Speaker 1: Hi there, Virgie. Here today, we've got something a little
Speaker 1: different for you. It's an episode of a new show
Speaker 1: from the Ted Audio collective called Body Stuff with Doctor
Speaker 1: Jen Gunter. In every episode, the podcast bust the lies
Speaker 1: you're told about your personal health. I'm a huge fan
Speaker 1: of doctor Jen's work, and I have a feeling you
Speaker 1: will be too. If you like what you hear. You
Speaker 1: can find and follow Body Stuff with Doctor Jen Gunter
Speaker 1: wherever you're listening to this. Okay, here's the first episode.
Speaker 1: I'm doctor Jen Gunter. I love science and I hate
Speaker 1: when people twist it. Your immune system needs a big
Speaker 1: scorbal supplement's milk a week, and there's a lot of
Speaker 1: twisted medical misinformation out there. Are toxins literally purify you. Yeah,
Speaker 1: that's ridiculous. Chugging a gallon of water means you'll eat
Speaker 1: fewer calories. Oh, it's so painful. We're exposed to medical myths,
Speaker 1: whether we're looking for them or not. There are news
Speaker 1: stories Instagram and Facebook, post Flying Past twenty four seven,
Speaker 1: TikTok Twitter. Who has balid information and who's just trying
Speaker 1: to sell you something? How do you sort the medicine
Speaker 1: from the mayhem I'm doctor Jen Gunter, and I'm here
Speaker 1: to help. From the Ted Audio Collective, this is body stuff.
Speaker 1: I'm a doctor, a practicing gynecologist, and I've made up
Speaker 1: my mission to give women the facts that they need
Speaker 1: to understand their bodies. In my twenty five years of
Speaker 1: talking with pay, I've learned that medical misinformation is a
Speaker 1: problem for everyone, and every single one of us is susceptible.
Speaker 1: So this show is about debunking some of the stickiest
Speaker 1: myths out there while helping you understand how your body
Speaker 1: really works today. Why you don't need eight glasses of
Speaker 1: water every day, you need a water day. We're going
Speaker 1: back in time to find the origins of that myth,
Speaker 1: and then we're going to meet a kidney expert who's
Speaker 1: going to illuminate just how hard our bodies work for
Speaker 1: us to maintain our hydration. It works like an exquisitely
Speaker 1: designed atomic balance machine, right, you need to keep everything
Speaker 1: in balance. But first I want to tell you about
Speaker 1: something that happened to me when I was ten years old.
Speaker 1: It was a time in my life when I got
Speaker 1: asked a lot about my urine and it ended up
Speaker 1: setting me on a path to become a doctor. It
Speaker 1: was the first good weekend of spring nineteen seventy seven
Speaker 1: in Winnipeg, Manitoba, the kind where the sun feels hot
Speaker 1: and you're just raring to get outside. I was messing
Speaker 1: around with my brother's skateboard, going down the street, and
Speaker 1: then all of a sudden, I was flat on my
Speaker 1: back on the concrete and I was in a terrible
Speaker 1: amount of pain. It felt like my insides were on fire.
Speaker 1: The next day, I'm sure I didn't look well, so
Speaker 1: we went to the pediatrician, who took one look at
Speaker 1: me and called a general surgeon, who took one look
Speaker 1: at me and sent us to the emergency department. They
Speaker 1: gave me something called an angiogram, and I remember the
Speaker 1: doctor pointing to the X ray screen explaining what he
Speaker 1: was seeing, and of course it just looked like a
Speaker 1: snowstorm to me. But that's when I learned that when
Speaker 1: I fell off my skateboard, i'd ruptured my spleen. The
Speaker 1: good news was I wasn't going to need surgery, but
Speaker 1: there was something else. It looked like I had hydro nephrosis,
Speaker 1: meaning my kidney was full of fluid, and I needed
Speaker 1: to see a pediatric urologist. He sat us down in
Speaker 1: his consultation room and started to explain to my mom
Speaker 1: what needed to happen. And I could tell she was
Speaker 1: very confused. I think the doctor could tell as well,
Speaker 1: and so he gestured to me and said, hey, you
Speaker 1: come over here. This is your body. You should know
Speaker 1: how it works. So I came over and I sat down.
