mast cell activation syndrome MCAS histamine intolerance symptoms

Mast Cell Activation Syndrome (MCAS) – The Root Cause of Histamine Intolerance?

Is mast cell activation syndrome responsible for your histamine intolerance?

One thing is for certain: you can suspect you have a histamine problem if you develop symptoms like chronic runny nose, digestive upsets, headaches or migraines, or are tired all the time. In addition to this, you experience multiple other, seemingly unrelated, medical conditions that crop up when you are exposed to histamine-containing foods, or factors that increase your body’s histamine concentration.

The question you want to answer is not related to how or what, but why. Why is this happening to you, when it doesn’t seem to be happening to anyone else around you?

Is MCAS the underlying cause of histamine intolerance symptoms?

Histamine intolerance isn’t so much a diagnosis in itself, it's more a collective description that covers a group of symptoms related to increased levels of histamine in the body.

In order to be more specific with what the root cause is, we need take a deeper dive to find out whats really going on.

When you try to identify the mechanism responsible for your histamine levels rising, there are several possibilities. You may have a predisposition to increased histamine production (by certain types of gut bacteria, for example), or you might have a reduced capacity to make the histamine degrading enzymes HMNT or DAO due to genetic changes or reduced liver capacity. Finally, it could be that your mast cells are too active.

Mast Cell Activation Syndrome (MCAS) is now a term commonly being used as the more accurate diagnosis for histamine intolerance.

So, let’s explore this condition and find out whether its the reason for your histamine intolerance or not.

What are mast cells, you ask?

To recap, they're primary cells of the immune system, found in all tissues that we have(1). They interact with potentially threatening compounds, which is why they are prevalent in areas that are in constant contact with environmental stimuli, namely in the gut and skin(2).

When these cells encounter a threat, it's their job to defend the body. They do this by releasing histamine and other chemical compounds to ensure overall tissue balance (3,4,5).

The problem is, in some people, there are simply too many mast cells.

What’s worse, however, is that these people tend to have slightly altered DNA, which causes the mast cells to malfunction.

This mutation causes the cells to release too many chemicals, which can end up affecting every organ in the body. It is for this reason that MCAS is associated with so many diverse and debilitating symptoms(6), such as obesity, chronic skin conditions, irritable bowel syndrome, mental health disorders and even diabetes(7,8). Any of these sound familiar?

MCAS wasn’t a recognized condition until 2007, and it took a further 3 years for scientists to propose the criteria for diagnosing it(9). Since 2010, however, there has been a significant amount of progress in understanding the condition and its causes.

The research is by no means complete, but the medical community has a few ideas...

Mast cell activation syndrome: causes

There’s still much we have to learn about MCAS. There are, however, two widely accepted reasons for its onset which are:

  1. Too many heavy metals in your system
  2. An infection

The body is able to tolerate low levels of heavy metals, but higher amounts can be destructive. Heavy metals are toxic to many of your organs, and your immune system is no exception. Aluminium and mercury, in particular, have been shown to destabilize mast cells, which causes them to be overzealous in their activity(10).

Infections typically disrupt the balance in your gut, which is where 80% of your immune reactions stem from. When your gut microorganisms are out of balance or under threat, the large contingent of mast cells housed in the gut are also disrupted. Whether it is a bacterial, viral, parasitic, or even a fungal infection, your mast cells may begin to flare up with the presence of invading pathogens, which causes histamine intolerance symptoms.

For example, studies confirm that both Helminth parasites and the candida yeast infection have strong effects on mast cells(11,12,13).

In order to stabilize your mast cells, there are two important interventions that focus on these two root causes.

Discovering the root cause of your histamine intolerance

So, what can you do?

Two things for starters: it's worthwhile getting a heavy metal test performed, in addition to reviewing your individual possibility of infection.

If you often eat fish, have dental fillings, or use aluminium lined cook wear, for example, heavy metal concentrations might be a problem for you. This is particularly true if your liver is already operating sub-optimally, limiting its ability to detoxify these agents.

