WEBVTT - Ep 195 Salt Part 2: The Substance 0:00:00.120 --> 0:00:05.360 Intake of salt is a biological imperative inextricably woven into 0:00:05.360 --> 0:00:11.600 physiological systems, human societies, and global culture. However, excessive salt 0:00:11.640 --> 0:00:15.800 intake is associated with high blood pressure. The crucial question 0:00:16.000 --> 0:00:20.000 is whether salt exerts a causal influence on patient centered 0:00:20.040 --> 0:00:25.640 health outcomes such as myocardial infection, stroke, and death. However, 0:00:25.920 --> 0:00:30.560 this issue is controversial and fiercely debated. Despite the controversy, 0:00:30.800 --> 0:00:34.760 two broad points of consensus exist. The first is that 0:00:34.800 --> 0:00:39.520 the uncertainty could be resolved by better quality data, that is, large, 0:00:39.600 --> 0:00:43.639 randomized clinical trials with sufficient follow up to assess robust 0:00:43.760 --> 0:00:48.600 cardiovascular outcomes. The second is that the barriers to performing 0:00:48.640 --> 0:00:52.159 such trials are so substantial that they will be rarely, 0:00:52.520 --> 0:00:53.880 if ever surmounted. 0:01:43.040 --> 0:01:45.440 Okay, so many questions. 0:01:45.840 --> 0:01:46.680 What was that? From? 0:01:47.000 --> 0:01:49.320 When was that? From? Who wrote that? 0:01:50.480 --> 0:01:53.200 I can't wait to tell you? Okay? So that was 0:01:53.520 --> 0:01:56.960 I pulled clips like little bits from the intro and 0:01:57.000 --> 0:02:00.919 from later in a paper, from a very very recent paper. 0:02:02.240 --> 0:02:04.120 I have just scrolled. Why didn't I put this up? 0:02:04.400 --> 0:02:06.040 I'm scrolling all the way to the bottom of my 0:02:06.120 --> 0:02:11.680 notes from Nature Reviews Nephrology from twenty twenty two by 0:02:11.760 --> 0:02:15.200 hunter at All titled the Impact of Excessive Salt Intake 0:02:15.280 --> 0:02:22.560 on Human Health, and this paper that little intro, that's 0:02:22.600 --> 0:02:23.520 the end of my. 0:02:24.400 --> 0:02:26.720 I mean, that's what like, That's what kills me, is 0:02:26.760 --> 0:02:30.200 that I feel like since that could The reason I 0:02:30.280 --> 0:02:32.720 asked where when is it from? Is because that could 0:02:32.720 --> 0:02:37.160 have been from so many different points in history over 0:02:37.160 --> 0:02:40.720 the salt debate. We need better data, we need randomized 0:02:40.720 --> 0:02:45.760 control trials, we need long term data sets and follow up. 0:02:45.960 --> 0:02:52.960 And it is from twenty twenty two. So that's what 0:02:53.000 --> 0:02:55.800 we're going to talk about today in this episode. 0:02:56.840 --> 0:02:59.240 Hi, I'm Aaron Welsh. 0:02:58.600 --> 0:03:00.200 And I'm Aaron Allman updight. 0:03:00.240 --> 0:03:03.720 And this is this podcast will kill you. Welcome back 0:03:03.720 --> 0:03:07.639 to Salt Salt. Here we go again, Yeah. 0:03:07.480 --> 0:03:13.760 We go again. I'm really excited about today's episode. I 0:03:13.800 --> 0:03:15.480 don't know how many answer any of your questions, but 0:03:15.560 --> 0:03:17.280 I think I think we'll come to some clarity. I 0:03:17.320 --> 0:03:19.320 honestly really actually do at the end of this. 0:03:19.720 --> 0:03:25.079 I am hopeful. I know that if there is a 0:03:25.800 --> 0:03:29.240 thread to be pulled, you will find it and yank 0:03:29.320 --> 0:03:33.280 it out from the yank Yeah, yeah, I do. I'm 0:03:33.360 --> 0:03:37.480 thrilled for this. Yeah, I already want to start asking questions, 0:03:37.520 --> 0:03:39.720 and that is a first like that is early for me, 0:03:39.880 --> 0:03:41.080 so good. 0:03:41.240 --> 0:03:43.320 I can't wait. I can't wait for you to ask 0:03:43.360 --> 0:03:45.680 me questions and then I'll be like that's the one 0:03:45.720 --> 0:03:47.960 I don't have an answer for, or like, oh my god, 0:03:47.960 --> 0:03:50.040 now I have to scroll one hundred years in my notes. 