Science → Why your brain needs electrolytes (especially sodium)

Your brain is an intricate command center, directing your nervous system like a conductor directs an orchestra. And a brain without electrolytes? That’s like a conductor without arms — no amount of vigorous head bobbing will keep the band on track.

Electrolytes are charged minerals that — among other things — help regulate mood, maintain energy, and facilitate cognition. Without them, you couldn’t move or even think. Sodium, in particular, is the big one.

You’ve probably experienced the foggy slump of sodium deficiency firsthand, even if you were unaware of its acute cause. I certainly have, and let me tell you… Dull headaches and a cloudy mind do not help you write books, raise two girls, or avoid getting strangled on the jiu-jitsu mat. Bumping up my sodium intake was a massive epiphany for me. I felt the difference immediately.

Sodium is the star of this article, but your brain also needs other electrolytes like calcium, magnesium, chloride, potassium, phosphorus, and bicarbonate. We’ll cover the relevant science shortly. First, though, let’s absorb the big picture of how electrolytes influence that gray hunk of noodles in your noggin.

Electrolytes and Your Brain

Electrolytes have two primary roles in your body:

  1. Conducting nerve impulses and other cellular communications
  2. Regulating fluid balance

Big surprise: The first job is critical for cognitive function. Your brain is a dense cluster of nerve cells (neurons) that continually transmit electrical messages, and electrolytes help facilitate exchanges between these neurons. The ratio of electrolytes inside and outside of a cell dictates whether or not a nerve impulse fires and sends its valuable message.

Put simply: If you short your body on electrolytes, you short the system’s circuit. For a more complex, detailed explanation (and possibly a headache), check out this resource on the mechanics of electrochemical signaling.

Besides cellular communication, electrolytes like sodium and potassium influence the distribution of water inside and outside cells. Maintaining this fluid balance keeps your brain cells the proper size and the brain as a whole suspended in the proper amount of fluid. We much prefer that to brain swelling or shrinkage.

Let’s examine sodium more closely now.

How Your Brain Regulates Sodium Status

Your brain is keen on maintaining your sodium status. Why? Because sodium balance helps regulate blood volume, blood pressure, and cellular communication — all essential to keeping us alive.

Here’s how the brain keeps your blood sodium levels in check. A brain region called the hypothalamus monitors sodium levels via specialized neurons called osmoreceptors. If the osmoreceptors report low osmolality (low sodium concentration), your brain stops secreting antidiuretic hormone (ADH). Less ADH makes you pee more, reducing blood fluid levels and restoring blood sodium concentration.

The opposite happens if sodium levels rise. Your brain secretes ADH to retain fluid, and triggers thirst to encourage water consumption. Both maneuvers dilute sodium levels back to normal ranges. But sometimes, fluid levels may shift too quickly for your body to keep up. Then, you have an imbalance on your hands.

How Sodium Imbalance Affects Your Brain

There are two types of sodium imbalance: hyponatremia (low blood sodium levels) and hypernatremia (high blood sodium levels). Both can cause neurologic issues.

#1: Hyponatremia

Hyponatremia has many possible causes, but overhydration is the most preventable. When someone drinks plain water beyond thirst, it dilutes blood sodium levels and leads to a bunch of neurologic issues. Athletes in particular are susceptible because we’re taught from a young age to guzzle water while exercising to stay hydrated.

Exercise-associated hyponatremia may cause athletes to be light-sensitive, confused, sluggish, agitated, and dizzy. As sodium levels drop further, there’s a risk of brain swelling, brain damage, coma, and, in the most extreme cases, death. Fortunately, exercise-associated hyponatremia can be treated by restricting fluid intake or by taking super concentrated saline (oral or IV).

That said, diagnosis and treatment is tricky and should be handled by a qualified medical professional. Many hyponatremic patients are asymptomatic or have subtle symptoms like headache, irritability, mild nausea, and forgetfulness. These chronic cases carry a higher risk of osmotic demyelination syndrome (a type of brain cell damage) if sodium status is corrected too rapidly. Please, folks, work with a medical professional if you’re dealing with a sodium imbalance.

#2: Hypernatremia

Severe dehydration is the primary cause of hypernatremia. When you significantly lower blood volume, the concentration of sodium in that blood rises. Most people are unlikely to develop hypernatremia because they have access to water and a functioning thirst mechanism. Older folks may be at relatively greater risk for hypernatremia because aging can wear on the thirst mechanism. They’re also more likely to be on diuretics, increasing loss of water.

The symptoms of rising blood sodium levels include headache, fatigue, cramps, dark urine, etc. — many of which overlap with the symptoms of dehydration.

In the brain, hypernatremia causes water to flow out of cells, shrinking them. If hypernatremia becomes chronic, the brain adapts by adding more osmolytes to the scene. Osmolytes are particles that help cells suck up water and return cells to their regular size. But this adaptation carries a risk: If plain fluids are reintroduced too quickly, the extra osmolytes can cause brain swelling.

