MCAS lectin and histamine banner with woman running free and happy

MCAS, Histamine & Lectin Intolerance Recovery Tips — Diet, Methods and Supplements

I may receive a commission if you purchase through links in this post. I am not a doctor; please consult your practitioner before changing your supplement or healthcare regimen.

This article shares with you the methods I used to address Mast Cell Activation Syndrome (MCAS) and lectin sensitivity, significantly improving my health status! I discuss diet, causes and supplements. I now eat a variety of foods again, from low to high histamine, and some lectins.

If you haven’t already downloaded or printed it, here is the food and grocery list for a combined low-histamine and low-lectin diet.

After damaging exposure to dioxins last summer, my body became highly intolerant to both lectins and histamines. After largely removing both from my diet, I began the more important quest for deeper healing. How to heal my histamine intolerance meant searching for its root cause.

MCAS lectin and histamine banner with woman running free and happy

What is histamine intolerance?

Histamine intolerance is not a histamine sensitivity, but an indication that the body has developed too much of it. When histamine levels get too high, it can affect normal bodily functions.

We naturally produce histamine along with the enzyme diamine oxidase (DAO). DAO is responsible for breaking down histamine that we take in from foods.

Normal levels of DAO enzymes can’t break down the increased levels of histamine in the body, causing a reaction. DAO deficiency is a possible cause of histamine intolerance.

What triggers histamine intolerance and MCAS?

Mast cells are a kind of white blood cell found in the skin, lungs, connective tissue, intestinal lining, cardiovascular system, neural system and reproductive system.

Mast cells release alarm chemicals when pathogens or toxins attach to their binding sites. The alarm chemicals call other white blood cells and histamines to the site.

Undesirable allergic reactions (hives, rashes, mucous production and many more symptoms including fatigue, anxiety, diarrhea, rapid pulse, shortness of breath and headaches) result.

An increase in toxins and stress in modern times means more people struggle with common allergy symptoms — histamines responding to environmental toxins.

In contrast to common allergies, Mast Cell Activation Syndrome (MCAS) assumes an individual has malfunctioning mast cells, a full-blown immune disorder resulting in over-responsive mast cells.

Known possible triggers for mast cell activation include:

  • Underlying genetic factors increasing inflammation (including variants affecting conversion and absorption of vitamins A, D, and B12)
  • Hormone changes
  • Inflammatory foods (like lectins, glutamates, oxalates, histamines, salicylates, additives and preservatives)
  • Processed foods and additives (including carrageenan, guar gum, flavorings, colorings, and preservatives)
  • Stress of any kind (emotional, mental and physical)
  • Alcohol
  • Fatigue
  • Certain medications
  • Insect bites and stings
  • Injuries (including head injuries)
  • Infections (systemic and gut-related)
  • Heat or cold
  • Over-exercise or over exertion
  • Chemicals (including those in perfumes, skin care products, cleaning products, forest fire smoke 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 drinking water, shower, swimming pool, or hot tub)
  • Certain liver conditions

As one PubMed study says, “The cornerstone of therapy is avoidance of identifiable triggers.” (source)

While certain supplements are used to alleviate symptoms and improve quality of life by reducing mast cell over-responsiveness, regimens are used to control but not heal the condition. Only partial improvement is considered possible.

Low-Histamine and Low-Lectin Diet

To reduce symptoms, for several months, I adopted a combined low-histamine and low-lectin diet. My goal was to be able to reintroduce histamine foods and to address the underlying root cause of the imbalance.

I also trialed and used several suggested supplements.

I hoped to broaden my diet and reduce my supplements over time.

Most importantly, I wanted to protect my body from other imbalances and worse illnesses that can go hand in hand with the body’s inability to break down histamines. I wanted deeper healing.

I also had aggravating symptoms from which I wanted relief.

My goal was not necessarily to eventually reintroduce foods with lectins, as they are by nature aggravating to the gut. I have, however, since recovering, added some lectin foods back into my diet for convenience sake without incident.

Given how far I’ve come, I assume that over time I will be able to reintroduce more of these foods in moderation as my gut integrity continues to heal.

list of foods that are high histamine or high lectin


Low Vitamin A Diet (Treatment for histamine intolerance?)

After reading about the causes of and treatments for MCAS, histamine over-reactivity and lectin sensitivity, I searched MORE … well beyond the usual and most-read sites. I spent immeasurable hours looking for answers and reading studies. (And I prayed for an answer.)