0:03:50.080 --> 0:03:52.880 I can't wait. I have fifteen pages of notes here 0:03:53.040 --> 0:03:56.000 erin so like, I've got to have answers to something. 0:03:57.880 --> 0:04:01.320 But firstarantiny time it is? 0:04:01.520 --> 0:04:06.600 It is we're again drinking the grains of salts, which 0:04:06.640 --> 0:04:08.520 is based on a salty dog. I mean it is 0:04:08.520 --> 0:04:12.480 a salty dog, which is great fruit juice and vodka 0:04:12.600 --> 0:04:15.080 or gin, whichever you prefer. Make sure your rim is 0:04:15.080 --> 0:04:18.200 salted unless you're dealing with high blood pressure. No, just kidding, 0:04:18.240 --> 0:04:23.080 I don't know, but that is the technical recipe. Also, 0:04:23.360 --> 0:04:26.440 this reminds me that if you are just now tuning in, 0:04:26.760 --> 0:04:28.679 then you didn't see at the top that it says 0:04:28.720 --> 0:04:31.080 Salt Part two. You really don't have to listen to 0:04:31.120 --> 0:04:33.920 the first episode, but you should. It's not like there's 0:04:33.920 --> 0:04:37.240 a narrative that you'll miss, but you'll miss a lot. 0:04:37.520 --> 0:04:41.360 You'll miss some. It'll help you with trivia. It's got 0:04:41.360 --> 0:04:43.680 some cool It's a great episode. Do you want to 0:04:43.760 --> 0:04:47.159 learn where the term grain of salt comes from? Check 0:04:47.200 --> 0:04:47.520 it out. 0:04:47.680 --> 0:04:49.160 You've got to listen to that episode. We're not going 0:04:49.200 --> 0:04:49.720 to tell you now. 0:04:49.880 --> 0:04:51.159 Yeah. 0:04:51.520 --> 0:04:53.920 Anyways, we'll post the recipe for the drink on our website. 0:04:54.000 --> 0:04:55.960 This podcast with you dot com and our social media 0:04:55.960 --> 0:04:57.920 is so make sure you're following us there. You find 0:04:57.960 --> 0:04:59.680 lots of other cool stuff on our website too, like 0:04:59.720 --> 0:05:02.719 trans scripts and a bookshop dot orgiphiliated account, and a 0:05:02.720 --> 0:05:06.040 good Reads list and merch and all the sources from 0:05:06.040 --> 0:05:08.000 all of these episodes. Boy do I have a long 0:05:08.000 --> 0:05:13.159 list for this one bloodmobile? Who does our music? You know? 0:05:13.880 --> 0:05:14.960 Contact us form. 0:05:14.800 --> 0:05:15.480 Lots of things. 0:05:15.760 --> 0:05:17.920 I'll check it out. 0:05:18.279 --> 0:05:20.160 Is there any other business or can we like get 0:05:20.200 --> 0:05:22.040 straight to things? Let's do this? 0:05:22.400 --> 0:05:50.599 Oh yes, very short break life evolved in the oceans, 0:05:51.200 --> 0:05:52.680 which are salty. 0:05:53.560 --> 0:05:55.919 I loved this. I'm like, wait a second, have I 0:05:56.000 --> 0:05:56.800 said this before? 0:05:57.160 --> 0:05:59.520 No, you haven't, but it is the most Aaron Welsh 0:05:59.560 --> 0:06:01.680 way to start the thing. Ever that I was like 0:06:01.920 --> 0:06:04.240 thrilled that you didn't start that way and that I 0:06:04.240 --> 0:06:04.800 could do it. 0:06:05.240 --> 0:06:08.159 I did think about going into the evolutionary origins and 0:06:08.200 --> 0:06:09.560 then I was like stop. 0:06:09.800 --> 0:06:12.800 Yeah, no, no, I'm not going any further than that. Life 0:06:12.839 --> 0:06:16.400 evolved in the oceans. Yeah, the oceans are salty, and 0:06:16.480 --> 0:06:21.599 with the evolution from single celled organisms to multicellular organisms, 0:06:21.720 --> 0:06:26.680 salt became a major component of our extracellular fluid, that is, 0:06:26.760 --> 0:06:29.640 the fluid that is on the outside rather than the 0:06:29.640 --> 0:06:35.120 inside of our cells. Our bodies are basically just made 0:06:35.200 --> 0:06:41.560 up of tiny little water balloons bathing in more water. Yeah, okay, 0:06:42.000 --> 0:06:44.880 and all of the water inside and outside of our 0:06:44.920 --> 0:06:48.560 cells is salty water. Yeah, but the salt on the 0:06:48.720 --> 0:06:53.720 inside of our cells is mostly potassium. So the ions 0:06:53.760 --> 0:06:57.279 that make up the salt mostly are potassium, and the 0:06:57.400 --> 0:07:02.960 salts outside of our cells most are made up of sodium. So, 0:07:03.120 --> 0:07:06.680 as we moved from our ocean homes to land, and 0:07:06.680 --> 0:07:09.240 by we I mean like, you know, creatures and not 0:07:09.320 --> 0:07:10.160 like humans. 