WEBVTT - Body Stuff with Dr. Jen Gunter 0:00:00.800 --> 0:00:05.720 Hi there, Virgie. Here today, we've got something a little 0:00:05.800 --> 0:00:09.080 different for you. It's an episode of a new show 0:00:09.320 --> 0:00:14.040 from the Ted Audio collective called Body Stuff with Doctor 0:00:14.160 --> 0:00:18.800 Jen Gunter. In every episode, the podcast bust the lies 0:00:18.880 --> 0:00:23.639 you're told about your personal health. I'm a huge fan 0:00:23.680 --> 0:00:26.080 of doctor Jen's work, and I have a feeling you 0:00:26.120 --> 0:00:29.120 will be too. If you like what you hear. You 0:00:29.120 --> 0:00:33.080 can find and follow Body Stuff with Doctor Jen Gunter 0:00:33.440 --> 0:00:39.760 wherever you're listening to this. Okay, here's the first episode. 0:00:41.159 --> 0:00:45.720 I'm doctor Jen Gunter. I love science and I hate 0:00:45.760 --> 0:00:49.479 when people twist it. Your immune system needs a big 0:00:49.680 --> 0:00:56.840 scorbal supplement's milk a week, and there's a lot of 0:00:57.040 --> 0:01:07.120 twisted medical misinformation out there. Are toxins literally purify you. Yeah, 0:01:07.120 --> 0:01:11.160 that's ridiculous. Chugging a gallon of water means you'll eat 0:01:11.280 --> 0:01:18.720 fewer calories. Oh, it's so painful. We're exposed to medical myths, 0:01:18.760 --> 0:01:22.199 whether we're looking for them or not. There are news 0:01:22.240 --> 0:01:26.160 stories Instagram and Facebook, post Flying Past twenty four seven, 0:01:26.600 --> 0:01:31.800 TikTok Twitter. Who has balid information and who's just trying 0:01:31.840 --> 0:01:35.720 to sell you something? How do you sort the medicine 0:01:35.920 --> 0:01:40.760 from the mayhem I'm doctor Jen Gunter, and I'm here 0:01:40.760 --> 0:01:46.760 to help. From the Ted Audio Collective, this is body stuff. 0:01:48.960 --> 0:01:52.320 I'm a doctor, a practicing gynecologist, and I've made up 0:01:52.320 --> 0:01:55.000 my mission to give women the facts that they need 0:01:55.200 --> 0:01:59.120 to understand their bodies. In my twenty five years of 0:01:59.240 --> 0:02:03.320 talking with pay, I've learned that medical misinformation is a 0:02:03.360 --> 0:02:08.720 problem for everyone, and every single one of us is susceptible. 0:02:09.400 --> 0:02:13.279 So this show is about debunking some of the stickiest 0:02:13.360 --> 0:02:17.720 myths out there while helping you understand how your body 0:02:18.000 --> 0:02:23.400 really works today. Why you don't need eight glasses of 0:02:23.400 --> 0:02:31.920 water every day, you need a water day. We're going 0:02:32.040 --> 0:02:35.040 back in time to find the origins of that myth, 0:02:35.600 --> 0:02:37.640 and then we're going to meet a kidney expert who's 0:02:37.680 --> 0:02:41.400 going to illuminate just how hard our bodies work for 0:02:41.480 --> 0:02:45.040 us to maintain our hydration. It works like an exquisitely 0:02:45.280 --> 0:02:48.959 designed atomic balance machine, right, you need to keep everything 0:02:49.000 --> 0:02:51.960 in balance. But first I want to tell you about 0:02:52.000 --> 0:02:55.040 something that happened to me when I was ten years old. 0:02:55.680 --> 0:02:57.720 It was a time in my life when I got 0:02:57.760 --> 0:03:01.120 asked a lot about my urine and it ended up 0:03:01.160 --> 0:03:06.919 setting me on a path to become a doctor. It 0:03:06.960 --> 0:03:11.040 was the first good weekend of spring nineteen seventy seven 0:03:11.160 --> 0:03:15.040 in Winnipeg, Manitoba, the kind where the sun feels hot 0:03:15.080 --> 0:03:19.400 and you're just raring to get outside. I was messing 0:03:19.440 --> 0:03:22.680 around with my brother's skateboard, going down the street, and 0:03:22.720 --> 0:03:26.400 then all of a sudden, I was flat on my 0:03:26.480 --> 0:03:29.320 back on the concrete and I was in a terrible 0:03:29.360 --> 0:03:33.800 amount of pain. It felt like my insides were on fire. 0:03:35.520 --> 0:03:38.760 The next day, I'm sure I didn't look well, so 0:03:38.800 --> 0:03:41.200 we went to the pediatrician, who took one look at 0:03:41.240 --> 0:03:43.800 me and called a general surgeon, who took one look 0:03:43.800 --> 0:03:46.800 at me and