Using Salt to Optimize Mental & Physical Performance

High-Level Overview

In this Essentials episode, Andrew Huberman takes a fresh look at salt, or sodium, well beyond the usual warnings about blood pressure. He explains how dedicated neurons monitor salt levels and drive thirst, how hormones and the kidneys balance salt and water, why the right amount of sodium varies widely between people, and how salt interacts with stress, sugar cravings and the basic electrical signaling of neurons. He is careful to flag where evidence is limited or controversial and repeatedly urges listeners to know their blood pressure and consult their physician before changing their salt intake.

The tone is educational and methodical, building from brain anatomy to kidney physiology to practical guidelines. Before the main topic, Huberman highlights new research from Diego Bohórquez's lab on gut cells that sense sugar and even distinguish it from artificial sweeteners. The episode then flows from how the brain detects salt, through thirst and fluid balance, to how much salt people need, performance and stress, other electrolytes, the salty-sweet trap in processed food, and finally why sodium is essential for every thought and movement.

The Discussion Explores:

• Gut sensor cells that drive subconscious sugar cravings and can tell sugar from sweeteners
• The OVLT, a brain region with a weak blood-brain barrier that monitors salt and blood pressure
• Osmotic versus hypovolemic thirst, vasopressin, and how the kidney conserves water
• What studies say about how much sodium is healthy, and who may need more
• Hydrating for exercise and mental work with the Galpin equation
• Why stress drives salt cravings, and the roles of potassium, magnesium, low-carb diets and caffeine
• How salty and sweet tastes interact to drive overeating of processed foods
• Sodium's role in the action potential, and the danger of drinking too much plain water

Deep Dive into Main Ideas

A Gut Sense for Sugar

Huberman opens with work from Diego Bohórquez's lab at Duke on neuropod cells, nerve cells in the gut that detect fatty acids, amino acids and sugar. When we eat sugar, these cells signal through the vagus nerve to the brain and trigger dopamine release, promoting craving for more sugary food entirely below conscious awareness. This runs in parallel with the taste of food in the mouth, which he notes matters for processed foods containing hidden sugars. A new paper in Nature Neuroscience, "The Preference for Sugar Over Sweetener depends on a gut sensor cell," found these cells send a distinct signal for non-caloric sweeteners, meaning the gut can subconsciously tell caloric sugar from sweeteners, though the downstream effects aren't yet clear.

Huberman stresses he doesn't demonize artificial sweeteners. Animal studies showing gut microbiome disruption used high doses, and there's still no evidence sweeteners affect insulin in all people. He himself consumes stevia and the occasional diet soda, and recalls drinking lots of diet soda in graduate school and later losing his taste for it. He notes that sweet taste, even without calories, can drive more craving for sweet foods, which may be why manufacturers add sweeteners.

How the Brain Senses Salt

Most of the brain is protected by the blood-brain barrier, which Huberman explains is critical because most neurons can't be replaced; the ovaries and testes have similar barriers, likely to protect genetic material. But a few circumventricular organs, located near the fluid-filled ventricles, have weaker barriers so their neurons can sample the blood. The most important for salt is the OVLT (organum vasculosum of the lamina terminalis). It acts as a border detector, sensing whether sodium or blood pressure is too high or low and triggering hormone release that tells the kidneys to excrete or hold onto water. Without it functioning, he says, you would soon be dead. A quick unit clarification: one gram of table salt contains roughly 388 milligrams of sodium, so salt grams and sodium grams are not the same.

Two Kinds of Thirst

Osmotic thirst is driven by salt concentration. When you eat something salty, like the kettle chips Huberman admits to enjoying occasionally, OVLT neurons detect high osmolarity and signal the supraoptic and paraventricular nuclei. This leads to release of vasopressin, also called antidiuretic hormone, from the posterior pituitary, which reduces urine output. When sodium concentration is low, the system shuts off and urine flows more freely. Hypovolemic thirst is triggered by a drop in blood pressure, for example from blood loss, heavy vomiting or diarrhea. The OVLT has baroreceptor neurons that sense pressure, and the kidney releases renin, which activates angiotensin II (from the lungs, remarkably), which also acts on the OVLT to drive thirst. Both kinds of thirst seek not just water but salt, and thirst is a form of interoception, awareness of the body's internal state.