0:07:10.120 --> 0:07:12.320 Global evolutionary we yeah. 0:07:12.080 --> 0:07:18.560 Exactly, we were no longer bathing in sodium all the time, right, 0:07:19.320 --> 0:07:23.600 and thus we had to find ways to ingest it. Yeah. 0:07:23.640 --> 0:07:29.240 So animals evolved taste receptors to be able to detect salt, 0:07:30.080 --> 0:07:32.720 and in general, like you kind of mentioned, Aaron, most 0:07:32.760 --> 0:07:36.600 animals have actually a pretty consistent like upside down U 0:07:36.680 --> 0:07:40.800 shaped preference curve for saltiness, right, but I think it's yeah, 0:07:40.880 --> 0:07:43.720 upside down you so like it's delicious right in the middle. 0:07:43.760 --> 0:07:46.240 If it's not salty enough, it doesn't taste good. If 0:07:46.280 --> 0:07:50.960 there's too much salt also doesn't taste good. Right. So 0:07:51.320 --> 0:07:53.760 when we talk about salt in this episode, like you 0:07:53.800 --> 0:07:56.680 said last week as well too, I'm talking about sodium 0:07:56.880 --> 0:08:00.800 chloride NaCl uh huh. I mean when I set it 0:08:00.840 --> 0:08:02.960 in the bodies where there's other salts in your bodies, 0:08:03.360 --> 0:08:05.880 and there's other ions that are important, But from now 0:08:05.920 --> 0:08:07.760 on out, I'm just talking about sodium chloride. 0:08:07.880 --> 0:08:11.120 Okay, Can I already ask a question? Yeah, Garby, you 0:08:11.160 --> 0:08:14.240 mentioned potassium is on the inside and sodium is on 0:08:14.280 --> 0:08:14.840 the outside. 0:08:15.120 --> 0:08:17.760 Huh. 0:08:18.440 --> 0:08:20.520 And what happens then? 0:08:20.800 --> 0:08:23.320 Like okay, yeah, let me let's sorry. 0:08:23.360 --> 0:08:26.200 Yeah, well it's not a question. It was more just 0:08:26.280 --> 0:08:27.760 like tell me more. 0:08:28.200 --> 0:08:31.560 Yes, let me continue setting the scene and then I 0:08:31.600 --> 0:08:36.959 will I will get into that, okay, very shortly. Well, 0:08:37.000 --> 0:08:40.880 we're talking mostly about sodium chloride today. Lots of other 0:08:40.920 --> 0:08:45.040 salts exist in chemistry, salt like table salt, Sodium chloride 0:08:45.360 --> 0:08:49.600 is about forty percent sodium. Yeah, like by weight, so 0:08:49.840 --> 0:08:52.079 ten grams of salt. This is important for one work 0:08:52.120 --> 0:08:54.320 because like all of the dietary guidelines and things talk 0:08:54.360 --> 0:08:57.360 about sodium, right, But then a lot of studies just 0:08:57.400 --> 0:09:00.559 talk about salt. So we can use these interchange ten 0:09:00.640 --> 0:09:04.360 grams of salt four grams of sodium. That's the equivalence there. 0:09:04.400 --> 0:09:07.360 Okay, guess what there are like online calculators that I 0:09:07.400 --> 0:09:10.319 had to use to be like how much sodium are wet? 0:09:10.440 --> 0:09:11.920 I would be like how much salt does the average 0:09:11.920 --> 0:09:16.320 American eat? Oh? You know, however thirty two hundred milligrams 0:09:16.320 --> 0:09:18.640 of salt or sodium, So like right, no, but how 0:09:18.679 --> 0:09:19.520 much salt are we eating? 0:09:19.520 --> 0:09:22.960 How much salt does that? Yeah? Exactly. Also, then some 0:09:23.040 --> 0:09:25.400 studies like to use millimals just to make them sound 0:09:25.679 --> 0:09:27.680 more smart, and you're just like, now I have to 0:09:27.679 --> 0:09:31.120 take it from mills to milligrams, Like stop it, it's unnecessary. 