Using Salt to Optimize Mental & Physical Performance
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Welcome to the huberman la podcast, where we discussed science and science space tools for everyday life. I'm Andrew huberman and i'm a professor of neutral logy and optometry gy at stanford school of medicine. Today we are going to discuss salt, refer to and sodium.

Most of us think of salt as something that we put on in our food, maybe something to avoid. Maybe some of you are actually trying to get more salt. Some of you are trying to get less salt.

We all seem to associate sault with things like blood pressure. At seta. Today, we are going to go down a different set of avenues related to sault. We will certainly cover how salt regulates blood pressure. We are also going to talk about how the brain regulates our appetite for salt or our aversion for salt.

We are also going to talk about how our sensing of salty taste actually mediate how much sugar we crave and whether not we ingest more or less sugar than we actually need. So what you're going to learn today is that the so called salt system, meaning the cells and connections in our brain body that mediate salt craving and avoidance, are regulating many, many aspects of our health and our ability to perform in various context seems like athletic performance, things like cognitive performance. We're also going to talk about aging and dementia and avoidance, aging and dementia and what role salt and salt avoidance might play in that.

We're going to touch on some things that, for some of you might seem controversial. And indeed, if they are controversial, i'll be sure to highlight them as such, i'm going to cover a lot of new data that point to the possibility I will emphasize the possibility that for some people, more salt might help them in terms of health, cognitive and bodily functioning. And for other people, less salt is going to be Better.

I'm going to talk about what the various promoters are. I'm going to give you some guidelines that in concert with your physician who should absolutely talk to before adding or changing anything to your diet, supplementation regime can help you arrive at assault intake. That's going to optimize your mental physical health and performance.

So are going to cover neutral logy. We're going to cover hormonal biology. We're going talk about liver function.

We're going to talk about kidney function and of course, brain function. I'm excited to share this information with you today. I'm certainly to come away with a lot of information and actionable items.

Before we dive into the topic of today's episode, I want to highlight a really exciting new study. This is a study from the ago horab at duke university. The boris lab studies interactions between the gut and the brain, and has made some incredible discoveries of the so called neuropathy. Ells neuroprotective ls are neurons, nerve cells that reside in our gut and that detect things like fatty acids and mino acids. And some neuropace cells sense sugar.

Previous work from the slb oratory has shown that when we ingest sugar, these neuro pod cells respond to that sugar and send electrical signals up a low wire that we call acts on through the vague nar for those who do you want to know and into the brain, and through subsequent stations of neural processing, evoke the release of dopa. Dopamine is a molecule known to promote craving and motivation, and indeed action. And what these neuropace cells that sent sugar afford to do is to promote seeking and consumption eating of more surgery foods.

Now, the incredible thing is that it's also conscious. This is a taste system in the gut that is not available to your conscious awareness. Now, of course, when you in just sweet food, you taste them on your mouth, too. And so part of the reason that you crave sweet foods, perhaps, is because they takes good to you. And the other reason is that these neuroprotective ls are driving a chemical craving below your conscious detection.

So there are really two systems your god is sensing at a subconscious level, what in IT, and sending signals to your brain that work in concert, in parallel with the signals coming from your alth, in your experience of the taste of the food. Now that alone is incredible and has been the subject of many important landmark papers over the last decade or so. You can imagine how the system would be very important for things like hidden sugars.

When nowaday in a lot of process foods that are putting hidden sugars, they're putting a lot of things that cause your gut to send signals, your brain, that make you crave more of those foods. So for those of you that really love sugar, just understand it's not just about how that sugar taste. The new study from the baha's lab deserves attention.

I believe this is a paper published just recently, february twenty fifth, this year twenty twenty two, in nature neuroscience and excEllent journal. And the title of the paper is the preference for sugar over sweet tener depends on a gut sensor cell. The boss lab is now discovered a neurologic ell, meaning a category of neurons that can distinguish between sweet things in the gut that contain calories, for instance, sugar, and things in the gut that are sweet but do not contain calories, artificial sweetness ers like aspartame, su curse and so forth.

There are also, of course, non artificial, non colour sweeteners like stevia on fruit. At seta, they did not explore the full gallery of artificial sweeteners. What they did find, however, ought to pertain to all forms of sweet, non coLoring substances.

What they discovered was that there is a signature pattern of signals sent from the gut to the brain when we ingest artificial or non cleric sweeteners. This is important because what IT says is that at a subconscious level, the gut can distinguish between sweet things that contain calories and sweet things that do not. Now what the downstream consequences of this sensing is, or what they are, isn't yet clear.

Now I believe everyone should be aware of these kinds of studies for a couple of reasons. First of all, it's important understand that what you crave, meaning the food ds you crave and the drinks you crave, is in part due to your conscious experience of the taste of those things, but also due to biochemical and neural events that start in the body and in pinch on your brain and cause you to seek out certain things. Even though you might not know why you're seeking out more sugar, you find your craving a lot of sugar or you're craving a lot of foods with artificial sweeteners ers, and you don't necessarily know why now artificial sweeteners themselves are somewhat controversial topic.

I want to highlight that someone's back. I described a study from yale university about how one can condition the insulin system. Insulin is involved in mobilizing a blood sugar and so forth in the body, as many of you know.

And I described some studies that we're done from yale university school of medicine, looking at how artificial sweeteners can actually evoke and insulin response under certain conditions. Now a couple of key things. I got a little bit of push back after covering those studies, and I encourage push back all the time.

Push back is one of those things that forces all of us to drill deeper into a topic. I want to be clear. First of all, I not want to demonize artificial sweet tenners.

There is evidence in animal models, in animal models that artificial sweet tener can disrupt gut, but those were fairly high doses of artificial sweeteners, and it's unclear the same thing pertains to humans. Still unclear, I should say, has not been investigated. Some people don't like the taste artificial sweet tener.

Some people do. Some people find that they really help them avoid excessive chlor can take, some people believe, and yet I should emphasize, their still is evidence that they can adjust the insuing response in all people. I just want to repeat that three times so that people are clear on that fact.

What these new data emphasize, however, is that we need to understand how artificial sweeteners ers are consumed at the level of the gut, or I should say, registered at the level of the gut, and how that changes brain function. Because one thing that i'm familiar within that many people report is that when they first taste artificial sweaters, they task sort of not right to them. They don't like the taste, but over time, they actually start to crave that taste.

I've experiences, I used to drink a lot of diet sodas when I was in graduate school. So this would be ascertain. And I found that I would, I actually needed them.

Now, maybe I was the caffeine, maybe I just like the sweet taste of the carbonation. We actually have an a drive for carbonation, which is the topic of a future epo de. But when I finally quit them, for reasons that were independent of any fear of artificial, I found that I didn't like the taste.

Nowadays, I only occasionally drink a diet soda, usually do that far on a plane, and there's nothing else available to me. So I don't demonize them. I might drink one every once in a while.

No big deal. I also want to be clear. I consume stevia on a number of different supplements and foods that I consume.

Stevia, of course, a plant based non color sweetener. So I myself, consumer artificial sweater's. Many people hate them, many people like them and find them useful for their nutrition.

And in fact, to keep their color can take in arrange, that's right for them. And many people like myself are curious about them and somewhat wary of them, and yet continue to consume them in small amounts. I think most people probably fall into that category.

I should also mention that many food manufacturer put artificial sweetness ers such a suit that are into foods, and it's always been unclear as to why they might anna do that. And yet we know that the sweet taste consumption, even if IT doesn't contain calories, can drive more craving of sweet food. So there may be a logic or strategy to why they do that.

Again, a topic for exploration on today's podcast e and in future podcast, because we were headed today, is a discussion about how salt insult sensing, both consciously and unconsciously, can adjust our craving for other things like sugar and water and so on. So I want to highlight this beautiful work from the boss lab. We would put a link to the study.

I want to open this as a chapter for further exploration. I like to think that the listeners of this podcast are looking for answers where we have answers but are also, I would hope, excited about some of the new and emerging themes in what we call nutritional neurobiology. And indeed, the hours lab really stands as one of the premier laboratories out there that's looking at how foods as consumed in the gut are modifying our nervous system, the foods we crave and how we utilize those foods.

Before we begin, i'd like to emphasize that this podcast is separate from my teaching and research roles at stanford. IT is, however, part of my desire and effort to bring zero cost to consumer information about science and science related tools to the general public. In keeping with that team, i'd like to think the sponsors of today's podd cast, our first sponsor, is athletic Greens.

Athletic Greens is in all in one of vitamin, mineral probiotic drink. I've been taking athletic Greens since two thousand and twelve. So i'm delighted that their sponsor in the podcast, the reason I started taking athletic Greens and the reason I still take athletic Greens once or twice a day is that IT helps me cover all of my basic nutritional need to make up for any deficiencies that I might have.

In addition, IT has probiotics, which are vital for microbial on health. I've done a couple of episodes now on the so called gut microbiome and the ways in which the microbiome interacts with your immune system, with your brain to regulate mood, and essentially with every biological system relevant to health throughout your brain and body. With deleted Greens, I get the vitals I need, the minerals I need and the probiotic to support my microbial.

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And k two is also important because IT regulates things like cardiovascular function, cause um in the body and so on. Again, go to athletic Greens, dcom, sla, huberman to claim the special offer of the five free travel packs and the year supply of vitamin d three k two. Today's episode is also brought to us by waking up, waking up as a meditation APP that includes hundreds of meditation programs, mindfulness trainings, yoga ea, recessions in n sdr, non sleep depressed protocols.

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Let's talk about salt. Assert has many, many important functions in the brain body. For instance, IT regulate fluid baLance, how much fluid you desire and how much fluid you excrete.

IT also regulates your desire for salt itself, meaning your assert appetite. You have a homeostatic ally driven a salt appetite. I'll talk about the mechanisms today. Make them all very clear. What that means is that you crave salty things, beverages in foods when your salt stores are low, and you tend to avoid salty beverages and foods when your salt stores are high.

Although that's not always the case, there circumstances where you will continue to grave salt even though you don't need salt, or indeed even if you need to eliminate salt from your system. Salt also regulates your appetite for other new trends, things like sugar, things like carbon hydrates. And today will explore all of that.

Technically, salt is a mineral. And I should mention that when I say salt, I am indeed referring to sodium in most cases, although I will be clear to distinguish a salt from sodium, meaning table sault from sodium, most people don't realize this, but one gram of table salt contains about three hundred and eighty eight milligrams of sodium. So technically, we should be talking about sodium today.

And that salt, I will use them interchangeably unless i'm referring to some specific recommendations or ideas about trying to define your ideal salt, A K sodium intake. okay. So this is important. I think that right off the bat, a lot of people get themselves into a place of confusion and potentially even into a place of trouble by thinking that table salt in grahams always equates to sodium in grams, and that simply not the case.