sent us to the emergency department. They 0:03:46.800 --> 0:03:50.440 gave me something called an angiogram, and I remember the 0:03:50.520 --> 0:03:53.160 doctor pointing to the X ray screen explaining what he 0:03:53.240 --> 0:03:55.360 was seeing, and of course it just looked like a 0:03:55.400 --> 0:03:59.400 snowstorm to me. But that's when I learned that when 0:03:59.400 --> 0:04:03.480 I fell off my skateboard, i'd ruptured my spleen. The 0:04:03.480 --> 0:04:06.160 good news was I wasn't going to need surgery, but 0:04:06.360 --> 0:04:11.520 there was something else. It looked like I had hydro nephrosis, 0:04:12.120 --> 0:04:16.360 meaning my kidney was full of fluid, and I needed 0:04:16.400 --> 0:04:20.600 to see a pediatric urologist. He sat us down in 0:04:20.680 --> 0:04:23.400 his consultation room and started to explain to my mom 0:04:23.560 --> 0:04:26.640 what needed to happen. And I could tell she was 0:04:26.920 --> 0:04:30.200 very confused. I think the doctor could tell as well, 0:04:30.960 --> 0:04:33.039 and so he gestured to me and said, hey, you 0:04:33.120 --> 0:04:38.440 come over here. This is your body. You should know 0:04:38.520 --> 0:04:42.640 how it works. So I came over and I sat down. 0:04:42.720 --> 0:04:45.640 I traded places with my mom, and he drew a 0:04:45.640 --> 0:04:50.960 little diagram and he explained how the kidney worked and 0:04:51.640 --> 0:04:53.600 what he thought was wrong, and the test that I 0:04:53.640 --> 0:04:56.240 was going to have to have, and the surgery that 0:04:56.440 --> 0:05:00.000 I was probably going to have to have as well. 0:05:00.000 --> 0:05:03.200 And that doctor took the time to explain my body 0:05:03.240 --> 0:05:08.039 to me. It really helped me not feel scared or overwhelmed. 0:05:08.640 --> 0:05:11.320 And that experience made me decide I wanted to be 0:05:11.360 --> 0:05:15.479 a doctor. I loved the science and I wanted to 0:05:15.480 --> 0:05:18.400 be able to give to my patients what that doctor 0:05:18.480 --> 0:05:23.640 gave me that day, that empowerment of knowing how your 0:05:23.680 --> 0:05:28.359 body works and how to use that knowledge to help 0:05:28.440 --> 0:05:36.360 improve your health. Eventually, I did have surgery to remove 0:05:36.400 --> 0:05:39.760 my left kidney. I've lived most of my life with 0:05:39.839 --> 0:05:44.599 just one kidney, the organ that's largely responsible for regulating 0:05:44.600 --> 0:05:48.760 our body's hydration. But you want to know something, None 0:05:48.880 --> 0:05:52.240 of my doctors ever told me to worry about how 0:05:52.320 --> 0:05:57.479 much water I was drinking. I graduated from medical school 0:05:57.480 --> 0:05:59.719 when I was twenty three, so I've been a doctor 0:05:59.760 --> 0:06:03.919 more than half my life, and I've seen firsthand the 0:06:04.000 --> 0:06:07.560 problems that happen when people get misconceptions about their health. 0:06:08.360 --> 0:06:12.520 And a lot of these misconceptions they start with the Internet. 0:06:14.160 --> 0:06:16.520 I'm not one of those doctors who rolls her eyes 0:06:16.600 --> 0:06:19.280 when her patient comes in with reams of advice from 0:06:19.400 --> 0:06:23.240 doctor Google. That tells me that my patient is engaged, 0:06:23.680 --> 0:06:26.440 she wants to learn. But there are a lot of 0:06:26.640 --> 0:06:30.800 bogus recommendations out there, and often they're being pushed by 0:06:31.120 --> 0:06:35.360 brands and influencers. A lot of them sound like they're 0:06:35.360 --> 0:06:38.800 making sense in a sort of science ish way, like 0:06:38.960 --> 0:06:41.680 the eight glasses of water a day thing. Hey, we're 0:06:41.680 --> 0:06:44.320 made of water, so why wouldn't we need lots of water? 0:06:45.880 --> 0:06:51.720 But that's not science. So what's behind this myth? How 0:06:51.839 --> 0:06:57.120 did we get to eight glasses of water a day? Anyway? 0:06:58.600 --> 0:07:01.800 There are a couple of potential origin stories. One is 0:07:01.800 --> 0:07:04.480 a paper from nineteen forty five that suggests the body 0:07:04.560 --> 0:07:07.520 uses about eighty four ounces of water a day. And 0:07:07.680 --> 0:07:10.840 there's another paper from nineteen seventy four from a pair 0:07:10.840 --> 0:07:14.360 of nutritionists who recommended an equivalent of six to eight 0:07:14.400 --> 0:07:17.400 glasses of water a day for the body to function appropriately. 