 3: consumption in Northern Europe compared to the Mediterranean, where lactase
Speaker 3: persistence is lower and cheese tends to be the main
Speaker 3: dairy product consumed, and cheese can have less lactose in
Speaker 3: it depending on how it is prepared a lot. Yeah,
Speaker 3: and finally, another hypothesis about the evolutionary benefits of fresh
Speaker 3: milk is that for people living in arid environments, milk
Speaker 3: would have been a source of water, and if you
Speaker 3: had diarrhea every time you drank your only liquid source,
Speaker 3: you would be super dehydrated. Not good, not good, And
Speaker 3: we do see that in pastoralist groups in the hot
Speaker 3: arid parts of the world. Lactase persistence is pretty high,
Speaker 3: but it doesn't seem to be as cut and dry
Speaker 3: as lactase persistence evolving alongside the cultural tradition of drinking milk,
Speaker 3: because as we've talked about, milk or dairy products are
Speaker 3: regularly consumed in groups that have low lactase persistence. But
Speaker 3: as we said, lactase non persistence and lactose intolerance are
Speaker 3: different things. So you can kind of up your tolerance,
Speaker 3: but you'll never be able to digest lactose, right, Okay,
Speaker 3: So anyway, one paper I looked at tested these different
Speaker 3: hypotheses to see whether any of them are supported by
Speaker 3: patterns of where lactase persistence is high or low. And
Speaker 3: what they found was that the vitamin D hypothesis and
Speaker 3: the dehydration hypothesis weren't supported.
Speaker 1: Really, I'll also say that milk is actually a cruddy
Speaker 1: source of vitamin D. We add vitamin D to milk.
Speaker 3: Does that have anything to do with pasteurization or like
Speaker 3: the age of milk?
Speaker 1: I don't believe. So okay, yeah, I mean even like
Speaker 1: human breast, milk is a crappy source of vitamin D
Speaker 1: because we make it ourselves. If you're in the sun well,
Speaker 1: but I.
Speaker 3: Think their point was that if you're in northern Europe,
Speaker 3: there literally is no sun right in, so maybe any
Speaker 3: vitamin D would be better than none.
Speaker 1: Yeah, yeah, I mean it's not a very good source
Speaker 1: of vitamin D.
Speaker 3: Well, regardless, it's not. It doesn't seem to be supported.
Speaker 1: That makes sense.
Speaker 3: But they did find that the lactose persistence evolved in
Speaker 3: people who kept livestock, so that seemed to be the
Speaker 3: best supported hypothesis. So basically pastoralism led to the spread
Speaker 3: of the mutation that allowed for lactose digestion into adulthood.
Speaker 3: Makes sense, and we probably see different rates of lactase
Speaker 3: persistence geographically because selective pressures for lactase persistence may have
Speaker 3: been different in different regions, which makes sense. So if
Speaker 3: you didn't rely heavily on milk, for instance, then that
Speaker 3: selection pressure wouldn't be there, and the pressures probably weren't
Speaker 3: constantly applied, so like lactase persistence may have only been
Speaker 3: selected for during extreme circumstances, like during a famine. But regardless,
Speaker 3: it does seem that being able to digest dairy products
Speaker 3: into adulthood was beneficial, and a couple of papers I
Speaker 3: read argued that lactase persistence and the reliance on a
Speaker 3: dairy economy led to the widespread expansion of a group
Speaker 3: called the Proto Indo Europeans. I haven't heard of that.
Speaker 3: Why this is an important group Linguistically apparently so I learned.
Speaker 3: I hope I don't really butcher this whole explanation. But
Speaker 3: the Proto Indo Europeans were a group of people whose
Speaker 3: existence is mostly inferred from linguists rather than from like
Speaker 3: physical evidence. And they exist around the Late Neolithic, so
Speaker 3: like five or six thousand years ago, and were among
Speaker 3: the first to domesticate the horse, and so from somewhere
Speaker 3: probably in Eastern Europe, they spread across Europe, Western Asia,
Speaker 3: and the Indian subcontinent. And wherever they spread, their culture
Speaker 3: did as well. Dairy farming grew, particularly the in places
Speaker 3: where it was favored, such as Northern Europe, and their
Speaker 3: language spread also. The language that they spoke would eventually
Speaker 3: give rise to hundreds of languages, among them the most
Speaker 3: commonly spoken on Earth Spanish, English, Hindustani, Portuguese, German, Russian, French, Persian, Bengali.