Today, we're going to explore the neural mechanisms by which we regulate our salt appetite and the way that the brain and body interact in the context of salt seeking, salt avoidance. How to determine when we need more salt, when we need less salt will talk about kidney function. We'll get into all of IT, and we're going to do IT very systematically.

So let's start in the brain. We all harbour small sets of neurons. We call these sets of neurons nuclear ye, meaning low clusters of neurons, that since the levels of salt in our brain and body, there are couple of brain regions that do this.

And these brain regions are very, very special, special because they lack biological fences around them. The other brain areas have, and the those ends, I should say, that fence goes by a particular name, and that name is the blood brain barrier, or B B B. Most substances that are circulating around in your body do not have access to the brain.

In particular, large molecules can't just pass into the brain. The brain is a privilege. Dorgan, in this sense, there are couple of other organs that are privileged and that have very strict barriers, very particular senses, if you will.

Those other organs include things like the overs and testes. And that makes sense for the following reason. First of all, the brain, at least most of the brain, cannot regenerate after injury.

You just simply can't replace brain cells after injury. I know people get really excited about neurogenesis is the birth of new neurons. And neurogenesis has been demonstrated in animal models into some extent. IT exists in humans in a few places, for instance, the al factory bub, where neurons are responsible for detecting odors in the environment for smell, that is.

And in a little sub region of the hippocampus of memory area, there's probably some neurogenesis, but the bulk of really good data out there point to the fact that in humans, there's not much turn over of neurons. What that means is that the neurons you're born with are the ones that you're going to be using most, if not all, of your life. In fact, you're born with many more neurons that you'll have later, and there's a process of naturally occurring cl death called apoptosis occurs during development.

So you actually born with many more neurons than you have later in life. And that's the reflection of a Normal healthy process of nerve cell elimination. So the estimates vary, but anywhere from, you know, a third to maybe even half, even two thirds of neurons, depending on the brain, is just gna die across development.

That might sound terrible, but that's actually one of the ways which you go from being kind of like a little potato bug, flopping around, helpless, sly in your crib, to being an organism that can walk and talk and and articulate and calculate math or do whatever is that you do for a living. So the brain has a set of elements, these nerve cells and other cells, and IT needs to use those for the entire life span. So having A B, B, B, A blood brain barrier around the brain is absolutely critical.

The overall and testes have a barrier for, we assume the reason that they contain the genetic material by which we can pass on our genes to our offspring. Project means, make children. And those children will have our genes, at least half of them, other half from the partner.

Of course, if the cells within the overs, antsy are muted, well, then you can get mutations in offspring. So that's very costly in the evolutionary sense. So that makes sense that you could have a barrier from the blood. So if you invest what to call the mugen, if you adjust something that can mutate the genes of of cells, you can imagine why there would be a premium or not allowing those mugen to get into the brain, the overall of the tests OK.

So the brain has this bbb, this blood in barrier er around IT, which makes IT very, very hard for substances to pass into the brain unless those substances are very small or those substances and molecules are critically required for brain function. However, there are a couple of regions in the brain that have a fence around them, but that fence is weaker. okay? It's sort like going from a really big world, thick electronics, twenty four hour surveilLance fence where nothing compassed through except only the exclusive cargo that's allowed to go through to having a little cyclone fence with A A couple holes in IT or it's a kind of a picket fence that swilling over and substances can move freely in from the blood circulating in the body into the brain.

And IT turns out that the areas of the brain that monitor salt baLance and other features of what happening in the body at the level of what we call osama ity at the concentration of salt. Resided in these little sets of neurons that sit just on the other side of these weak fences. And the most important and famous of these, for the sake of today's conversation, is one called O V L T.

O V L T stands for the organum vascular osm of the lateral terminal is hit, is what's called a circum ventricular organ. Why circumventing illar? Well, not to bog you down with their anatomy, but your brain is a big, squishy mass of neurons and other cell types.

But IT has to be nourished. And through the middle of that brain, there is a tube, there is a hollow that creates spaces. In those spaces are called ventral. The ventral are spaces in which the liberal spinal fluid circulate, and IT ignored shes. The brain IT does a number of other things as well.

The circumstance trick lar organs are areas of the brain that are near that circulating fluid, and that circulating fluid ID has access to the bloodstream and the bloodstream has access to IT. And the structure that i'm referring to O V L T or going to vascular some of the lateral terminals has neurons that can sense the the contents of the blood and to some extent of cerebral spinal fluid. There are couple other brain areas that can do this as well.

They go also by the name of circumventing ual organs. And i'll talk about the names of some of those other areas. But for today, and I think for sake of most of the discussion, understand that the oil is specially why? Because IT doesn't have this thick barrier fence, which sounds like a bad thing, and yet it's a terrific border detector.

The neurons in that region are able to pay attention to what's passing through in the bloodstream and can detect, for instance, if the levels of sodium in the bloodstream are too low, if the level of blood pressure in the body is too lower, too high, and then the oval can send signals to other brain areas, and then those other brain areas can do things like released hormones that can go and act on tissues in what we call the peery in the body. And for instance, have the kidneys to create more urine to get rid of salt, that excessive salt in the body, or have the kidney's hold on to your in, to hold onto whatever water fluid that one might need. So before I go any deep into this path, we just understand that the oval has a very limited barrier.

IT can detect things in the bloodstream. And this incredible area of the brain, almost single handily sets off the cascades of things that allow you to regulate your salt baLance, which turns out to be absolutely critical, not just for your ability to think and for your neurons to work, but indeed for all of life. If the ovl t doesn't function correctly, you're effectively dead or dead soon.

So this is a very important brain region. So let's talk about the function of the O V L T and flesh out some of the other aspects of its circuitry of its communication with other brain areas and with the body in the context of of something we are all familiar with, which is thirst. Have you ever wondered just why you get thirsty? Well, it's because neurons in your O L T are detecting changes in your bloodstream, which detect global changes within your body.

And in response to that, your ov sets off certain events within your brain and body that make you either want to drink more fluid or to stop drinking fluid. There are two main kinds of thirst. The first one is called osmotic thirst, and the second is called hypo volume c first osmotic c thirst has to do with a concentration of salt in your bloodstream.

So let's you, and just something very, very salty. Let's you just know, a big bag of I confessing, all need. These are very often, but I really like those kettle potato chips.

And there pretty salty. I have never actually measured how much, so you missing them sure the information there everyones in a while i'm particularly interested in doing so. I'll just down a bag of those things and I really like them.

They're very salty, but they almost always make me feel thirsty. And the reason is that by eating those, i've adjusted a lot of sodium, again, not a frequent occurrence for me, but happens every now again. And I don't have too much shame about that because I think I have a pretty healthy relationship to food, and I enjoy them.

And I understand that I will drive salt levels up in my blood stream, and that will cause maybe thirsty. But why? why? Because neurons in the oval t come in two main varieties.

One variety senses the osama ity of the blood, that getting across that weak little fence that we talked about before and when the osama ity, meaning the salt concentration, the blood is high. IT activates the specific neurons in the ov, and by activate time, I mean, causes them to send electrical potentials, literally send electrical signals to other brain areas. And those other brain areas inspire a number of different downstream events.

So what are those other brain areas? Well, the O L T signals to an area called the super optic nucleus, the name and why it's called this, you bob, at nucleus, is not necessarily important. IT also signals to the so called paradoxically, lar nucleus and nucleus that sits near the ventral and can monitor the qualities, the chemical qualities of the three were spinal fluid, as well as probably the bloodstream as well.

And the consequence of that communication is that a particular hormone is eventually released from the posterior patti. Now, the petite itri is a gland that sits near the roof of your mouth. IT releases all sorts of things like growth hormone and luti zing hormones.

Tanzer hormone will stimulate things like estrogen and testosterone production and release from the over reason, teases and so on. The petitionary has a bunch of different departments in functions. But what's really cool about the battery ory is that certain regions of the patrica actually contained the actions, the wires of neurons, and the neurons reside in the brain.

And so the superos nucleus gets a signal from the O L T. The signal is purely in the form of electrical activity. Remember, neurons aren't talking in one another about what's happening out there that are saying him, hey, there's, you know, too much salt in the bloodstream.

Let's do something about IT. All they receive our so called action potential waves of electricity. The neurons in the superb pitic nucleus then release their own electrical signals within the patuit ory. And some of those neurons and nearby neurons are capable of releasing hormones as well as electrical signals. So from the potuit tary, there's a hormonal signal that its released called vaso present.

VISA present also goes by the name anti diuretic c hormonal and antia erec hormonal has the capacity to either restrict the amount of euro that we secrete or when that system is turned off, to increase the amount of urine that we secrete. So there's a complicated set of cascades that evoked by having high salt concentration in the blood. There's also a complicated set of cades that are evoked by having low concentrations of sodium in the blood.

But the pathway is nonetheless the same. It's oba t is detecting those osmiae changes communicate to the super nuclear super nucleus is either causing the release of or is releasing VISA present antidilutive cormon or that system is shut off so that the anti diuretic cormon is not secreted, which would allow you into flow more freely right? Antidilutive means anti release of your in.

And by shutting that off, you are going to cause the release of you and your sort of allowing a system to flow, so to speak. The second category of thirst is hype of olympic thirst. Hype of illimited thirst occurs when there is a drop in blood pressure.

okay. So the O V L T is, I mention before, can sense osmia ity based on the fact that IT has these neurons that can detect how much salt as in the bloodstream. But the O V L T also harbors neurons that are of the barrow receptor mechano recept category.

Now more on barrel recept tors in mean receptors later. But barrel recept tors are essentially a recept, a meaning of protein that in a cell that responds to changes in blood pressure. So there are number things that can cause decreases in blood pressure.

Some of those include, for instance, if you lose a lot of blood, right, if you're bleeding quite a lot or in some cases, if you vomit quite a lot or if you have extensive diary or any combination of those. And there are other things that can reduce blood volume. And we will talk about some of those later.

But in the classic case of hypo volume c thirst, one is simply losing blood, and therefore blood pressure goes down. So very simple to imagine your money of these pipes, which are the arteries, veins and capital ies. And when you lose some blood volume, the pressure in those arteries vein tapulous goes down.

O, L, T has neurons that can sense that reduction and blood pressure because of reduction, because of the presence of barrow receptors in no. V, L, T. There are other elements that also playing to the response to what we call hypo illimited first, for instance, the kidney will secrete something called running runnin will activate something called ng o tension two from the lungs of all things amazing.

And ani attends into itself can act on O V L T organizations, cultivate terminals, which in turn will create first, okay, so in both cases, right, the osama ity sensing system, meaning as thirst, and in hype of olympic thirst, where blood pressure has dropped, the end result is a desire to drink more. And that desire to drink more comes to a variety of pathways that are both direct and indirect include VISA present, and donor include VISA present. But I think for just sake of general example, and even for those of you that don't have any biology background or physiology background, just understand that they're two main types of thirst, both types of thirst osmotic thirst in hype of olympic first, are not just about seeking water, but they also about seeking salt.

