When someone says that "electrolytes balance hormones," what do they really mean? That's about as vague and nondescript as saying plants breathe air.
They could mean lots of things. They could mean that low sodium levels increase cortisol, your primary stress hormone. Or they might be talking about the somewhat controversial link between sodium and thyroid hormones.
Even less likely, they’re referring to aldosterone, an adrenal hormone which plays a key role in regulating sodium and potassium levels in the blood. Aldosterone doesn’t get much airplay, but it has a big impact on blood pressure.
If you search the internet, you won’t find many popular articles on electrolytes and hormones—so the widespread confusion isn’t surprising. Sure, there’s lots of scientific research. But there’s little summing it all up, and even less in a concise and easy-to-digest manner.
That’s why I wrote this article. To blaze a new trail, tune up your BS detector, and share some potentially useful knowledge on how these vitals components—hormones and electrolytes—work together to function systematically. Let’s start with sodium, because this electrolyte will be our star today.
The Hormonal Dangers of Low Sodium
The US government recommends consuming under 2.3 grams of sodium per day, ostensibly to lower the risk of heart disease. In other words, they recommend a low sodium diet.
Here’s the thing though. There’s NO EVIDENCE that low sodium diets improve heart health outcomes. Actually there’s evidence to the contrary.
Read Robb's article on sodium for more on this. Today, I want to talk about how sodium restriction puts certain hormones on overdrive—and how these changes could be detrimental to health.
At the most basic level, when you restrict salt, your body is like: “Ah crap, I need to hold onto what little sodium I have!” It’s a smart mechanism to save sodium, but it has consequences. Let’s talk physiology now.
Sodium-retention is governed by a system of hormones called the renin-angiotensin-aldosterone system. I’ll talk more about this system later but, for now, understand that when sodium levels drop, this trio of hormones tells the kidneys to stop peeing out sodium. These hormones also serve to increase blood pressure.
This likely explains data from the Framingham Heart Study which found that folks on low-sodium diets had HIGHER blood pressure than folks eating more reasonable levels of salt. I suspect renin, angiotensin, and aldosterone had a lot to do with this.
But sodium deficiency affects more than just the renin-angiotensin system. Restricting sodium also spikes adrenal hormones like adrenaline, noradrenaline, and cortisol.
These hormones help you retain sodium—yes—but they also have a cascade of potentially undesirable effects. For instance, if adrenaline is constantly stimulated, insomnia can result.
Beyond hormones, the end-stage consequence of sodium restriction is a dangerous condition called hyponatremia. Typical hyponatremia (or low serum sodium) symptoms include muscle cramps, fatigue, headaches, insomnia. If sodium levels continue to fall, the symptoms can progress to seizures, brain damage, and even death.
The average person on a low-salt diet probably won’t develop clinically-relevant hyponatremia. Sodium-retention hormones like aldosterone and renin prevent that from happening. But if that same person starts sweating profusely and drinking electrolyte-free water, the chances of hyponatremia increase exponentially.
Next, we’ll take a deeper dive into the major hormones and their relationship with electrolytes.
Hormones and Electrolytes: How They Interrelate
Electrolytes and hormones are like two sets of vehicles sharing traffic on a two lane street. When one set of vehicles starts malfunctioning, it affects the entire system.
Here’s an overview of the main hormones driving on this street, and how electrolytes factor in.
Cortisol is a glucocorticoid hormone that exerts its influence by binding to receptors (called glucocorticoid receptors) in nearly every human cell. Commonly known as a “stress hormone”, cortisol does indeed trigger a stress response. Specifically, cortisol:
- Increases blood sugar
- Increases fat-storage
- Breaks down muscle
- Decreases bone formation
These are all positive adaptations—if you’re in survival mode. Your rising blood sugar provides quick energy, and your muscle breakdown provides amino acids for more immediate bodily functions. But if you’re going for longevity, cortisol is not your friend.
Lots of things raise cortisol levels. Stress is the obvious trigger, but low sodium can trigger a cortisol response too.
The relationship between sodium and cortisol is bidirectional. Low sodium causes high cortisol, and high cortisol depletes sodium levels. Case in point: Those with Addison’s disease (a disease of insufficient cortisol production) have problems regulating sodium and calcium levels.
#2: Adrenaline and noradrenaline
Along with cortisol, adrenaline and noradrenaline (also called epinephrine and norepinephrine) round out the stress hormones. These adrenal hormones have more immediate effects than cortisol, and are largely responsible for the “fight or flight” feeling associated with the stress response: flushing, increased heart rate, dilation of pupils, etc.