If you travel frequently, it's quite possible that you've been exposed to food borne microorganisms, particularly if you’ve eaten foods where you have little information regarding the source or its freshness. You may also have even been exposed to impurities in the water you drink or bathe in while travelling without realizing it.

Other causes of infections and gut imbalances are frequent use of antibiotics, and opportunistic microorganism influx into your system.

Once you uncover if any of these factors are the cause of your badly behaving mast cells, you can target it with specific therapies. In the mean time, following a low histamine diet is the best thing you can do, reducing the load of histamine your body has to deal with.

Not sure what to eat? Here is a great list of foods to eat and those to avoid to get you started.

Want to step it up a notch? Vitamin C, turmeric and other natural therapies have also been found to be helpful in the treatment and management of histamine intolerance and MCAS. See a list of our top 7 supplements, as one way of incorporating them or aim to include these in your diet.

Want the full low histamine diet guide sent directly to your inbox? Use the link below to get my comprehensive eBook for free!

Get the Low Histamine Diet

While you’ve likely been pushed from pillar to post in your mission to find out what exactly is wrong with you and why you’re suffering from these debilitating symptoms, there is finally a light at the end of the tunnel. When you discover where things have gone oh-so wrong, there’s an opportunity to make them right.

By figuring out the underlying cause of your mast cell dysfunction and high histamine load, you can begin to put practices in place that bring about balance to your system so that you may once again get your health back on track and start enjoying life as you’ve so desperately wanted to.

  1. Da Silva, E., et al. Mast Cell Function. J Histochem Cytochem. 2014 Oct;  62(10): 698–738.
  2. Metcalfe DD, Boyce JA. Mast cell biology in evolution. J Allergy Clin Immunol. 2006 Jun; 117(6):1227-9.
  3. Jutel, M., et al. Histamine, histamine receptors and their role in immune pathology. Clin Exp Allergy. 2009 Dec;39(12):1786-800.
  4. Galli S., et al. Phenotypic and functional plasticity of cells of innate immunity: macrophages, mast cells and neutrophils. Nat Immunol. 2011 Oct 19; 12(11):1035-44.
  5. Weller C., et al. Mast cells in health and disease. Clin Sci (Lond). 2011 Jun; 120(11):473-84.
  6. Moon, T., et al. Mast Cell Mediators: Their Differential Release and the Secretory Pathways Involved. Front Immunol. 2014; 5: 569.
  7. Naunyn Schmiedebergs Arch Pharmacol. 2012 Jul;385(7):657-70.
  8. Rao K., & Brown M. Mast cells: multifaceted immune cells with diverse roles in health and disease. Ann N Y Acad Sci. 2008 Nov; 1143():83-104.
  9. kin, C., et al. Mast Cell Activation Syndrome: Proposed Diagnostic Criteria. J Allergy Clin Immunol. 2010 Dec; 126(6): 1099–104.e4.
  10. Bent, S., et al. The effects of heavy metal ions (Cd2+, Hg2+, Pb2+, Bi3+) on histamine release from human adenoidal and cutaneous mast cells. Agents and Actions. June 1992, Volume 36, Supplement 2, pp C321–C324.
  11. Lopes, J., et al. Opportunistic pathogen Candida albicans elicits a temporal response in primary human mast cells. Scientific Reports volume 5, Article number: 12287 (2015)
  12. Saluja, R., et al. Role and Relevance of Mast Cells in Fungal Infections. Front Immunol. 2012; 3: 146.
  13. Lee, T., et al. Mast cell responses to helminth infection. Parasitol Today. 1986 Jul;2(7):186-91.
Author Photo

Anita Tee

My name is Anita Tee. I'm a nutritional scientist who specializes in histamine intolerance. I hold a Master of Science in Personalized Nutrition and a Bachelor of Science in Human Biology and Psychology.For the past ten years, I have used my experience in nutritional and medical health sciences to create a scientifically backed, natural approach to healthcare that relies 100% on evidence-based research.As I previously suffered from - and overcame - histamine intolerance, my focus is to increase recognition and expand the available resources and protocols available for resolving this particular disorder. To date, I have helped over 4,000 individuals fully resolve or better manage their histamine intolerance symptoms.

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