0:07:18.000 --> 0:07:21.960 But these papers became distorted over time like a bad 0:07:22.000 --> 0:07:28.600 game of telephone. These experts were recommending that we drink 0:07:28.720 --> 0:07:31.960 six to eight glasses of water a day on top 0:07:32.040 --> 0:07:35.720 of everything else. They were saying, this is the amount 0:07:35.720 --> 0:07:40.000 of water the body needs to function, But that water 0:07:40.080 --> 0:07:42.480 doesn't have to be water you drink from a glass 0:07:42.480 --> 0:07:47.920 out of your tap. Water is in everything. Think about 0:07:47.920 --> 0:07:51.800 a breastfed baby. All they're drinking is milk. The body 0:07:51.880 --> 0:07:54.080 is able to remove the water from the milk, so 0:07:54.200 --> 0:07:58.000 the baby never gets dehydrated. In the same way, once 0:07:58.080 --> 0:08:01.800 we start eating slid food, our bodies continue to extract 0:08:01.920 --> 0:08:07.560 water from everything we consume. Everything we eat or drink counts, 0:08:08.640 --> 0:08:11.400 So the water in your apple counts, the water that's 0:08:11.400 --> 0:08:15.080 in the bread that you eat counts, even coffee counts. 0:08:15.800 --> 0:08:20.640 Any fluid counts. Look, I get this as a real 0:08:21.080 --> 0:08:24.000 record scratch freeze frame moment for a lot of people. 0:08:24.560 --> 0:08:27.400 But we don't just get the water we need from 0:08:27.560 --> 0:08:31.080 plain water. And if you have one of those days 0:08:31.200 --> 0:08:34.000 where you just drink coffee all morning and you don't 0:08:34.040 --> 0:08:38.199 feel great, maybe you're a little headachy or a little jittery, 0:08:38.320 --> 0:08:41.960 it's not because you're dehydrated. Maybe you had a little 0:08:42.000 --> 0:08:45.199 too much coffee or you had it on an empty stomach. 0:08:46.400 --> 0:08:49.800 If you like drinking six glasses eight glasses of water 0:08:49.920 --> 0:08:53.680 day and your doctor hasn't advised against it, that's probably fine. 0:08:54.240 --> 0:08:58.440 What I'm saying is that there's nothing medical about this number. 0:08:59.160 --> 0:09:01.000 We get to make choice races about what we put 0:09:01.040 --> 0:09:03.640 into our body, and this is one of those choices. 0:09:04.360 --> 0:09:07.040 If you think about it, just using common sense and 0:09:07.080 --> 0:09:10.800 putting the medicine aside, does it seem realistic that we 0:09:10.920 --> 0:09:15.680 evolve needing to consume that much clean water every day 0:09:16.440 --> 0:09:20.160 In the span of human history, access to clean, plentiful 0:09:20.240 --> 0:09:24.840 drinking water is a relatively recent phenomenon, and even today, 0:09:24.880 --> 0:09:28.040 in many parts of the world, accessing clean drinking water 0:09:28.160 --> 0:09:31.280 sadly isn't as easy as walking into your kitchen and 0:09:31.480 --> 0:09:36.679 filling up a glass. It seems unlikely that our ancestors 0:09:36.760 --> 0:09:39.679 carry giant water bottles around with them at all times. 0:09:40.720 --> 0:09:47.280 And yet the mythspread and spread and spread. But why 0:09:47.440 --> 0:09:51.240 is this myth so sticky? It turns out there's a 0:09:51.280 --> 0:09:55.080 mix of factors, including a little bit of intrigue and 0:09:55.240 --> 0:09:58.600 one particular culprit that deserves a lot of the blame, 0:10:00.080 --> 0:10:11.680 the beverage industry. Sometimes water just isn't time unquenched. Thirst 0:10:12.200 --> 0:10:17.559 has become a chronic problem America. If you are going 0:10:17.640 --> 0:10:20.240 to sell something, you've got to have a reason to 0:10:20.320 --> 0:10:22.439 sell it. You've got to create a market for it. 0:10:25.679 --> 0:10:28.320 Things like pre hydrate. I mean, what's that mean? Drink 0:10:28.320 --> 0:10:30.880 ahead of your first train. You've got to tolerate more fluid. 