Your immune system exists to protect you from dangerous pathogens. If you’re exposed to a virus, for instance, your immune system is your first, second, and third line of defense.
But like everything else in your body, your immune system doesn’t exist in a vacuum. It relies on the proper functioning of a vast constellation of cells, organs, and signaling pathways.
These pathways, in turn, require certain nutrients to run properly. That’s where electrolytes come in.
Electrolytes like sodium, potassium, magnesium, and calcium have both direct and indirect roles in regulating your immune system. They protect against infections, modulate the intensity of the immune response, and even play a role in cancer treatment.
So whether you’re sick, healthy, or in-between—you want to be getting enough electrolytes. In fact, preventing electrolyte deficiencies is essential for good immune health.
In this article, you’ll learn the basics of immunity, how electrolytes factor in, and what happens to hydration needs during infection. Sound good? Let’s dig in.
How Immunity Works
Think of your immune system like a 24-hour security team. Always patrolling, ready to mobilize its forces against intruders.
The “patrol team” takes the form of sensor proteins circulating throughout your body. When these agents identify a germ, they marshal an immune response.
This initial response is called the innate immune response, and it brings a storm of immune cells to the site of infection. These cells include:
- Signaling molecules like interferons and cytokines
- White blood cells like natural killer cells and macrophages
- Other forms of inflammation
Another word for the innate immune response? Inflammation. Depending on the context, inflammation can be either helpful or harmful. We’ll return to this later.
Sometimes, the innate immune response eliminates the pathogen. But often, the initial response isn’t sufficient to solve the problem, and your security team needs to call in reinforcements.
The reinforcements are your adaptive immune response—a team that includes T cells, antibodies, and white blood cells which specifically target the pathogen. Unfortunately, it takes anywhere from 3 to 10 days for white blood cells to form antiviral antibodies like IGG and IGA. That’s why you don’t get better right away.
It’s also why vaccines don’t immediately confer protection against disease. They activate your adaptive immune system, which takes weeks to rally the troops.
Next we’ll look at three electrolytes—sodium, potassium, and magnesium—and how they influence innate and adaptive immunity.
Sodium and Immunity
Sodium, or Na, regulates a myriad of functions in the human body, including:
- Conducting nerve impulses
- Regulating fluid balance
- Regulating blood pressure
- Helping absorb water and glucose through the gut
- Protecting against certain infections
Let’s zoom in on the last bullet. As it turns out, high sodium concentrations (especially in the skin) have a potent antimicrobial effect.
In one study, mice fed a high-salt diet (salt is 40% sodium by weight) showed increased protection against a dangerous parasite called Leishmania major. The high-salt mice had higher sodium concentrations in the skin, which triggered increased immune protection (in the form of anti-parasitic macrophages) in those areas.
Higher sodium intakes may also have anti-cancer effects. A 2019 paper from the journal Frontiers In Immunology found that a high-salt diet blocked certain cells (called myeloid suppressor cells) that create favorable conditions for tumor growth. In other words, high salt intakes enhanced anti-cancer immunity.
To be clear, this result was in mice, and there’s no human evidence that sodium can block cancer. But those with cancer need sodium for another reason: to prevent hyponatremia.
Hyponatremia, or dangerously low sodium levels, is linked to increased mortality in cancer patients. That’s why preventing low sodium (often through intravenous saline) is a pillar of modern oncology.
Finally, those with autoimmune disease may want to avoid high sodium intakes. As you learned earlier, heavy doses of salt may activate the innate immune system. That said, many people experience remarkable improvements in their autoimmune condition when shifting to a low carb or even carnivore diet. Fundamentally, a ketogenic diet is highly anti-inflammatory—and to make it work properly, one likely needs to supplement sodium intake. So, folks with autoimmune conditions would do well to monitor symptoms when tinkering with both low carb and supplemental electrolytes. This may be a story in which sodium is a problem in the context of a modern, highly processed diet—not in the case of whole-food based, low-carb eating.
Potassium and Immunity
Potassium, or K, has a balancing effect on sodium. Together, they regulate blood pressure, nerve signals, and the immune system.
Specifically, potassium regulates the membrane potential, or the difference between the electrical charge inside and outside a cell. The membrane potential not only allows cells to stay powered (like a battery), but also allows for the transmission of signals within and between cells. These signals, in turn, help direct immune activity.