Speaker 3: The list goes on and on and on. So it's
Speaker 3: estimated that about half, So like forty six percent of
Speaker 3: the world's population speaks a language that has its roots
Speaker 3: in the Proto Indo European language. And so that's how
Speaker 3: milk drinking shaped language across the world. There's your connections
Speaker 3: moment for the day. So, even though lactose intolerance had
Speaker 3: been written about or known about for millennia, lactose the
Speaker 3: sugar was only discovered in the seventeenth century, and lactose
Speaker 3: intolerance only got a formal definition in the twentieth century,
Speaker 3: so not that long ago. Actually. I think one of
Speaker 3: the interesting things that this has revealed is a pretty
Speaker 3: good amount of bias in medical advice. So milk was
Speaker 3: often recommended to prevent or treat certain conditions like peptic ulcers,
Speaker 3: or to increase calcium or prevent osteoporosis or vitamin D
Speaker 3: or whatever else the case may be. But if you
Speaker 3: can't digest lactose, milk consumption is only going to make
Speaker 3: things a whole lot worse. But the assumption was that
Speaker 3: lactose digestion was the normal state, and so it wasn't
Speaker 3: only until recently that we have sort of learned a
Speaker 3: bit more about maybe drinking milk isn't good for you
Speaker 3: if you can't digest it. But despite this, milk consumption
Speaker 3: continues at high rates in some places and even seems
Speaker 3: to be increasing in popularity where lactase persistence is low,
Speaker 3: such as China. Like, China is drinking a lot more milk,
Speaker 3: the US is drinking a lot less. Yeah, So, Aarin,
Speaker 3: why don't you tell me what the lowdown is on
Speaker 3: milk today? Are there treatments besides like lactate?
Speaker 1: Let's talk about it, Aarin. We'll take a quick break first. Great,
Speaker 1: so let's reiterate to make it as clear as possible
Speaker 1: that globally, lactase non persistence is the norm and probably
Speaker 1: around seventy percent of the global population does not have
Speaker 1: the lactase enzyme that stays on in adulthood. Okay, yeah, cool, Okay,
Speaker 1: But like you said, this ranges a lot across the globe,
Speaker 1: and there's a really great map. I think there's probably
Speaker 1: a whole bunch of them that we can post. But
Speaker 1: what's really interesting is so I was looking into how
Speaker 1: what milk production and consumption is like across the globe,
Speaker 1: and by far the highest consumer country of milk is India. Okay,
Speaker 1: like by a long shot, greater than the whole EU
Speaker 1: and the US by like twofold. And when I was
Speaker 1: looking at these maps, I was like, India has lactase
Speaker 1: malabsorption sixty one percent non persistence overall, and I was like,
Speaker 1: this doesn't make any sense. But then you mentioned that
Speaker 1: between the northern and southern India it's very different. So
Speaker 1: that's super interesting. So I wonder if they broke the
Speaker 1: map of milk consumption down if it would correlate with that,
Speaker 1: and I bet that it probably would.
Speaker 3: Yeah, that's really interesting though.
Speaker 1: It is. Yeah, but besides India, the EU, the US overall,
Speaker 1: actually milk consumption, like you mentioned, is going up worldwide,
Speaker 1: So milk consumption is on the rise and milk production
Speaker 1: is on the rise globally.
Speaker 3: And this is like a per capita yes, oh.
Speaker 1: Yeah, yeah. Some of the most recent data that I
Speaker 1: could find, I have to say, was from Statista. Is
Speaker 1: that a good website, I don't know. I couldn't get there,
Speaker 1: like where they got their data from without signing up
Speaker 1: for an account, and I didn't want to do that.