Speaker 1: I traded places with my mom, and he drew a
Speaker 1: little diagram and he explained how the kidney worked and
Speaker 1: what he thought was wrong, and the test that I
Speaker 1: was going to have to have, and the surgery that
Speaker 1: I was probably going to have to have as well.
Speaker 1: And that doctor took the time to explain my body
Speaker 1: to me. It really helped me not feel scared or overwhelmed.
Speaker 1: And that experience made me decide I wanted to be
Speaker 1: a doctor. I loved the science and I wanted to
Speaker 1: be able to give to my patients what that doctor
Speaker 1: gave me that day, that empowerment of knowing how your
Speaker 1: body works and how to use that knowledge to help
Speaker 1: improve your health. Eventually, I did have surgery to remove
Speaker 1: my left kidney. I've lived most of my life with
Speaker 1: just one kidney, the organ that's largely responsible for regulating
Speaker 1: our body's hydration. But you want to know something, None
Speaker 1: of my doctors ever told me to worry about how
Speaker 1: much water I was drinking. I graduated from medical school
Speaker 1: when I was twenty three, so I've been a doctor
Speaker 1: more than half my life, and I've seen firsthand the
Speaker 1: problems that happen when people get misconceptions about their health.
Speaker 1: And a lot of these misconceptions they start with the Internet.
Speaker 1: I'm not one of those doctors who rolls her eyes
Speaker 1: when her patient comes in with reams of advice from
Speaker 1: doctor Google. That tells me that my patient is engaged,
Speaker 1: she wants to learn. But there are a lot of
Speaker 1: bogus recommendations out there, and often they're being pushed by
Speaker 1: brands and influencers. A lot of them sound like they're
Speaker 1: making sense in a sort of science ish way, like
Speaker 1: the eight glasses of water a day thing. Hey, we're
Speaker 1: made of water, so why wouldn't we need lots of water?
Speaker 1: But that's not science. So what's behind this myth? How
Speaker 1: did we get to eight glasses of water a day? Anyway?
Speaker 1: There are a couple of potential origin stories. One is
Speaker 1: a paper from nineteen forty five that suggests the body
Speaker 1: uses about eighty four ounces of water a day. And
Speaker 1: there's another paper from nineteen seventy four from a pair
Speaker 1: of nutritionists who recommended an equivalent of six to eight
Speaker 1: glasses of water a day for the body to function appropriately.
Speaker 1: But these papers became distorted over time like a bad
Speaker 1: game of telephone. These experts were recommending that we drink
Speaker 1: six to eight glasses of water a day on top
Speaker 1: of everything else. They were saying, this is the amount
Speaker 1: of water the body needs to function, But that water
Speaker 1: doesn't have to be water you drink from a glass
Speaker 1: out of your tap. Water is in everything. Think about
Speaker 1: a breastfed baby. All they're drinking is milk. The body
Speaker 1: is able to remove the water from the milk, so
Speaker 1: the baby never gets dehydrated. In the same way, once
Speaker 1: we start eating slid food, our bodies continue to extract
Speaker 1: water from everything we consume. Everything we eat or drink counts,
Speaker 1: So the water in your apple counts, the water that's
Speaker 1: in the bread that you eat counts, even coffee counts.
Speaker 1: Any fluid counts. Look, I get this as a real
Speaker 1: record scratch freeze frame moment for a lot of people.
Speaker 1: But we don't just get the water we need from
Speaker 1: plain water. And if you have one of those days
Speaker 1: where you just drink coffee all morning and you don't
Speaker 1: feel great, maybe you're a little headachy or a little jittery,
Speaker 1: it's not because you're dehydrated. Maybe you had a little
Speaker 1: too much coffee or you had it on an empty stomach.
Speaker 1: If you like drinking six glasses eight glasses of water
Speaker 1: day and your doctor hasn't advised against it, that's probably fine.
Speaker 1: What I'm saying is that there's nothing medical about this number.