0:10:31.200 --> 0:10:35.680 Your brain doesn't know when you are thirsty. Doctor deb 0:10:35.720 --> 0:10:39.160 Cohen went to medical school in the UK, but instead 0:10:39.160 --> 0:10:42.880 of becoming a clinician a doctor who sees patients, she 0:10:42.960 --> 0:10:47.880 became a journalist. Back in twenty twelve, during the lead 0:10:47.920 --> 0:10:51.280 up to the London Olympics, she was the investigative editor 0:10:51.360 --> 0:10:54.800 at the British Medical Journal. She wrote a report called 0:10:55.120 --> 0:10:59.480 The Truth about Sports Strengths and It's set off a 0:10:59.720 --> 0:11:04.040 bar arm in the beverage industry. The report looked at 0:11:04.080 --> 0:11:08.359 the history of sports drinks like Gatorade and how they're advertising. 0:11:08.840 --> 0:11:13.080 Basically invented the modern fear of dehydration. It was really 0:11:13.120 --> 0:11:15.120 in the kind of the boom of the marathon era 0:11:15.160 --> 0:11:18.960 in the nineteen seventies that sports drinks really took off. 0:11:19.200 --> 0:11:22.840 It started life in Florida at the University of Florida 0:11:22.920 --> 0:11:26.920 and Robert Cade was the renal physician and he developed 0:11:26.920 --> 0:11:33.240 this drink for the Gators football team. It was effectively water, sugar, 0:11:34.440 --> 0:11:37.240 dasher sodium, and a bit of lemon juice, so quite simple, 0:11:37.280 --> 0:11:40.280 and it was supposed to help alleviate cramps. And then 0:11:40.280 --> 0:11:44.920 it was brought up by Quaker Oats and they spotted 0:11:45.000 --> 0:11:48.760 a big market, and that's really where the science of 0:11:49.160 --> 0:11:55.320 dehydration started. Okay, so we're not talking about clinical dehydration, 0:11:55.480 --> 0:11:58.840 which is a real condition. For example, the time I 0:11:58.880 --> 0:12:01.200 had food poisoning and I was up all night vomiting, 0:12:01.280 --> 0:12:03.400 so I had to go to the emergency department and 0:12:03.440 --> 0:12:07.120 get an intravenous But this is healthy people, So this 0:12:07.160 --> 0:12:11.200 is a whole different phenomenon. And so what they turned 0:12:11.600 --> 0:12:18.559 into an illness was exercise induced dehydration. Exercise induced dehydration, 0:12:19.120 --> 0:12:22.400 now that sounds a lot more important than you're a 0:12:22.440 --> 0:12:25.160 bit First, you if you've been running and sweating. If 0:12:25.200 --> 0:12:28.679 you tell people that it's all about the science, then 0:12:29.400 --> 0:12:34.360 people are more likely to believe it. Beverage companies, especially Gatorade, 0:12:34.520 --> 0:12:38.600 commissioned studies looking for results that would bolster their sales pitches. 0:12:39.360 --> 0:12:42.600 By the time doctor Cohens started looking into these studies, 0:12:42.640 --> 0:12:46.480 there were a lot of them. Glaxo smith Kline at 0:12:46.480 --> 0:12:49.640 the time, the company behind a popular British sports drink 0:12:49.640 --> 0:12:52.720 called lucas Aid, claimed they had more than a hundred 0:12:52.800 --> 0:12:58.160 clinical trials. That's a lot of studies, and the studies 0:12:58.240 --> 0:13:01.960 were a little bit off. Some of the studies we're 0:13:01.960 --> 0:13:04.520 actually having a bit of a laugh about. So what 0:13:04.559 --> 0:13:10.240 you would do is you would starve people overnight, you'd 0:13:10.280 --> 0:13:12.960 fast them overnight, and then you'd ask them to cycle 0:13:13.000 --> 0:13:16.000 to exhaustion. One group you would give a sports drink 0:13:16.160 --> 0:13:20.000 containing sugar, and the other group you would give water. Well, 0:13:20.480 --> 0:13:22.600 guess what, the people have had a bit of sugar 0:13:23.000 --> 0:13:25.520 are going to well perform the people that have been 0:13:25.600 --> 0:13:30.000 starved and had water. It's not rocket science. And so 0:13:30.040 --> 0:13:32.200 they are all sorts of these all sorts of these 0:13:32.280 --> 0:13:35.080 kinds of studies that they do, and you look at 0:13:35.080 --> 0:13:37.640 it and go that just does not happen, and it 0:13:37.679 --> 0:13:40.240 doesn't matter that it's not clinically relevant. Now you've got 0:13:40.320 --> 0:13:43.319 something that looks statistically different, and you can peg a 0:13:43.480 --> 0:13:46.400 marketing campaign around that exactly. And if you throw enough 0:13:46.440 --> 0:13:49.240 darts at a dark