Using Salt to Optimize Mental & Physical Performance | Huberman Lab Podcast #63

Salt and Health: What You Need to Know

In this podcast, Andrew Huberman, a professor of neurobiology and ophthalmology at Stanford School of Medicine, discusses the role of salt in regulating blood pressure, appetite, sugar cravings, athletic performance, cognitive performance, aging and dementia. He also provides guidelines for optimizing mental and physical health through salt intake.

The Role of Salt in Regulating Blood Pressure

• Salt is often associated with blood pressure regulation.

• The brain regulates our appetite for salt or our aversion for salt.

• Our sensing of salty tastes mediates how much sugar we crave and whether or not we ingest more or less sugar than we actually need.

The Impact of Salt on Health and Performance

• The so-called salt system regulates many aspects of our health and ability to perform in various contexts such as athletic performance and cognitive performance.

• For some people, more salt might help them in terms of health, cognitive functioning and bodily functioning while for others less salt is better.

• Guidelines can be provided by physicians to arrive at a salt intake that's going to optimize your mental, physical health, and performance.

Brain Functioning

• Neurobiology plays an important role in regulating the impact of salt on our body.

• Hormone biology also plays an important role in regulating the impact of salt on our body.

• Liver function is another factor that affects how much salt we should consume.

• Kidney function is also affected by the amount of salt we consume.

Live Events

• Andrew Huberman is hosting two live events in Seattle and Portland in May.

• Presale tickets for these events are available at hubermanlab.com/tour.

Neuropod Cells

• Neuropod cells are neurons that reside in our gut and detect things like fatty acids, amino acids, and sugar.

• When we ingest sugar, neuropod cells respond to that sugar and send electrical signals up a little wire that we call an axon through the vagus nerve into the brain.

• These neuropod cells promote seeking and consumption of more sugary foods subconsciously.

The Gut-Brain Connection

In this section, the speaker discusses how the gut and brain work together to process food and how this system can distinguish between sweet things that contain calories and those that do not.

The Gut-Brain Connection

• The gut senses what is in it at a subconscious level and sends signals to the brain in parallel with signals from the mouth. This system is important for detecting hidden sugars in processed foods.

• A recent study published in "Nature Neuroscience" by the Bohorquez Lab discovered a neuropod cell that can distinguish between sweet things in the gut that contain calories (like sugar) and those that do not (like artificial sweeteners).

• There is a signature pattern of signals sent from the gut to the brain when we ingest artificial or noncaloric sweeteners. It is unclear what downstream consequences this sensing has on our bodies.

• Understanding how artificial sweeteners are consumed at the level of the gut and how they change brain function is important because it affects what we crave, which can lead to excessive caloric intake.

Artificial Sweeteners and Salt Sensing

In this section, the speaker talks about his experience with artificial sweeteners and how they affect our cravings. He also introduces the topic of salt sensing and its impact on our craving for other things.

Artificial Sweeteners

• The speaker used to drink diet soda but found that he didn't like the taste after quitting them.

• Many people consume artificial sweeteners to keep their caloric intake in check.

• Food manufacturers put artificial sweeteners into foods, which can drive more craving for sweet food even if it doesn't contain calories.

Salt Sensing

• Salt sensing can adjust our craving for other things like sugar and water.

• The Bohorquez Lab is one of the premier laboratories looking at how foods consumed in the gut are modifying our nervous system, the foods we crave, and how we utilize those foods.

• This podcast is part of an effort to bring zero cost to consumer information about science and science-related tools to the general public.

Sponsors

• Athletic Greens is sponsoring this podcast. The speaker has been taking AG1 since 2012 as a way to ensure he gets all his vitamins and minerals.

• LMNT is also sponsoring this episode.

Understanding Salt Intake

In this section, the speaker discusses the importance of ingesting appropriate amounts of salt and how to determine what those needs are. He also talks about his personal experience with LMNT, a drink that provides necessary minerals without sugar. The speaker then introduces InsideTracker, a personalized nutrition platform that analyzes data from blood and DNA to help individuals better understand their body.

Importance of Salt

• Salt regulates fluid balance in the brain and body.

• It regulates your desire for salt itself, meaning your salt appetite.

• Salt also regulates your appetite for other nutrients like sugar and carbohydrates.

Sodium vs Table Salt

• One gram of table salt contains about 388 milligrams of sodium.

• Technically, we should be talking about sodium intake instead of salt intake.

Neural Mechanisms for Regulating Salt Intake

• The speaker explains the neural mechanisms by which we regulate our salt appetite and how the brain and body interact in the context of salt-seeking and avoidance.

• He discusses how to determine when we need more or less salt based on factors such as background blood pressure, activity levels, sweat production, cognitive demands, and physical demands.