What I found to be the most compelling, as I searched for causes of histamine issues, was the concept of chronic vitamin A toxicity.

While initially very skeptical, I read extensively on the subject and found it compelling enough to try. In addition to a combined low-histamine and low-lectin diet, I started the diet that corresponds to the concept of vitamin A toxicity and saw immediate results. You can read more about the Vitamin A Detox diet here.

I had an 11-month long chronic histamine related rash (on my face and behind my ears) that gradually disappeared within two weeks of starting the Vitamin A Detox diet. I was also struggling with depression, and that lifted immediately upon starting the diet.

The additional improvements I’ve seen are incredible: Every day is an adventure of symptoms: ups and downs as my body detoxes vitamin A.

By far the most exciting symptom that lifted for me was my histamine sensitivity. I marvel and feel thankful daily! I can now eat sauerkraut, cinnamon, aged meats and cheeses, kombucha and leftovers all without incident. I can also eat foods with seeds that used to cause a rash within 12 hours; foods with lectins no longer cause a reaction.

The dramatic improvement I’ve experienced is uncommon in the MCAS community. Can there really be such a concrete answer and cause to elusive histamine issues? I think so.

What causes MCAS and histamine intolerance?

The man who insightfully discovered the concept of vitamin A toxicity is Grant Genereux. I recommend both of his free e-books, here and here.

While many of us have read that histamine issues arise partially or largely from mast cell over-reactivity and various triggers, that explanation conveys a vague understanding.

The concept of vitamin A toxicity is specific and built upon hundreds of scientific studies.

Further research into the correlation between mast cell (histamine) triggers and vitamin A toxicity is still needed. But the organ systems involved are the same: gut, skin, lungs etc. We know that one of mast cells’ main jobs is defense against toxins. And science has already acknowledged that the processing of vitamin A is one main trigger for mast cell activation. Science also recognizes liver conditions as triggers for MCAS.

As one educator states, “Mast cells are the sentinels of the innate immune system, on the lookout for environmental changes or insults to the body. They respond by releasing mediator molecules that influence the behavior of other cells and tissues in an effort to maintain normalcy, or ‘homeostasis.'” (source)

Perhaps a full and toxic liver (the liver stores vitamin A) has no room to store or process additional toxins, so the body is sent into survival mode (think white blood cells and histamines racing to the site) when exposed to new triggers or additional excess vitamin A.

What is a possible solution to mast cell over-reactivity? Reduce vitamin A, so the liver can unload its burden and once again, over time, handle a normal amount of daily toxins.

I know: Most of us have been educated to believe that vitamin A is vital for eye health and many other systems in the body. I won’t go into all of the details of the theory here, but suffice it to say: The original lab studies on vitamin A that all of our modern views are built upon were conducted in ignorance before scientists understood the precursors to vitamin A. Chronic vitamin A toxicity is a known risk in the medical community: for those who supplement with vitamin A or eat diets high in vitamin A (think liver, sweet potatoes and cod liver oil).

My eyesight and skin health have both drastically improved since I reduced my intake of this “vitamin”. Curious? Skeptical? Read more on the theory here and decide for yourself.

When you have nothing to lose and really want to get better, a short stint on a diet of steak, hamburgers, cauliflower and white rice or parsnips is a pretty easy way to test for improvement in one’s symptoms! If you’re open-minded and desperate enough, like many of us searching for healing solutions to frustrating health diagnoses, I think you’ll find this theory worth considering.

Remember, MCAS is not a root cause. MCAS is an autoimmunity theory or description of symptoms. One of the reasons MCAS isn’t a curable condition is that it’s a theory which identifies a problem; but the theory doesn’t identify the root cause of the reactivity.

MCAS is considered idiopathic: a disease having no known cause.

If the vitamin A toxicity theory is correct, it is a root cause that comes with a solution.

Find a printable grocery list for the Vitamin A Detox diet here, if you’d like to try it.

Other root cause theories for MCAS include: heavy metal toxicity from vaccines (the purpose of using metals like aluminum and mercury as vaccine adjuvants is to create a heightened inflammatory immune response, to destabilize mast cells), pathogen overgrowth (stimulators of mast cell activation) and CIRS (Chronic Inflammatory Response Syndrome, a constant activation of mast cells to clear mycotoxins from the body). (source)

woman running through field feeling free of histamine issues

Methods for Recovery

The following methods also helped me to support normal cellular function and reduce over-reactivity:

1. Reduce stress. If there’s one thing that continues to throw our bodies out of whack, it is stress. Stress comes not only from relationships and job or life pressures.