0:09:31.800 --> 0:09:33.960 But so the questions that I want to answer today 0:09:34.200 --> 0:09:36.320 in this episode are number one, why do we give 0:09:36.320 --> 0:09:38.360 a crap about sodium? And that's going to get it 0:09:38.440 --> 0:09:40.480 your question of like sodium potassium, what does that mean? 0:09:40.520 --> 0:09:42.520 What does it do in our bodies? Why do we 0:09:42.559 --> 0:09:46.160 actually need it. What is the problem or is there 0:09:46.160 --> 0:09:49.240 a problem with excess sodium and how much? What does 0:09:49.280 --> 0:09:53.360 excess actually mean? And why is there so much debate 0:09:53.360 --> 0:09:56.319 about this? Yeah, that's going to be a big part 0:09:56.360 --> 0:09:59.080 of the episode. What I am not going to talk 0:09:59.120 --> 0:10:03.360 about is hypo and hyper natremia. That is when your 0:10:03.360 --> 0:10:05.560 blood sodium is too low or too high. I'm not 0:10:05.600 --> 0:10:08.240 going to talk about it in any great detail. If 0:10:08.280 --> 0:10:11.560 you are a medical student or a resident, you're welcome 0:10:11.760 --> 0:10:14.280 for not making you listen to that. If you don't 0:10:14.320 --> 0:10:17.040 know what that means, you can watch some doctor Glalcum 0:10:17.080 --> 0:10:20.920 Flecken videos because they sum up both my knowledge and 0:10:21.000 --> 0:10:24.040 also why I have no interest in talking about those things, because. 0:10:23.960 --> 0:10:26.359 Are those acute stages. 0:10:26.880 --> 0:10:29.840 They can be acute or chronic. Okay, okay, yeah, and 0:10:29.880 --> 0:10:32.920 it's all just a mess. But you will understand why 0:10:32.920 --> 0:10:34.920 it's important when I tell you why do we have 0:10:34.960 --> 0:10:38.320 to give a crap about sodium? Right at its core, 0:10:38.520 --> 0:10:43.080 at its most important, sodium is what determines our total 0:10:43.120 --> 0:10:48.319 body fluid balance. So because it is the most abundant 0:10:48.480 --> 0:10:53.320 cat ion, positively charged ion in our extracellular fluid, it 0:10:53.440 --> 0:10:57.680 is what determines how much fluid volume we actually have 0:10:57.960 --> 0:11:02.200 in our bodies. Right, Because the salt on the inside 0:11:02.320 --> 0:11:05.400 of our cell bags is mostly potassium and the salt 0:11:05.440 --> 0:11:09.600 on the outside is mostly sodium, it doesn't matter which 0:11:09.679 --> 0:11:13.120 is which as long as their concentrations are the same. 0:11:13.640 --> 0:11:16.680 Our bodies have to keep a balance of these fluids. 0:11:16.760 --> 0:11:19.200 So the concentration of particles on the inside of our 0:11:19.240 --> 0:11:22.480 cell has to match the concentration on the outside if 0:11:22.520 --> 0:11:25.160 they don't, Like if you were to dump a bunch 0:11:25.160 --> 0:11:29.160 of sodium into your bloodstream into your extracellular fluid, then 0:11:29.200 --> 0:11:32.800 your body would have to compensate by extracting fluid from 0:11:33.000 --> 0:11:35.480 cells in order to make up for that. 0:11:35.960 --> 0:11:41.480 Right, Okay, And the identity of sodium versus potassium doesn't 0:11:41.520 --> 0:11:44.560 necessarily matter, I imagine it does at a point. 0:11:44.920 --> 0:11:48.400 It does, absolutely, but it doesn't for the purposes of 0:11:48.480 --> 0:11:50.920 just understanding that, like at its core, you just have 0:11:50.960 --> 0:11:54.520 to have balance. It so happens that potassium is what 0:11:54.640 --> 0:11:57.840 exists inside of our cells, and sodium primarily exists outside 0:11:57.840 --> 0:12:00.199 of our cells, And our cells do a lot of 0:12:00.280 --> 0:12:04.720 transmitting sodium and potassium back and forth through these atp 0:12:04.880 --> 0:12:09.560 ion channels, and that is all very important. But to 0:12:09.720 --> 0:12:12.640 understand fluid balance. You need to know that potassiums on 0:12:12.679 --> 0:12:14.600 the inside and sodiums on the outside, and they got 0:12:14.640 --> 0:12:16.600 to be concentration wise balanced. 0:12:16.920 --> 0:12:17.079 Right. 