In very general terms, salt A K sodium can help retain water. Now that doesn't mean that salt always retains water. If you have excessive amounts of salt, will you retain excessive amounts of water? Well, sort of as IT will soon learn, its all contextual.

But for most cases we can say that by having salt in our system, our brain in our body can function Normally, provided the levels of assault are adequate and not too high or too low. And first, while we often think of IT is just a way to bring fluid into our body, is designed as a kind of a interaction tive perception. What I mean by that and interaction tion, as many of you know now from within this podcast, is paying of attention or or a recognition, rather a conscious recognition of the events going on with in our body.

So when we are thirsty, it's a certain form of interaction tion. We go, oh, I need something and I crave something. May not know exactly what you need, but when you are thirsty, you're not just seeking water.

You're also seeking to baLance your osama ity, which means you maybe seeking sault fluid or fit. In some cases, you'll trying accomplish this by eating or IT maybe that you're trying to avoid or you will be inspired to avoid salty fluid and fits. But if you want to understand sodium and its roles in the body, you have to understand first.

And if you want to understand first, you have to understand how fluid baLance is regularly in the body. That's not surprising at all. But sodium and water work together in order to generate what we call the sodium water work together in order to either retain water or inspire us to let go of water to you in IT.

So before we can dive into the specifics around salt and had to use salt for performance and various recommendations and things to avoid, we need to drill a little bit deeper into this fluid baLance mechanism in the body. And for that reason, we have to pay at least a little bit of attention to the kidney. The kidding is an incredible organ.

And one of the reasons the kidney is so amazing is that is responsible for both retaining, holding onto or allowing the release of various substances from the body, substances like glue cos or mino assets. Ia you're a acid salt pattani um magnesium it's basically a filter, but it's a very, very intelligent filter. Intelligent meaning IT doesn't have its own mind.

But the way IT works is is really beautiful. Basically blood enters the kidney and IT goes through a series of tubes which you arrange into loops if you want to look more into this, there's the the beautiful loop of henley and other aspects of the kidney design that allow certain substances to be retained in other substances to be released. Depending on how concentrated those substances are in the blood, the kidney responds to a number of four mono signals, including VISA present in order to, for instance, and entire radical on in order to hold on to more fluid if that's what your brain and body need.

And he responds to other harmonic signals as well. So it's a pretty complex organ. None the less. There's a key point, which I already mentioned, that I think people don't realize. This is actually something that I like to tell kids when I meet them, provided the there of appropriate age.

I'll say often times that with kids learn on a scientist to ask a question about something released to science, and hopefully, for my sake, at something about neuroscience, but one thing that i'll tell kids, i'll say, you do you know that your your ear in your p is actually filtered blood. And occasionally that will really terrify a kid, but that also occasionally really terrifying an adult. But indeed, your yarn is filtered blood.

They see blood gets into the kidney. The kidney gonna filter out certain things. Certain things are going be allowed to pass through, and others are not. okay. So the way the kidney is designed is that about ninety percent of the stuff that's absorbed from the blood is gone to be absorbed early in the series of tubes and only a small percentage is gonna regulated or worked out as you get into what's called the dial kidney.

Me distal just means the further urgest part away, okay, the proximal is up close um so like your shoulder is proximal to your midline of your body and your hand is distal. So in biological terms to you hear about proximal dial which just means near or far from. So just to give a really simple example, let's say that you are very low on fluid, you haven't had much to drinking while maybe you're walking around on a hot day.

Chances are that the neurons in your O V L T will sense the increase in osmotic ity, right? The concentration of salt is going to be increased relative to the fluid volume that's circulating. This, of course, assumes that you haven't excluded a lot of soda on for one reason or another, but that increasing all similarities detected by the obt, the obt is going to signal a bunch of different cades to the supermarket tic nucleus at seta, and then VISA present is going to be released into the bloodstream.

And VISA present, again, also called anti direct hormones, is going to act on the kidney and change the kidney function in a couple of different ways, some mechanical, some chemical. Okay, in order to make sure that your kidney does not release much water doesn't make you want to your innate. And in fact, even if you would try to uren ate, your body's going to tend to hold onto its fluid stores.

A very simple, straight forward example. We can also give the other example, whereby if you are interesting a lot, a lot, a lot of water and it's not a particularly hot day, you're not sweating very much, but to assume your sault intake is constant to or is low for whatever reason, well then the osmotic ity, the sole concentration in your blood is going to be lower. Your oil t will detect that because of these osm sensing non in your royal, your opelt will fail to signal to the super optic nucleus.

And there will not be the release of the oregon anta eric core mod. And you can get all the water that your body wants to excrete, meaning you'll be able to urinate. There's no holding to water at the level of the kidding.

Okay, very simple examples, but hopefully illustrates how events within the blood, meaning the concentration of ult, relative the amount of fluid right? That's what authoritarian is is detected by the O V L T, the brain that communicates to the peaty, the patuit ory sends a hormone out in the blood and the hormonal acts on the kidney to either hold onto or let go of fluid, meaning to prevent you from wanting to urinate or from stimulating you to want to urinate. Very, very simple kind of, yes, no type situation here.

There's a lot of nuance to this. In reality, they're a lot of other hormones in this pathway. But I think for at least the stage of the discussion, that should be sufficient.

Some of you may have noticed that a molecule we've been talking a lot about today, these are present was also mentioned on a previous episode of the human room in lab podcast. But in a very different context, molecule are referred to his viasa present. And I mentioned it's a hormone involved in anti dia est, meaning in urination.

It's an anti diode tic. But we also talked about these are present in the context of desire, love and attachment. We talked about in the context of monogamy and non monogamy in a species of animal called the prai wal.

You can check out that episode. I believe VISA present in the non monogue praise walls are mentioned in the timestamps, so should be easy to fined. This a present is made at multiple locations in the nervous system, mainly the supermarket nucleus.

And indeed, it's also involved in aspects of sexual behavior in mating. Now IT does that through mechanisms that are distinct from its anti diuretic effects. In fact, there are all people and who take VISA present as an afford jack.

Now i'm certainly not suggesting people do that, but I have all the confidence in the world that the moment I talk about VISA Price and someone in the confidence can say, what do you think about VISA present nasal spray and this kind of thing? These are present. And in the oxide tosa, another hormone that's involved in pair bonding and various aspects of brain body function are available as a nasal spray that can get up into the deeper recesses of the brain.

And you can impact some of these core, what we call hypothalamic c functions, these primitive drives and hythloday c functions. I would encourage a lot of caution um maybe be an extreme caution in recreational use of things like VISA present in oxytocin as you are working with md and md, excuse me, and they prescribed, but they really know what they are doing. These are powerful hormones that have a lot of different effects on the brain body.

The way that VISA present, meaning anti diuretic ormon prevents the release of fluid as you're in from the body, is pretty interesting. IT acts directly on the kidney. So as I mention before blood flows into the kidney, a number of things are retained in the early part of the kidney.

VISA present acts at a fairly distal, meaning kind of in in game, a part of the of the loops of tubes through the kidney. And IT increases the permeability of those tubbs, in other words, and make sure that the fleur that would otherwise pass into a collecting duct and then go out to the blade never actually makes IT to the batter. I point this out because what anti diabetic ormond does is IT prevents the blatter from filling at all.

It's not as if IT locks fluid in the bladder and prevents you from urinating. I think the way have been describing things up until now, the way you will hear about anti dia re ment might sound like IT a locks up the blatter prevents you from being able to you and ate. You have a full blade that would be very uncomfortable.

That's not the way IT works. IT actually causes the tubes headed towards the blatter from the kidney to become premier, meaning to allow fluid to go back into the bloodstream, into the rest of the body. So that flu, I never actually fills the blood.

And so you never feel the urge to uren ate. Now, this is an episode about salt. A key thing understand about the kidney is that the kidney uses sodium in order to conserve water, which has everything to do with the fact that sodium can actually hold water.

Put differently, water tends to follow sodium. So where we have sodium, we tend to have water. And sodium, when it's concentrated, can hold onto water. And that's one of the main ways that the kidney holds onto water in the body. And as will soon learn, there is no simple and direct formula to say, for instance, okay, if salt levels are high, a lot of water is retained and assault levels are low, a lot of water is released. On the one hand, that can be true, but it's also the case because these systems are homeostatic, meaning they're always seeking baLance both within system, within the solar system and between systems.

The salt and water system is also the case often in that if we have enough sodium, well, then we can secrete sodium in some water will follow or if we don't have enough sodium, then yes indeed, because we're not holding onto water, more fluid can be excluded. But if that condition of low sodium last long enough, then we start to retain water, because the body recognizes up salt as low and water is being, and eventually a system will kick in to retain water. So i'd love to give you a simple black and White yes or no answer for low sodium, high sodium, moder sodium and water baLance.

But it's all contextual. And when I say contextual, I mean, IT will depend on blood pressure, hypertension, prehension tension, if that's there. Maybe Normal tension hormone levels exercise at eta.

A pretty good example of how complicated this canopy is, one that some of you may be familiar with. It's pretty well known that during certain phases of the menstrual cycle, when estrogen and progesterone in other hormones are fluctuating, that water can be retained in the body. There's it's what's called edema or a swelling sometimes.

So the the common assumption and indeed IT can be true that when estrogen levels are high, there's water attention in the body. Also in males, if emergent levels are high, there can be water retention in the body. This is one of the reasons why a athletes and a pretty ur body builders who take animal exterior ds like testoon, which can be converted into emergent sometimes they they Walker on, they look like they were partially inflated.

They look like they're going going to pop and and that looks like a swelling of the skin, not just because they have large muscles. And that's not always, but often water retention due to testosterone conversion into estrogen. Now that all sounds consistent, right? Estrogen levels flushed in the mentor cycle.

In males where there is an increase in estrogen, there's retention of water, but actually estrogen access a diagram. So one would think, okay, when estrogen levels go up, there should be a lot of fluid excreted. But I bring up this example to point out that it's a very complicated and dynamic baLance between hormones and salt and fluid.

You can't draw one to one relationship there. And that turns out to be a very important point. And we can use that not as a way to further complicate things, but as a way to understand on which context less sodium intake or more sodium take can be beneficial.

So that's why i'd d like to turn our attention now. So how much sult do we need and what can we trust in terms of trying to guide our injections of salt? First of all, I want to be very, very clear that there are a number of people out there that have free hypertension or hypertension.

You need to know if you have free hypertension or hypertension. You need to know if you have Normal tension, meaning Normal blood pressure. Everyone should know their blood pressure is absolutely crucial measurement that has a lot of impact on your immediate and long term health outcomes. IT informs a lot about what you should do.