Potassium also balances sodium’s effect on the innate immune system. Sodium fires it up, potassium cools it down. In fact, high potassium concentrations have been shown (in the lab) to inhibit an inflammatory complex called the NLRC4 inflammasome.
But wait. Don’t you need inflammation to fight infection?
Yes, you need some, but there’s a Goldilocks amount. Too little and you won’t mount a sufficient immune response. Too much, however, and your immune system will significantly damage tissues.
Heart disease is a prime example of inflammation gone overboard. When inflammation is high, LDL particles are more likely to become engulfed by white blood cells and form dangerous plaques inside blood vessels.
Reduced inflammation may explain, in part, why a high potassium intakes are protective against heart disease. It may also explain why potassium-deficient patients are at higher risk for inflammatory kidney infection.
Magnesium and Immunity
Found in dark leafy greens, magnesium is a mineral that does it all. Physiologically speaking, that is. For example, you need magnesium to make adenosine triphosphate (ATP), the coin that powers every cell in your body.
Magnesium also influences immune health, an effect most obvious in magnesium-deficient patients. Here are several immune-related consequences of magnesium deficiency:
Increased inflammation. Low magnesium is linked to rampant production of inflammatory particles like cytokines and macrophages. High levels of these particles drive many destructive processes, including the formation of plaques inside arteries. This process, called atherosclerosis, is the defining feature of heart disease.
Impaired apoptosis. Apoptosis is a form of programmed cell death, and it’s a key defense mechanism against cancer. When apoptosis works properly, damaged cells self-destruct before they become cancerous. Magnesium deficiency can hinder this mechanism.
Shrinks the thymus. The thymus is an organ located near the top of your chest. It helps nurture T-cells and supports adaptive immunity. The thymus naturally shrinks with age, and magnesium deficiency appears to accelerate this process.
Exercise-induced immunosuppression. Intense activity depletes sodium, potassium, and magnesium, which in turn can lead to impaired immune function.
Asthma symptoms. Asthma is an inflammatory condition in which the airways and lungs constrict, making it difficult to breathe. Relevant here: magnesium supplementation has been shown to improve asthma symptoms.
Vulnerability to age-related disease. Magnesium deficiency is linked to heart disease, cancer, neurodegenerative disease, and many other chronic diseases. Why? Probably because low magnesium levels have a pro-inflammatory effect.
Electrolyte Deficiency During Infection
When someone is critically ill, their medical team needs to pay close attention to fluid and electrolyte intake. In particular, they need to ensure the patient gets enough sodium.
That’s because an infection impairs your ability to regulate sodium levels. Specifically, inflammation interferes with the secretion of antidiuretic hormone, a chemical which helps you sleep through the night without waking up to pee every three hours.
If sodium levels aren't managed during infection, the patient may develop hyponatremia. Hyponatremia not only causes symptoms like headaches, cramps, fatigue, insomnia—it also significantly worsens a patient’s prognosis. For some infections (H1N1 influenza virus, for instance), sodium deficiency can be the cause of death.
But sodium isn’t the only electrolyte depleted by infection. Often, potassium gets depleted too.
Potassium deficiency commonly occurs with infections (like cholera) involving diarrhea. Diarrhea rapidly depletes potassium levels, and can lead to a dangerous low-potassium state called hypokalemia.
Still, a patient needn’t have gastrointestinal symptoms to develop hypokalemia. This was illustrated in a sample of 175 Chinese patients with COVID-19, the disease caused by the novel coronavirus.
In this sample, well over half the patients (108) developed hypokalemia, and they developed it independent of GI symptoms. The good news is, the hypokalemic patients responded well to potassium supplementation.
Recap: Electrolytes and Immunity
It’s rarely discussed, but it’s true: Your immune system needs electrolytes. Here are the main points you learned today:
- When your body detects a threat, the innate immune response shows up to squash it. If the threat persists, your adaptive immune system targets the pathogen with specialized defenses like T cells and antibodies.
- High sodium concentrations may have antimicrobial and anti-cancer effects, but more clinical research is needed.
- Potassium fuels immune signaling mechanisms, and high intakes of this nutrient are anti-inflammatory.
- Magnesium deficiency increases inflammation, impairs cancer defense mechanisms, and increases susceptibility to age-related diseases.
- Electrolyte needs increase during infection, and proper management is key to promote better health outcomes.
Want to learn more about electrolytes, including how to supplement properly? Check out our comprehensive guide What Are Electrolytes and Why Are They Important?. Thanks for reading.