• The speaker talks about kidney function in relation to regulating salt intake.

Overall, this section provides an overview of why appropriate salt intake is important for our health. It also highlights some key considerations when determining individualized needs for sodium intake.

The Blood-Brain Barrier and Organ Privilege

In this section, the speaker discusses the blood-brain barrier (BBB) and why it is important for the brain to have a BBB. The speaker also talks about other organs that have strict barriers, such as the ovaries and testes.

The Importance of BBB

• Most substances in the body cannot pass into the brain due to the BBB.

• Neurons in most parts of the brain cannot regenerate after injury, so having a BBB is critical.

• Substances can only pass through the BBB if they are very small or critically required for brain function.

Organ Privilege

• Other organs that have strict barriers include ovaries and testes.

• These organs contain genetic material by which we can pass on our genes to our offspring.

• Mutagens that can mutate cell genes are prevented from entering these privileged organs.

Weaker Fences in Brain Regions

In this section, the speaker talks about weaker fences around certain regions of the brain that allow substances to move freely from circulating blood into those regions.

Weaker Fences in Brain Regions

• Certain areas of the brain have weaker fences around them compared to other areas with a strong BBB.

• These regions monitor salt balance and other features happening in the body at osmolarity concentration levels.

The Importance of the Circumventricular Organs

In this section, we learn about the importance of the circumventricular organs, specifically the organum vasculosum of the lateral terminalis (OVLT), in regulating salt balance and thirst.

The Role of Circumventricular Organs

• The ventricles in the brain create spaces called ventricles where cerebrospinal fluid circulates to nourish the brain.

• The OVLT is a circumventricular organ that has neurons that can sense changes in blood and cerebrospinal fluid levels.

• The OVLT does not have a thick barrier fence, allowing it to detect what's passing through in the bloodstream.

• If the OVLT doesn't function correctly, it can lead to death.

Thirst Regulation

• Neurons in the OVLT detect changes in your bloodstream and set off certain events within your brain and body that make you either want to drink more fluid or stop drinking fluid.

• There are two main kinds of thirst: osmotic thirst and hypovolemic thirst.

• Osmotic thirst has to do with changes in salt concentration in your bloodstream.

• One variety of neurons senses osmolarity of blood while another senses volume.

The Osmotic Thirst Mechanism

This section explains the osmotic thirst mechanism, which is triggered by changes in the concentration of salt in the blood.

The Supraoptic Nucleus and Paraventricular Nucleus

• Signals from the OVLT are sent to the supraoptic nucleus and paraventricular nucleus.

• The supraoptic nucleus releases electrical signals within the pituitary gland.

• Certain regions of the pituitary contain axons of neurons that release hormones as well as electrical signals.

Vasopressin and Antidiuretic Hormone

• Neurons in the supraoptic nucleus release vasopressin or antidiuretic hormone (ADH).

• ADH restricts urine secretion when released, while its absence allows urine to flow more freely.

Hypovolemic Thirst

This section explains hypovolemic thirst, which is triggered by a drop in blood pressure.

Baroreceptors and Mechanoreceptors

• The OVLT has neurons that can detect how much salt is in the bloodstream.

• It also harbors baroreceptor neurons that respond to changes in blood pressure.

Causes of Hypovolemic Thirst

• Hypovolemic thirst occurs when there's a drop in blood pressure due to loss of blood volume.

• Other factors such as vomiting, diarrhea, or reduced blood volume can also cause hypovolemic thirst.

Thirst and Fluid Balance

This section discusses the two main types of thirst, osmotic thirst and hypovolemic thirst, and how they are related to fluid balance in the body. It also explains how salt plays a role in retaining water and regulating thirst.

Types of Thirst

• Osmotic thirst and hypovolemic thirst are the two main types of thirst.

• Both types of thirst are not just about seeking water but also about seeking salt.

Salt's Role in Fluid Retention

• Salt can help retain water, but excessive amounts of salt can lead to excessive retention of water.

• The brain and body need adequate levels of salt to function normally.

Interoceptive Perception of Thirst

• Thirst is a form of interoceptive perception, which means it is a conscious recognition of events going on within our body.

• When we are thirsty, we seek to balance our osmolarity by seeking salty fluids or foods.

Kidney's Role in Fluid Balance

• The kidney is responsible for retaining or releasing various substances from the body, including salt, glucose, amino acids, urea, uric acid, and potassium. It responds to hormonal signals such as vasopressin to hold onto more fluid if needed.

• Urine is actually filtered blood that passes through the kidney's series of tubes arranged into loops called Loop Henle depending on how concentrated those substances are in the blood.