Should, should you be doing more quarter of vascular exercise? Should you be interesting more or less salt? Should you be adJusting any number of different lifestyle factors so you need to know that? And without knowing what your blood pressure is, I can't give a one size fits all recommendation.

And indeed, i'm not going to give medical recommendations. I'm simply gona spell out what I know about the research, which hopeful we will point you in the direction of figuring out what's right for you in terms of solved and indeed fluid intake. There is a school of thought that everybody is consuming too much salt. And I do want to highlight the fact that there are dozens, if not hundreds, of quality papers that point to the fact that a court and called high salt diet can be bad for various organs and tissues in the body, including the brain. IT.

Just so happens that because fluid baLance, both inside and outside of cells, is crucial, not just for your heart and for your lungs and for your liver and for all the organs of your body, but also for your brain, that if the salt concentration inside of cells in your brain becomes too high, neons suffer, right? They will draw fluid into those cells, because water tends to follow salt, as I mentioned before, and those cells can swear, you can literally get swelling a brain tissue. Conversely, if salt levels are too low inside of cells in any tissue of the body, but in the brain included, then the cells of the body and brain can shrink, because water is pulled into the extra cellular space away from cells.

And indeed, under those conditions, brain function can suffer, and indeed the overall health of the brain can suffer. So there are many reports out there indicating both in experimental models into some extending humans that overconsumption assault is bad for brain function and longevity. And yet there is also decent evidence in both animal models and humans that if saw consumption is too low, then brain health and launch event will suffer as well.

Other organism tissues of the body. So like most things, apology, you don't want things too high or too low. Now I would say that the vast majority of studies out there point to the fact that a high salt diet is detrimental to brain health in function.

Most of the studies have focused on that aspect of salt baLance and its consequences on brain function. One critical issue with many of those studies, however, is that the high salt diet is often coupled to other elements of diet that are also unhealthy, things like excessively high levels of carbon hydrate or fats, or combinations of carbo, hydrates and fats. And so, well, I know there are many burning questions out there about how much salt one needs if they are on a low carbo hydroid diet, or if they are fasting, or if they are on a vegan diet.

There haven't simply not been many studies that have explored the low, moderate and high salt conditions on a backdrop of very controlled nutrition. And that's probably reflective of effect that there are not a lot of very well controlled nutrition studies out there. There are some, of course, but it's very hard to get people to add here to nutritional plans in a very strict way, and to do that for sufficient periods of time that would allow that the various health outcomes to occur none's.

There are some interesting reports that indicate that the amount of salt intake can indeed predict health outcomes or what we call hazards events, things like cardiff asked lar events and stroke and so forth. And what's interesting is that indeed a lower, nothing low, because I don't believe that you want you died to be truly low in anything except perhaps poison. But a lower salt diet can reduce the number of these so called hazardous events.

But it's a somewhat of a shallow u shaped function such that, yes, indeed, a high salt intake can be very detrimental for your health, both in terms of cardiff asked lar events, stroke and another gillette ious health events. But somewhere in the middle that actually sits quite to the right, meaning higher than what is typically recommended for all intake, can actually reduce the number of these hazards. Dous events, at least some reports point to that.

And so I want to emphasize what one of those particular reports says. And I also want to be sure to counter IT from the perspective of the context that that study was said in because, again, my goal here is not to give you a strict set of recommendations at all, is to point you to the literature, try to make that literature as clear as possible and allow you to evaluate for yourself. And I don't just say that to protect us.

I say that to protect you because indeed, you are responsible for your health and your health choices. So the paper that are referring to a very interesting one. We, of course, never want to put too much weight on any one report, but this is a paper that was published in two thousand eleven in the journal of the american medical association.

The title of the paper is urinary sodium and plastic um excretion and a risk of cardiovascular lar events. We have not talked much about patasse um yet, but sodium in patasse um tend to work in concert in the brain and body in order to regulate various physiological functions and health. And we'll talk more about patashie as time goes on. The key plot or set of data in this study for those who they want to look at up, we will link to IT. There are a lot of data in here, but is figure one, which is basically evaluating the amount of urinary excretion of sodium, which is a somewhat indirect but nonetheless valuable measure of how much sodium people were ingesting and applaud IT against that is what they call the hazard ratio.

And the hazard ratio points to um the composition of cardiovascular death, stroke, miter, cardio in function and an in fact is an injury and hospitals ation for a congestive heart failure and what IT points to is the fact that the hazard ratio is low dish at sodium excretion of about two grams per day but then continues to go down until about four point five to five grams per day that remember this is sodium expression so it's reflective of how much sodium was in the body, which is reflective of how much so he was injured, ted. And then the hazard ratio increases fairly dramatically, a very steep, slow heading anywhere from seven to eight to ten and out towards, you know twelve grams of sodium and per day. So the simplest way to interpret these data are that at fairly low levels of sodium, meaning IT, about two grams per day, you run fewer health risks.

But the number of risk continues to decline as you move towards four and five grams per day, and then as you increase your salt intake further than the risk dramatically increases. So no study is holy, nor is any figure in any study or any collection of study is holy. Rather, we always want to look at what the bulk of data in a particular field reveal none's.

I think the plot that we described, meaning the graph that we described as pretty interesting in light of the twenty twenty to twenty twenty five dietary recommendations for americans, which are which is that people consume no more than two point three grams, meaning twenty three hundred milligrams of sodium per day. That's about half a tea spoon of salt per day. Now most people are probably consuming more than that because of the fact that they are ingesting proceed foods.

And processed foods tend to have more salt in them than non processed food is. Now of course, that's not always the case, right? Sea salt is not a processors in most cases um and there are a lot of unprocessed oos that can be high and sodium, but process foods in particular tend a lot of sodium.

You can see this simply by looking at the packaging of any number of different foods. But if we are to take this number of two point three grams that the got recommended cut off in gestion of sodium IT actually falls in a portion of the curve that we were talking about a moment ago that indeed is associated with low hazard out, low incidence of hazardous outcomes. Cardiff asked lar rent stroke at sea.

But the according to that plot, the congestion of four or five grams of sodium, almost double or more sodium than is currently recommended, is associate even lower numbers of of hazard events. So we need to think about this, and we need to exploit in the context of other studies, of course, and we need to evaluate in terms of this thing that we've been going back to again and again, which is context, right? These recommendations of two point three gram per di cut off is in the context of a landscape where.

Some people do indeed have hypertension or free hypertension. The incidence of hypertension has gone up dramatically in the last hundred years and seems to continue to go up, whether or not that because of increased salt intake or weather adds because of increased salt intake and other things such as like highly process foods, that isn't clear. Again, pointing to the the chAllenge in doing these epidemiologic studies and really parsing what aspects of a change in h some health metric is due to, for instance, the injections of more sugars versus more salt or simply because of the injection and more sault.

It's a complicated, almost barbed wires topic by now, but we can search to pull apart that barbed ire tangle and start to evaluate some of the other people and other conditions that exist out there, maybe for you that actually weren't more sodium intake and where more sodium intake might actually be beneficial. So again, I want to be very, very clear that you need to know your blood pressure. If you have high blood pressure, your proper pretensions, you should be especially cautious about doing anything that increases your blood pressure.

And as always, you want to, of course, talk to your doctor about doing anything that could adjust your health in any direction. But nonetheless, there are some important papers have been published in recent years. I want to point to one of them in particular.

This is a paper that was published in the journal autonomic neuroscience, basic and clinical. Because this paper, like several other papers, ask the question, and indeed they asked the question in the title to review dietary sodium. How much is too much for those with orthodontic disorders? Now, ortho static disorders come in to a bunch of different varieties, and we're going to talk about those in a moment.

But there are a number of people out there that have low blood pressure, right? People that get dizzy when they stand up, people that are feeling chronically fatigue, and in some case is not all those groups can actually benefit from increasing their sodium intake. Several pisos ago on the huberman lab pocket, I gave IT what is just clearly what we call annic data, which is not even really data, just an ego's data of an individual who was always feeling hungry and craving sugar.

And based on the fact that they also had low blood pressure, I had them torture a physician, and they got permission to try a little mini experiment on themselves. And so they did. And that mini experiment was, any time they felt like they were craving sugar or they were feeling a little light head and dishy rather than reaching for something with chloric and take, they took a little bit of see, saw a little pinch of salt and put IT into some water and drank.

Or in, uh, the case of this individual, they would actually take a little sea salt packet and they would actually just downs's salt packet. And for them that provided tremendous relief for their dizen. Ss, but that, of course, was in the context of somewhat abNormally low blood pressure.

So I don't think that they are alone in the fact that many people out there suffer from a low water pressure condition. Many people out there suffer from a high blood pressure condition. So know your blood pressure and understand that blood pressure in part is regulated by your sodium intake and your sodium male.

why? Well, because of the osama ity of blood that we talked about before, where if you have a certain concentration of sodium, meaning sufficient sodium in your bloodstream, that will tend to draw water into the bloodstream, and essentially the pipes that are your capital ies arteries and invade will be full, the blood pressure will get up to your head, where, as some people, their blood pressure is low, because the osmotic of their blood is low. And that can have a number of downstream consequences.

I should also mention that can be the consequent itself of chAllenges or or even deficits in kidney function. But all of these organs are working together. So the encouragement here is not necessarily to adjust more sodium, is to know your blood pressure and to address whether not an increase in sodium intake would actually benefit your blood pressure in a way that could relieve some of the detainees other symptoms of things like author static disorders.

But of course, to do that in a safe context, and to never play games with your blood sugar or your blood similarity that could set your system down a cade of negative events. Let's look at what the current recommendations are for people that suffer from orthodontic disorders like ortho static hypo, meaning too low tension orthodontic hype tion postal tack cardio syndrome, sometimes referred to s POS P O T S or idiom athi ortho static tacket cardio in syncope. These have the incredibly elaborate names.

Those groups are often told to increase their salt intake. In order to combat their symptoms. The american society of hypertension recommends anywhere from six thousand to ten thousand. These are very high levels.

So this is six grams to ten grams of salt per day, keeping in mind again that salt is not the same as sodium so adequately to about twenty four hundred to four thousand milligrams of sodium per day. Again, if you want to learn more about this and get more of the citation ation, I refer you back to this, a study on dietary sodium and health. How much is too much for those authors of static s sorts? We will put a link to this in the the caption shown notes.

So that's not just in the us. The salt recommendations from the canadian Carter of asia society, ten thousand milligrams of salt per day. So four grams of sodium is what adequately to and on and on and on, four things like pots for these postural syndromes that result from, I should say, from these syndromes that involve low blood pressure when people stand up or in certain posters.

