Calming MCAS with Halotherapy

Salt Cave Convert

I didn’t feel well that day. Borderline crashing/flaring. The kind of day where if I were smart, I’d have called in sick. At noon, I headed to The Nurture Collective to try out Dr. Kristy’s halotherapy room.

I wasn’t expecting much from a 30-minute session breathing a mist of micronized salt. I was already drinking salt water every day for adrenal support so how could this be any different, but by the end of the 30 minute session, I felt well.

No whisper of the low cortisol state I was in that morning. No raw histamine-y feeling I’d been battling since breakfast. No impending headache. Well.

And, I had to know why.

Why was this different from drinking salt water? And, just why is salt so important for healthy cortisol levels (which calms MCAS by default)?

The Cortisol/MCAS Link

Before we dive in, if you’re struggling with MCAS and don’t already know what this says about your cortisol rhythm, let’s talk.

Mast cell activation syndrome (MCAS) is driven by dysregulated cortisol, and even though the interplay is complex (involving other hormones in the hypothalamus-pituitary-adrenal (HPA) axis), this table highlights how dysregulated cortisol rhythms sensitize mast cells.

The takeaway? When cortisol rhythms are out of sync, whether too low, too high, or just off kilter, mast cells become hypervigilant.

What Does Salt Have to Do with Cortisol?

Even though salt doesn’t build cortisol (cortisol is a hormone created from cholesterol in the adrenal cortex, outer layer of the adrenal glands, and these glands sit on top of each kidney), salt affects how much cortisol the adrenals make. Numerous studies show that high salt diets result in higher levels of cortisol excretion in urine, which suggests that the adrenals are making more cortisol in a salt replete diet.

Another Hormone Pathway: How Salt Impacts the Raas

The adrenal glands are complex. With multiple layers and the ability to create many different hormones, the health of your adrenals determines your overall well-being and resilience.

One of the hormones the adrenals make is aldosterone. It is a hormone in the renin-angiotensin-aldosterone system (RAAS or now increasingly commonly referred to as RAS), and this system controls blood pressure.

For many people struggling with low cortisol (hypocortisolism) whether due to Addison’s, adrenal fatigue, or HPA dysfunction, the RAAS system is often dysregulated. And, for some of us, that means low aldosterone paired with low cortisol.

The RAAS also impacts the body’s ability to regulate sodium and potassium. Chronically low aldosterone = low sodium. If you have salt cravings, this might be why.

Why Did My Headache Disappear?

There is a saying, water follows salt. Where there’s salt, there’s good blood volume (and therefore good blood pressure) and sufficient water in the body to nourish tissues/organs.

In a body that struggles with salt depletion, blood volume (and pressure) is often lower. This basically starves tissues of oxygen creating a hypoxic state. In hypoxia, inflammation reigns making you more susceptible to all sorts of aches, pains, and disease processes. Cortisol as a steroid molecule, is anti-inflammatory. However, for many people struggling with chronic inflammation, cortisol production is low.

I’ve known for years I struggle with low cortisol and, while actively working to rebuild my body’s ability to maintain healthy cortisol rhythms day in and day out, I still haven’t achieved the level of resilience I know is possible. I’ve also struggled with low blood pressure, and although blood pressure is not something I test as frequently these days, I still suspect low aldosterone as a contributor to the low blood pressure.

I was already drinking salt water daily to support higher cortisol production through adrenal stimulation. So, why on earth would inhaling salt be any different?

Salt Caves and Halotherapy For Adrenal Support

The piece that is missing from this picture is another part of the RAAS.

Bear with me for a minute while we get technical:

• Renin: a peptide hormone made by the kidneys
• Angiotensin I: renin acts as an enzyme to convert the protein angiotensinogen (made by the liver) into angiotensin I
• Angiotensin II: Angiotensin I is converted to Angiotensin II by the enzyme, ACE (Angiotensin Converting Enzyme). The highest concentration of ACE enzymes in the body is in the lungs.

Possible Pathways for Conversion of Angiotensin II

• Angiotensin 1-7: Another ACE enzyme, ACE2 in the lungs, converts angiotensin II to Angiotensin 1-7. Angiotensin 1-7 has a vasodilating (relaxing blood vessels, lowering blood pressure).
• Aldosterone: Angiotensin II stimulates aldosterone secretion by the adrenal glands (indirectly increasing ACTH released from the pituitary). Angiotensin II has a vasoconstrictive (narrowing blood vessels, raising blood pressure) and inflammatory effect.

The RAAS Cascade Simplified

1. The kidneys release renin.
2. The liver produces angiotensinogen (renin converts it into angiotensin I).
3. In the lungs, the ACE enzyme converts angiotensin I to angiotensin II.
4. Another enzyme, ACE2, converts Angiotensin II to Angiotensin 1-7.
5. Angiotensin II acts on the pituitary stimulating production of ACTH, which tells the adrenals to make aldosterone.

These ACE and ACE2 enzymes are both expressed in the alveoli (air sacs) of the lungs.