Speaker 1: We get to make choice races about what we put
Speaker 1: into our body, and this is one of those choices.
Speaker 1: If you think about it, just using common sense and
Speaker 1: putting the medicine aside, does it seem realistic that we
Speaker 1: evolve needing to consume that much clean water every day
Speaker 1: In the span of human history, access to clean, plentiful
Speaker 1: drinking water is a relatively recent phenomenon, and even today,
Speaker 1: in many parts of the world, accessing clean drinking water
Speaker 1: sadly isn't as easy as walking into your kitchen and
Speaker 1: filling up a glass. It seems unlikely that our ancestors
Speaker 1: carry giant water bottles around with them at all times.
Speaker 1: And yet the mythspread and spread and spread. But why
Speaker 1: is this myth so sticky? It turns out there's a
Speaker 1: mix of factors, including a little bit of intrigue and
Speaker 1: one particular culprit that deserves a lot of the blame,
Speaker 1: the beverage industry. Sometimes water just isn't time unquenched. Thirst
Speaker 1: has become a chronic problem America. If you are going
Speaker 1: to sell something, you've got to have a reason to
Speaker 1: sell it. You've got to create a market for it.
Speaker 1: Things like pre hydrate. I mean, what's that mean? Drink
Speaker 1: ahead of your first train. You've got to tolerate more fluid.
Speaker 1: Your brain doesn't know when you are thirsty. Doctor deb
Speaker 1: Cohen went to medical school in the UK, but instead
Speaker 1: of becoming a clinician a doctor who sees patients, she
Speaker 1: became a journalist. Back in twenty twelve, during the lead
Speaker 1: up to the London Olympics, she was the investigative editor
Speaker 1: at the British Medical Journal. She wrote a report called
Speaker 1: The Truth about Sports Strengths and It's set off a
Speaker 1: bar arm in the beverage industry. The report looked at
Speaker 1: the history of sports drinks like Gatorade and how they're advertising.
Speaker 1: Basically invented the modern fear of dehydration. It was really
Speaker 1: in the kind of the boom of the marathon era
Speaker 1: in the nineteen seventies that sports drinks really took off.
Speaker 1: It started life in Florida at the University of Florida
Speaker 1: and Robert Cade was the renal physician and he developed
Speaker 1: this drink for the Gators football team. It was effectively water, sugar,
Speaker 1: dasher sodium, and a bit of lemon juice, so quite simple,
Speaker 1: and it was supposed to help alleviate cramps. And then
Speaker 1: it was brought up by Quaker Oats and they spotted
Speaker 1: a big market, and that's really where the science of
Speaker 1: dehydration started. Okay, so we're not talking about clinical dehydration,
Speaker 1: which is a real condition. For example, the time I
Speaker 1: had food poisoning and I was up all night vomiting,
Speaker 1: so I had to go to the emergency department and
Speaker 1: get an intravenous But this is healthy people, So this
Speaker 1: is a whole different phenomenon. And so what they turned
Speaker 1: into an illness was exercise induced dehydration. Exercise induced dehydration,
Speaker 1: now that sounds a lot more important than you're a
Speaker 1: bit First, you if you've been running and sweating. If
Speaker 1: you tell people that it's all about the science, then
Speaker 1: people are more likely to believe it. Beverage companies, especially Gatorade,
Speaker 1: commissioned studies looking for results that would bolster their sales pitches.
Speaker 1: By the time doctor Cohens started looking into these studies,
Speaker 1: there were a lot of them. Glaxo smith Kline at
Speaker 1: the time, the company behind a popular British sports drink
Speaker 1: called lucas Aid, claimed they had more than a hundred
Speaker 1: clinical trials. That's a lot of studies, and the studies
Speaker 1: were a little bit off. Some of the studies we're
Speaker 1: actually having a bit of a laugh about. So what
Speaker 1: you would do is you would starve people overnight, you'd
Speaker 1: fast them overnight, and then you'd ask them to cycle
Speaker 1: to exhaustion. One group you would give a sports drink
Speaker 1: containing sugar, and the other group you would give water. Well,
Speaker 1: guess what, the people have had a bit of sugar
Speaker 1: are going to well perform the people that have been
Speaker 1: starved and had water. It's not rocket science. And so
Speaker 1: they are all sorts of these all sorts of these
Speaker 1: kinds of studies that they do, and you look at
Speaker 1: it and go that just does not happen, and it
Speaker 1: doesn't matter that it's not clinically relevant. Now you've got
Speaker 1: something that looks statistically different, and you can peg a
Speaker 1: marketing campaign around that exactly. And if you throw enough
Speaker 1: darts at a dark boat, if you've got your eyes blindfolded,
Speaker 1: then one of them is going to hit the dark boat.