0:12:18.200 --> 0:12:22.200 Sodium is also an incredibly important cad on outside of 0:12:22.200 --> 0:12:26.120 fluid balance. It's a neurotransmitter. It is essential for our 0:12:26.200 --> 0:12:29.480 muscles to be able to contract, and so it's something 0:12:29.520 --> 0:12:33.480 that our cells also use in communication with other cells. So, 0:12:34.040 --> 0:12:37.920 make no mistake, we cannot exist without sodium. 0:12:38.400 --> 0:12:40.040 It's necessary for life. 0:12:40.240 --> 0:12:44.480 It is necessary for life, and the volume of our 0:12:44.559 --> 0:12:49.320 fluid in our bodies is proportional to our total body 0:12:49.360 --> 0:12:53.560 content of sodium. Right, So, in order to if you 0:12:53.720 --> 0:12:56.640 lose a bunch of volume, for example, if you're bleeding, 0:12:57.120 --> 0:13:00.240 or if you're even just peeing out way too much, 0:13:00.360 --> 0:13:04.040 or you're sweating or you're having diarrhea, in order to 0:13:04.160 --> 0:13:09.240 replace the volume that you've lost of fluid, you have 0:13:09.520 --> 0:13:14.080 to also replace sodium. You cannot replace it with just water, 0:13:14.280 --> 0:13:19.040 it will not work. Right. We lose sodium predominantly through 0:13:19.040 --> 0:13:22.920 our kidneys. In fact, shout out to our kidneys. They 0:13:22.920 --> 0:13:27.079 are so stellar at this that they excrete about ninety 0:13:27.160 --> 0:13:29.880 to ninety five percent of what we ingest regardless of 0:13:29.920 --> 0:13:33.320 how much we ingest. Isn't that interesting? 0:13:33.920 --> 0:13:37.240 Wait? So okay, but you said it's a proportion that 0:13:37.280 --> 0:13:39.000 they excrete out or. 0:13:38.960 --> 0:13:42.320 Is it ninety to ninety five percent of what you 0:13:42.559 --> 0:13:44.560 ingest you're going to pee out in your kidneys. 0:13:44.640 --> 0:13:47.439 So let's say we're talking about sodium sodium. Yeah, so 0:13:47.520 --> 0:13:49.480 let's say that you, you know, going back to last 0:13:49.480 --> 0:13:54.720 week's episode when the ridiculous estimate, shocking estimate of one 0:13:54.800 --> 0:13:59.440 hundred grams of salt a day a day, let's say, so, 0:13:59.480 --> 0:14:04.880 that's forty grams of sodium oday. Yeah, that ninety percent 0:14:05.440 --> 0:14:08.120 that's excreted out. You've got a lot more salt remaining 0:14:08.160 --> 0:14:09.520 in your body than if you're. 0:14:09.880 --> 0:14:11.880 Oh, Aaron, you're so right. 0:14:14.840 --> 0:14:16.760 Thank you for leading me perfectly to that. 0:14:17.800 --> 0:14:21.320 You did it all on your own. Oh my god, Yes, exactly, 0:14:21.520 --> 0:14:26.160 exactly right. Proportionally percent of what we ingest, regardless of 0:14:26.200 --> 0:14:28.560 what we're ingesting. Right, we're gonna lose some through our 0:14:28.560 --> 0:14:31.480 gi tract, via your poop. You're gonna lose some via sweat, 0:14:31.560 --> 0:14:35.800 et cetera. Okay, most of its kidneys, Most of it's kidneys, 0:14:35.800 --> 0:14:38.320 and our kidneys. They do a really good job of 0:14:38.360 --> 0:14:40.880 deciding how much to kick out and how much to 0:14:40.960 --> 0:14:43.000 keep depending on how much we eat, because it is 0:14:43.000 --> 0:14:46.360 going to be variable. Right, if you're not getting enough, 0:14:46.840 --> 0:14:50.560 if you are deficient in your sodium intake, or if 0:14:50.560 --> 0:14:53.200 you've got other reasons that your body decides, hey, we 0:14:53.240 --> 0:14:56.200 need to hold onto this. Your kidneys can actually keep 0:14:56.440 --> 0:14:59.440 almost all of it. They can They can keep almost 0:14:59.480 --> 0:15:15.120 one hundred percent of your sodium if they need to. 0:15:15.200 --> 0:15:18.680 Two questions, Okay, what are some of the conditions that 0:15:18.920 --> 0:15:22.840 your kidneys might keep more sodium than is necessary? And 0:15:23.400 --> 0:15:28.040 how often does someone actually not consume enough sodium in 0:15:28.400 --> 0:15:30.640 like the your like a normal day to. 0:15:30.640 --> 0:15:35.040 Day you know, such great questions. How often in the 0:15:35.720 --> 0:15:38.640 year twenty twenty five is someone not getting enough sodium? 