Stress also comes from the environment. In my case, it came from forest fire smoke. But consider other forms of day-to-day stress to see what you can remove:

  • Wearing shoes all day. Get connected instead with the earth by intentionally going barefoot, called grounding or earthing. This modality helps our organ systems to function more effectively, and it helps our bodies to detoxify. I get grounded daily by touching my feet, sitting or laying outside on our grass for 20 to 30 minutes. (This practice also helps me to get Vitamin D from the sun, another way of supporting detoxification.)
  • Working long hours and then neglecting exercise or exercising intensely to make up for a sedentary lifestyle. Instead, consider several short walks and stretching throughout the day or long daily gentle walks and yoga.
  • Eating inflammatory foods such as sugar and processed foods.
  • Exposure to chemicals.
  • Persevering in relationships that may be detrimental. Consider neurofeedback for mental health, to improve gentle communication with the people in your life.
  • To heal past emotional traumas, mild or extreme, and nagging feelings of frustration, insecurity or hurt, consider the wonderful book The Emotion Code.

2. Supplements

Before I found and started the Vitamin A Detox diet, I could barely shut the doors on my supplements cabinet: It was full of pill-filled plastic bottles. While I considered each of these supplements well and carefully chosen, I am daily delighted that I am now off more than half of those supplements! The cupboard is half empty, and my esophagus finally has a break from all of that swallowing.

A couple of supplements are worth mentioning. These supplements have noticeably helped me in reducing histamine issues and improving my general wellness:

  • Most importantly, don’t miss out on Histaminum Hydrochloricum. This is the most liberating and wonderful supplement, and amazingly, I haven’t read about it in any histamine articles. I discovered it through my own personal experience. Because of Histaminum Hydrochloricum, I was able to stop buying expensive DAO supplements and all of the others I had read about. This tiny homeopathic works effectively. (Find Histaminum Hydrochloricum 30C here.) Please comment below this article in the Comments section when you’ve tried this homeopathic. I’ve recommended this supplement to many friends, and everyone agrees: It is the most exciting and effective homeopathic remedy for anyone with histamine issues! I took just one to two pellets under the tongue before meals. Now I take just one pellet very occasionally. This homeopathic can also be used after you begin your meal (or exposure to other triggers) to abate symptoms, but it’s best to prevent the onset of symptoms. HH can also be used to reduce seasonal allergy symptoms.
  • Basic Detoxification & Drainage Kit by Pekana. This liquid homeopathic trio addresses liver, lymphatic and kidney function and can be used highly diluted. Because it comes in an alcohol base, I wasn’t sure about the dosage and if the alcohol would cause a histamine flare. I found that just one to two drops in a couple of inches of water had a noticeable effect on my healing process without causing a flare, and can be used several minutes after taking Histaminum Hydrochloricum to prevent a flare. This product came recommended by my N.D. I used it daily (off and on) for many months. Initially it helped my lymph nodes to drain (after my exposure to dioxins and onset of symptoms).
  • Tea Tree Oil — I believe that tea tree oil is the most powerful, safe and effective alternative to antibiotics. To add to its remarkable protective and restorative qualities, tea tree has unique anti-histamine properties. A 2005 study showed the antihistamine effects of TTO within ten minutes of dermal application. (source) Our internal body is dermal too (consists of skin). Using a carrier oil (always), TTO can have profound effects on our gut and cell function. I used TTO internally for six consecutive weeks. It was during this six weeks that I overcame my histamine intolerance. Further investigation and case studies are needed to determine just how directly TTO affects MCAS and histamine intolerance. Read more about how to safely use tea tree oil internally here. Find the tea tree oil I use here.

Perhaps Mast Cells Know What They’re Doing

In conclusion …

I would like to propose an alternative theory regarding MCAS, based on the diet that helped me to improve. Perhaps mast cells are not over-reacting. Perhaps mast cells in those who struggle with histamine issues are actually reacting to a toxin in the body that hasn’t yet been recognized.

My current diet supports the theory that this hidden toxin is excess vitamin A.

If you experiment with the diet yourself, to see what effect it may have on your wellness process, please comment below.

Please share your thoughts on MCAS and histamine over-reactivity.