Understanding Osmolarity and Vasopressin

In this section, Dr. Huberman explains how the brain detects changes in osmolarity and regulates fluid balance through the release of vasopressin.

Osmolarity and Fluid Balance

• The OVLT senses an increase in osmolarity when salt concentration is increased relative to fluid volume.

• The OVLT signals cascades through the supraoptic nucleus, leading to the release of vasopressin into the bloodstream.

• Vasopressin acts on the kidney to prevent urination and hold onto fluid stores.

• When ingesting a lot of water, with low salt intake, there is a decrease in osmolarity which leads to no signal from OVLT to supraoptic nucleus. This results in excretion of excess water.

Vasopressin's Role in Antidiuresis

• Vasopressin is involved in antidiuresis by preventing urination.

• Vasopressin has distinct mechanisms for its antidiuretic effects and its involvement in sexual behavior and mating.

Note that vasopressin has been mentioned before on another episode of Huberman Lab Podcast where it was discussed in relation to desire, love, attachment, monogamy, nonmonogamy among prairie voles.

Caution in Recreational Use of Vasopressin and Oxytocin

In this section, the speaker discusses the importance of caution when using vasopressin and oxytocin recreationally. These hormones have powerful effects on the brain and body, so it is important to work with a medical professional who can prescribe them or knows how to use them properly.

Effects of Vasopressin

• Vasopressin acts directly on the kidney to prevent fluid release as urine from the body.

• It increases permeability in distal tubes through the kidney, allowing fluid to go back into the bloodstream instead of passing into a collecting duct and then out to the bladder.

• Antidiuretic hormone prevents the bladder from filling at all by making sure that fluid never actually fills up in it.

Sodium and Water Balance

• The kidney uses sodium to conserve water because sodium can hold onto water.

• There is no simple formula for low sodium, high sodium, moderate sodium, and water balance because these systems are homeostatic.

• If we don't have enough sodium, more fluid can be excreted. But if that condition lasts long enough, eventually a system will kick in to retain water.

Complications with Hormones

• During certain phases of menstrual cycles or when estrogen levels are high in males, water can be retained in the body causing edema or swelling.

• Bodybuilders who take anabolic steroids like testosterone may experience water retention due to testosterone conversion into estrogen.

This transcript covers only a small part of a larger video.

Hormones, Salt, and Fluid Balance

In this section, the speaker discusses the complicated relationship between hormones, salt, and fluid balance in the body. The speaker emphasizes that there is no one-to-one relationship between these factors and highlights the importance of understanding how they interact in different contexts.

Hormones, Salt, and Fluid Balance

• The relationship between hormones, salt, and fluid balance is complex and dynamic.

• Understanding how much salt we need and how to guide our ingestion of salt depends on whether we have prehypertension or hypertension.

• It's crucial to know your blood pressure as it informs what you should do regarding cardiovascular exercise, salt intake adjustment or other lifestyle factors.

• Overconsumption of salt can be bad for brain function and longevity while low consumption can lead to shrinkage of cells in the body including the brain.

Effects of Salt Concentration on Brain Function

In this section, the speaker discusses how high or low levels of salt concentration inside cells can affect brain function. The speaker highlights that most studies point to a high-salt diet being detrimental to brain health but notes that many studies couple high-salt diets with other unhealthy elements.

Effects of Salt Concentration on Brain Function

• If the salt concentration inside cells in your brain becomes too high neurons suffer leading to swelling of brain tissue.

• Conversely if salt levels are too low inside cells then cell shrinkage occurs which leads to poor brain function.

• Most studies point out that a high-salt diet is detrimental to brain health while some studies suggest that low salt consumption can lead to poor brain health and longevity.

• There are not many studies that have explored the low, moderate, and high-salt conditions on a backdrop of very controlled nutrition.

Salt Consumption and Controlled Nutrition

In this section, the speaker discusses how there are not many well-controlled nutrition studies exploring the effects of low, moderate, and high-salt conditions. The speaker highlights that it is difficult to get people to adhere to nutritional plans in a strict way for sufficient periods of time.

Salt Consumption and Controlled Nutrition

• There are not many studies exploring the effects of low, moderate, and high-salt conditions on a backdrop of very controlled nutrition.

• It's hard to get people to adhere to nutritional plans in a strict way for sufficient periods of time which makes it difficult to conduct well-controlled nutrition studies.

Salt Intake and Health Outcomes

In this section, the speaker discusses how salt intake can predict health outcomes such as cardiovascular events and stroke. They also discuss a study that evaluates the relationship between sodium excretion and hazardous events.

Lower-Salt Diet

• A lower-salt diet can reduce the number of hazardous events.