boat, if you've got your eyes blindfolded, 0:13:49.280 --> 0:13:50.880 then one of them is going to hit the dark boat. 0:13:50.920 --> 0:13:55.080 At some point. The studies were junk, but the science 0:13:55.120 --> 0:14:00.280 fish conclusions they made began to spread, especially the idea 0:14:00.440 --> 0:14:02.880 that we couldn't rely on our own bodies to tell 0:14:03.000 --> 0:14:07.079 us while we were thirsty. One of Gatorade scientists even 0:14:07.200 --> 0:14:10.680 said in two thousand and eight, and I quote, the 0:14:10.880 --> 0:14:14.920 human thirst mechanism is an inaccurate short term indicator of 0:14:15.000 --> 0:14:19.840 fluid needs. Unfortunately, there is no clear physiological signal that 0:14:20.000 --> 0:14:24.760 dehydration is occurring. I think even the Mayo Clinic had 0:14:24.840 --> 0:14:28.840 information that was based on science that have been ultimately 0:14:29.360 --> 0:14:34.360 derived from the sports strengths industry about when you should 0:14:34.400 --> 0:14:38.640 hydrate and how you should hydrate, and it filtered down 0:14:38.680 --> 0:14:43.040 to influence school guidance in the UK where kids playing 0:14:43.280 --> 0:14:45.880 soccer would have to go and stop every fifteen minutes 0:14:45.920 --> 0:14:49.200 twenty minutes to rehydrates. And you speak to the teachers 0:14:49.240 --> 0:14:51.480 and be like, yeah, it's just kids like running around. 0:14:51.520 --> 0:14:53.920 They just need to peel all the time, So kids 0:14:54.000 --> 0:14:58.600 running off constantly. Even the US military was in on 0:14:58.640 --> 0:15:02.160 the quasi science. In the early eighties, the Pentagon was 0:15:02.160 --> 0:15:06.680 citing Gatorade Sports Science Institute studies claiming their drinking sports 0:15:06.720 --> 0:15:10.920 drinks could prevent heat stroke, a huge concern for soldiers 0:15:10.920 --> 0:15:14.760 fighting desert wars. But those studies were bunk. There was 0:15:14.840 --> 0:15:18.680 no evidence that drinking fluids reduced the risk of heat stroke. 0:15:19.400 --> 0:15:23.480 Even today, the US military remains Gatorade's the biggest customer, 0:15:24.280 --> 0:15:28.640 your taxpayer dollars at work. I was warned off several 0:15:28.640 --> 0:15:30.960 times as well from doing the story. Are you sure 0:15:31.000 --> 0:15:33.600 you know what you're doing? And a spot some people 0:15:33.640 --> 0:15:36.400 in the US quite a bit of sources, and they 0:15:36.600 --> 0:15:40.200 tried to have studies published that were negative and they 0:15:40.240 --> 0:15:43.520 just could not get them published. And they'd been warned 0:15:43.560 --> 0:15:46.080 off doing their research as well, and they were saying 0:15:46.120 --> 0:15:49.960 to me, do you realize how what you're doing here? 0:15:49.960 --> 0:15:56.280 And I literally probably naively just thought, well, sugary water, guys, 0:15:56.280 --> 0:16:00.400 I mean, how big a deal is this? But as 0:16:00.480 --> 0:16:04.000 doctor Cohen started her investigation, she began to see. There 0:16:04.080 --> 0:16:07.720 was a lot of money intertwined with the junk science. 0:16:08.520 --> 0:16:13.440 Sports drink companies spent huge sums sponsoring youth sports, funding 0:16:13.480 --> 0:16:17.560 sports medicine doctors, and putting their logos on the world's 0:16:17.600 --> 0:16:21.280 most beloved teams, and it was like a holy grail. 0:16:21.400 --> 0:16:25.880 You go to sports conferences, to sports medicinal sports science conferences. 0:16:26.360 --> 0:16:32.280 It's displayed everywhere you know sponsored and you don't criticize 0:16:32.440 --> 0:16:36.720 the sports drink. So sports strinths have somewhat fallen out 0:16:36.760 --> 0:16:39.760 of favor since their heyday in the nineteen eighties and nineties. 