Speaker 1: At some point. The studies were junk, but the science
Speaker 1: fish conclusions they made began to spread, especially the idea
Speaker 1: that we couldn't rely on our own bodies to tell
Speaker 1: us while we were thirsty. One of Gatorade scientists even
Speaker 1: said in two thousand and eight, and I quote, the
Speaker 1: human thirst mechanism is an inaccurate short term indicator of
Speaker 1: fluid needs. Unfortunately, there is no clear physiological signal that
Speaker 1: dehydration is occurring. I think even the Mayo Clinic had
Speaker 1: information that was based on science that have been ultimately
Speaker 1: derived from the sports strengths industry about when you should
Speaker 1: hydrate and how you should hydrate, and it filtered down
Speaker 1: to influence school guidance in the UK where kids playing
Speaker 1: soccer would have to go and stop every fifteen minutes
Speaker 1: twenty minutes to rehydrates. And you speak to the teachers
Speaker 1: and be like, yeah, it's just kids like running around.
Speaker 1: They just need to peel all the time, So kids
Speaker 1: running off constantly. Even the US military was in on
Speaker 1: the quasi science. In the early eighties, the Pentagon was
Speaker 1: citing Gatorade Sports Science Institute studies claiming their drinking sports
Speaker 1: drinks could prevent heat stroke, a huge concern for soldiers
Speaker 1: fighting desert wars. But those studies were bunk. There was
Speaker 1: no evidence that drinking fluids reduced the risk of heat stroke.
Speaker 1: Even today, the US military remains Gatorade's the biggest customer,
Speaker 1: your taxpayer dollars at work. I was warned off several
Speaker 1: times as well from doing the story. Are you sure
Speaker 1: you know what you're doing? And a spot some people
Speaker 1: in the US quite a bit of sources, and they
Speaker 1: tried to have studies published that were negative and they
Speaker 1: just could not get them published. And they'd been warned
Speaker 1: off doing their research as well, and they were saying
Speaker 1: to me, do you realize how what you're doing here?
Speaker 1: And I literally probably naively just thought, well, sugary water, guys,
Speaker 1: I mean, how big a deal is this? But as
Speaker 1: doctor Cohen started her investigation, she began to see. There
Speaker 1: was a lot of money intertwined with the junk science.
Speaker 1: Sports drink companies spent huge sums sponsoring youth sports, funding
Speaker 1: sports medicine doctors, and putting their logos on the world's
Speaker 1: most beloved teams, and it was like a holy grail.
Speaker 1: You go to sports conferences, to sports medicinal sports science conferences.
Speaker 1: It's displayed everywhere you know sponsored and you don't criticize
Speaker 1: the sports drink. So sports strinths have somewhat fallen out
Speaker 1: of favor since their heyday in the nineteen eighties and nineties.
Speaker 1: But another product has taken its place, and now it's
Speaker 1: the number one selling beverage in the world, bottled water,
Speaker 1: and big Bottled Water is very happy to have you
Speaker 1: believe that you can't trust your thirst and that you
Speaker 1: need a minimum of eight glasses of water a day.