0:15:38.840 --> 0:15:41.400 Very rare? Okay, it's very hard to not get enough 0:15:41.400 --> 0:15:46.040 sodium for most people. You If you, for example, were 0:15:46.080 --> 0:15:47.600 to lose a lot of blood or lose a lot 0:15:47.600 --> 0:15:50.280 of volume for any reason, then your blood pressure would 0:15:50.280 --> 0:15:52.360 probably drop. Then your kidneys would say, hey, we need 0:15:52.400 --> 0:15:54.040 to hold onto blood pressure. We're going to do that 0:15:54.080 --> 0:15:55.960 by holding on all of our sodium. We're not going 0:15:56.000 --> 0:15:58.200 to let any sodium go, and that's going to help. 0:15:58.240 --> 0:16:01.000 You're going to need to ingest sodium, either via like 0:16:01.040 --> 0:16:03.520 ivy fluids or just eating salt in order to make 0:16:03.600 --> 0:16:05.720 up for those losses. But your kidneys are also going 0:16:05.760 --> 0:16:07.800 to react very quickly to hold on to as much 0:16:07.800 --> 0:16:11.400 as possible. There's other like disease states. For example, if 0:16:11.440 --> 0:16:14.920 you have issues with your adrenals where you're not producing 0:16:14.960 --> 0:16:18.480 certain hormones. Because it's a lot of very complicated it's 0:16:18.480 --> 0:16:21.520 your kidneys, it's your brain, it's your blood vessels and 0:16:21.560 --> 0:16:24.480 sensors that are in your blood vessels. It's hormones that 0:16:24.520 --> 0:16:27.400 are controlling all of this. So if you have deficiencies 0:16:27.400 --> 0:16:29.960 in certain hormones, then your kidneys might flip on and say, hey, 0:16:30.000 --> 0:16:31.600 we need to hold on to all the sodium that's 0:16:31.640 --> 0:16:34.720 possible because we are you know, at risk of losing 0:16:34.800 --> 0:16:37.720 it or whatever. Or maybe you have deficiencies and hormones 0:16:37.720 --> 0:16:39.680 and you can't do that and so you're losing a 0:16:39.720 --> 0:16:43.000 lot of sodiums. So then you might have what so 0:16:43.080 --> 0:16:46.960 many animals have big bone lick stake park and that 0:16:47.080 --> 0:16:51.720 is what's called sodium appetite. Yes, and sodium appetite is 0:16:51.760 --> 0:16:56.000 this idea that we know exists in animals that in 0:16:56.080 --> 0:17:00.400 a state of sodium deficiency. Animals will exhibit these pretty 0:17:00.400 --> 0:17:04.919 extreme sodium seeking behaviors and they will do extra work 0:17:05.080 --> 0:17:07.720 to seek out and consume salt. And we see this 0:17:07.840 --> 0:17:11.880 in a lot of different animals, mice, rats, rabbits, pigeons, goats, 0:17:11.920 --> 0:17:17.600 we learned, kangaroos, sheep, cattle, monkeys, horses. So the question 0:17:17.760 --> 0:17:21.800 is does this sodium appetite exist in humans, And we 0:17:22.080 --> 0:17:25.919 think probably yes, though the data is based on a 0:17:26.000 --> 0:17:30.080 few cases of like, for example, kids who had no 0:17:30.280 --> 0:17:35.200 functional adrenals, so they were salt wasting. Their kidneys could 0:17:35.240 --> 0:17:38.239 not hold on to salt, and so they had an 0:17:38.359 --> 0:17:42.400 increased need for salt and exhibited these kinds of salt 0:17:42.440 --> 0:17:44.960 seeking behaviors. In the literature, these are like really old 0:17:45.280 --> 0:17:49.920 single case type studies. Yea, but then yeah, so those 0:17:50.040 --> 0:17:53.360 individuals in those studies did exhibit that kind of sodium 0:17:53.400 --> 0:17:57.119 seeking what we would call sodium appetite. That's not the 0:17:57.160 --> 0:18:01.200 same thing as what we experience now, which is sodium 0:18:01.400 --> 0:18:05.119 preference where we like it so we eat it because 0:18:05.119 --> 0:18:07.719 it tastes good. That does not mean that we are 0:18:07.720 --> 0:18:09.040 sodium deficient. 0:18:09.400 --> 0:18:12.440 Right, even though it feels sometimes like the same thing. 