0:16:40.480 --> 0:16:43.640 But another product has taken its place, and now it's 0:16:43.680 --> 0:16:47.560 the number one selling beverage in the world, bottled water, 0:16:48.560 --> 0:16:52.320 and big Bottled Water is very happy to have you 0:16:52.400 --> 0:16:55.360 believe that you can't trust your thirst and that you 0:16:55.440 --> 0:16:58.920 need a minimum of eight glasses of water a day. 0:16:59.440 --> 0:17:02.120 After the break, we're going to talk about why this 0:17:02.280 --> 0:17:10.159 myth just won't die. We're back before the break. We 0:17:10.280 --> 0:17:12.920 learned the origin of the eight glasses of water a 0:17:13.000 --> 0:17:16.760 day myth. We believe myths like this for a lot 0:17:16.800 --> 0:17:20.560 of reasons, but a big one is something psychologists call 0:17:21.200 --> 0:17:27.199 the illusory truth effect. When a piece of information is widespread, 0:17:27.760 --> 0:17:31.920 and you hear it over and over again, you're more 0:17:32.000 --> 0:17:35.760 likely to believe that it's true. There are a lot 0:17:35.800 --> 0:17:38.879 of examples, statements like we only use ten percent of 0:17:38.880 --> 0:17:42.000 our brains, or eating carrots will help you see in 0:17:42.040 --> 0:17:45.280 the dark. None of these things are true, but I 0:17:45.359 --> 0:17:50.320 bet you've heard them repeated over and over again. Politicians 0:17:50.359 --> 0:17:53.679 and marketers take advantage of this all the time, and 0:17:53.760 --> 0:17:56.800 it works because when you're assessing whether something you've heard 0:17:56.960 --> 0:18:01.800 is true, you typically rely on two things. Whether the 0:18:01.880 --> 0:18:08.280 information makes common sense and whether it feels familiar. The 0:18:08.440 --> 0:18:12.359 research has shown that familiarity can even be more convincing 0:18:12.440 --> 0:18:17.640 than rationality. Rationality is hard, but remembering if you've heard 0:18:17.680 --> 0:18:21.840 something before, that's easy. And here's the thing about the 0:18:21.880 --> 0:18:27.480 illusory truth effect. No one is immune, not even doctors. 0:18:28.080 --> 0:18:30.840 There's a one day a year in March we call 0:18:30.960 --> 0:18:35.199 World Kidney Day, dedicated to improving awareness of kidney disease, 0:18:35.640 --> 0:18:38.240 and a few years ago the theme of World Kidney 0:18:38.240 --> 0:18:41.400 Today was drink a glass of water to help your kidneys, 0:18:41.400 --> 0:18:44.200 which is just crazy, right, It doesn't make any sense. 0:18:44.280 --> 0:18:47.879 It's not grounded in science, but you know it is 0:18:47.920 --> 0:18:51.159 grounded in funding for World kidney day, which I believe 0:18:51.280 --> 0:18:54.120 comes from dan in a manufacture of bottled water. It's 0:18:54.160 --> 0:19:01.960 like the deep state of hydration. That's doctor Joel Toff. 0:19:01.960 --> 0:19:06.320 He's a kidney doctor, otherwise known as an nephrologist. I 0:19:06.400 --> 0:19:09.280 called up doctor Toff because what do we do in 0:19:09.320 --> 0:19:12.000 medicine When we don't know the answer, We look for 0:19:12.040 --> 0:19:15.920 an expert, we call a consult and doctor Toff is 0:19:15.960 --> 0:19:19.080 just the chemistry wizard for the job. I'm a lifelong 0:19:19.160 --> 0:19:21.600 nerd who has been fascinated by the chemistry of body 0:19:21.600 --> 0:19:25.280 fluids going on three decades. I love nerds. There are 0:19:25.400 --> 0:19:29.960 an infinite number of fascinating aspects of body physiology or 0:19:30.080 --> 0:19:34.199 disease states. And one of the truths about medicine is 0:19:34.200 --> 0:19:37.280 that once you start learning about any one of these conditions, 0:19:37.720 --> 0:19:40.920 they become more interesting. And back in nineteen ninety five, 0:19:40.960 --> 0:19:44.560 when I was a senior in medical school, I became 0:19:44.640 --> 0:19:49.240 real interested in fluids and electrolytes. So the precious bodily fluids, 0:19:49.520 --> 0:19:53.440 the precious bodily fluids. That's right, that's my favorite movie. 