So I point out this paper and I point out these higher salt recommendations to emphasize, again, that context is vital, right, that people with high blood pressure are going to need certain amounts of salt intake. People with lower blood pressure, and maybe with some of these postal ortho static s synergy are going to need higher amounts assault. And for most people out there, you're going to need to evaluate how much salt intake is going to allow your brain and body to function optimally.

And there are some fairly straight ford ways to explore that. And there are some ways to explore that in the context of what you already know about first insult appetite that can make that exploration one in which it's not going to be a constant wandering around in the dark and where you can figure out what's right for you. For most people, a modern increase in salt intake is not going to be detrimental, provided that you consume enough fluid, in particular water.

Okay, meaning, if you happen to over salt a bit, you'll get thirsty, you will adjust more water, and you will excrete the excess sodium. There is evidence that the body can store sodium in various organs, that storage of sodium may or may not be a detrimental thing. In general, access storage of sodium and tissues and organs of the brain body is not fought to be good for a long term health, so eating much more sodium than you need for long periods of time is indeed bad for you.

Earlier, I mention that salt, and your hunger and thirst for salt is homeless esthetically regulated. And indeed, that's the case, much like temperature is homeostatic ally regulated. What that means is, if you pay attention to IT, if your salt levels are low, you will tend to crave salt and I beverages and salty foods, and in most cases, you should probably follow that craving, provided those salty beverages and salty foods are not bringing in a lot of other things or anything.

Ideally, that's bad for you. So I think it's fair to say that whether not your vegan, vegetarian, carnivore, omnivore, that we should all try to limit our industry of processes. I my read of the literature is that sure, some process foods are acceptable for us and aren't gonna kill us out, right? But that for most people in the world, eating fewer processes is is just going to be a good thing to do.

So following your salt, hunger and thirst in most cases, is going to be beneficial, provided that is in the context of eating healthy, non profess foods, on whatever backdrop of nutritional dietary recommendations is right for you. I simply can't tell you what to eat and what not to eat, because I acknowledge the fact that some people are vegans because of ethical reasons related to animals, or some people are vegans because of reasons related to the climate and and the environment. Other people do IT for specific health reasons.

Likewise, I know plenty of people that eat meat and avoid vegetables, believe in or not, and I know people that eat both, and they do this often. Each, I should say, all citing literature that supports their particular camp. In their particular view, it's not a territory I wanted get into.

But with respect of salt intake and the fact that, that salt intake is homeostatic ally regulated IT is the case that if you're craving salt, you probably need IT. So for those of you that are sweating excessively, or even if you're in a very hot environment and you're not exercising and you're just losing, you're losing water insult from your system, remember also that you can be in a very cold and vivement. Very cold, dry environments often go together, and you can be losing a lot of fluid from your body and you will crave fluid and sult even though it's cold and you're not actually you noticeably perspiring.

So if you're exercising lot, if you're particular cold, dry environment or a particular hot environment, you ought to be ingesting sufficient amounts of salt and fluid, a rule of thun for exercise based replenishment of fluid. Um comes from what eh some episodes back referred to as the gallopin equation, uh, the galen equation. Uh, I named IT ill after andy galpin.

And I think a that is the appropriate attribution there. Andy galpin is an exercise physiologist at h kal state fulton, I believe. And he's going to be a cast guest here on the huberman land podcast.

He's in the exceptional muscle physiologist. He also lives in the practical rum where he gives recommendations about exercise to expert athletes as well as the everyday person. So the gallopin equation is based on the fact that we lose about one to five pounds of water per hour, which can definitely impact our mental capacity in our physical performance.

And the reason that loss of water from our system impacts mental passing, physical performance has a lot to do with literally the changes in the volume of those cells, the size of those cells based on how much so team is contained in or outside those cells and something that evaluated to before on the podcast. And i'll talk about more in a moment, which is that neurons signal to one another by way of electricity through something called the action potential, and that actually requires sodium and potash and magnetic. So the gulp equation suggest that we start exercise hydrated with electorates, not just with water.

So that means water that has some sodium, potassium and magnesium. There are simple, low cost ways to do that will talk about. And the formula for hydration, the equation is your body way in pounds, divided by three equals. The answer of fluid you should drink every fifteen minutes that may turn out to be more fluid than you can comfortable ly consume during the activity that you're performing.

No, the gulp an equation is mainly designed for exercise, but I think is actually a very good rule of thun for any time that you need to engage mental capacity, not just physical performance, your body weight compounds divided by three equals, the the answers of fluid you should drink every fifteen minutes does not necessarily mean you have to injustice every fifteen minutes on the dot. And I think many activities, physical activities, but also cogent activities like zoo m meetings or in person meetings, or lecturing, or running or cycling, are going to make IT complicated to in just the appropriate amount of fluid every fifteen minutes on the dot. I'm not going to speak for andy for doctor galpin, but I think he would probably agree that these are averages to shoot for and that unless you're hyper neurotic, the idea is to make sure that you're entering the activity, cognitive or or physical, sufficiently hydrated and that throughout that activity you're hydrogen regularly.

And IT points to the fact that most people are probably under hydrating, but not just under hydrogen, from the perspective of not interesting enough water that they're probably not getting enough electoral lights as well. Sodium, potassium and magnesium. So i've said two somewhat contradictory things. On the one hand, I said, follow your salt appetite. Follow your salt thirst if you're craving salt in just some salt until you stop craving the saul t on the other hand, i've given you this fairly specific recommendation based on the galpin equation that you should ingest your body waiting pounds divided by thirty that so many answers of fluid you should drink every fifteen minutes, which i'm guessing for most people is going to be more fluid than they're currently drinking on average.

And so how could I be that you can have a recommendation for what's optio that's different than the amount that you would reflexively drink? And IT has to do with the fact that a lot of the hormone systems like these are president antia oec hormones, other hormones like a dos ter one, and a lot of the neural and hormonal signals that govern salt and water baLance are fairly slow to kick in. So for instance, if you eat a fairly salting meal and you sense that salt you're probably meaning you detected and perceive IT because the food taste salty, you will probably want to drink a fair amount of fluid with IT.

Whereas if some of the sault is disguised by other flavor, something that will talk about in a few minutes, when we talk about the neural representation of things like salty and sweet, well then you might not notice that something salty. And then a few minutes or hours after ingesting that meal, you might feel very, very tired. You might even wonder whether or not it's because of some blood sugar effect, maybe it's a crash blood you might think um or something else related to that meal or maybe you think it's because of you know some other event in your life.

But actually what you what has happened is you're dehydrated because you didn't recognize that you needed to drink more fluid. So I want to acknowledge the uh the contradiction in the idea that everything is home aesthetically regulated and therefore you are aware of what you need and the counter argument that h you need to follow these strict recommendations is actually going to be somewhere in between. And of course, your body brain can start to adapt to certain levels.

Assault intake. There's now fairly famous study that was done in germany which looked at different phases of salt intake, meaning they had subjects in just either twelve grams of salt per day or nine grams per day, or six grams per day for fairly long periods of time, and they collected urine for testing. This was actually a very controlled study.

I'm just going to paraphrase from the national institutes of health report on the study because they did a very nice right up of IT um and they say that you know a big surprise of these results is that whatever the level of salt that was consumed, sodium was stored and released from the subjects bodies in fairly regular weekly and monthly patterns, meaning people tended to adapt to a certain level of salt intake and then IT LED to a fairly constant amount of salt retention and urine fluid excretion. And that's because of the various hormones like a dos drone which regulate sodium excretion from the kidney and glucocorticoid, which will talk about more in a moment, which help regulate meta and luca cortecs are released from the address inal gLance, which ride to top the kidneys. And there is a very close relationship between the stress system, gluck a cortecs and the salt system.

So the the reason why your salt appetite isn't a perfect read out of how much salt you should adjust and why IT might be helpful to follow some of these formulas like the galpin equation, especially if you're engaging and exercise where you're going to be perspiring, of course, is that your body will tend to adapt to a certain amount assault and take over time, and then you're appetite for assault won't necessarily be the best indication of how much thought you should adjust or avoid. Before I move on, I want to really reemphasize the fact that inside of the galloping equation, there is that mention of every fifteen minutes, and people have come back to me again and again about the saying, I can't drink that much water every fifty minutes. It's too much volume of fluid in my stomach.

I can't run with that. I said to remember, these are averages, so that's what you want to average around a particular activity. These are not strict recommendations where a buzz goes off in every fifteen minutes, you have to truck that exact amount of containing solution. Another key feature of the study, uh, that I was referred to before, which instantly was polishing the journal of clinical investigation, is that the body regulates its salt and water baLance not just by extreme sodium, but by retaining a releasing water.

And this is because of the relationship between thirteen and water that we are talking about before and the advantage of this mechanism, they stayed here on paraphrasing, is that the long term maintenance of body fluids dependent is not as dependent on external water as once believed, right? What this system probably evolved to do was to adjust to different levels of sodium availability in the environment. And that raises a really key element of salt and its importance in human history and human evolution and human health.

We can talk too much about this, and there several very good books about the history assault. You know, sault was a was a very valuable and heavily sought after substance throughout much of human history, so much so that they're actually written reports of people being paid for labor in the form of salt. And the assault at when IT scares could uh has been quite expensive in certain regions of the world, especially regions located further away from the sea.

And a friend of mine who um has deep roots within the colony community told me about travelling to um to somewhat impoverish areas of of europe some years ago and going into homes where in the middle of the kitchen table there was A A fish assault fish hanging from thread above the table and that because of a lack of availability of table salt, the common practice was to take any food that needed some salt for additional flavors and actually rubb that food on this salty Fishers to squeak the fish bit onto a onto the food substance in order to get salt from IT. So you know, that's a very, uh, kind of extreme example. Now is we kind of take salt for most of the discussion out there is about excess salt.

But as I pointing out that you salt for a long time, has in a very sought after commodity, and one that people really cherished for their health. In the episode that I did on metabolic, I talked about the relationship between insult and I adine. If you're interested in ideal, and whether I die, salt or non, I I salt is best are required.

Um i'd enough you to listen to that episode, which was about, again, metabolism. Some people may need more ideal intake, some people perhaps do not. Some people might even want to just things like cup. Some people might not. So please listen to that episode if you're interested in the iodine aspects, assault, which have direct impact on thyroid hormone and thyroid function, which of course, relates to nowadays, there's a lot of interest in and even a kind of proliferation of what I call fancy salts.

So whether not you should be adJusting sea salts or where are not come table salt of in most cases um for what we're discussing here comment table salt is fine but I should point out that sea salt often contains other minerals which can be very useful and we will do entire epo des on those other minerals. So sea salt can contain um you dozens or more of mineral, some of which can be quite valuable to our health, others of which are are less less important, only need to be consumed in trace amounts. But you're not going to get many minerals, if any, from common table salt.