0:18:12.840 --> 0:18:17.640 Right, hard to distinguish perhaps. 0:18:18.240 --> 0:18:21.560 Okay, I have a question about you said like salt appetite, 0:18:21.600 --> 0:18:27.080 this instinctual drive to find salt, and you said that 0:18:27.080 --> 0:18:29.919 they tested out in kids that lacked adrenals. Tell me 0:18:30.040 --> 0:18:33.400 why that would. What's happening there is their kidneys aren't 0:18:33.440 --> 0:18:35.000 holding on like yeah. 0:18:35.240 --> 0:18:39.160 Yes, exactly that. So your adrenals they do a lot, 0:18:39.240 --> 0:18:42.400 but one of the hormones that they make is called aldosterone, 0:18:42.920 --> 0:18:47.280 which is a very important part of mediating the resorption 0:18:47.440 --> 0:18:50.960 of sodium in your kidneys. And so without being able 0:18:51.000 --> 0:18:54.760 to make that particular hormone, then you can't have a 0:18:54.800 --> 0:18:57.400 signal to tell your kidneys to hold on to sodium, 0:18:57.440 --> 0:19:00.400 and so you're basically sodium wasting. And there's other conditions 0:19:00.400 --> 0:19:03.200 as well too. There's like genetic conditions, or there's maybe 0:19:03.280 --> 0:19:07.840 damage to the kidney. There's medications that can make you 0:19:07.960 --> 0:19:13.040 lose more sodium in your urine through your kidneys. Okay, yeah, 0:19:13.320 --> 0:19:15.280 but a lot of it is under that hormonal control. 0:19:15.320 --> 0:19:17.520 So that's why it was in kids who had like 0:19:17.640 --> 0:19:19.560 not either they didn't have adrenals or they had non 0:19:19.560 --> 0:19:23.800 functional adrenals. I can't remember which one. Okay, And your 0:19:23.880 --> 0:19:26.400 drenals do a lot more than just teldosterone, but that's 0:19:26.440 --> 0:19:27.320 important for salt. 0:19:27.760 --> 0:19:31.560 And your kidneys do a lot more than just sodium too, yes, Vato. 0:19:33.400 --> 0:19:38.800 But so this all begs the question how much sodium 0:19:39.320 --> 0:19:41.280 do we actually need? 0:19:43.920 --> 0:19:44.400 How much? 0:19:44.440 --> 0:19:51.480 Aaron? This is my favorite question that I've asked myself, yeah, 0:19:51.520 --> 0:19:56.200 in a while, and it is very hard to come 0:19:56.240 --> 0:20:00.040 to an actual answer on this. So you mentioned, and 0:20:00.920 --> 0:20:03.480 I'm so glad that you did in last episode, that 0:20:03.640 --> 0:20:08.800 our early hominid ancestors, their estimated amount of salt intake 0:20:09.040 --> 0:20:12.080 was about one gram of salt per day or less. 0:20:12.200 --> 0:20:18.679 That's four hundred milligrams of sodium. Now, there also was 0:20:18.800 --> 0:20:22.720 a study that came out in the late eighties called 0:20:22.840 --> 0:20:26.000 inter Salt, and this was this one of these big, 0:20:26.119 --> 0:20:30.720 big observational studies that first showed a relationship. Not first 0:20:30.760 --> 0:20:32.040 because you said it was like you know, in the 0:20:32.040 --> 0:20:33.440 early nineteen hundreds. 0:20:33.440 --> 0:20:37.600 Twenty six, if you're talking, you know, correct hard hard 0:20:37.640 --> 0:20:38.560 pulse that hardens. 0:20:39.040 --> 0:20:41.879 Yeah, But this was one of like a big important 0:20:41.920 --> 0:20:45.600 observational study that looked at a bunch of different populations 0:20:46.040 --> 0:20:50.760 with variation in their average salt intake and found a 0:20:50.880 --> 0:20:54.360 very strong relationship between higher salt intake and blood pressure. 0:20:54.840 --> 0:20:58.600 In this study, they also looked at several remote human 0:20:58.640 --> 0:21:02.560 populations in Brazil, Kenya, and Papula, New Guinea, and in 0:21:02.600 --> 0:21:05.399 those populations, people, yes, had very low blood pressure, but 0:21:05.440 --> 0:21:10.439 they also had substantially lower sodium intakes compared to what 0:21:10.480 --> 0:21:13.080 we see today, one to three grams of salt on average, 0:21:13.080 --> 0:21:16.240 which is four hundred milligrams to one point two grams 0:21:16.280 --> 0:21:17.280 of sodium per day. 0:21:17.800 --> 0:21:20.199 I mean, it's to be hard, I feel like, in 0:21:20.320 --> 0:21:23.639 our like in the US, to eat that, to select 0:21:23.760 --> 0:21:24.960 that diet, right. 