Additional Sources /

Comments 8

  1. Meagan, Thank you for this helpful post! I think it’s incredible that you reversed the symptoms of both issues. Thank you for the supplement recs, too. So helpful!! I just started manifesting (what I think is) histamine intolerance. I also have oxalate intolerance, so this post is super timely for me. How did you prepare your meat for the lowest histamine possible? I’m struggling with thawing a pound of ground beef (for example) and having too many left overs. I don’t need a fancy preparation, just anything. Thank you so much! Also, do you know if red potatoes are low histamine? (They are the only ones that are medium oxalate).

    1. Post

      Hi Anna, you’re welcome! I’m so glad this post is helpful and timely!! 🙂 Great questions, and I remember having the same problem with meat. I ended up eating a lot of scrambled eggs, which for me were less of a trigger than beef. The best thing to do re beef is to buy it freshly butchered, then to get home and form it into patties, and freeze those immediately layered with parchment paper. The frozen patty can be cooked up in a pan without defrosting, especially if you put a lid on so it partially steams. I hope that method helps you! Also, I hope you get to try the homeopathic mentioned above, because that completely liberated me (until I found the vitamin A concept and recovered). With HH, I could eat meat and leftovers again and not have to worry about it.

      Regarding red skinned potatoes, I recommend peeling them no matter what, because the peel contains precursors to vitamin A; anything you can do to reduce vitamin A intake is best IMO. Regarding the histamines in potatoes, potatoes are generally considered low in histamines, but they do actually cause histamine flares in some people, and are quite inflammatory for some people, as you know. Peeling does make them gentler. Eating them with K2 (butter if it agrees with you) also helps with their digestion.

      1. Megan,
        Thank you for your thoughts about the beef and potatoes. So helpful!
        My HH arrived today. : ) It allowed you to eat leftovers?! I’m so encouraged.
        Thank you!

  2. Megan, my doctor picked up my histame issues with the 23andme test when in 2011 I started breaking out in rashe/hives. I have had rosacea for years and have really struggled with diet. Your Vit A concept is interesting. Just trying to stay on a low histame diet is VERY challenging not seems even more restricted for Vit A. I noticed that you do not recommend fish oil, chia seeds, etc. How do you get enough Omega #.

    1. Post

      Hi Peggy, thanks for your comments and question! The Vitamin A Detox diet has had amazing results for those with rosacea. I have a client who saw lasting improvement within the first week on the diet, and there are many testimonies in forums on this condition being resolved by the diet. I hope you get to try it and see results. Regarding omega 3s, I do not worry about getting the right nutrition right now for so many reasons. One is, this diet is meant to be temporary, 6 months to 1 year, or sometimes 2 years when there are a lot of health issues to be resolved. During that time, I am still eating a nutrient-dense diet. Most importantly, I am healing or preventing debilitating diseases in my body; so that takes precedent over omega-3 consumption. I have had five autoimmune diseases over the last 25 years, all while consuming plenty of omega-3 fats, pretty ironic. In contrast, now my body is healing one issue after the next, and I am not supplementing or eating with fatty acids in mind. Instead, I focus on getting enough K2, vitamin C, taurine and protein … as well as a few other things I know my individual body needs, like B12. So it’s an issue of priorities: detoxing my body of vitamin A is the most important thing right now. Many of us prioritize omega-3 fatty acids for years, all the while not realizing our bodies either aren’t assimilating the nutrients (like in unfermented chia seeds) or we’re getting too much vitamin A, like in fish oil. I hope this helps, and best wishes!

      1. Improvement within a week for one of your clients is really incredible!

        I am so impressed and inspired you are doing this diet and helping others with it. Thank you for sharing your research so that we can learn, too. The diet sounds so overwhelming to me right now, even though it is probably something I should consider. Three years of low-medium oxalate has left me a little weary…in part because it is not particularly healing, but that’s a different story. : )

  3. Dear Megan, Thank you very much for your articles. This one is surprisingly relevant to my over-all health. I am going to try the homeopathic treatment recommended to see if things settle down a bit. I have had histamine issues for as long as I can remember. Thank you again. Blessings, Suzanne

    1. Post

      Thank you for sharing Suzanne. I’m sorry, I know how hard and limiting histamine issues are! I’m so happy the article is helpful, and I think you’re going to love the homeopathic and the relief it provides! I’d love to hear back how it works for you and if you have any other questions. Praying for your improvement!!

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