Speaker 1: So the other source of this info is kind of old,
Speaker 1: but it's from the FAO so at least that's a
Speaker 1: legit source of info, but it's like ten years old,
Speaker 1: so I don't know why they haven't updated their data
Speaker 1: in ten years. But anyways, anyways, in any case, people
Speaker 1: drink a lot of milk around the globe. So because
Speaker 1: we know that the normal state is lactase non persistence,
Speaker 1: there's a lot of interest in trying to treat or
Speaker 1: manage the symptoms of lactose malabsorption, right, And I do
Speaker 1: think that one of the most interesting pieces that I
Speaker 1: found was a number of meta analyzes that show that
Speaker 1: in general, even people who are self identified as lactose
Speaker 1: intolerant so they know that drinking milk gives them symptoms,
Speaker 1: can actually handle up to about twelve grams of lactose
Speaker 1: in a single sitting before they become symptomatic. Okay, so
Speaker 1: that's actually like a whole glass of milk, And it's
Speaker 1: kind of a ton of cheese, because a lot of cheeses,
Speaker 1: especially aged cheeses like cheddar, have like about zero point
Speaker 1: five grams of lactose per ounce, where if milk has
Speaker 1: like nine to fourteen grams of lactose per cup of milk,
Speaker 1: So per serving.
Speaker 3: And lactose intolerance or lactase non persistence is very different
Speaker 3: than allergy.
Speaker 1: So when people have allergies to milk, it's generally to
Speaker 1: the protein casin that's found in milk when they have
Speaker 1: a cow's milk allergy, and yes, that is very different.
Speaker 3: Okay.
Speaker 1: The other thing though, and this is probably why products
Speaker 1: that are lactose free have become more and more popular,
Speaker 1: even in places where lactase persistence is really common, is
Speaker 1: because the symptoms of lactose intolerance overlap with symptoms like IBS,
Speaker 1: and it can actually be really difficult to tell what
Speaker 1: is it that's causing your symptoms. Is it really the
Speaker 1: milk or is it something different?
Speaker 3: Gotcha? Yeah?
Speaker 1: And so yeah, so there've been a big rise in products,
Speaker 1: like in products that are lactose free, so whether it's
Speaker 1: cow's milk or goat's milk that have been treated with
Speaker 1: certain enzymes, the lactase enzyme, whether it's from bacteria or yeast,
Speaker 1: that actually break down that lactose into monosachrides, so that
Speaker 1: even if you are lactase non persistent, you can drink
Speaker 1: that milk. You can also take it in a pill form,
Speaker 1: like we said already, and there has been some research
Speaker 1: on probiotics and things like that. We're just not from
Speaker 1: my understanding at least what I've seen, we don't really
Speaker 1: have a good another good answer. But the other thing
Speaker 1: that's because really really popular is just non dairy milks, right, Yeah,
Speaker 1: So there's a lot in the the United States medical
Speaker 1: literature of like, ooh, we have to make sure that
Speaker 1: we drink milk because it's such an important part of
Speaker 1: our diet, like handwringing at the idea of someone cutting
Speaker 1: dairy out of their diet, right, And I think that
Speaker 1: that's very interesting because you know, the vast majority of
Speaker 1: the world can't digest dairy, and they do just fine
Speaker 1: in the American diet. Cow's milk is our number one
Speaker 1: source of calcium. So if you're not drinking milk or
Speaker 1: eating cheese or getting your calcium from dairy, then yeah,
Speaker 1: you do need to make sure that you get your
Speaker 1: calcium from somewhere else, But that can be from a
Speaker 1: lot of other things that are calcium fortified or just
Speaker 1: from a calcium supplement. Yeah, but that is the main
Speaker 1: nutrient that is found in milk that we don't see
Speaker 1: in a lot of other foods. So most other foods
Speaker 1: that we eat have a much lower amount of calcium.
Speaker 1: Vitamin D is actually something that we add to milk
Speaker 1: because calcium and vitamin D work together in your body
Speaker 1: for bone health, so it makes sense, you know. And
Speaker 1: because a lot of us live at northern latitudes and
Speaker 1: now we wear clothes and cover our bodies, so we're
Speaker 1: not making as much vitamin D because normally you make
Speaker 1: it from sun exposure, but we don't expose ourselves to
Speaker 1: the sun because skin cancer.
Speaker 3: Question answer, So, historically, if people were not getting calcium
Speaker 3: from milk, which probably not many people were, what was happening?
