Salt is easy to blame for bloating, high blood pressure, or that heavy feeling after a takeout meal. But neuroscientist Andrew Huberman says the real story is more interesting, because sodium also helps brain cells fire, guides thirst, and tells the kidneys when to hold on to water.
The main message is not to eat more salt blindly. It is to understand your own context, especially your blood pressure, your workouts, your diet, and whether you have a condition that changes fluid balance. Most Americans already get too much sodium, with the CDC reporting average intake above 3,300 milligrams a day, while federal guidance recommends less than 2,300 milligrams for teens and adults.
Salt is a brain signal
Andrew Huberman, Ph.D., is a tenured associate professor of neurobiology and ophthalmology at Stanford University School of Medicine, according to his Stanford profile. In a Huberman Lab episode on salt, he described sodium as essential for the nervous system, especially for the electrical signals that neurons use to communicate.
“Sodium is one of the key elements that allows neurons to function at all,” Huberman explained. Put simply, brain cells do not work in plain water. They depend on charged minerals, including sodium, potassium, and magnesium, to keep the body’s wiring online.
Why thirst is complicated
Ever wonder why a salty snack makes water suddenly feel urgent? Huberman pointed to the organum vasculosum of the lamina terminalis (OVLT), a brain area that can detect changes in the blood and help trigger thirst signals.
He described two main forms of thirst. Osmotic thirst is linked to a higher concentration of salt in the blood, while hypovolemic thirst happens when blood pressure or blood volume drops. In both cases, the body may be looking for more than water, because sodium and fluid balance are tightly connected.
The kidneys get the message
The brain does not manage hydration alone. Huberman explained that vasopressin, also known as antidiuretic hormone, acts on the kidneys and helps the body conserve fluid when needed.
In practical terms, that means the body is constantly adjusting. After a salty restaurant lunch, after a sweaty run, or during a day when you are drinking a lot of coffee, the brain and kidneys are quietly negotiating how much water and sodium to keep.
Too much can still be risky
None of this makes excess salt harmless. The FDA says sodium attracts water into the bloodstream, which can increase blood volume and blood pressure, and long-term high blood pressure can harm the heart, kidneys, brain, eyes, and arteries.
The American Heart Association recommends no more than 2,300 milligrams of sodium a day for most adults, with an ideal target of no more than 1,500 milligrams for many people. That 2,300 milligrams is about one teaspoon of table salt, not 2.3 grams of salt.
Too little may matter too
Here is where the story gets less tidy. Huberman emphasized that blood pressure should guide the conversation, saying he could not give a universal recommendation without knowing it.
Some people with orthostatic disorders, including postural orthostatic tachycardia syndrome (POTS), may be told by specialists to increase fluids and salt. A Heart Rhythm Society consensus statement says up to 10 to 12 grams of sodium chloride a day (about 1.7 to 2 teaspoons of table salt, or roughly 4,000 to 4,800 milligrams of sodium) may be considered for some POTS patients, which is far above the general public health target and should be medically supervised.
Electrolytes work together
Sodium does not act alone. Huberman also emphasized potassium and magnesium, noting that sodium and potassium work closely together in the brain and body.
Low-carbohydrate diets can also change the picture. Huberman noted that people eating very few carbohydrates may excrete more water, sodium, and potassium, which is one reason some people feel better when electrolytes are adjusted. Still, this is not a green light to guess.
Processed foods blur the signal
For most people, the bigger problem is not a tiny pinch of salt added at home. It is the sodium built into packaged, prepared, and restaurant foods, which account for more than 70 percent of the sodium Americans eat, according to the American Heart Association.
Huberman also warned that salty and sweet tastes can interact in processed foods, nudging people toward eating more than they planned. Think chips, cookies, sauces, and ready-made meals. The label may tell a clearer story than your appetite does in the moment.
What to keep in mind
The safest takeaway is simple. Know your blood pressure, read Nutrition Facts labels, and look at sodium across the whole day, not just at the salt shaker. Most people do not need a complicated protocol to start making better choices.
At the end of the day, salt is not just a seasoning. It is part of a system that helps the brain, kidneys, blood vessels, and muscles stay in sync. The trick is keeping that system in range, not pushing it to either extreme.
The official podcast episode was published on Huberman Lab.
