Mast cell activation syndrome, or MCAS, is an immunological condition where the mast cells in the body release excessive amounts of chemical mediators such as histamine, leading to symptoms such as hives, flushing, rashes, swelling, low blood pressure, dizziness, brain fog, breathing difficulties, and even anaphylaxis.
I have found that mast cell disorders can impact mood, energy, neurological function and a broad array of other body functions. MCAS can also impact the digestive system, leading to nausea, diarrhea, constipation, bloating, abdominal pain, and intestinal cramping.
Further, MCAS can make one more sensitive to both foods and other substances including herbs, supplements and medications. Thus MCAS must be addressed in these cases in order to be able to treat other issues that might be going on in the body such as infection with chronic Lyme/co-infections, and mycotoxin issues.
MCAS is common in both these issues – Lyme disease and mycotoxin illness. I believe that both illnesses can act as a trigger for MCAS. It becomes a bit of a chicken and egg situation – while Lyme and mycotoxins can cause MCAS, MCAS may prevent an individual from being able to treat the other diseases adequately because of major hypersensitivities it can create to the things that address them.
Parasites can also be a trigger for MCAS given that mast cells are one of our protective mechanisms for parasites. Recent emerging information also points to EMFs as another significant trigger.
In many cases, MCAS is a clinical diagnosis. Welts on the skin, hypersentivity to many foods, itching, sneezing, headaches, intolerance to other substances, can all be clues.
There are some lab markers that may be helpful in addressing MCAS:
- DAO enzymes – this is an enzyme that breaks down histamine, so checking for deficiencies can be helpful.
- MMP-9 – one of the key indicators of MCAS
- Histamine (plasma)
- N-Methylhistamine (24-hour urine)
- Prostaglandin D2
- Chromogranin A
- Tryptase (serum)
- Gene testing for variations in DAO, HNMT, MTHFR, MAT
A little more about MMP-9.
MMP-9 is a substance that is secreted in the body and is found in the central nervous system, extracellular matrix, and serum.
It is involved in allergic and non-allergic inflammatory response. When MMP9 is in balance it aids in regeneration and remodelling of tissue. However, when it is out of balance it sets up an inflammatory cascade of cytokines and chemokines; and those tissues when have higher levels of histamine.
It is also a marker that can be tracked over time to monitor response to treatment.
It can be “provoked” with high-histamine foods to see if levels increase; or it can be retested after a period on a low-histamine diet, to see if numbers have fallen.
MMP9 is also used as a marker to evaluate mycotoxin illness/CIRS. There are two clues in evaluating which issue is causing the elevation in MMP-9 (although as with many of these things, this is not a black and white matter).
One is the degree of elevation.
Normal reference range: 0-983 mg/mL
If MMP-9 is 250-400 mg/mL, then it could point to MCAS or mycotoxin illness.
But if MMP-9 is over 400 mg/mL, then MCAS is likely.
Therefore we typically see higher levels of MMP-9 in MCAS than we do mycotoxin illness.
The second is when using one MMP-9 level as a baseline, then either provoking it with high-histamine foods, or doing a low-histamine diet, then rechecking.
Of course in assessing other underlying triggers, we might want to test –
- Lyme and co-infections – IgeneX Lyme/Co-infection panels.
- Mycotoxins – Great Plains Lab Urine Mycotoxin Test.
- Parasites – Great Plains Lab Comprehensive Digestive Stool Analysis.
- C4a/ TGF-beta – Labcorp
- Candida – Great Plains Lab Microbial Organic Acid Test.
- Heavy metals – Doctor’s Data Urine Metals Test.
Nutrition and MCAS
As always, we need to evaluate the role that foods may be playing in one’s mast cell reactivity. There are certain foods that have high histamine content, or trigger histamine release in the body (see list below).
Freshness of ingredients is also a huge factor, which can be difficult to control outside the house. If preparing food at home, make sure to eat food fresh, or freeze leftovers immediately in single-use portions.
The following foods have high histamine levels:
- Pickled or canned foods – sauerkrauts
- Matured cheeses
- Smoked meat products – salami, ham, sausage
- Beans and pulses – chickpeas, soy beans, peanuts
- Nuts – walnuts, cashew nuts
- Chocolates and other cocoa based products
- Ready-made meals
- Salty snacks, sweets with preservatives and artificial colorings
The following foods can trigger the release of histamine:
- Most citric fruits – kiwi, lemon, lime, pineapple, plums…
- Cocoa and chocolate
- Beans and pulses
- Wheat germ
- Additives – benzoate, sulphites, nitrites, glutamate, food dye
The following foods can block diamine oxidase (DAO), an enzyme that helps break down histamine:
- Black tea
- Energy drinks
- Green tea
- Mate tea
If that seems like a lot of things to avoid, let’s shift gears and focus on things that are low in histamine – there are still plenty of things to eat!
- Fresh meat (cooled, frozen or fresh)
- Freshly caught fish
- Chicken (skinned and fresh)
- Egg yolk
- Fresh fruits – with the exception of strawberries, most fresh fruits are considered to have a low histamine level (also see histamine liberators below)
- Fresh vegetables – with the exception of tomatoes
- Grains – rice noodles, yeast free rye bread, rice crisp bread, oats, puffed rice crackers, millet flour, pasta (spelt and corn based)
- Fresh pasteurised milk and milk products
- Milk substitutes – coconut milk, rice milk
- Cream cheese, butter (without the histamine generating rancidity)
- Most cooking oils
- Most leafy herbs
- Most non-citric fruit juices
- Herbal teas – with the exception of those listed as DAO blockers.