The Kidney and Fluid Balance

Huberman likes to tell kids that "your urine, your pee, is actually filtered blood." Blood passes through a series of looping tubes in the kidney, with about 90% of reabsorption happening early and fine-tuning happening in the distal part. Vasopressin acts there by making the tubes more permeable, so water returns to the bloodstream and never fills the bladder, rather than locking urine in a full bladder. The key principle is that "water tends to follow sodium," which is how the kidney conserves water. But the system is homeostatic and context-dependent: low sodium can at first increase water loss and later trigger water retention. Hormones complicate things further. Estrogen is linked to water retention during parts of the menstrual cycle and in bodybuilders whose testosterone converts to estrogen, yet estrogen also acts as a diuretic. He adds that vasopressin also plays roles in pair bonding and mating, and cautions strongly against recreational use of vasopressin or oxytocin nasal sprays without a physician.

How Much Salt Do You Need?

Huberman insists everyone should know their blood pressure, since he can't give one-size-fits-all advice. Both too much and too little salt can harm cells, including neurons, by making them swell or shrink. Many studies link high-salt diets to poor health, but they often confound salt with high-fat, high-carb processed diets. He highlights a 2011 study in the Journal of the American Medical Association on urinary sodium and potassium excretion and cardiovascular events. Risk of cardiovascular death, stroke, heart attack and heart failure hospitalization was fairly low at about 2 grams of sodium per day, lower still around 4.5 to 5 grams, then rose steeply from about 7 up to 12 grams. By comparison, the 2020 to 2025 U.S. dietary guidelines recommend no more than 2.3 grams of sodium per day, about half a teaspoon of salt, in a landscape where hypertension has become much more common.

Some people may need more. A review in Autonomic Neuroscience asked "how much is too much" for people with orthostatic disorders, those with low blood pressure who get dizzy on standing, including postural tachycardia syndrome (POTS). The American Society of Hypertension recommends 6 to 10 grams of salt (about 2.4 to 4 grams of sodium) daily for these conditions, and the Canadian Cardiovascular Society 10 grams of salt (about 4 grams of sodium). Huberman recalls an anecdote of a person with low blood pressure who, with their physician's permission, found relief from dizziness and sugar cravings by taking a pinch of sea salt in water. For most people, he says, a moderate increase in salt isn't harmful if they drink enough water, but chronically eating far more sodium than needed is bad for long-term health. Because salt appetite is homeostatic, cravings often signal real need, especially with heavy sweating or very hot or cold, dry environments, ideally satisfied through unprocessed foods.

Hydrating for Performance: The Galpin Equation

For exercise, Huberman cites the Galpin equation from exercise physiologist Andy Galpin. We can lose about one to five pounds of water per hour, affecting mental and physical performance. Start exercise hydrated with electrolytes (sodium, potassium and magnesium), and drink your body weight in pounds divided by 30, in ounces, every 15 minutes. He thinks it's also a good rule of thumb for demanding cognitive work, and stresses these are averages to aim for, not a buzzer every 15 minutes.

Why doesn't thirst alone suffice? Hormonal systems like vasopressin and aldosterone are slow, and salt hidden by other flavors can leave you dehydrated and tired hours later, which you might mistake for a blood sugar crash. The body also adapts: a controlled German study published in the Journal of Clinical Investigation, with people eating 12, 9 or 6 grams of salt per day, found sodium was stored and released in regular weekly and monthly patterns, so long-term fluid maintenance depends less on outside water than once believed. Huberman adds historical color about salt's value, including people being paid in salt and a friend's story of households rubbing food on a hanging salted fish. He notes table salt is fine for most purposes, while sea salt contains additional minerals, and refers listeners to his metabolism episode on iodine.

Stress and Salt Cravings

The adrenal glands, sitting atop the kidneys, release hormones like aldosterone that shape salt appetite. Animal studies removing the adrenals show a dramatic shift toward preferring and tolerating very salty solutions, revealing a direct link between the stress system and salt craving. That makes sense: stress is a generic response to challenges like infection, famine or blood loss, and bringing in salt raises blood volume and pressure to help meet them. Huberman adds that short-term stress activates rather than suppresses the immune system, which is why people often get sick right after a stressful stretch ends. Animal data, and some human evidence, suggest low dietary sodium can worsen anxiety. For people who aren't hypertensive, he suggests there may be room to explore whether slightly more salt, through sea salt in water or salting whole food a bit more rather than processed foods, helps buffer stress. Craving salty food under stress, he says, is a hardwired biological response rather than a pathology.