Recall from earlier that, since adrenaline helps you retain sodium, it’s part of your body’s response to low sodium levels. Less sodium, more adrenaline.
Low-sodium induced adrenaline could explain, in part, why so many low-carb folks suffer from insomnia. Later, I’ll explain why this affects low-carbers more than others.
Of all the hormones that influence electrolytes, aldosterone is the most underappreciated. Many people have never even heard of it.
Let’s start with some basics. Aldosterone is produced in the adrenal glands, and regulates blood pressure, sodium levels, and potassium levels.
Specifically, aldosterone tells the kidneys to retain sodium and excrete potassium. It’s a sodium preservation hormone. It kicks in when sodium levels are low.
Unfortunately, losing potassium is generally not desirable. That’s because inadequate potassium increases the risk of hypertension (high blood pressure), a key heart disease risk factor.
To sum up: Being low on sodium raises aldosterone, which can deplete potassium levels and raise blood pressure.
Renin is produced by specialized cells in the kidney. It raises blood pressure and helps you retain sodium. Like aldosterone, renin shows up when sodium levels drop.
In fact, renin stimulates aldosterone production. Renin also helps create two other hormones—angiotensin and angiotensin II—which also increase blood pressure and sodium retention.
All together, aldosterone, renin, and angiotensin work together to manage your sodium, potassium, and blood pressure. The name of this collaboration? The renin-angiotensin-aldosterone system.
#5: Thyroid hormones
The thyroid hormones T3 and T4 act on most cells to increase metabolic rate, muscle protein synthesis, bone development, and much more.
The evidence is a bit thin, but researchers have found a link between electrolytes and thyroid health. For instance, in a sample of 9,052 emergency room patients, those with hypothyroidism (low thyroid hormones) were more likely to suffer from hyponatremia and hypokalemia (low potassium) than chance would predict.
To be clear, this correlation doesn’t prove causation. Some other factor (underlying illness, lifestyle factor, or stress) could be driving the low thyroid.
But the best known connection between electrolytes and thyroid health is indirect: The consumption of iodine through iodized salt.
Iodine is a mineral needed to produce thyroid hormones, and it’s hard to find in the Standard American Diet. As a bandaid to this problem, iodine was added to table salt. Presto—iodine is now on every table in America.
But believe me: You don’t want to be eating iodized, refined salt.
First of all, the actual iodine content of this salt, research has shown, is unpredictable. You may be getting very little iodine. You’re better off consuming kelp or taking an iodine supplement.
More importantly, table salt is full of toxic anti-caking agents like sodium aluminosilicate. Sodium aluminosilicate, by the way, contains aluminum, a potent neurotoxin. No thank you.
That’s why I use sodium chloride in LMNT, my electrolyte drink mix. I don’t want you (or anyone) consuming that crap.
#6: Antidiuretic hormone (ADH)
Antidiuretic hormone—or vasopressin—functions, predictably enough, as an antidiuretic. When ADH goes up, you retain more fluid.
Practically speaking, ADH helps you sleep through the night without waking up to pee every 2 hours. Ever wonder why alcohol leads to frequent bathroom breaks? It’s because alcohol interferes with vasopressin secretion.
Being low on sodium also impairs vasopressin secretion. This is why a pinch of salt before bed can help you stay asleep.
Finally, many people suffer from a condition called syndrome of inappropriate antidiuretic hormone secretion (SIADH). When someone has SIADH, they make too much ADH and retain too much fluid. Hyponatremia often results from this excessive fluid retention, and needs to be remedied with intravenous saline.
How A Low-Carb Diet Affects Hormones and Electrolytes
When you eat a low-carb diet, a number of hormonal changes occur. One of these changes is a decrease in the hormone insulin. In turn, low insulin increases the risk of sodium deficiency.
Here’s how that works, step-by-step:
- Low-carb diets keep blood sugar low
- Low blood sugar keeps insulin (your blood sugar regulation hormone) low, too
- Low insulin means less aldosterone is secreted by the adrenals
- Less aldosterone means less sodium is retained
You can see how this complexity could be missed. And when it gets missed, folks catch a case of keto flu. Or, as I like to call it, “low sodium flu”.
The symptoms of keto flu—headaches, fatigue, cramps, and insomnia—are all tied up with the hormones we discussed earlier. Low sodium impacts cortisol, adrenaline, aldosterone, renin, T3, T4, and ADH. Think this can cause symptoms? You bet.That’s why I include plenty of sodium in LMNT, my tasty electrolyte drink mix — non-iodized, remember? It’s an electrolyte insurance policy for low-carb folks, intermittent fasters, active folks, and everyone in-between.