Mast Cell Activation Syndrome Histamine Intolerance Fact or Fiction Debunking Myths 2

Debunking Mast Cell Activation Syndrome and Histamine Intolerance Myths

I know when I was learning about Mast Cell Activation Syndrome (MCAS) and Histamine Intolerance, there was a lot of misinformation out there. It took me a long time and a lot of research to wade through the facts and myths. Unfortunately, many practitioners are not educated in Mast Cell Activation Syndrome and Histamine Intolerance. This has led to a kind of Wild West of Mast Cells and Histamine Information online. I see misinformation every day on websites, Facebook groups, and even from health practitioners themselves. Some practitioners even say it isn’t possible to heal from Mast Cell and Histamine issues.

I want to help you cut through some of the confusion in this post. Because believing these myths can get in the way of our healing.

I’ve personally experienced extensive healing from both Mast Cell Activation Syndrome (MCAS) and Histamine Intolerance. And I have worked with and talked to many others who have healed as well.

You can read more about the difference between Mast Cell Activation Syndrome and Histamine Intolerance here.

Myth # 1: Mast Cell Activation Disorders are Rare

When I knew I was struggling with histamine sensitivity, I turned a blind eye to reading anything about Mast Cell Activation Syndrome because I thought it was rare and surely couldn’t be something I was struggling with. Boy, was I wrong!

When I was finally diagnosed, I learned that sometimes Mast Cell Activation Syndrome (MCAS) is confused with Mastocytosis, which is a rare, but more widely known, disorder of mast cell activation with increased numbers of mast cells. Mast Cell Activation Syndrome, on the other hand, is a type of Mast Cell Activation Disorder where the mast cells exist in normal numbers, but are over-responsive.

Do you have Mast Cell Activation Syndrome? If so, it might not be that rare. Leading Mast Cell Disorder experts, Dr. Afrin and colleagues, assert that Mast Cell Activation Syndrome is much more common than previously thought. It may even be as common as 8 to 14% of the population. (1)(2)

Many people who only think they have Histamine Intolerance actually have some mast cell involvement too. And may even have Mast Cell Activation Syndrome.

Myth # 2: The Major Trigger for Mast Cell Activation Syndrome is Histamine

I used to think my main issue was histamine. I thought if I could just control histamine through my diet choices and stress reduction, then I would heal. This worked pretty well for me for a few years, until I had a number of major mast cell triggers in a row. This included an extended trip to Seoul, Korea. On that trip, I was working long hours. Then I returned home with the flu. I got sick two more times in five months. Finally, I was in a car accident. My body completely crashed on me at that point. This was when I realized I needed to be aware of much more than just histamine.

I found out that while Mast Cells release histamine, they also release nearly 200 other chemicals. Histamine foods and histamine-provoking allergens can certainly trigger mast cell activation. There are many more possible triggers, though. These can include (3)(4)(5):

  • Underlying genetic factors increasing inflammation
  • Hormone changes
  • Inflammatory foods (like glutamates, oxalates, histamines, salicylates, lectins, additives, preservatives)
  • Processed foods and additives, including carrageenan, guar gum, flavorings, colorings, and preservatives
  • Stress of any kind – emotional, mental, physical
  • Alcohol
  • Fatigue
  • Some medications
  • Insect bites and stings
  • Injuries, including head injuries
  • Infections – systemic and gut-related
  • Heat or cold
  • Over-exercise
  • Chemicals, including those in perfumes, skin care products, cleaning products, and cigarette smoke
  • Friction, including from riding in a car or an airplane
  • Low oxygen levels, due to elevation, poor air quality, or airway obstructions
  • Too much sun
  • Chlorine (in shower, swimming pool, or hot tub)

Do you have trouble with any of these underlying triggers? If so, you may need to consider Mast Cell Activation Syndrome for yourself. Be sure to find a practitioner who is an expert in Mast Cell Activation Syndrome.

Myth #3: There is Nothing We Can Do About the Genetics Underlying Mast Cell Activation Syndrome and Histamine Intolerance

This idea never rang true with me. Does it ring true for you? Before I was diagnosed with Histamine Intolerance and Mast Cell Activation Syndrome, I already made some headway with addressing some of my genetic variants. This greatly improved my health. After my diagnoses, I started digging into the many different genetic issues that can affect Mast Cell Activation and went on to get certified in Functional Genomic Analysis.

While the field exploring the genetic factors affecting Mast Cell Activation Syndrome (MCAS) is very new, more information is coming out each day. I’m excited to share these developments with you.

Most people who know something about the genetics of Mast Cell Activation Syndrome and Histamine Intolerance only look at the DAO, HNMT, MTHFR, and COMT genes.  But the truth is, there are way more genes involved in Histamine Intolerance and Mast Cell Activation Syndrome.