Magnesium, Potassium, Low-Carb Diets and Caffeine

On magnesium, Huberman says many people get enough from diet, but forms differ: magnesium malate may reduce exercise soreness, magnesium threonate (taken 30 to 60 minutes before bed) may aid sleep and possibly cognition, bisglycinate is an alternative for sleep, and citrate acts as a laxative. Sodium and potassium work closely together, but recommended ratios vary widely; LMNT, for example, uses 1 gram of sodium to 200 milligrams of potassium and 60 milligrams of magnesium.

Diet matters: carbohydrates hold water, so low-carb dieters excrete more water, sodium and potassium and often need more of each, with some taking 99-milligram potassium tablets with meals. People fasting in the morning while drinking coffee or tea should know that caffeine is a diuretic that increases sodium loss. His rule of thumb is to drink about one and a half times as much water as caffeinated coffee or tea (for example, about 12 ounces of water per 8-ounce coffee), perhaps with a tiny pinch of salt, and to replenish fluids and electrolytes around fasted exercise. He cautions that even a quarter teaspoon adds up quickly if repeated all day.

The Salt Fix and a Suggested Range

Huberman points to the book The Salt Fix by James DiNicolantonio, a cardiovascular research scientist and doctor of pharmacy, which covers salt's history and argues some past interpretations of salt and disease were mistaken. When Huberman asked him directly, DiNicolantonio suggested, with caveats for people with hypertension or prehypertension, about 8 to 12 grams of salt per day, which is 3.2 to 4.8 grams of sodium, or roughly one and a half to two teaspoons, along with about 4 grams of potassium and 400 milligrams of magnesium, noting many people are magnesium deficient. Huberman observes this is one and a half to two times current guidelines but aligns with the low-risk zone in the 2011 study, while agreeing that very high intakes, past about six or seven grams of sodium, should be avoided.

The Salty-Sweet Trap

We have separate taste pathways for salty, sweet, bitter and umami, in the mouth and gut, which run in parallel but interact, much like the visual system perceives red by comparing red- and green-sensing cells (the reason you see a green afterimage after staring at something red). Work from Charles Zuker's lab at Columbia shows distinct groups of neurons respond to sweet and salty tastes, and a different ensemble entirely responds to the combination. Because each taste is homeostatically limited, mixing salty and sweet masks each one, bypassing our natural stop signals, which is why "salty sweet interactions can be very diabolical" and drive overeating of processed foods. Hidden sugars work similarly. A splash of lemon or vinegar can quickly neutralize an overly sweet taste, the logic behind palate cleansers.

His practical advice: explore your ideal salt intake on a background of relatively unprocessed foods, whatever your diet, and monitor your blood pressure. He notes that many people find, as reviewed in The Salt Fix, that raising salt intake within an unprocessed diet can greatly reduce sugar cravings.

Sodium Powers Every Neuron

Finally, Huberman explains the action potential, the electrical spike by which neurons communicate. Neurons rest with a negative charge inside, while positively charged sodium is concentrated outside. When stimulated enough, pores open and sodium rushes in, flipping the charge positive, triggering release of chemical signals to the next neuron. Pumps like the sodium-potassium pump then restore the resting state. Every movement, word and breath depends on this.

That's why drinking a lot of plain water very quickly, for example after sporting events, can be deadly: excreting too much sodium disrupts neurons' ability to fire. It takes a lot of water to reach that point, and more sodium won't make neurons work better than normal, but too little impairs them. This is also why dehydration causes confusion, dizziness and poor coordination, as seen in endurance athletes who become disoriented near the finish line.

Conclusion

Huberman's message is that salt is not a villain; "nothing could be further from the truth." Our brains contain specialized neurons positioned to monitor sodium and blood pressure, driving thirst, hormone release and kidney function to keep us in balance, and every neuron depends on sodium to fire. The right intake varies with blood pressure, diet, activity, climate, stress, caffeine use and hormones, so there is no universal number: guidelines cap sodium at 2.3 grams, some research suggests risk is lowest around 4 to 5 grams, and people with low blood pressure may need more. The practical path is to know your blood pressure, work with your doctor, eat mostly unprocessed foods, pair fluids with electrolytes during exercise and caffeine use, avoid the salty-sweet trap of processed foods, and let your body's signals guide you within safe limits.

This is a summary of "Using Salt to Optimize Mental & Physical Performance" from Huberman Lab, giving you the GIST so you can decide if you want the REST. Listen to the full episode.