In many lung conditions such as asthma, COPD, etc., ACE and/or ACE2 enzyme levels are altered from healthy states (here and here). Studies conflict regarding expression of ACE2 enzymes and ACE/ACE2 ratios for COPD compared with healthy populations (here and here). For asthmatics and people with allergic tendencies (often overlapping with MCAS), ACE and ACE2 enzymes have been found to be lower than in healthy populations (also here).

And, now you might be sitting up straighter.

Here’s why all this science matters: Angiotensin II increases sympathetic activity (fight-or-flight pathway of the nervous system) stimulating the adrenals and release of cortisol.

Now for the moment you’ve been waiting for…

Boosting Cortisol by Breathing Salt

Here’s the twist: Salt interferes with ACE2 binding sites, reducing conversion of Angiotensin II into Angiotensin 1-7. That leaves more Angiotensin II in circulation, which stimulates ACTH secretion by the pituitary and both aldosterone and cortisol production within the adrenals.

Salt has been shown to block the receptors on ACE2 so that it doesn’t bind as well to Angiotensin II. Since ACE and ACE2 are expressed in the air sacs (alveoli), this is why breathing salt is different from drinking salt.

Let’s dispel a common myth before moving on. Cortisol is not a demon. Cortisol is necessary for life. It is anti-inflammatory (most steroid drugs (prednisone, fluticasone, triamcinolone) are used to do what cortisol does naturally, reduce inflammation). Cortisol supports healthy energy production (and utilization of glucose) supporting mitochondrial health and giving you energy to get up and go every day. It also orchestrates the circadian rhythm in a beautiful balance with melatonin.

And, when cortisol is well-regulated (produced at the right levels and the right rhythm), mast cells are not sensitized, standing guard with hypervigilant granulation at every perceived threat, and instead respond as designed to real immunological threats within the body.

Other Thoughts on Halotherapy

I am sure there is more to the story than this. We haven’t even discussed how a high salt diet increases both ACE and ACE2 enzymes or taken a look at high salt diet vs. nebulized salt and its impact on ACE/ACE2 levels in different organs of the body. Unfortunately, there aren’t a lot of studies that look at this angle, so I’m offering a hypothesis, one I haven’t seen yet in my own research but is definitely worth exploring.

The alveolar epithelium, the skin surrounding each tiny air sac in the lungs, maintains a thin fluid layer on the surface that’s essential for air exchange. Three main mechanisms regulate the fluid layer:

• Starling’s forces (basically capillary action): Passive transport
• Active sodium transport via the cystic fibrosis transmembrane conductance regulator
• Active sodium transport via the epithelial sodium channel (ENaC)

In people with poor metabolism—like hypothyroidism, chronic fatigue, MCAS, diabetes, or mitochondrial dysfunction—ATP production is compromised. So even if sodium is available systemically (from the diet), the epithelial cells lining the lungs may not have the energy required to actively transport it to where it’s needed. This could impair fluid regulation in the alveoli disrupting gas exchange.

When the lungs are directly exposed to inhaled salt though, whether via halotherapy or nebulized saline, sodium becomes instantly available to the alveolar surface, bypassing the need for intracellular ATP-driven transport. This “outside-in” access to sodium sidesteps both passive transport (which depends on vascular integrity and pressure) and active mechanisms (which depend heavily on cellular energy and mitochondrial function).

Therefore, inhaled salt may bypass this bottleneck, offering a metabolic workaround that restores local sodium balance and potentially alters the ACE/ACE2 expression profile in lung tissue—a mechanism that’s been largely overlooked and deserves closer investigation.

NOTE: Interestingly, aldosterone promotes active transport of sodium and as we discussed above, aldosterone is at the end of the RAAS cascade and production may be downregulated in people with deficient ACE and ACE2 enzymes.

How to Choose Halotherapy

Not all halotherapy or salt caves are created equal. Salt caves with brick salt are one option. Halotherapy rooms with micronized salt (typically ground to less than 10 microns) are another option. Dry salt inhalers are often sold online as well, and these should be sold with a caution.

If choosing a dry salt inhaler, ideally it would contain micronized salt (to get into the lungs instead of just the upper airway). The safest salt choices are compendial with one of the pharmacopoeia (USP, EP, etc.). This ensures that the salt isn’t contaminated with lead or other heavy metals and also ensures against microbial and endotoxin contamination. If you choose a local halotherapy center, ask to see the salt container and look for USP (US Pharmacopeia) or EP (European Pharmacopeia) marks.

For at home use, the most cost effective option is to buy sterile saline solution for a nebulizer unit.

We Need Your Help

More people than ever are reading Hormones Matter, a testament to the need for independent voices in health and medicine. We are not funded and accept limited advertising. Unlike many health sites, we don’t force you to purchase a subscription. We believe health information should be open to all. If you read Hormones Matter, and like it, please help support it. Contribute now.

Yes, I would like to support Hormones Matter. 

Feature Image: Photo by Jeroen van de Water on Unsplash