0:21:24.840 --> 0:21:28.800 Listen, we'll get there. It's very hard, Okay, But this 0:21:28.880 --> 0:21:31.000 all becomes really important because, as I'm going to talk 0:21:31.040 --> 0:21:34.080 about later, there is a lot of weird debate about 0:21:34.600 --> 0:21:39.320 what our quote unquote physiologic need actually is. Okay, and 0:21:39.359 --> 0:21:42.080 we'll get into the people who are claiming things that 0:21:42.119 --> 0:21:46.879 they're claiming, but it is very clear from these early 0:21:47.400 --> 0:21:49.520 you know, these estimates of early hominid we can't we 0:21:49.560 --> 0:21:52.320 can't have exact data on that, right, but these estimates 0:21:52.359 --> 0:21:56.200 based on the sodium content of the types of foods 0:21:56.200 --> 0:21:58.719 that early hominids would be eating, plus the fact that 0:21:58.760 --> 0:22:01.320 there are, or at least in the eighties and seventies 0:22:01.359 --> 0:22:05.800 were societies in which people were consuming very minimal amounts 0:22:05.800 --> 0:22:10.119 of salt and they were living, surviving, maybe thriving, I 0:22:10.119 --> 0:22:14.800 don't know, but their bodies were functioning just fine. So physiologically, 0:22:15.040 --> 0:22:18.680 most estimates say we need at a minimum about five 0:22:18.760 --> 0:22:22.720 hundred milligrams of sodium a day in order to continue 0:22:22.720 --> 0:22:25.679 our bodily functionings, to keep up with losses from our kidneys, 0:22:25.720 --> 0:22:27.720 from our sweat, from our GI tract. And that's going 0:22:27.760 --> 0:22:29.479 to vary based on how much you're sweating, how much 0:22:29.480 --> 0:22:32.760 you're pooping, and how great your kidneys are at retaining sodium. 0:22:33.119 --> 0:22:35.879 What about potassium, great question. 0:22:36.280 --> 0:22:40.560 Potassium is incredibly important and actually plays a huge role 0:22:40.920 --> 0:22:45.480 in this sodium blood pressure, et cetera debate. And I 0:22:45.480 --> 0:22:48.200 didn't write down the exact like what the RDA the 0:22:48.280 --> 0:22:51.359 recommended amount of potassium that you get is, so I 0:22:51.440 --> 0:22:53.960 don't know the exact numbers of that, but potassium is 0:22:54.040 --> 0:22:56.520 absolutely essential to consume every day as well. 0:22:57.080 --> 0:22:59.880 And we're but I'm asking about the intrasalt study. Were 0:23:00.080 --> 0:23:04.080 those populations, the remote populations, were they consuming some other 0:23:04.200 --> 0:23:06.760 types of salt, you know, potassium or whatever. 0:23:07.200 --> 0:23:11.920 They were probably consuming more potassium than what we consume 0:23:12.480 --> 0:23:15.960 or what a lot of other populations consume. Because foods 0:23:15.960 --> 0:23:18.240 that tend to be low in sodium are often high 0:23:18.400 --> 0:23:23.080 in potassium. That's very interesting, because whole foods are very 0:23:23.119 --> 0:23:25.800 high like fruits, vegetables, these kinds of things tend to 0:23:25.800 --> 0:23:30.679 be very high in potassium. Harm. Okay, we'll get there, Okay, okay, 0:23:31.080 --> 0:23:33.920 So that's how much salt we need, like bare minimum 0:23:33.920 --> 0:23:38.080 to survive. We think, right, how much salt do we get? 0:23:38.440 --> 0:23:43.080 On average? Global daily salt intake is estimated. Most estimates 0:23:43.119 --> 0:23:46.320 and by the World Health Organization are about ten grams 0:23:46.320 --> 0:23:49.560 of salt per day, which is about four grams of sodium. 0:23:50.080 --> 0:23:53.680 There is a lot of variation, so the average ranges 0:23:53.720 --> 0:23:57.080 from just over two grams to just over five grams 0:23:57.119 --> 0:24:00.280