And that's why in addition to the pretty colors and perhaps some people report that they actually takes Better um some of these so called fancy salts or sea salts, you might want to consume A A more advanced form assault, if you will. Although I suppose it's actually the more privative form assault, if is actually the one that comes from the ocean. So we've all heard about how excess salt is bad for blood pressure, gamers, the heart, the brain, sea.

I do want to give some voice to situations where too little salt can actually cause problems. And this has everything to do with nervous system. So without getting into excessive amounts of detail, the kidneys, as we talked about before, are going to regulate salt and fluid baLance.

The address inal gLance, which right to top the kidneys are going to make look a cortical. It's like aldosterone. Those are going to directly impact things like fluid baLance. And in part, they do that by regulating how much craving for and tolerance of salty solutions we have. And there's some really nice studies that have looked at so called a real electives es.

Now this is an extreme case and is typically done in animal models, but IT illustrates the role of the adrenals in salt preference, basically, when the global cord cord system, meaning the release of these particular hormones from the adrenal glands, is eliminated by a real active, active, my means removal. Then the threshold for what's considered too salty really shifts. okay? So typically, when the address ines are intact, a animal or a human.

Will prefer a mildly salty to moderately sault solution, if given a choice. And at some point it's so salty that IT just feels aversive like, just like taking a gulp of sea water is almost always a versions. I can think of an instance where it's not diverse ve and actually drink seawater.

Water can kill you because of the high osmotar ity of seawater. He certainly don't want to drink seawater. Under conditions where the adrin als are missing, animals and humans will tend to prefer a higher sodium concentration fluid, and they will be willing to tolerate ingesting very high concentrations of sodium.

Now, that's a very crude experiment, and not one that you want to do, I promise you. But I mention that because IT illustrates the very direct relationship between the stress system, which is the glucocorticoid system, and the salt craving system. And this actually makes sense earlier, as we were talking about hype of olympic thirst, when there's a loss of blood pressure from, usually due to a loss of blood from the body, there is a salt craving in order to bring that blood volume back up.

Because by ingesting salt, you bring fluid into the bloodstream, you're increasing that blood pressure and you can restore the blood that's lost. Now there are many examples where if sodium levels get too low in the bloodstream, either because people are interesting too little salt, or they're interesting too much water and therefore exciting too much salt, that IT can cause stress and anxiety. There are some really nice data that point to the fact that low dietary sodium can actually exacerbate anxiety in animal models.

And to some extent, there is evidence for this in humans as well. And that should not come as a surprise. The whole basis for a relationship between the address inal system, these google cortecs, things like a dosa rone craving for sodium, is that the stress system is a generic system designed to deal with various chAllenges to the organism, to you or to me, or to an animal.

And those chAllenges can arrive in many different forms. There can be an infection, IT can be farming, IT can be lack of water and so on. But in general, the stress response is one of elevated heart rate, elevated blood pressure in the ability to maintain movement and resistance to that chAllenge.

A said this before, but i'll emphasize IT again, there's this common misperception that stress makes us sick and indeed of stress last too long. IT has a number of negative effects on our health. But more often than not, if we're pushing, pushing, pushing, we're studying or taking care of somebody, you're travelling like crazy.

We don't tend to get sick under those conditions. But as soon as we stop, as soon as we reduce hard general and output, as soon as we reduce our global cord code output from our genes, then we will get sick. That's a very common accurate.

And it's because stress actually activates our immune system in the short term. So i'd like to trying to dispell this, miss that. Stress actually suppresses the immune stem at at least not in the short term. Long term stress is a different issue.

You don't want long term ongoing stress, especially of several weeks or more none's IT makes sense that bringing sodium into the body would be at least one way that we would be wired to counteract or to resist stress stores, right? Stressors being the things on the outside coming at us. So IT could be stressful relationships, stressful job situation, again, infection and so on. It's clear from a number of studies that if sodium levels are too low, that our ability to meet stress chAllenges is impaired. Now that doesn't mean to place your sodium take cosmetically high, but IT does point to the fact that if you're feeling anxious, perhaps from low blood pressure, which can also give symptoms of anxiety we talked about before.

But even if its independent of low blood pressure, that slightly increasing sodium intake, again, I would encourage people do this, not in the context of process foods and drinks, but ideally in the form maybe a little bit of sea salt and water or salt on food, a little bit more that that can stabilize blood pressure and visibility to lean into stresses and chAllenges. And I say this because I think that most people assume that adding salt is always bad, when, in fact, that simply not the case. There are conditions such as when we are under stress chAllenge, when there is a natural craving for more sodium, and that natural craving for more sodium is hard wired into us as a way to meet that chAllenge.

So it's hard for me to know whether or not people out there, especially the listeners of this podcast, are getting too much, just enough or to little sodium. So I can't know that i'm shouting into a tunnel here. You have to decide how much sodium you are ingesting, but I think that there's some for most people, especially people who are not hypertensive rehydrating sive, if there's some wago room to explore whether more intake of sodium could actually be beneficial for suppressing some of the anxiety responses that they might feel under conditions of stress.

Again, more studies need to be done. Certainly more studies and humans need to be done. But the relationship between stress and sodium intake, in the fact that additional sodium intake may be beneficial and indeed is naturally stimulated by stress, shouldn't be necessarily looked at as a pathological event.

I know when some people get stressed, they crave sault foods that actually a hard wired biological phenomenon that you see, not just in humans, but in animals, because this is a very primitive mechanism. Thereby your body is preparing to meet any additional chAllenges and stressors. Now we can have a discussion about sodium without having a discussion about the other electro lights magnesium and patasse magnesium um is important enough and an an extensive enough topic that we should probably do an entire episode just on magnesium purpose.

Today's discussion, I just will briefly touch on some of the forms of magnesium that we discussed on the podcast before in different context. And one emphasized that many people are probably getting enough magnesium in their diet that they don't need to supplement magnesium. Some people, however, opt to supplement magnesium in ways that can support them.

And there are many different forms of magnesium. And just in very brief passing, i'll just say that there is some evidence that you can reduce muscle sourness from exercise by injection of magnesium mallet ml. A E. I've talked before about magnesium three unit T H R E N O A T E, magnesium three, eight for sake of promoting the transition into sleep and for depth of sleep.

And perhaps again, highlighted perhaps because right now it's mainly animal studies and ongoing human studies, but the data are not in perhaps magnesium three and eight can be used as a way to support cognitive function and longevity. That was discussing the episode with doctor jack feldman from ucla. Typically, magnesium three and eight is taken thirty or sixty minutes before bedtime.

In order to be encourage sleep, you can go to our neural network newsletter and look for the one on sleep h and you can see the recommendations or I should say that the um options for that because again, you should always h check with your physician. Those aren't strict across the board recommendations and then there are other forms of magnesium. Magnesium, which license, which is someone of alternative to three and eight, not known to have coalition enhancing effects, but seems at least on par with my museum, three, eight, in terms of promoting transition into the depth of sleep and so on.

There other forms of magnesium magnesium state which um as other functions actually maui um centrate is is a fairly effective lacie not known to promote sleep and things in that sort. It's a lot of different forms of magnetic sim and there are still other forms out there. Many people are not getting enough magnesium.

Many people are okay. So that's magnesium. Anytime we're talking about sodi imbaLance, we have to take into consideration patache because the way that the kidney works and the way that sodium mbale ces regulated, both in the body, in the brain, is that third man patasse are working in close concert with one another.

There are a lot of different recommendations about ratios out there, and they range widely from two to one ratio of patagium to sodium. I ve heard IT in the other direction too. I've heard a two to one sodium to patashie um the recommendations vary.

One of the sponsors of this podcast for insinuation ment i've talked about in this episode and before the ratio there is a gram of sodium m to two hundred milligrams of paci um sixty milligrams of bonesetter. So there they've opted for A A five to one ratio of sodium to potassium. And of course, many people have to make their own hydration elector light formulas.

They'll sea sault into water, maybe even in just a peasticks tablet. IT all depends on the context. And an important contextual element is your diet. So for instance, cover hydrates tes, hold water in the body.

So regardless how much salt and how much fluid, you're interesting, if you're interesting, carbon hydrate and you drink fluid water, some of that fluids can be retained in the body. For people that are following low carbo hydroid diets, one of the most immediate effects of a low carbohydrates diet is that you're going to excrete more water. And so under those conditions, you're also going to lose not just water, but you will probably also lose sodium in patashie.

And so some people, many people, in fact, find that when they are in a lower or low carbon hyder diet, then they need to make sure that they're getting enough sodium and enough parasitic. And some people do that by taking ninety nine milgram paci um tablets every time they eat. Some people do that by interesting more foods that contain potassium.

And of course, some people who are on low carbon hydrates ets do ingest vegetables, you know, other forms of a food that that Carry along with them patasse. So it's quite variable from person to person. I mean, you can imagine if carbo hydrates holds water, water and salt baLance in peason go hand in, hand in hand, that if you're on a low cover hydro diet, that you might need to adjust your sault antin peasant.

And conversely, that if you're on a carbo hydrox ich diet or a moderate carbo hydroid diet, then you may need to just less sodium and less potash. And fact, a certain amount of water is probably coming in through the foods eat as well. So I don't say all this to confuse you again.

I say this because IT all depends on the context. I'll give you yet another context that I think is fairly common nowadays, which is many people are following a pattern of eating that more less resembles intermit fasting or at least time restricted feeding. So they're eating proof between particular feeding windows.

And then in the certain parts of the tour four hour cycle, not just sleep, but during certain parts they're waking cycle. They're also actively avoiding food banking on, I think, either the possible, I want to say, possible longevity promoting effects of international testing or. And or I should say, they are banking on the fact that for many people, not eating is easier than portion control for certain parts of the day.

And so they find IT beneficial to limit calories overall to a given amount, depending on what their goals are by not consuming food for certain periods of the day. But usually during those parts of day, they're consuming fluid. And often times those fluid include not just water, but caffeine. And caffeine is a diores tic. IT actually causes the excretion of fluid from the body, in part because IT causes the expression of sodium.

All of that to say that if you're somebody who, for instance, eat your first meal around noon or one or two P M, and you're fasting for the early part of the day and you're drinking coffee or tea or and or ingesting a lot of water, you are going to be executing sodium along with that water. And so many people, including myself, fine, that is useful, especially when i'm drinking caffeine during that so called fasting. We're you know non food didn't take part of the of time, are started feeding that i'm making sure to get enough salt either in the form of something like element electrical, like drink, or putting some sea salt and and some water or certainly any time one is interesting, caffeine replacing some of the lost water by increasing one's water intake.

There are some simple rules of thumb around this that I think can get most people into a place where they are more comfortable and functioning Better, which is for every ounce of coffee or tea that you drink, which is a caffeine, coffee or tea that you drink, that you consume one and a half times as much water. So let's say, you have, you know, in advance coffee you try and drink about, you don't want to be exact, but I drink about a twelve olds glass of water. And you might want to put a tiny bit of sodium into that by tiny bit.