The takeaway is that chronic hypernatremia may take a week of slow and steady rehydration to correct. Again, treatment is best handled by a medical professional.

How Sodium Deficiency Affects Your Brain

Sodium deficiency — unlike sodium imbalance — is not severe enough to appear on a blood test, but it affects the brain nonetheless. I already touched on subtle symptoms of low dietary sodium like low energy, headache, brain fog, and fatigue. They plagued me for years both on and off the jiu-jitsu mat.

Chronic low sodium consumption is so undesirable that your brain may even adapt to prevent it, increasing sodium appetite at the expense of other pleasures. A study on rodents helps illustrate this. When researchers induced salt deficiency in rats, the animals stopped doing things they usually enjoyed — like drinking sugar water and slapping a lever connected to electrically stimulated pleasure centers in their brains (got to get me one of those!). After restoring sodium levels by drinking a saline solution, the rats resumed their normal happy rodent behaviors.

Human evidence has also suggested a connection between low sodium and depression, albeit in a small population. This article on sodium and mood explores the topic more deeply.

Other Electrolytes and Brain Health

Sodium isn’t the only electrolyte that affects cognition. The other six primary electrolytes play a role too.

#1: Magnesium 

As a cofactor to over 300 enzymes in the human body, it’s no surprise that magnesium affects the nervous system. Being low on magnesium can cause seizures, tremors, muscle spasms, and weakness, among other symptoms.

Poor magnesium status can also affect your mood. Magnesium may help with anxiety and depression by decreasing glutamate (an excitatory neurotransmitter), increasing GABA (a calming neurotransmitter), and increasing serotonin (a mood-regulating hormone). Read this article on magnesium and mood for a deeper dive.

#2: Chloride 

Chloride and sodium are chemically and physiologically linked — and they appear together in nature — so there hasn’t been much research on chloride (specifically) and brain health. Some mouse data, however, suggests healthy chloride levels may play a role in combating Alzheimer’s disease.

#3: Potassium 

Neither potassium nor sodium intake predicted cognitive decline in older adults over a 6.9-year follow-up. Still, potassium does support healthy blood pressure, and high blood pressure is a well-documented risk factor for dementia.

#4: Calcium 

Calcium works with sodium, chloride, and potassium to facilitate cellular communication in the nervous system. Consequently, low blood levels of calcium can cause cognitive symptoms like fatigue, depression, anxiety, and irritability. Hypocalcemia usually stems from issues related to parathyroid hormone, kidney disorders, and certain medications.

Suboptimal dietary calcium — below 1 gram per day — is pretty rare. The science also suggests that getting calcium via diet is safer for your heart than supplements. Read this article for a broad understanding of calcium, or this article for a deeper understanding of calcium imbalance.

#5: Phosphorus 

Phosphorus deficiency can cause neuromuscular problems like muscle weakness, tremors, and respiratory dysfunction. But since phosphates are abundant in the food supply, deficiency is rare and supplementation usually isn’t necessary. In fact, researchers have linked high-phosphorus American diets to increased fracture risk.

#6: Bicarbonate 

This unsung electrolyte is a byproduct of respiration and helps tissues maintain a proper pH. Research links low bicarbonate levels to lower performance on cognitive tests, but it’s unclear if the relationship is causal. Low bicarbonate may be a warning flag for another pathology.

Keeping Your Brain Happy With Electrolytes

Before I sign off, I want to share some takeaways for maintaining a brain-friendly electrolyte status. These build on what you learned today:

  • Drink to thirst. Drinking to thirst lowers your risk of overhydrating and developing exercise-associated hyponatremia.
  • Eat electrolyte-rich foods. Most plants are rich in electrolytes like magnesium, potassium, and calcium. Read this article for suggested foods.
  • Get enough sodium. The evidence suggests that 4–6 grams daily is a wise baseline for heart health and longevity. Modulate accordingly based on these diet and lifestyle factors.
  • Track and supplement if needed. Track electrolyte status using an app like Cronometer, and supplement to make up any shortfalls. Deficiencies in sodium, potassium, and magnesium are most common; research-backed targets for those electrolytes are 4–6 grams of sodium3.5–5 grams of potassium400–600 mg of magnesium.

When your body has access to the right amount of electrolytes, life goes more smoothly and you don’t get strangled on the jiu-jitsu mat as often! I hope this information helps you operate better in your own day-to-day, as it’s helped me.

***Are you ready to take back control of your life? Meet with our Board Certified Holistic Nutritionist to learn more about how we can help you create a nutrition plan that is right for you. Click HERE for your Alanis Nutrition Intro Consultation

Originally Published by Robb Wolf


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