• The speaker emphasizes that a truly low diet is not recommended except for poison.

Relationship Between Sodium Excretion and Hazardous Events

• High salt intake can be detrimental to health.

• There is a shallow U-shaped function where higher than recommended salt intake can reduce hazardous events.

• Some reports point to this fact, but it's important to evaluate the context of these studies.

Study on Urinary Sodium and Potassium Excretion

• The paper "Urinary Sodium and Potassium Excretion and the Risk of Cardiovascular Events" was published in 2011 in the Journal of American Medical Association.

• The study evaluates urinary excretion of sodium plotted against hazard ratio for cardiovascular death, stroke, myocardial infarction, hospitalization for congestive heart failure.

• At about 2 grams per day, there are fewer health risks.

• As you move towards 4 or 5 grams per day, the number of risks continues to decline.

• However, at around 7 to 12 grams per day, risk dramatically increases.

Recommended Sodium Intake

• The recommended cutoff for ingestion of sodium is no more than 2.3 grams or about half a teaspoon of salt per day.

• Most people consume more than that due to processed foods having more salt in them than nonprocessed foods.

The Relationship Between Sodium Intake and Hazardous Events

In this section, the speaker discusses how lower sodium intake is associated with even lower numbers of hazardous events.

Lower Sodium Intake and Fewer Hazardous Events

• Lower sodium intake is associated with fewer hazardous events.

• This relationship needs to be explored in the context of other studies.

• Evaluating this relationship requires considering the context in which it occurs.

Hypertension and Salt Intake

In this section, the speaker discusses hypertension and salt intake.

Incidence of Hypertension

• The incidence of hypertension has gone up dramatically in the last 100 years.

• It's unclear whether increased salt intake or other factors such as highly processed foods are responsible for this increase.

Epidemiological Studies on Health Metrics

• Epidemiological studies can be challenging when trying to parse what aspects of a change in some health metric are due to increased sugar or salt intake or simply because of increased salt intake.

Orthostatic Disorders and Sodium Intake

In this section, the speaker discusses orthostatic disorders and sodium intake.

Orthostatic Disorders

• Orthostatic disorders come in different varieties, but many people suffer from low blood pressure conditions that cause dizziness when standing up.

Increasing Sodium Intake for Low Blood Pressure Conditions

• Some groups with low blood pressure conditions can benefit from increasing their sodium intake.

• An individual with low blood pressure who was always feeling hungry and craving sugar found relief by taking a little bit of sea salt when feeling lightheaded or dizzy.

Blood Pressure Regulation

• Blood pressure is regulated by sodium intake and balance because of the osmolarity of blood.

• Sufficient sodium in the bloodstream draws water into the bloodstream, filling up capillaries, arteries, and veins, which increases blood pressure.

Sodium Intake and Orthostatic Disorders

In this section, the speaker discusses the relationship between sodium intake and orthostatic disorders such as orthostatic hypotension, postural tachycardia syndrome (POTS), idiopathic orthostatic tachycardia, and syncope. The speaker also talks about the current recommendations for salt intake for people with these conditions.

Current Recommendations for Salt Intake

• The American Society of Hypertension recommends 6,000 to 10,000 milligrams of salt per day for people with orthostatic disorders.

• The Canadian Cardiovascular Society recommends 10,000 milligrams of salt per day.

• These high levels equate to 2,400 to 4,000 milligrams of sodium per day.

• Context is vital when it comes to salt intake. People with high blood pressure need certain amounts of salt intake while those with lower blood pressure may need higher amounts.

Moderation in Salt Intake

In this section, the speaker emphasizes that moderation is key when it comes to salt intake. They discuss how excess storage of sodium in tissues and organs can be detrimental to long-term health. The speaker also talks about how hunger and thirst for salt are homeostatically regulated.

Excess Storage of Sodium

• Excess storage of sodium in tissues and organs is not good for long-term health.

• Eating much more sodium than you need for long periods of time is bad for you.

Homeostatically Regulated Salt Hunger and Thirst

• Salt hunger and thirst are homeostatically regulated much like temperature.

• If your salt levels are low, you will tend to crave salty foods and beverages.

• Following your salt hunger and thirst in most cases is beneficial provided that it's in the context of eating healthy, nonprocessed foods.

Conclusion

In this section, the speaker concludes by emphasizing that they cannot tell people what to eat and what not to eat. They encourage people to evaluate how much salt intake is going to allow their brain and body to function optimally and explore that in the context of what they already know about thirst and salt appetite.

Evaluating Salt Intake

• People need to evaluate how much salt intake is going to allow their brain and body to function optimally.

• There are some straightforward ways to explore that in the context of what you already know about thirst and salt appetite.