I just seen a tiny pinching of sodium because remember, even if we're talking about increasing the amount of sodium intake overall, the total amount of sodium contained in salt s sufficiently high that even just, you know, a quarter teaspoon on is gonna start to move that number up towards that range that's still within the safe arrange. But you're going to if you keep doing that all day long, you're very quickly going going to get into that excessive salt intake range that is dilatory ious for health. So again, if you're consuming more caffeine, you're going to be executing water and salt and potassium.

And so you're going to have to find ways to bring water soil in possing back in. Again, this has to be evaluated for each of your own individual situations. If you're exercising fasted and you're doing that after drinking caffeine, then before daring and certainly after exercise, you're going to want to replenish the fluid and electorates ts that you lost, including sodium.

So you can imagine how there's all starts to become pretty and yet IT doesn't have to be dozing. We can provide some useful ranges that for most people will work. And so let's talk about with those ranges are and i'm going to point to a resource that explores what those ranges are in these various context of nutrition, exercise and so on.

The resource is is a book that was authored by doctor James dee nickell antonio. He's not a medical doctor. He's A A scientist um his cardiovascular physiology as well, I believe as a doctor. Pharmacy in the title of the book is the sault fix so fix is an interesting read because IT points to first of all the history of salt um in society and as IT relates to health, IT actually emphasizes some of the major missteps may be even pretty drastic errors that have been made in terms of trying to interpret the role that salt has in various diseases and emphasizes some of the ways in which perhaps increasing salt can actually improve health outcomes and I think IT strikes a pretty nice baLance between what's commonly known about salt and what I believe ought to be known about salter at least taken in the consideration you the book does provide certain recommendations and actually reach out to the author. I i've never met him in person or talked him directly.

And I asked him, alright, I said, how much salt a do you recommend people take on average? And he gave, of course, the appropriate coverage about prepotent and high potential, etta, but made a recommendation which um i'll just share with you and if you want to learn more about the support for this recommendation, you can check out his book the the recommended he made was anywhere from eight to twelve grams of salt today which corresponds to three point two to four point eight grams of so going back to the current uh, recommendations that we talked about before, two point three grams of sodium per day. This is about one and a half times to double the amount of sodium that's currently recommended um in most circles and what this corresponds to is about one and a half to two tea spoons of salt per day to arrive at at three point to four point in grams of sodium.

Again is the recommendation that was passed along for most people, most conditions, barring you know specific health health issues. Now what was also interesting as he pointed to a sodium to paci um ratio which is a four drams of paci um and he also mentioned four hundred milligrams of magnesium and pointed out and I generally agree here that many people are deficient in magnesium so again, um that was a three point two to four point nine grams of sodium, four grams of paci um you might think. Well, kash, that one and hand to two times the current recommendation but we can go back to that study that was mentioned earlier in the episode that two thousand and eleven study where I described this um sort of jay shaped curve in which when you look at the occurrence of these negative health events, they were fairly low at low sodium intake, lower still at slightly higher sodium take much in line with the recommendations that are made, or that dr.

d. Nicolle tonio passed along to me and then they increased quite those health risk increased quite substantially as one moves out past, you know, six grams of sodium, seven grams of sodium per day. That's when things I really do seem to get hazard this and really IT makes sense.

I think, given the consensus around this, to really avoid very high salt intake. So the salt fix describes the rationale behind those recommendations. So fix also describes in in quite beautiful detail the relationship between salt intake, potassium intake and the relationship to the sugar consumption system.

I'd like to pick up on this idea of the relationship between salt and sugar, because I think that one key aspect of the way that salt can work and can benefit us or can harm us has to do with the way that sodium and sugar are regulated and actually perceived by the brain, and how, under conditions of certain levels of sodium intake, we might be inspired to seek more sugar or to crave sweets more or less. So up until now, we've been talking about salt as a substance in a way to regulate fluid baLance and blood volume and so on. We even talked a lot about salt as a taste, or the taste of things that are salty.

And yet we know that we have salt receptors, meaning neons, that fire action potentials when salty substances are detected much in the same way that we have sweet detectors and bitter detectors, and we have detectors of omi the savery flavor on our tongue. And earlier at the beginning of the epo de, I talked about the fact that we have sweet receptors, neons, that responded, the presence of sugar, or even non chloric sweet things, in the gotten, in that signals up to the brain, through the veggies, nerve, and those signals converge on pathways related dopamine and so on. Well, we also have salt sensors at various locations throughout our digester track, although at the sensation in the taste of sult actually exercise very robust effect on certain areas of the brain that can either make us crave more or set meaning, fulfill our desire for salt.

And you can imagine why this would be important. Your brain actually has to register, whether not you're bringing in salt in order to know whether or not you are going to crave salt more or not. And beautiful work that's been done by the soccer lab, Z K E R sicker lab at columbia university, as well as many other labs, have used imaging techniques and other techniques, such as molecular biology, to define these so called parallel pathways.

Parallel, meaning pathways that represent sweet or the presence of sweet taste in the mouth, and cut. Pro pathways, meaning neural circuits that represent the presence of sault taste in the mouth and gut, and so on. And that those go into the brain, move up through brain stem centres and up to the new cortex in need, where our seed of our conscious perception is to give us a sense and a perception of the components of the foods that would happen to be interesting and sense in a perception of the fluids and the components of those fluid that we happen to be interesting.

Now, parallel l pathways, as i'm describing them, are a fundamental feature of every sensory system, not just the state system, but also the visual system. We are, are low pathways for perceiving dark objects, or his light objects for perceiving red versus Green. And set a, this is a fundamental feature of how we are built and how our system works. And in the test system, much like in these other systems, these pathways are indeed parallel, but they converge and they can influence one another. And I think the simplest way to put this is in the context, first of the visual system weren.

Your ability to detect the color red has everything to do with the fact that you have neurons in your eye that absorb long wavelength of light that we call reds, red wavelength of light, which are longer wavelengths, then, say, blue light, a shorter wavelength IT is really the comparison of the electrical activity of the neurons that absorbed red light with the activity of the neurons that absorb Green light, which actually gives you the perception of red. So that might team a little counterintuitive, but indeed, it's not it's actually because something is red and has less Greenness that we perceive IT as more red than the Green. And this is actually the way that your entire nervous system works is that we aren't really good at evaluating absolute levels of anything in the context of perception, is only by comparison.

And actually, there is a fun experiment that you can do. I think you will probably find IT easily online. You can also do this experiment at home.

You can stare at something that's red or Green for that matter, for a while. So you make an active, a decision to not blink, to stare at something that's red. And then you look away from that thing and you'll actually see a Green after image of that red object.

Conversely, if you look at something that's Green for a while, you stare at and you look away, you will see the red after image of that thing. Now the test system doesn't have quite the same after taste type effect, but the pathways, the parallel pathways for sault and the parallel pathways for sweet and bitter and so on can actually interact. And this has important relevance in the context of food choices and sugar craving.

One of the things that common place nowaday is in many profess foods. There is a business, literally a business of putting so called hidden sugars. And these hidden sugars are not always in the form of color ic sugar s.

There are sometimes in the form of artificial sweeteners into various foods. And you might say, well, why would they put more sugar into a food and then disguise, ed, the sugar taste? Given that sweet taste often compel people to eat more of these things, well, it's a way, actually, of bypassing some of the homeostatic mechanisms for sweet.

You know, even though we might think that the more sweet stuff we eat, more sweet stuff we crave, in general, people have a threshold. Thereby they say, okay, i've had enough a sugary stuff you can actually experiences. If you ever feel like something is really, really sweet, take a little sip of a water with a little bit of lemon, juicy or vinegar.

And IT will quickly quality, that overly sweet sensation or perception disappear almost immediately. There is actually a practice in a fancy meals of cleansing the palate through the injustice of different foods. And that's the same idea that you're cleaning the party, actually neutralizing previous taste. So then they can bring you another dish to over indulge you, h in decades, ts, and so forth. So these sensory systems interact in this way by putting sugars into foods, in hiding the sugar y taste of those foods.

Those foods, even if they contain artificial sweeteners, can activate the sorts of neurons that we talk about at the beginning of the episode, like the neutral pod cells that will then signal to the brain to release more dopamine, to make you crave more of that food. Where, as had you been able to perceive the true, sweetest of that food, you might have consumed a lesson. And he, that's what happens.

So these hidden sugars are kind of diablo. Why am I you talking about all of this in the context of an episode on salt? Well, as many of you probably noticed, a lot of foods out there contain a salty, sweet combination and IT, that combination of sault and suite, which can actually lead you to consume more of the salty sweet food then you would if IT had just been sweet or IT had just been salty.

And that's because both sweet taste and sault case have a homeostatic baLance. So if you injust something that's very, very sault pretty senior appetite for saluti foods will be reduced. But if you mask some of that was sweet, well, because of the uh, interactions of these parallel pathways, you somewhat shut down your perception of how much salt you're ingesting or conversely, by interesting some salt with sweet foods, you mask some of the sweetness of the sweet foods that you're tasting.

And you will continue to indulge in those foods. So salty, sweet interactions can be very diablo. They can also be very tasty, but they can be very diablo in terms of inspiring you to eat more of a particular food then you would otherwise if you were just following your homeostatic salt or your homeostatic sugar baLance systems.

And the beautiful imaging work that's been done by the circle lab and other labs has actually been able to reveal how some of this might work by showing for is that a certain on sambo, meaning a certain group of neurons is activated by a sweet taste. And I, non overlapping, distinct set of neurons just nearby, sitting, you know, chip to jail with those other nurse would be activated by sault taste, and yet others by bitter taste. IT said us, so there's a separate map, these different parallel pathways, but that when foods or fluid are injustices that are both salty and sweet, you get a yet entirely different on sambo of neurons activated.

So your brain, every weather not is for your visual system or your auditory system or your taste system, has a way of representing the pure form of taste, salty, sweet, Better at a and has a way of representing their combinations. And fill manufacturer have have exploited this um to large degree, I mention all of this because if you're somebody who is looking to explore either increasing or decreasing your sodium intake for health benefits, for performance benefits, in many ways, IT is useful to do that in the context of a fairly pure, meaning unprocessed food and take background whether or not that's kito, carnie, omnivore, inner man fasting or what have you IT doesn't really matter. But the closer that foods are to their basic form and taste, meaning not large combinations of large amounts of ingredients and certainly avoiding highly processed oos, the more quickly you're going to be able to hone in on your specific salt appetite and salt needs, which has ever point out numerous times throughout this episode, are gona vary from person to person, depending on nutrition, depending on activity, depending on hormones, status or even portion of your menstrual cycle, for that matter.