Speaker 1: After the break, we're going to talk about why this
Speaker 1: myth just won't die. We're back before the break. We
Speaker 1: learned the origin of the eight glasses of water a
Speaker 1: day myth. We believe myths like this for a lot
Speaker 1: of reasons, but a big one is something psychologists call
Speaker 1: the illusory truth effect. When a piece of information is widespread,
Speaker 1: and you hear it over and over again, you're more
Speaker 1: likely to believe that it's true. There are a lot
Speaker 1: of examples, statements like we only use ten percent of
Speaker 1: our brains, or eating carrots will help you see in
Speaker 1: the dark. None of these things are true, but I
Speaker 1: bet you've heard them repeated over and over again. Politicians
Speaker 1: and marketers take advantage of this all the time, and
Speaker 1: it works because when you're assessing whether something you've heard
Speaker 1: is true, you typically rely on two things. Whether the
Speaker 1: information makes common sense and whether it feels familiar. The
Speaker 1: research has shown that familiarity can even be more convincing
Speaker 1: than rationality. Rationality is hard, but remembering if you've heard
Speaker 1: something before, that's easy. And here's the thing about the
Speaker 1: illusory truth effect. No one is immune, not even doctors.
Speaker 1: There's a one day a year in March we call
Speaker 1: World Kidney Day, dedicated to improving awareness of kidney disease,
Speaker 1: and a few years ago the theme of World Kidney
Speaker 1: Today was drink a glass of water to help your kidneys,
Speaker 1: which is just crazy, right, It doesn't make any sense.
Speaker 1: It's not grounded in science, but you know it is
Speaker 1: grounded in funding for World kidney day, which I believe
Speaker 1: comes from dan in a manufacture of bottled water. It's
Speaker 1: like the deep state of hydration. That's doctor Joel Toff.
Speaker 1: He's a kidney doctor, otherwise known as an nephrologist. I
Speaker 1: called up doctor Toff because what do we do in
Speaker 1: medicine When we don't know the answer, We look for
Speaker 1: an expert, we call a consult and doctor Toff is
Speaker 1: just the chemistry wizard for the job. I'm a lifelong
Speaker 1: nerd who has been fascinated by the chemistry of body
Speaker 1: fluids going on three decades. I love nerds. There are
Speaker 1: an infinite number of fascinating aspects of body physiology or
Speaker 1: disease states. And one of the truths about medicine is
Speaker 1: that once you start learning about any one of these conditions,
Speaker 1: they become more interesting. And back in nineteen ninety five,
Speaker 1: when I was a senior in medical school, I became
Speaker 1: real interested in fluids and electrolytes. So the precious bodily fluids,
Speaker 1: the precious bodily fluids. That's right, that's my favorite movie.
Speaker 1: That's a doctor Strange love. Doctor Toff knows that the
Speaker 1: most important thing about precious bodily fluids is that they
Speaker 1: stay in balance, which brings us to the tragic case
Speaker 1: of Jennifer Strange. So I want you to kind of
Speaker 1: rewind back to two thousand and seven, and the hottest
Speaker 1: thing in two thousand and seven was the Nintendo Wii,
Speaker 1: and this radio station got their hands on one and
Speaker 1: they were running a radio contest. The contest was don't
Speaker 1: we for a Wei? The radio station invited eighteen contestants
Speaker 1: down to their studio to see who could drink the
Speaker 1: most water without having to pee, and there was one
Speaker 1: person who entered. Her name was Jennifer Strange, twenty eight
Speaker 1: year old mother of three, and she ended up drinking
Speaker 1: two gallons of water in an hour. That's a lot
Speaker 1: of water, so much water that a nurse actually called
Speaker 1: into the station to warn them this was dangerous. You
Speaker 1: can overload your system with too much water. It can
Speaker 1: be really unsafe. As Jennifer left the radio station and
Speaker 1: she was already complaining of a headache, and what she
Speaker 1: actually had was a condition called cerebral edema, which happens
Speaker 1: when you wash your body out from all the critical salts,
Speaker 1: and when you do this, water will shift from your
Speaker 1: bloodstream into your brain. Cause increased swelling of your brain
Speaker 1: that cause headaches, nausea, seizures, coma, and death. And she
Speaker 1: ended up dying on her own bathroom floor. A couple
Speaker 1: of hours later, Jennifer died from a condition called hyponatremia,
Speaker 1: meaning a dangerously low level of sodium in her blood.