• For most people, a moderate increase in salt intake is not going to be detrimental provided that they consume enough fluids, particularly water.

Salt Intake and Hydration

In this section, Dr. Huberman discusses the importance of salt intake and hydration for physical and cognitive performance.

Salt Intake

• Salt intake is homeostatically regulated.

• If you're craving salt, you probably need it.

• People should ingest sufficient amounts of salt and fluid when exercising or in a particular cold, dry environment or a particular hot environment.

Galpin Equation

• The Galpin equation suggests that we start exercise hydrated with electrolytes, not just with water.

• Your body weight in pounds divided by 30 equals the ounces of fluid you should drink every 15 minutes.

• These are averages to shoot for, and unless you're hyperneurotic, the idea is to make sure that you're entering the activity sufficiently hydrated.

• Most people are probably underhydrating from the perspective of not ingesting enough water and electrolytes: sodium, potassium, and magnesium.

Recommendations

• Follow your salt appetite. If you're craving salt, ingest some salt until you stop craving it.

• Make sure that throughout any activity (cognitive or physical), you're hydrating regularly with fluids containing electrolytes.

Salt and Water Balance

In this section, the speaker discusses how hormone systems like vasopressin antidiuretic hormone, other hormones like aldosterone, and a lot of the neural and hormonal signals that govern salt and water balance are fairly slow to kick in. The speaker also talks about how your body adapts to certain levels of salt intake.

Hormonal Signals for Salt and Water Balance

• Hormone systems like vasopressin antidiuretic hormone, other hormones like aldosterone, and a lot of the neural and hormonal signals that govern salt and water balance are fairly slow to kick in.

• If you eat a salty meal but don't drink enough fluids with it because some of the salt is disguised by other flavors, you might feel very tired later on due to dehydration.

• Your body can adapt to certain levels of salt intake over time.

Study on Salt Intake

• A study conducted in Germany found that people tend to adapt to a certain level of salt intake which leads to a fairly constant amount of salt retention and urine fluid excretion.

• Glucocorticoids released from the adrenal glands help regulate metabolism. There's a close relationship between glucocorticoids (stress system) and the salt system.

• Your body will tend to adapt to a certain amount of salt intake over time, so your appetite for salt won't necessarily be the best indication of how much salt you should ingest or avoid.

Galpin Equation

• The Galpin equation recommends drinking electrolyte-containing solution every 15 minutes during exercise. However, these are averages, not strict recommendations.

• The Galpin equation is what you want to average around a particular activity. It's not a strict recommendation where a buzzer goes off and every 15 minutes you have to chug that exact amount of electrolyte-containing solution.

Salt and Water Balance

• The body regulates its salt and water balance, not just by excreting sodium but also by retaining or releasing water due to the relationship between sodium and water.

The Importance of Salt in Human History and Health

In this section, the speaker discusses the historical significance of salt as a valuable commodity and its importance to human health.

Historical Significance of Salt

• Salt was a valuable and heavily sought-after substance throughout much of human history.

• People were paid for labor in the form of salt, and when it was scarce, it was quite expensive.

• Lack of availability of table salt led to creative ways to obtain salt for food flavoring.

• Nowadays, we take salt for granted, but it has been cherished for its health benefits.

Types of Salt

• Common table salt is fine for most cases, but sea salt can contain other minerals that are useful to our health.

• Sea salt can contain dozens or more minerals that are valuable to our health.

• Some people report that fancy salts or sea salts taste better than common table salt.

Importance of Salt Intake

• Excess salt is bad for blood pressure and can damage the heart and brain.

• Too little salt can cause problems with the nervous system.

• The adrenal glands regulate fluid balance by making glucocorticoids like aldosterone. These hormones impact craving for and tolerance of salty solutions.

Relationship between Stress and Salt Craving

In this section, the relationship between stress and salt craving is discussed. The glucocorticoid system and the salt craving system are directly related to each other. When there is a loss of blood pressure due to a loss of blood from the body, there's a salt craving in order to bring that blood volume back up.

Glucocorticoid System and Salt Craving

• The stress system, which is the glucocorticoid system, and the salt craving system are directly related to each other.

• When there is a loss of blood pressure due to a loss of blood from the body, there's a salt craving in order to bring that blood volume back up.

• Low dietary sodium can exacerbate anxiety in animal models and humans as well.

• Bringing sodium into the body would be at least one way that we would be wired to counteract or resist stressors.

Sodium Levels and Stress Challenges

• If sodium levels are too low, our ability to meet stress challenges is impaired.

• Long-term ongoing stress should be avoided.

• Adding salt can stabilize blood pressure and one's ability to lean into stressors and challenges.