Remember, food preparation is key as well. Some foods that are low-histamine foods when fresh, will increase in histamines as they age. For example, meat, poultry and fish contain bacteria, which cause fermentation, which increases the histamine levels. That is why I suggest freezing meals for leftovers as soon as they are prepared.
For help in figuring out the diet parts, I recommend the App, All I Can Eat. It’s available for Android and IOS. It provides information on fructose, lactose, gluten, histamine, salicylates and sortibol in foods.
Treatments for MCAS
There are many interventions that can be helpful for MCAS as well.
From a pharmaceutical standpoint, some people utilize H1, H2 blockers and mast cell stabilizers.
H1 blockers include cetirizine (Zyrtec), loratadine (Claritin), levocetirizine (Xyzal), fexofenadine (Allegra) or chlorphenamine (Chrorphen).
H2 blockers include famotidine (Pepcid) or ranitidine (Zantac). However, these are not ideal to be using long term due to their suppression of stomach acid. Also Zantac recently was pulled off the pharmacy shelves because of containing low levels of a substance that could cause cancer.
Mast cell stabilizers include ketotifen and cromolyn sodium. These are both obtained through compounding pharmacies and can be very helpful.
Natural Interventions for MCAS
There are lots of natural substances that can help with MCAS, so I’m going to list a few, but I have also formed a list of specific products I like the most, that combine these ingredients well and reduce the number of supplements one needs to take.
- DAO with meals
- Quercetin – 500mg starting once daily, working up to 3 times daily 30 minutes before meals.
- Vitamin C
- Certain probiotic strains eg L rhamnosus; soil-based probiotics (see list below)
- Milk thistle and other liver support
Here is a good line-up that can be used as a MCAS protocol along with the low-histamine diet:
This blend of seven natural agents works on both H1 and H2 receptors to both reduce the amount of histamine released, as well as blocking receptor binding. I have found this to be very effective and reducing mast cell activation.
Dose: 2 capsules twice day.
Cytoquel is a formula that reduces systemic inflammation using natural substances including NAC, black tea, curcumin and resveratrol. It helps to promote anti-inflammatory cytokine activity and reduce pro-inflammatory cytokine activity. It has been effective in lowering MMP-9 levels, which are a marker of inflammation.
Dose: 3 capsules once daily with a meal (more sensitive people may need to start at 1 capsule and work up).
This is a soil-based probiotic, which as previously discussed, does not fuel histamine reactions like other strains of probiotic. I have found this formula to be very well tolerated in those struggling with MCAS, as well as SIBO. CoreBiotic contains three different spore-forming probiotics that withstand stomach acid and travel to the intestines, where they promote healthy balance of flora.
Dose: 2 capsules daily.
Vitamin C is well known as a mast cell stabilizer, and an immune support. C-RLA is a liposomal vitamin C, which means that each molecule is coated with a lipid layer, giving it superior absorption through the mucous membranes of the digestive tract. This gives the body more of the vitamin it needs, without the GI upset that some vitamin C can cause.
Dose: 1 Tablespoon in water on empty stomach first thing in the morning (can eat/ drink 10 mins later).
Glutathione is one of our key antioxidants in our bodies, reducing levels of oxidative stress. Oxidative stress can worsen MCAS, therefore anything that counters it is helpful in our approach to MCAS. Glutathione is also important to facilitate phase 2 liver detoxification – histamine and other mediators of mast-cell activation are degraded/detoxified by the liver. Glutathione also helps to reduce systemic inflammation.
Dose: 1 teaspoon daily in water on empty stomach.
Tip – mixing the plain liposomal glutathione with the caramel/vanilla flavored C-RLA masks the taste and makes for a delicious morning health shot!
All of the above are produced by Researched Nutritionals and are available from our online store.
Quercetin can also be a good addition – it is generally well tolerated, but some people will need to start with a smaller dose and work up to full dose.
Dose: 500mg once daily, working up to 3 times daily ½ hour before meals.
I like Pure Encapsulations Quercetin, not only for their quality, but the capsules are 250mg so sensitive folks can build up slowly.
People with high reactivity to foods may want to add DAO – the enzyme that helps to neutralize histamine – 1 with each meal. I like this one from Seeking Health.
Another intervention that has been helpful in some cases is the peptide BPC-157. This peptide must be dispensed by a compounding pharmacy, but it has been helpful in healing leaky gut and addressing a range of digestive issues.
There are also some natural substances to avoid during MCAS. N-acetyl cysteine, for example, can fuel histamine responses. Also, some strains of probiotics can worsen MCAS – these include
- Lactobacillus bulgaricus
- Lactobacillus casei (reduces oxalates)
- Lactobacillus reuteri
- S. thermophilus
Histamine Neutral Strains: Lactobacillus acidophilus (reduces oxalates)
- Lactobacillus Lactis
- Lactococcus Lactis
Probiotic and Probiotic Strains Supportive of MCAS include:
- Soil-Based Probiotics
- Bifidobacterium infantis
- Bifidobacterium longum
- Lactobacillus gasseri
- Lactobacillus rhamnosus
- Lactobacillus plantarum
- Lactobacillus salivarius
Mast cell activation syndrome can be yet another complicating piece in the already complicated world of chronic illness; however, it is one that must be addressed for people to make progress. Curbing MCAS can also boost tolerance to other treatment protocols that address other areas such as chronic infection and mold toxicity, making it an important priority.