0:19:53.480 --> 0:19:57.240 That's a doctor Strange love. Doctor Toff knows that the 0:19:57.320 --> 0:20:01.200 most important thing about precious bodily fluids is that they 0:20:01.280 --> 0:20:06.679 stay in balance, which brings us to the tragic case 0:20:07.040 --> 0:20:10.359 of Jennifer Strange. So I want you to kind of 0:20:10.400 --> 0:20:14.200 rewind back to two thousand and seven, and the hottest 0:20:14.200 --> 0:20:16.760 thing in two thousand and seven was the Nintendo Wii, 0:20:17.520 --> 0:20:19.600 and this radio station got their hands on one and 0:20:19.640 --> 0:20:23.439 they were running a radio contest. The contest was don't 0:20:23.640 --> 0:20:27.960 we for a Wei? The radio station invited eighteen contestants 0:20:28.080 --> 0:20:30.840 down to their studio to see who could drink the 0:20:30.880 --> 0:20:33.800 most water without having to pee, and there was one 0:20:33.800 --> 0:20:37.080 person who entered. Her name was Jennifer Strange, twenty eight 0:20:37.119 --> 0:20:40.360 year old mother of three, and she ended up drinking 0:20:40.800 --> 0:20:44.480 two gallons of water in an hour. That's a lot 0:20:44.520 --> 0:20:48.200 of water, so much water that a nurse actually called 0:20:48.200 --> 0:20:51.679 into the station to warn them this was dangerous. You 0:20:51.840 --> 0:20:55.840 can overload your system with too much water. It can 0:20:55.920 --> 0:21:00.159 be really unsafe. As Jennifer left the radio station and 0:21:00.240 --> 0:21:02.879 she was already complaining of a headache, and what she 0:21:02.920 --> 0:21:06.359 actually had was a condition called cerebral edema, which happens 0:21:06.359 --> 0:21:09.600 when you wash your body out from all the critical salts, 0:21:10.480 --> 0:21:14.879 and when you do this, water will shift from your 0:21:14.880 --> 0:21:18.400 bloodstream into your brain. Cause increased swelling of your brain 0:21:18.440 --> 0:21:22.520 that cause headaches, nausea, seizures, coma, and death. And she 0:21:22.640 --> 0:21:26.040 ended up dying on her own bathroom floor. A couple 0:21:26.080 --> 0:21:31.480 of hours later, Jennifer died from a condition called hyponatremia, 0:21:32.000 --> 0:21:35.840 meaning a dangerously low level of sodium in her blood. 0:21:36.960 --> 0:21:42.000 She threw off her body's delicate balance, something we've evolved 0:21:42.040 --> 0:21:48.320 to rely on. It's called homeostasis. The body maintains a 0:21:48.480 --> 0:21:52.840 stable internal environment to provide optimal health for the cells 0:21:52.840 --> 0:21:55.520 of the body. Right, you can imagine for these cells 0:21:55.560 --> 0:21:58.320 to grow and to be healthy, they need regulated amounts 0:21:58.320 --> 0:22:02.040 of sodium, potass seem even things like body temperature needs 0:22:02.040 --> 0:22:04.359 to be regulated. All these things need to be in 0:22:04.440 --> 0:22:08.960 an optimal range for growth and health, and that process 0:22:09.000 --> 0:22:12.560 of maintaining everything in that type band is called homeostasis. 0:22:14.440 --> 0:22:18.800 We've evolved to maintain homeostasis through finely tuned mechanisms. The 0:22:18.920 --> 0:22:22.520 sense when things are awry, when we've gone a little 0:22:22.520 --> 0:22:24.280 bit too far in one direction or a little bit 0:22:24.280 --> 0:22:27.159 too far in the other, and makes adjustments to return 0:22:27.240 --> 0:22:31.560 us to our state of balance. Think about the mechanisms 0:22:31.600 --> 0:22:36.960 that maintain us in homeostasis, like autopilots. I think that's perfect, right, 0:22:37.000 --> 0:22:40.360 So you can think about body temperature is a classic one, right. 0:22:40.359 --> 0:22:42.920 So if we get too hot, we start to sweat, 0:22:43.280 --> 0:22:46.000 water evaporates from our skin that lowers our body temperature 0:22:46.040 --> 0:22:48.960 back down. We get too cold, we shiver and all 0:22:49.000 --> 0:22:50.840 that generates heat and brings us back to a normal 0:22:50.880 --> 0:22:53.640 body temperature. So we have processes that control us from 0:22:53.640 --> 0:22:56.560 getting too hot and from getting us too cold. Body 0:22:56.560 --> 0:23:00.000 temperature is just one example of the autopilots that are 0:23:00.040 --> 0:23:05.240 body has to maintain homeostasis, and our kidneys well, they're 0:23:05.280 --> 0:23:08.920 the quarterback of homeostasis. They help to maintain the balance 0:23:08.960 --> 0:23:12.199 of almost every electrolyte in our body. They help with 0:23:12.240 --> 0:23:16.480 blood pressure, they're crucial for maintaining pH and they maintain 0:23:16.640 --> 0:23:22.159 our level of hydration. One of these autopilots is called osmolality, 0:23:22.480 --> 0:23:26.120 and osmolality is just a measure of the total amount 0:23:26.160 --> 0:23:29.840 of compounds