Introduction

This section provides an introduction about how our bodies work when it comes to thirst.

Thirst Mechanisms

• Our bodies have two different mechanisms for thirst: hypovolemic thirst (thirst caused by low fluid volume in the bloodstream), and osmotic thirst (thirst caused by high concentration of solutes in the bloodstream).

• Hypovolemic thirst is caused by a loss of blood pressure due to a loss of blood from the body.

• Osmotic thirst is caused by high concentration of solutes in the bloodstream.

Hormones and Thirst

• The hormone vasopressin plays a key role in regulating fluid balance in the body.

• Vasopressin is released when there's an increase in osmolality (concentration of solutes) in the bloodstream, which causes water to be reabsorbed into the bloodstream from the kidneys.

• Aldosterone is another hormone that regulates fluid balance by increasing sodium reabsorption in the kidneys.

Hydration Myths

This section debunks common myths about hydration.

Myth: Drink 8 Glasses of Water a Day

• There's no scientific evidence to support drinking 8 glasses of water a day.

• The amount of water you need depends on various factors such as your age, sex, weight, activity level, and climate.

Myth: Caffeine Dehydrates You

• Caffeine does not dehydrate you if consumed in moderation.

• Caffeine can have diuretic effects but only at very high doses.

Myth: Clear Urine Means You're Hydrated

• Clear urine does not necessarily mean you're hydrated. It could also mean that you've been drinking too much water and your body is excreting excess fluids.

Hydration Strategies

This section provides tips on how to stay hydrated.

Tip: Listen to Your Body

• The best way to know if you're hydrated is to listen to your body.

• Thirst is a good indicator of hydration status.

Tip: Drink Water Regularly

• Drinking water regularly throughout the day can help maintain hydration levels.

• It's important to drink water before, during, and after exercise.

Tip: Eat Foods with High Water Content

• Eating foods with high water content such as fruits and vegetables can also contribute to hydration.

Tip: Avoid Alcohol and Sugary Drinks

• Alcohol and sugary drinks can dehydrate you and should be avoided or consumed in moderation.

Conclusion

This section concludes the discussion on hydration and emphasizes the

Sodium and Magnesium

In this section, the speaker discusses the relationship between sodium intake and stress. They also briefly touch on magnesium and its different forms.

Sodium Intake and Stress

• For most people who are not hypertensive or prehypertensive, there is some wiggle room to explore whether more intake of sodium could actually be beneficial for suppressing anxiety responses under conditions of stress.

• Additional sodium intake may be beneficial and naturally stimulated by stress.

• Craving salty foods when stressed is a hardwired biological phenomenon that prepares the body to meet additional challenges and stressors.

Magnesium Forms

• The kidney works in close concert with both sodium and potassium to regulate sodium balance in the body and brain.

• Many people are probably getting enough magnesium in their diet that they don't need to supplement it, but some people opt to supplement magnesium in ways that can support them.

• There are many different forms of magnesium, including magnesium malate which can reduce muscle soreness from exercise, and magnesium threonate which can promote sleep transition, cognitive function, and longevity.

• Other forms of magnesium include magnesium bisglycinate which promotes transition into sleep but does not have cognitive enhancing effects like threonate. Magnesium citrate is a fairly effective laxative but not known to promote sleep.

Potassium Ratio

• The ratio of potassium to sodium varies widely from two-to-one ratio of potassium to sodium or vice versa.

• LMNT has opted for a five-to-one ratio of sodium to potassium in their hydration electrolyte formula, but many people opt to make their own formulas by putting sea salt into water and ingesting a potassium tablet.

Effects of Low-Carbohydrate Diets

In this section, the speaker discusses the effects of low-carbohydrate diets on water, sodium, and potassium excretion.

Low-Carbohydrate Diet and Water Excretion

• Low-carbohydrate diets cause increased water excretion.

• Sodium and potassium are also lost along with water.

• People on low-carbohydrate diets need to ensure they get enough sodium and potassium through supplements or food.

Adjusting Salt Intake

• Salt intake needs to be adjusted based on carbohydrate intake.

• Water is also obtained from food.

• Intermittent fasting can lead to increased caffeine consumption which causes fluid loss.

Replacing Lost Fluids

• Drinking fluids during fasting periods is common but can lead to sodium loss.

• It's important to replace lost fluids by increasing water intake.

• For every ounce of caffeinated coffee or tea consumed, 1 1/2 times as much water should be consumed.

The Salt Fix

In this section, Dr. Peter Attia discusses the book "The Salt Fix" by Dr. James DiNicolantonio and its recommendations for salt intake.

Ranges for Salt Intake

• For most people, 8 to 12 grams of salt a day is recommended.