Speaker 1: She threw off her body's delicate balance, something we've evolved
Speaker 1: to rely on. It's called homeostasis. The body maintains a
Speaker 1: stable internal environment to provide optimal health for the cells
Speaker 1: of the body. Right, you can imagine for these cells
Speaker 1: to grow and to be healthy, they need regulated amounts
Speaker 1: of sodium, potass seem even things like body temperature needs
Speaker 1: to be regulated. All these things need to be in
Speaker 1: an optimal range for growth and health, and that process
Speaker 1: of maintaining everything in that type band is called homeostasis.
Speaker 1: We've evolved to maintain homeostasis through finely tuned mechanisms. The
Speaker 1: sense when things are awry, when we've gone a little
Speaker 1: bit too far in one direction or a little bit
Speaker 1: too far in the other, and makes adjustments to return
Speaker 1: us to our state of balance. Think about the mechanisms
Speaker 1: that maintain us in homeostasis, like autopilots. I think that's perfect, right,
Speaker 1: So you can think about body temperature is a classic one, right.
Speaker 1: So if we get too hot, we start to sweat,
Speaker 1: water evaporates from our skin that lowers our body temperature
Speaker 1: back down. We get too cold, we shiver and all
Speaker 1: that generates heat and brings us back to a normal
Speaker 1: body temperature. So we have processes that control us from
Speaker 1: getting too hot and from getting us too cold. Body
Speaker 1: temperature is just one example of the autopilots that are
Speaker 1: body has to maintain homeostasis, and our kidneys well, they're
Speaker 1: the quarterback of homeostasis. They help to maintain the balance
Speaker 1: of almost every electrolyte in our body. They help with
Speaker 1: blood pressure, they're crucial for maintaining pH and they maintain
Speaker 1: our level of hydration. One of these autopilots is called osmolality,
Speaker 1: and osmolality is just a measure of the total amount
Speaker 1: of compounds in solution. And so an analogous is just
Speaker 1: how salty the soup is. As the osmolality goes up,
Speaker 1: soup gets more salty. As the osmolality goes down, soup
Speaker 1: gets more dilute. In this case, the soup is our
Speaker 1: blood to be a little bit more precise. The fluid
Speaker 1: part of our blood our plasma, and the kidney regulates
Speaker 1: our osmolality so it stays in a healthy range. Jennifer's
Speaker 1: Strange died because she drank so much water that she
Speaker 1: pushed her osmolality far below the healthy range, and her
Speaker 1: kidneys just couldn't keep up. Today, hypenatremia is most often
Speaker 1: seen in athletes who are overhydrating while exercising. Doctors first
Speaker 1: started seeing it in ultra marathon runners and iron man
Speaker 1: triathletes in the nineteen eighties, a period of time that
Speaker 1: nicely coincides with the messaging coming out of the Gatorade
Speaker 1: Sports Science Institute. And it's not just extreme athletes. Doctors
Speaker 1: have seen hypenetremia in high school football players, students in
Speaker 1: yoga classes, and more. Thankfully, hypenetremia is relatively rare because
Speaker 1: of our body's amazing ability to defend homeostasis. I just
Speaker 1: want to run this morning, I went for three mile run,
Speaker 1: and I'm the thirsty and a bit hungary. So how's
Speaker 1: my one kidney because I only have one keeping me
Speaker 1: working right. So you came back from your run, and
Speaker 1: presumably during that run, you sweat, you lost a little
Speaker 1: bit of fluid that way, and that loss of fluid
Speaker 1: is going to make your body salt here, it's gonna
Speaker 1: make the soups alter. Your osmality goes up. This is
Speaker 1: you're pushing your body out of that homeostatic range and
Speaker 1: it needs to return that osmolality back down. And the
Speaker 1: way that it does that is two factors. One increased thirst.
Speaker 1: And so increased thirst is a sensation that your body
Speaker 1: gets that'll change your behavior. It'll make you go to
Speaker 1: the sink, pour yourself a glass of water and drink it.
Speaker 1: So in addition to thirst, your kidney is going to
Speaker 1: respond to that increase in osmolality. And the way that
Speaker 1: it does that is it's going to change the type
Speaker 1: of urine that you make. You're always making urine, you're
Speaker 1: always getting rid of You're constantly getting rid of waste products.