in solution. And so an analogous is just 0:23:29.960 --> 0:23:33.399 how salty the soup is. As the osmolality goes up, 0:23:33.480 --> 0:23:36.320 soup gets more salty. As the osmolality goes down, soup 0:23:36.359 --> 0:23:39.639 gets more dilute. In this case, the soup is our 0:23:39.720 --> 0:23:42.439 blood to be a little bit more precise. The fluid 0:23:42.520 --> 0:23:46.320 part of our blood our plasma, and the kidney regulates 0:23:46.320 --> 0:23:50.959 our osmolality so it stays in a healthy range. Jennifer's 0:23:50.960 --> 0:23:54.719 Strange died because she drank so much water that she 0:23:54.800 --> 0:23:59.240 pushed her osmolality far below the healthy range, and her 0:23:59.359 --> 0:24:04.720 kidneys just couldn't keep up. Today, hypenatremia is most often 0:24:04.760 --> 0:24:09.440 seen in athletes who are overhydrating while exercising. Doctors first 0:24:09.440 --> 0:24:12.440 started seeing it in ultra marathon runners and iron man 0:24:12.440 --> 0:24:15.959 triathletes in the nineteen eighties, a period of time that 0:24:16.400 --> 0:24:20.040 nicely coincides with the messaging coming out of the Gatorade 0:24:20.040 --> 0:24:24.560 Sports Science Institute. And it's not just extreme athletes. Doctors 0:24:24.600 --> 0:24:27.840 have seen hypenetremia in high school football players, students in 0:24:27.920 --> 0:24:34.920 yoga classes, and more. Thankfully, hypenetremia is relatively rare because 0:24:34.920 --> 0:24:40.760 of our body's amazing ability to defend homeostasis. I just 0:24:40.760 --> 0:24:42.880 want to run this morning, I went for three mile run, 0:24:42.960 --> 0:24:45.359 and I'm the thirsty and a bit hungary. So how's 0:24:45.400 --> 0:24:47.920 my one kidney because I only have one keeping me 0:24:48.800 --> 0:24:52.159 working right. So you came back from your run, and 0:24:52.240 --> 0:24:54.920 presumably during that run, you sweat, you lost a little 0:24:54.920 --> 0:24:57.479 bit of fluid that way, and that loss of fluid 0:24:57.520 --> 0:24:59.280 is going to make your body salt here, it's gonna 0:24:59.280 --> 0:25:02.879 make the soups alter. Your osmality goes up. This is 0:25:02.880 --> 0:25:06.480 you're pushing your body out of that homeostatic range and 0:25:06.520 --> 0:25:09.879 it needs to return that osmolality back down. And the 0:25:09.920 --> 0:25:15.480 way that it does that is two factors. One increased thirst. 0:25:15.920 --> 0:25:18.480 And so increased thirst is a sensation that your body 0:25:18.520 --> 0:25:21.000 gets that'll change your behavior. It'll make you go to 0:25:21.040 --> 0:25:23.560 the sink, pour yourself a glass of water and drink it. 0:25:24.080 --> 0:25:27.480 So in addition to thirst, your kidney is going to 0:25:27.600 --> 0:25:30.280 respond to that increase in osmolality. And the way that 0:25:30.320 --> 0:25:32.200 it does that is it's going to change the type 0:25:32.240 --> 0:25:34.160 of urine that you make. You're always making urine, you're 0:25:34.160 --> 0:25:36.920 always getting rid of You're constantly getting rid of waste products. 0:25:37.000 --> 0:25:39.919 But one of the variables is how much water is 0:25:39.960 --> 0:25:43.520 excreted along with those waste products. In other words, if 0:25:43.560 --> 0:25:46.240 you're drinking a lot of water, you're going to pay more, 0:25:46.840 --> 0:25:49.399 but that doesn't mean you're getting rid of more waste. 0:25:49.600 --> 0:25:52.240 You're getting rid of the same amount of waste. It's 0:25:52.359 --> 0:25:57.120 just diluted in more water. Yeah. My tagline on Twitter says, 0:25:57.480 --> 0:26:00.680 thinking the kidney's product is urine, it's like thinking a 0:26:00.760 --> 0:26:05.720 factories product is pollution. Urine is the byproduct. What the 0:26:05.800 --> 0:26:14.200 kidney produces is homeostasis. So how much water should we drink? 0:26:14.880 --> 0:26:17.200 We should drink enough water so that you're not thirsty. 0:26:17.760 --> 0:26:20.080 I tell my patients, you know, anytime that you're thirsty, 0:26:20.080 --> 0:26:22.080 go ahead and drink a glass of water, and maybe 0:26:22.119 --> 0:26:24.480 have one glass of water on top of that. It's 0:26:24.520 --> 0:26:27.119