Here are just some of the genetic factors that can affect mast cell activation:

  • Genetic variants affecting histamine breakdown, including genes coding for the HNMT and DAO (ABP1 gene) enzymes. Acetylation is important too, though. Those genes include ACAT, PANK and NAT genes
  • Methylation issues – there are many, many important methylation genes – way beyond just MTHFR.
  • Variants affecting inflammation lowering antioxidants like Glutathione, SOD, and catalase
  • Glutathione recycling variants
  • Variants increasing ammonia production
  • Variants causing excess Iron and Copper to oxidize
  • Variants affecting Energy Production
  • Variants contributing to hormonal imbalances
  • Genetic variants that lower stress tolerance
  • Predisposition to gut imbalances
  • Increased sensitivity to pesticides, medications, and EMFs
  • Variants impacting digestion of fats, proteins, and carbohydrates
  • Transulfuration issues
  • Challenges with Nitric Oxide production
  • Variants affecting conversion and absorption of Vitamin A, D, and B12
  • Genetic variants affecting Glutamate Pathways and other Neurotransmitter Pathways

Sounds like a lot, doesn’t it? I didn’t even list them all. It is important to work with a practitioner who understands the complexity of these genetic variants. And particularly how they impact mast cells and histamine levels.

Myth #4: Diet Changes Can’t Help Mast Cell Activation Syndrome

If you have made any changes in your diet and felt better, you know that this one isn’t true either. When I was in college, I lived out of vending machines or on ramen noodles. That would probably kill me today! Some people have immediate reactions to foods and can easily sort out what is causing them to react. Others take a couple days for reactions to become apparent. Those people have to follow a systematic process to figure out which foods trigger them.

I have improved dramatically through changing my diet. And I have seen many others improve as well. Any time we eat more healthfully, our bodies can heal and function better. However, what is healthy and best for one person may not be for another. For example, spinach is considered a superfood. But it is also high in histamine and oxalates. This makes it inflammatory for those with Mast Cell Activation Syndrome and Histamine Intolerance.

Finding your personal food sensitivities and eating to support your body can make a huge difference. Of course, please work with your health care practitioner or dietitian if you plan on making major diet changes. It is essential to eat a balanced diet that includes all the necessary nutrients. Extreme diets can lead to malnutrition.

Here are some of the types of foods that can trigger mast cell activation. They may can also affect Histamine Intolerance:

  • Common food triggers: wheat, dairy, corn, soy, sugar
  • High histamine foods
  • Processed foods and food additives
  • Preservatives
  • Oxalates (for those who are sensitive)
  • Lectins – found in most grains, nightshades, grain-fed meat
  • Salicylates
  • Glutamates

Wondering what can you eat? The key is to emphasizing whole, unprocessed, nutrient dense foods chosen for your personalized needs. Just let me know if you need help customizing your food choices.

Myth #5: Supplements Can’t Help much with Mast Cell Activation Syndrome and Histamine Intolerance

Fortunately for us, this isn’t true. There is an extensive amount of research on histamine lowering and mast cell stabilizing supplements. The tricky thing is that some supplements are going to work better for some people and not work for others, depending on genetics, health issues, and labs. Further, some supplements are contraindicated for certain conditions and genetic makeup, so supplementation recommendations are different for each person, individually. Before I had the ability to analyze my genetics and labs, I had a lot of dead ends. By reviewing and analyzing genetics, symptoms, and labs, I have now been able to target which supplements can work best for my body. This process guides me in deciding which may work best for others too.

Here are a few of the best known mast cell stabilizing supplements:

        • Quercetin has been shown to work as well as prescription mast cell stabilizers. This is a methyl compound, though, so those who are over-methylated may have difficulty with this one. Quercetin is difficult to absorb, so I’ve been using Histamine Scavenger (a blend of mast cell stabilizing and histamine lowering herbs) by Professional Health Products. You can order Histamine Scavenger through our office here. For a single source Quercetin, I really like Pure Encapsulations Quercetin Dihydrate* that has better absorbability than other forms.
        • Baicalein, also called Chinese Skullcap, is a very effective mast cell stabilizer.  Chinese Skullcap is very different from American Skullcap, so if you try this, be sure to get the kind called Chinese Skullcap or Baicalein. I’ve had really good luck with this supplement for reducing mast cell related inflammation. It can be hard to find Chinese Skullcap. I use this one from Swanson*.  There is also an organic Chinese Skullcap powder* available that you can mix into tea or make into your own capsules with empty capsules* and a capsule machine*.
        • Luteolin is a flavonoid that also can stabilize mast cells. Luteolin is even more effective when combined with the spectrum of great compounds in Olive Leaf Extract*. Keep in mind that Olive Leaf Extract works against pathogens. So if you might have active viruses, parasites, bad bacteria, or mold infections, be sure to work with your health care provider on how to integrate this into your protocol. Olive Leaf Extract shouldn’t be used long term. It is better for occasional use during flareups.
        • Holy Basil, also known as Tulsi, can be very effective. I use this regularly as a supplement* and a tea* and have had great results in inflammation reduction and also feeling generally more calm.
        • Boswellia is an extract of Frankincense resin. If you use Frankincense as an oil, be sure to use a pharmaceutical grade oil (such as Rocky Mountain Oils*) and dilute with a carrier oil before applying to your skin. I’ve had good results using this as a supplement and an essential oil to reduce inflammation and stabilize mast cells.
        • Vitamin C acts as a natural antihistamine, however many people with MCAS react to ascorbic acid because it is usually made from fermented corn. For a foods based option, I love Camu Camu* because it is low histamine and low oxalate. (I do get this through Amazon since it is dried.) I’ve found Vitamin C can help reduce my mast cell reactions, especially after accidental exposure to a trigger.