Speaker 1: But one of the variables is how much water is
Speaker 1: excreted along with those waste products. In other words, if
Speaker 1: you're drinking a lot of water, you're going to pay more,
Speaker 1: but that doesn't mean you're getting rid of more waste.
Speaker 1: You're getting rid of the same amount of waste. It's
Speaker 1: just diluted in more water. Yeah. My tagline on Twitter says,
Speaker 1: thinking the kidney's product is urine, it's like thinking a
Speaker 1: factories product is pollution. Urine is the byproduct. What the
Speaker 1: kidney produces is homeostasis. So how much water should we drink?
Speaker 1: We should drink enough water so that you're not thirsty.
Speaker 1: I tell my patients, you know, anytime that you're thirsty,
Speaker 1: go ahead and drink a glass of water, and maybe
Speaker 1: have one glass of water on top of that. It's
Speaker 1: not going to harm you. But I don't advise my
Speaker 1: patients to count their glasses of water unless unless they
Speaker 1: have kidney stones in their past, or if they have
Speaker 1: autosomal dominant polycistic kidney disease. If you have an intact
Speaker 1: thirst mechanism and you have access to water, are you
Speaker 1: going to get dehydrated? No, let's put it this way.
Speaker 1: People with increased sodium will drink from a toilet. The
Speaker 1: derived to drinking is so strong you will not get dehydrated.
Speaker 1: If there's a glass within a mile of you, you'll
Speaker 1: get that water. Then you'll be fine. See. Now you
Speaker 1: can be liberated from any anxieties you've ever had about
Speaker 1: whether you're drinking and off water. You're welcome. Then doctor
Speaker 1: Tooff told me something really cool about how our bodies
Speaker 1: know when we've dranken of water. Yeah. So there are
Speaker 1: what we call osmoreceptors. They're located in a center part
Speaker 1: of the brink called the hypothalamus, and they're going to
Speaker 1: constantly measure the osmolality of the body. And they're actually
Speaker 1: the butt is very sophisticated. It knows when you're drinking,
Speaker 1: and it'll start to suppress the hormone that drives thirst
Speaker 1: as soon as you start to drink, right. It doesn't
Speaker 1: even wait for that fluid to lower the osmolality in
Speaker 1: the body. It's absolutely aware of what happens when you drink,
Speaker 1: and it says, hey, we're gonna slow this cycle down.
Speaker 1: We know that you're already compensating for what we're seeing,
Speaker 1: so it'll suppress those hormones that are driving that thirst
Speaker 1: once you start to drink. Yeah, I thought that was fascinating.
Speaker 1: You know that it takes about ten minutes for the
Speaker 1: water that you drink, you know, to get into your bloodstream,
Speaker 1: and that your brain, you know, knows, you know, within
Speaker 1: a minute or so that you've consumed enough and it's
Speaker 1: already like making the calculations based on you know what
Speaker 1: it's sensing in your mouth and your esophagus. I mean,
Speaker 1: it's such a fascinating autopilot, right. It's just way more
Speaker 1: advanced than we had thought. The body is amazing, isn't it? Okay,
Speaker 1: I have a few more little things I want to
Speaker 1: clear up now that I have my own kidney consultant.
Speaker 1: So let's play a little game kidney fact or fiction.
Speaker 1: Staying hydrated makes your skin glue factor fiction fiction. No
Speaker 1: evidence that it improves the glow of skin. That said,
Speaker 1: if you really get dehydrated, skin's not going to be
Speaker 1: in good shape. Drinking eight glasses of water makes your
Speaker 1: brain work better? Yes, or now? So, there is some
Speaker 1: data that this was done in school children that increasing
Speaker 1: hydration right before some tests improved some aspects of cognition.
Speaker 1: There are two studies that I could find on this.