So if you want to home in on the appropriate amount of sodium for you, yes, blood pressure is going to be an important metric to pay attention to as you go along. And the parameters for healthy blood pressure ranges are readily available online. I'll let you refer to those in order to determine those for yourself, but in determining whether or not increasing your sault intake might be beneficial for a, for instance, for reducing anxiety a bit or for increasing blood pressure to offset some of these postal syndromes where you get dizzy set up for improving sports performance or cognitive performance.

I can only recommend that you do this in a in a fairly clean context where you're not trying to do this by ingesting a bunch of salty foods or salty sweet foods at sea. And indeed, many people find, and it's a reviewed a bit and some of the data reviewed in the book, to salt fix, that when people increase their sault intake in a backdrop of relatively unprocessed foods that sugar cravings can I D be vastly reduced. And that makes sense, given the way that these neural pathways for salty and sweet interact.

Now thus far, i've already covered quite a lot of material, but I would be completely remiss if I didn't emphasize the crucial role that sodium plays in the way that neurons function. In fact, sodium is one of the key elements that allows neurons to function at all, and that's by way of engaging what we call the action potential. The action potential is the firing of electrical activity by neons.

Neons can engage electronical activity in a number of different ways. They have graded potentials. They have gap junctions.

There's a whole landscape of different electro physiologies of neurons that I don't want to go into just yet, at least not in this episode. But the action potential is the fundamental way in which neons communicate with one another. There's sometimes called Spikes.

It's just kind Norman nature that neuroscientists use. I'm just going to briefly describe the action potential in the role that soda in plays. And this will involve a little bit of chemistry, but I promise I will be accessible to anyone, even if you don't have a chemistry or a physics background or electro physiology background, neurons have an inside in, an outside.

And inside are things like the genetic material, have a bunch of things floating around in there that allow themselves to function. And they turned out this wire extending out of them, sometimes a very long wire. So there's a short one that we call the acts on.

And at the end of that ware that acts on, they released little packets of chemicals that either caused the next neon to fire action potentials or prevent the next iron from firing action potential, so they can vomit IT out these little packets of of chemicals that either inspire or suppress action potentials in other neurons. The way that that whole process occurs is that a given neuron needs to change its electrical activity. So Normal neurons are hanging out, and they have what we call a negative charge.

And they recently have a negative charge is that the inside of the cell has things floating around in IT, like potassium, a little bit of sodium and some stuff like chLorine. These are literally just, just imagine these as little, little balls of stuff. And if they have a negative charge on them, then the inside of the cell is gonna end to be more negative.

And outside of the cell, IT turns out you're going to have a bunch of stuff that's passively charge. And one of the main factors in creating that positive charge is sodium. Sodium Carries a positive charge. So you have neurons that you can just imagine a for sake of this uh, discussion, you can just imagine as a sphere with wires sticking out of IT, they you put a minus on the inside for negative. You put a plus on the outside for positive.

And when that neuron is stimulated by another neuron, if the stimulation, the electrical stimulation, is sufficiently high, meaning enough low packets of neurotransmitter, or have been vomited onto its surface at sufficient concentration, what happens is little poor little spaces, little gaps open up in the membrane of that cell that separates the inside from the outside. And because it's positive, there's a lot of positive charge outside and there's a lot of negative inside. It's like a bother running downhill.

All the stuff tends to rush downhill. IT tries to create even amounts of charge as negative on the inside, positive on the outside. And what happens is sodium rushes into the cell, Carrying a lot of charge into the cell. And as a consequence, the charge of that cell goes from negative, actually very negative, to quite positive.

And if IT hits a certain threshold of positive charge because of all the sodium ions going into the the cell, then IT fires what's called an action potential, and IT vomits out its own set of chemicals onto the next year on. And so IT sets off a chain of one neuron, goes from negative, positive vo, mitts out chemicals under the next one, the next one, the next neuron that binds to receptors are, enters the cell. And that cell goes from negative to positive, charge vomit contents onto the next, and so on and so forth.

Sodium rushing into the cell, therefore, is the way that the action potential is stimulated. In other words, sodium is the way that neurons communicate with one another. Now the neurons don't stay in a positive charge, otherwise they would just keep bombing out their content.

But they need to maintain some of that, and they need to go back to preparing to do IT the next time and the next time by resting a bit. And turns out that the way they restore their charge is by pushing that sodium back out of the cell. There are mechanisms in place to do that, things like the so called sodium patasse pump.

There is a change in the levels of a potassium across the cell member, rain, and so on and so forth. If you want to look at the demonstration that you can just you can put into a web browser the action potential, you will find some beautiful descriptions there on youtube and elsewhere, maybe some time on instagram. Do a description with a diagram because I realized number of people are just listening to this.

I can do that here. I won't do that here because I want everyone to be able to get the same amount of a material regardless of where are there watching and we're listening to this. But the point i'd like to make, at least as a related to this episode on salt, is that having sufficient levels of salt in your system allows your brain to function, allows your nervous system to function at all.

Again, this is the most basic aspect of nervous system function. And there are cases where this whole system gets disrupted. And that brings us to the topic of soil and water baLance.

Many of you would probably hurt, but hopefully if you haven't, you'll take this message seriously. If you drink too much water, especially in a short amount of time, you can actually kill yourself, right? And we certainly want that to happen.

If you in just a lot of water, in a very short period of time, something called hyper nitre mia, you will excrete a lot of sodium very quickly in your ability to regulate kidney function will be disrupted. But in addition to that, your brain can actually stop functioning. So people have actually consumed water to access, especially after sports events and so forth.

And if that water doesn't contain sufficient al electoral lights, you can actually shut down neuron sibling to function at all by disrupting this baLance of sodium and potash and the amount of extra cellular sodium and neutron sbility to signal to one another through action potentials. And I can't emphasize the importance of action potentials enough. They are the way that I can lift my pen right now.

They're the way that I can speak to, the way that you breathe. They literally control all aspects of your nervous system function. Now IT takes quite a lot of water and take before you extreme enough sodium that your nerve system is going to shut down. I certainly don't want to give the impression that simply by ingesting more sodium, your neurons will work Better.

But IT absolutely is the case that if you don't just enough sodium, that your neurons won't function as well as they could, and that if your sodium levels are made too low by hamer's or by ingesting so much water fluid, that you excrete excess amounts sodium worth through any other mechanism, that is, then indeed your neons won't be able to fire. Action potentials in your brain, in our system simply won't work. And that's one of the primary reasons why dehydration leads to confusion and dizen ss and lack of coordination.

And I talked about this a bit and the episode on endurance, but there are instances in which, you know, competitive athletes have come into the stadium to finish a final lap of a long endurance racing, are completely disoriented ted, and actually can't find their way to the finish line. IT might sound like kind of a silly, crazy example, but there are examples of people having severe mental issues and physical issues post exercise, when that exercise involved a ton of sweating or hot environments or insufficient industry of fluid and electoral ze. Because included in the electrodes, mula, of course, is sodium.

And as you just learn, sodium is absolutely crucial for neurons to function. So to briefly recap some of what i've talked about today, we talked about how the brain monitors the amount of salt in your brain and body, and how that relates to first in the drive to consume more fluid. And or salty fluid.

Also talked a little bit about the hormones that come from the brain and Operated the level of the kidney in order to the retain or allow water to leave your system. Talk a little bit about the function of the kidding itself, beautiful organ. We talked about the relationship between salt intake and various health parameters and how a particular range assault intake might be optimal depending on the context in which that range is being consumed, meaning depending on whether not your hypertensive, free hypertensive or Normal tension.

We talked about fluid intake and electronic intake. So sodium, fantastic, the magnesium in the context of athletic or sports performance, but also in terms maintaining cognitive function. Talk about the gallopin equation, which you could easily adopt to your body weight into your circumstances, of course, adJusting the amount of fluid and election ali didn't take upwards, if you're exercising or working in very hot environments.

Downwards, maybe if you're in less hot environments, we are sweating less and so on. We also talked about the relationship between the stress system and the salt craving system, and why those two systems interact and why, for some people who may suffer a bit from anxiety or under conditions of stress, increasing salt intake provides done through healthy means might actually be beneficial. We also talked about conditions in which increasing salt intake might be beneficial for offsetting low blood pressure and some of these postal syndromes that can lead people to dizen ss and so forth.

These are things that have to be explored on an individual basis, and, of course, have to be explored with the support of your doctor. I mention the salt fix, which I think is an interesting read, keeping in mind that a lot of the information in there runs counter to the typical narrative that you hear around salt but nonetheless has some very interesting points that you might want to consider and um certainly will brought in your view of the history of and the applications of salt as IT relates to a great number of health and performance matrix. We also talk about the perception of salt meaning the perception of sault taste, and how the perception of salty taste and the perception of other taste like sweet can interact with one another to drive things like increased sugar intake when you're not even aware of IT, and indeed, how the combination of sault and sweet tax can buys you towards craving more, for instance, process foods, and why that might be a good thing to avoid.

And of course, we talked about salt and its critical role in the action potential, the fundamental way in which the nervous system functions at all. So I hope for you, and listening to this episode, is that you consider a question, and that question is what salt intake is best for you, and that you place that question in the context of your fluid intake, place that in the context of the diet you're following, the amount of caffeine you might be interesting, and the diabetic effects of caffeine. And crucially, that you place that in the context of the electronic lights more generally, meaning sodium, potassium and magnesium, someday there will be an online program or an APP, I imagine, where one could put a bunch of different parameters in about they're particular health status, their particular diet, their particular exercise.

That said, or maybe we would all be run by A I algorithm or something where we would monitor all of that for us, and then IT would spit out for us a precise amount of sodium that we should take in each day. Unfortunately, no such tooler device exist right now. And so all of us have to figure out the appropriate matter of sodium intake for ourselves.

And that has to be done in these under these contextual considerations. Who know maybe one of you will design such an APP or such a device? I think that would be very useful.

If nothing else, today's discussion ought to illuminate the fact that some strict recommended of salt intake cannot be made univerSally across the board for everybody. There's just simply no way that could that could be done. And yet, I think most of what we've learned about salt in the general discussions around health are that it's this evil substance.

Nothing could be further from the truth is an incredible substance. Our physiology is dependent on IT. Our cognition an is dependent, dependent on IT. Indeed, our mental and physical health in our performance in essentially all aspects of life is dependent on IT. And I hope i've been able to illuminate some of the beautiful ways in which the brain and the bodily organs interact in order to help us regulate this thing that we call sodi imbaLances.

And the fact that we have neurons in our brain that are both tuned to the levels of salt in our body and position in a location in the brain that allows them to detect the levels of assault in our body and to drive the intake of more or less salt and more or less fluid. And other electoral lights, religious points to the beauty of the system that we've all evolved, that allows us to interact with our environment and make adjustments according to the context of our daily and ongoing life. If you're learning from and or enjoying this podcast, please subscribe our youtube channel.

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