Speaker 3: I mean, do we see a lot of the problems
Speaker 3: that we associate with a lack of calcium in like
Speaker 3: skeletal remains of people historically.
Speaker 1: So if you eat a lot of seafood or legumes
Speaker 1: or leafy green these are other things that are also
Speaker 1: have good amounts of calcium. So probably in the past
Speaker 1: people just ate more things like that. So then calcium
Speaker 1: or then dairy wasn't their only source of calcium, gotcha, Yeah,
Speaker 1: because dairy is one of the main sources of calcium
Speaker 1: in the US and in some other countries. It's thought
Speaker 1: that not getting enough dairy could lead to calcium deficiency,
Speaker 1: which is a risk for osteoporosis. But there have been
Speaker 1: some studies that have found that in places where people
Speaker 1: don't consume dairy, in places where lactase non persistence is
Speaker 1: more common, osteoporosis is not any more common. So they're
Speaker 1: getting their calcium somehow.
Speaker 3: Interesting. Yeah, very interesting.
Speaker 1: Yeah, But then there is also things like cheese that
Speaker 1: have low levels of lactose because just of the way
Speaker 1: that cheese is prepared. A lot of yogurts have very
Speaker 1: low level of lactose because the bacteria that are found
Speaker 1: in like live culture yogurt actually convert lactose to lactic acid.
Speaker 1: So there's low levels of lactose. And then you know,
Speaker 1: there's lactose free milk. There's soy milks and things that
Speaker 1: are fortified with almost all the same nutrients that you
Speaker 1: would find in cow's milk. There's a lot of options.
Speaker 3: Speaking of options, we should mention that our quarantini could
Speaker 3: be could be the milk in our quarantini could be
Speaker 3: swapped out for any non dairy alternative. I love oat milk.
Speaker 1: You can use any milk you like. Yeah, you know,
Speaker 1: isn't there like they're trying to have it not be
Speaker 1: called milk if it's from like a nut or an oat,
Speaker 1: because yeah, not milk.
Speaker 3: I saw something like that. It's just like this late
Speaker 3: in the game. That's never going to catch on, right,
Speaker 3: It's like what.
Speaker 1: I'm not going to drink soy juice. That sounds way worse.
Speaker 1: Oh well, this was a fun episode.
Speaker 3: This was a fun episode. This was a short episode.
Speaker 1: What's time for one? We've had a lot of long
Speaker 1: ones lately.
Speaker 3: Yeah, all right, should we do sources?
Speaker 1: Yeah, we definitely should.
Speaker 3: Okay. So I read a couple of books. One was
Speaker 3: called the ten thousand Year Explosion, How Civilization Accelerated Human
Speaker 3: Evolution by Gregory Cochrane and Henry Harpending, And also a
Speaker 3: book called Milk by Mark Kolanski. And then a few articles.
Speaker 3: I just want to shout out a couple of them,
Speaker 3: The Origins of lactase persistence in Europe by itin at
Speaker 3: All two thousand and nine. And evolution of lactase persistence
Speaker 3: an example of human niche construction by gerbalt at All
Speaker 3: twenty eleven.
Speaker 1: I read a number of articles. There's a good one
Speaker 1: from American Family, The American Academy of Family Physicians that's
Speaker 1: just called lactose intolerance. Just for some basic background on
Speaker 1: what the clinical syndrome that we call lactose tolerances, and
Speaker 1: we will post all of our references on our website
Speaker 1: This podcast will kill you dot com for this episode
Speaker 1: and all of our episodes.
Speaker 3: Thank you so much to Katie for coming on and
Speaker 3: sharing her amazing poop story.
Speaker 1: We love to hear from you, seriously, thank you so much.
Speaker 3: Yes, and thank you to Bloodmobile for providing the music
Speaker 3: for this episode and all of our episodes.
Speaker 1: And as always, thank you to you listeners for sticking
Speaker 1: with us through all the You know, we didn't even
Speaker 1: talk about poop that much besides Katie's bit. I know,
Speaker 1: it's kind of surprising.
Speaker 5: Yeah, well okay, well with that, wash your hands, you
Speaker 5: filthy animals.
Speaker 1: M hm
Speaker 2: Oh god, I trusted that far, way too to, way
Speaker 2: too much