      For those with EDS, POTS, and many other Mast Cell symptoms with low blood pressure, I really like this brand of Sodium Ascorbate*. The ascorbic acid in this product is not from corn fermentation. (Just click on the link and enter your email address to order. When you click this link from Mast Cell 360, you automatically get 15% off all FullScript orders.)

If any of these supplements are new to you, try them with very low amounts first. Think sprinkles in a little water. If you have a tendency to react to supplements, be sure to work with a Histamine and Mast Cell specialist who can help you.

Do you need help understanding your Mast Cell Activation Syndrome or Histamine Intolerance?  Start here!


*Full disclosure: Some links in this website are affiliate links, which means I may make a very small commission if you purchase through the link. It never costs you any more to purchase through the links, and I try to find the best deals I can. I only recommend products that I love and use personally or use in my practice. Any commissions help support the newsletter, website, and ongoing research so I can continue to offer you free tips, recipes, and info. Thank you for your support!


  1. Maria Custer

    I am not interested in buying supplements at this time. I have spent probably thousands of dollars on them trying to figure out what was wrong with me.
    I just want to try to focus on diet for right now. How much of skullcap powder could I add to tea? I see you say start with sprinkles but what am I maxing at? Could I do the same with Camu Camu-add to tea or drink? Thank you for any advice you can offer. I appreciate your blog!

    1. Beth O'Hara

      I know what you mean. General supplement recommendations rarely work for people with Mast Cell Activation Syndrome or Histamine Intolerance. I spent several thousand dollars on failed supplements before I learned how to target supplementation needs based on labs and genetics. This is where we get the best success. For skullcap and camu camu, it depends on the concentration you have. I would follow the package directions, and possibly experiment with a little more if you are doing well with them.

    1. Beth O'Hara

      Pycnogenol has been shown in research to have mast cell stabilizing properties. Pycnogenol is a brand name of pine bark extract. It is so effective, I used it in my MC Stabilizer formula. You can read more about pine bark extract properties in the formula sheet. Here is more info on the MC Stabilizer formula:

  2. sherry

    I have just started taking chinese skullcap and camu camu and having really good results in just the past 3 days. However, I am reading on the internet that it can cause liver damage with other herbs. I do take other herbs. If I space them out, say 2 to 4 hours apart will that prevent liver damage? Or do you know if is it an issue even if you do that?

  3. Lené

    When I followed the link to the vitamin C you recommend, it says, “Ascorbyl palmitate is derived from corn dextrose fermentation and palm oil.” My impression from your post, though, is that this should offer a corn-free alternative for those who react. Did I misunderstand, or is there another product we should consider instead? Thanks.

    1. Beth O'Hara

      Thanks for bringing this to my attention! It used to be made from tapioca. I added a different Vitamin C option above. Beth

  4. Peggy Pysher

    I can’t even find a health care practitioner who can help me and diagnose if I have more than a histamine intolerance. A physician agreed to have my histamine level tested, which was high off the range, but he said there is not much known about it, and just gave me scripts for antihistamines and an epi pen. I search online myself and find people like you, spend more money than I have on supplements recommended, all trial and error. Dietary changes have helped some, and taking DAO enzyme has helped the most. How do I go about getting testing for more than the histamine? For mast cell, etc. ? Thank you.

  5. Nichole

    Just an FYI as I looked into a tapioca based Vitamin C (as ascorbic acid) for my MCAS daughter. I called the manufacturer and they confirmed it was derived by a fermented process. No corn, but fermentation, so it would be high in histamine and a no go for her unless we wanted to risk a reaction. We avoid fermented products or bi-products at all costs.
    Thank you for all your information and helping the MCAS community!

    1. Beth O'Hara

      Thanks so much, Nichole! Which brand was it? That info could really help a lot of people. Looking forward to hearing back from you.

  6. Sue Ann Walker

    Hi Beth. I notice you don’t mention tyramine intolerance as many of the issues MCAS folks can have as I know I have that and I think there are so many with migraine symptoms that also have never tried the low tyramine low histamine elimination diet to see if they improve without Tyramine triggers. I hope you bring this to light some and I am interested in working with you in the near future on my health issues ! thank you for this great blog!

    1. Beth O'Hara

      Hi Sue Ann. Thanks so much for reading! I’m really glad you enjoy the blog. The low histamine diet on the website is also low tyramine. Histamine is a type of tyramine, and a low histamine diet includes tyramine triggers as well as other types of histamine triggers and liberators. Hope that helps!

  7. Jill

    I appreciate the information you put out there but I have to be honest …this will terrifies me! I don’t even know if I actually have MCAS but reading about all these triggers and problems. Yikes. Very overwhelming!

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