• This corresponds to 3.2 to 4.8 grams of sodium per day.

• This is about 1 1/2 to 2 teaspoons of salt per day.

• These are the recommendations for most people, barring specific health issues.

Relationship Between Salt and Sugar

• "The Salt Fix" describes the relationship between salt intake, potassium intake, and sugar consumption.

• Sodium and sugar are regulated and perceived by the brain in similar ways.

• Under certain levels of sodium intake, we might be inspired to seek more sugar or crave sweets more or less.

Health Risks Associated with High Salt Intake

• Health risks increase quite substantially as one moves out past 6 grams of sodium or 7 grams of sodium per day.

• It makes sense given the consensus around this to avoid very high salt intake.

Perception of Salty Taste

• We have salt receptors that fire action potentials when salty substances are detected.

The Science of Taste

In this section, the speaker discusses how our brain processes taste and the importance of salt sensors in our digestive tract.

Salt Sensors and Dopamine Pathways

• Salt sensors are located throughout our digestive tract.

• The sensation and taste of salt have a robust effect on certain areas of the brain related to dopamine pathways.

• Our brain needs to register whether or not we're bringing in salt to know whether or not we will crave more salt.

Parallel Pathways

• Parallel pathways are a fundamental feature of every sensory system, including the taste system.

• These pathways represent sweet, salty, bitter tastes in the mouth and gut.

• They converge and can influence one another.

Perception by Comparison

• Our nervous system works by comparison rather than evaluating absolute levels of anything in context or perception.

• A fun experiment is staring at something red or green for a while then looking away. You'll see an afterimage that's opposite in color.

Hidden Sugars

In this section, the speaker talks about hidden sugars found in processed foods and their impact on sugar cravings.

Hidden Sugars

• Many processed foods contain hidden sugars, sometimes in the form of artificial sweeteners.

• This is a way to bypass some homeostatic mechanisms for sweet even though we might think that more sweet stuff we eat will make us crave less.

The Interaction of Sweet and Salty Taste

In this section, the speaker discusses how sweet and salty tastes interact in the brain, leading to overindulgence in certain foods.

Sweetness and Palate Cleansing

• Sweetness can activate neurons that signal the brain to release more dopamine, making you crave more of that food.

• Cleansing the palate through ingestion of different foods neutralizes previous taste so that another dish can be enjoyed.

Hidden Sugars

• Foods with hidden sugars can activate neurons that make you crave more of that food.

• Salty-sweet combinations lead to consuming more of the food than if it had just been sweet or salty.

Parallel Pathways

• There are separate maps for different parallel pathways for salty, sweet, bitter tastes.

• Masking saltiness with sweetness shuts down perception of how much salt is ingested.

Pure Food Intake Background

• Eating unprocessed foods helps hone in on specific salt appetite and needs.

• Blood pressure is an important metric to pay attention to when determining appropriate amount of sodium intake.

The Role of Sodium in Neuron Function

In this section, the speaker discusses the role of sodium in neuron function and how it allows neurons to communicate with one another.

Sodium's Role in Neuron Function

• Increasing salt intake in a backdrop of relatively unprocessed foods can reduce sugar cravings.

• Sodium is crucial for allowing neurons to function by engaging the action potential, which is the firing of electrical activity by neurons.

• The action potential is the fundamental way in which neurons communicate with one another.

• When a neuron is stimulated by another neuron, little gaps open up in its membrane, allowing sodium to rush into the cell and carry a lot of charge into it. This causes the charge of that cell to go from negative to quite positive, and if it hits a certain threshold of positive charge because of all the sodium ions going into the cell, then it fires an action potential.

Inside vs Outside Neurons

• Neurons have an inside and an outside. Inside are things like genetic material and other things that allow those cells to function.

• The inside tends to be more negative due to negatively charged particles like potassium while positively charged particles like sodium create a positive charge on the outside.

Neurotransmitters

• At the end of a neuron's axon, they release little packets of chemicals that either cause or prevent other neurons from firing action potentials.

• These packets inspire or suppress action potentials in other neurons.

Action Potential

• An electrical stimulation sufficiently high enough will cause little pores or spaces to open up in the membrane of a neuron, allowing sodium to rush into the cell and carry a lot of charge into it.

• If the charge hits a certain threshold of positive charge because of all the sodium ions going into the cell, then it fires an action potential and vomits out its own set of chemicals.

Sodium and Neuron Communication

In this section, we learn about how neurons communicate with each other through the use of sodium. We also learn about the importance of maintaining a balance between positive and negative charges in neurons.

Sodium Rushing into Cells

• Sodium is the way that neurons communicate with one another.

• Neurons need to maintain some positive charge but also need to restore their charge by pushing sodium back out of the cell.