Speaker 1: Neither of them were very large, neither of them are
Speaker 1: very convincing. But I also didn't find the big test
Speaker 1: that said this is absolutely fiction. I would guess fiction,
Speaker 1: but I would leave a possibility that there's some truth
Speaker 1: to that. Caffeine is a diuretic factor fiction fiction This
Speaker 1: has been studied pretty rigorously. There is no evidence at
Speaker 1: all that caffeine dehydrates. You can include that cup of
Speaker 1: war when you count your cups of water if this
Speaker 1: is something that you'd like to do, and coffee is
Speaker 1: no different. So there you go. Friends, if you'd rather
Speaker 1: have a cup of coffee than a glass of water,
Speaker 1: you do you. Before I can let doctor Talf go,
Speaker 1: I had just one more question, so I got to ask,
Speaker 1: did you check the color of your urine? Oh? Absolutely,
Speaker 1: I'm like every other person. No, I'm always interested in it.
Speaker 1: I'm always interested in it because it gives me a
Speaker 1: you know, it's a window into what's happening in my kidney, right,
Speaker 1: and I'm naturally intrigued by that. But I don't think
Speaker 1: it changes my behavior. If I'm thirsty, I drink. You
Speaker 1: let your body run the outer pilot. Yeah, here's one
Speaker 1: of the big secrets of medicine. It's not as hard
Speaker 1: as you might think, and it certainly doesn't all belong
Speaker 1: in ivory town hours or dressed up in lab coats.
Speaker 1: I had an AHA moment when I was twenty or
Speaker 1: twenty one years old, sitting in medical school, and the
Speaker 1: professor started talking about hydronephrosis, the exact same diagnosis that
Speaker 1: I had when I was a kid, and he explained
Speaker 1: it using the same language as my pediatric urologist. I
Speaker 1: sat there thinking, Wow, that knowledge is held up. What
Speaker 1: I heard when I was ten is not any different
Speaker 1: than what I'm hearing now ten years later in medical school.
Speaker 1: My knowledge is held up over all this time, And
Speaker 1: how empowering was it for me to actually understand how
Speaker 1: my body worked when I was going through all those
Speaker 1: scary things. A lot of medicine is very complex, and
Speaker 1: if you're going to be a doctor, you need to
Speaker 1: know all the background and the nitty gritty details matter
Speaker 1: a lot. But if you're just worried about taking care
Speaker 1: of your own health or your families, there's a lot
Speaker 1: in your power to understand. One of my favorite things
Speaker 1: about being a doctor is when I explain something to
Speaker 1: a patient about how their body works and they have
Speaker 1: that moment of realization. All the puzzle pieces fall into
Speaker 1: place and they say, Wow, I didn't know how that worked,
Speaker 1: and now I do. I hope you'll stick around for
Speaker 1: the rest of the season of body stuff. We'll be
Speaker 1: breaking down how your body works while busting one medical
Speaker 1: myth at a time. Next week, we're diving right in
Speaker 1: with your digestive system. Why just poop smell bad? Because
Speaker 1: of it? Things inside? Not many of us are comfortable
Speaker 1: talking about our poop, but I'm not many of us.
Speaker 1: We're going to talk about why today we're so freaked
Speaker 1: out by feces and we're going to find out what
Speaker 1: our poop can tell us about our health. Body Stuff
Speaker 1: is a member of the Ted Audio collective. It's hosted
Speaker 1: by me doctor Jen Gunter and brought to you by
Speaker 1: TED and Transmitter Media. This episode was produced by Lacy
Speaker 1: Roberts and edited by Sarah Knicks. The rest of the
Speaker 1: team includes Camille Peterson, Alice Wilder, Gretta Khane, Michelle, quint
Speaker 1: Ban Ban Chang, and Roxanne high Lash. Alex Overington is
Speaker 1: our sound designer and mix engineer. Paul Durban and Nierja
Speaker 1: Robindon fact checked this episode. Special thanks to my one
Speaker 1: kidney for keeping me going. We're back next week with
Speaker 1: more Body Stuff. Make sure you follow Body Stuff in
Speaker 1: your favorite podcast app so you get every episode delivered
Speaker 1: straight to your device, and leave us a review. We
Speaker 1: love hearing from our listeners. See you next week. An
Speaker 1: un