• There are mechanisms in place to push sodium back out of cells, such as the sodium-potassium pump.

Importance of Action Potentials

• Disrupting the balance of sodium and potassium can shut down neurons' ability to function at all by disrupting action potentials.

• Action potentials control all aspects of nervous system function, including lifting a pen or speaking.

• If you don't ingest enough sodium, your neurons won't function as well as they could.

Hypernatremia and Water Intake

In this section, we learn about hypernatremia and how drinking too much water can lead to an imbalance in electrolytes that disrupt neuron communication.

Drinking Too Much Water

• Drinking too much water can lead to hypernatremia, which disrupts kidney function and neuron communication.

• If ingesting excess water doesn't contain sufficient electrolytes, it can shut down neurons' ability to function at all by disrupting action potentials.

• Dehydration leads to confusion and dizziness due to a lack of coordination caused by disrupted neuron communication.

Importance of Electrolytes

• Insufficient ingestion of fluids and electrolytes can lead to severe mental and physical issues post-exercise, especially in hot environments or when sweating a lot.

Understanding Salt Intake

In this section, the speaker talks about the hormones that come from the brain and operate at the level of the kidney in order to either retain or allow water to leave your system. The speaker also discusses the function of the kidney itself, salt intake, fluid intake, and electrolyte intake.

Hormones and Kidney Function

• Hormones from the brain affect kidney function

• Optimal salt intake depends on health parameters

• Fluid and electrolyte intake important for athletic performance and cognitive function

Salt Cravings and Health Benefits

• Increasing salt intake may be beneficial for anxiety or low blood pressure

• Salt cravings interact with stress system

• Increasing salt intake may offset postural syndromes

Perception of Salty Tastes

• Perception of salty tastes can drive increased sugar intake

• Combination of salty and sweet taste can bias towards craving processed foods

Critical Role of Salt in Nervous System Functioning

• Salt plays a critical role in action potential

• Appropriate sodium intake must be determined based on individual factors

• No universal recommendation for salt intake can be made

Conclusion: Determining Optimal Sodium Intake

In this section, the speaker concludes by encouraging listeners to consider what salt intake is best for them based on their fluid and electrolyte intakes, diet, caffeine consumption, and other contextual considerations. The speaker notes that there is currently no tool or device that can determine the precise amount of sodium intake for an individual, and that this must be determined on an individual basis.

Determining Optimal Sodium Intake

• Consider fluid and electrolyte intakes, diet, caffeine consumption, and other contextual considerations

• No universal recommendation for salt intake can be made

• Someday there may be a tool or device to determine optimal sodium intake

The Brain and Sodium Balance

In this section, the speaker discusses how the brain and bodily organs interact to regulate sodium balance.

Neurons Tuned to Salt Levels

• Neurons in our brain are tuned to the levels of salt in our body.

• These neurons are positioned in a location that allows them to detect the levels of salt in our body.

Adjustments According to Context

• The brain and bodily organs work together to adjust sodium balance according to the context of our daily life.

• This system is beautiful and has evolved over time.

Supporting the Podcast

In this section, the speaker provides ways for listeners to support the podcast.

Subscribing and Leaving Reviews

• Listeners can subscribe to the podcast on YouTube, Spotify, or Apple.

• On Apple, listeners can leave up to a five-star review and a comment.

• Comments are best left on YouTube where suggestions for future guests or topics can be made.

Sponsors and Patreon

• Listeners can support the podcast by checking out its sponsors mentioned at the beginning of each episode.

• The podcast also has a Patreon page where listeners can support it at any level they like.

Supplements and Thorne Partnership

In this section, the speaker discusses supplements and their quality.

Benefits of Supplements

• While not necessary for everyone, many people benefit from supplements for enhancing sleep, focus, etc.

Quality Issues with Supplements

• One issue with supplements is that their quality varies tremendously from one brand to another.

Thorne Partnership

• The speaker has partnered with Thorne because their supplements are of high quality.

• Thorne supplements include precise amounts of ingredients listed on their bottles.

• They have partnered with major sports teams and the Mayo Clinic, so trust in their products is high.

• Listeners can get 20% off any Thorne supplements by going to thorne.com/u/huberman.

Social Media and Newsletter

In this section, the speaker discusses social media and a newsletter related to the podcast.

Social Media

• Listeners can follow Huberman Lab on Instagram and Twitter for science-based tools that sometimes overlap with the content of the podcast.

Neural Network Newsletter

• The "Neural Network" newsletter comes out once a month and is zero cost.

• It includes short summaries from podcasts, key takeaways, resources, and tools not found elsewhere.

• Listeners can sign up for it at hubermanlab.com.