Helpful Information and Interventions for Histamine Overload and Intolerance

by Dr. Susan Tanner, MD

The impact that mold and mycotoxins have on inflammation and their role as the basis of illness and disease in the body cannot be denied. In fact, the different mechanisms of inflammation that are activated in mold-injured patients cause a wide variety of seemingly unrelated symptoms that make the illness so difficult to diagnose. And, while mycotoxins target and negatively impact many organ systems, in this article, we will be focusing on the lining of the small intestine, referred to as the gut.

Mast Cell Activation Syndrome (MCAS)/Histamine Intolerance

While absorption of nutrients is a prime function of the gut, there is more, equally important activity going on in that region, much of it having to do with immunity and inflammation regulation. When things are off-balance in the gut, the widespread effect can be that of inflammation involving body parts and organ systems that are seemingly unrelated. One manifestation of immunity dysregulation is referred to as mast cell activation syndrome or histamine intolerance.

We are all familiar with over-the-counter “antihistamines” for allergies. These are medications able to lower histamines released from respiratory tissues in response to their exposure to pollens, dust, and even some foods.  Understand, then, that the gut also has the ability to form these histamines in response to stimulation by certain foods.  Why does this happen?  In the simplest of explanations, a substance called Diamino oxidase or DAO is produced in the brush border of the gut, and one of its purposes is to metabolize histamines released by certain foods in their metabolism.  Foods considered high in histamine include such healthy foods as citrus, tomatoes, oats, spinach, and fermented foods, as well as certain preservatives and coloring agents. The list can actually be exhaustive!

We suspect histamine intolerance in patients due to a multitude of symptoms.  These symptoms may be gastrointestinal in nature, such as bloating, gas, diarrhea, or constipation, but also can manifest as headaches, skin eruptions/hives, runny nose, and/or cough.  Typically, occurrences can occur after eating but the rate at which some foods are broken down in the gut may make cause and effect hard to correlate.

Histamine and Mold

In patients with mold and mycotoxin exposures, the mycotoxins are damaging to the brush border of the gut along with other impacts on the health of the lining which, in turn, reduces the production of DAO, which then allows much larger amounts of histamine circulation in the bloodstream. Thus, there are inflammatory symptoms that arise from this.  The lowering of natural gut immunity also complicates matters with the overgrowth of yeast/candida and undesirable bacteria, all adding to the inflammation burden.

Mast cell activation syndrome is not always caused by mold and mycotoxin exposure. It may be genetically linked, but in any event, keeping histamine stimulation as low as possible includes keeping your living environment as mold- and toxin-free as possible.  I think it is smart to always remember that mold and mycotoxins are never beneficial and always create some degree of burden on the immune and detoxification systems. Thinking this way helps us to recognize that at least low levels of inflammation can and will occur with continued mold exposure even in a seemingly healthy individual. Therefore, clean air MUST be in your surroundings before embarking on a direct evaluation of histamine-related issues. Without the clean air piece in place, it will be much more difficult to ascertain the main cause of the reactivity and treat it.

The Trouble With Diagnosis

So how do you know if you have mast cell activation syndrome or histamine intolerance/overload?  The symptoms are generally the first clue.  In patients in whom the symptoms are severe, then it is quite evident, as it can present with anaphylactic types of reactions including difficulty breathing, massive hives, a drop in blood pressure, and heart rhythm problems.  These symptoms require emergency measures to turn the situation around.  For others, the symptoms may be quite problematic but not necessarily life-threatening. These symptoms can include the following:

– Runny nose, sneezing

– Swel­ling, e. g. facial (angio­e­dema)

– Itching, Rashes

– Migraine-like headache

– Diar­rhea, Nausea, and Vomiting

– Asthma

– Flush (red colo­ring of the body)

– Migra­ting joint pain and inflamma­tory condi­tions

Lab testing has proven to be problematic for diagnosing histamine intolerance and MCAS.  Some professionals have suggested checking serum (blood) levels of both histamines and DAO, but there are limitations to this process.  For one thing, the levels fluctuate rather quickly, and DAO exists at such low levels even normally that detecting even lower levels is hard to do.  Food allergy testing is also indeterminate, in that when the gut lining is damaged or impaired,  foods may show up as problematic when they are consumed regularly, and the body begins reacting as if they are invaders. Finally, foods high in histamines do not necessarily show up as true food allergies as it is the process of histamine induction that is causing symptoms and not the actual food per se.

Helpful Interventions

A low histamine diet, that is, avoiding foods high in histamines (many lists of these are available online) can be followed and one can observe if symptoms improve substantially.  This takes an arduous approach of avoidance for a couple of weeks, not days, to really determine if, indeed, histamine high foods and DAO low are the culprits.  The combination effect of bacterial and yeast overgrowth plus food allergies can add to the confusion!

As a practitioner, I really like to do Organic Acids testing or a comprehensive digestive stool analysis to see if there is an overabundance of pathogens that could also be contributing to the issue. The microbiome needs to be addressed and corrected in all circumstances, especially when the gut is compromised. If indicated, then the use of IgG Gut Protect to help restore the immune lining is needed and helpful.

Most patients also benefit from digestive enzymes, as the pancreas typically will go into survival mode when the body is continually challenged in any way.  Digest Assist can be very helpful in this process, allowing the breakdown of proteins and fats to their smallest molecular components for absorption and less immune stimulation.

If excess histamine release is suspected and there are symptoms indicative of it, then the addition of Histamine Relief can be very helpful during this gut healing process. Histamine Relief includes quercetin, a powerful flavonoid, to support healthy histamine levels, bromelain to enhance the absorption of quercetin and support mucosal tissue health, stinging nettles leaf extracts to balance the immune response, and N-acetyl cysteine to clear the airways by promoting normal viscosity of mucus. This powerful combination actively promotes healthy nasal and sinus passages for individuals with elevated histamine and respiratory irritation. Histamine Relief also contains Vitamin C. Vitamin C has many immune-boosting properties but is distinctively beneficial for individuals with seasonal discomfort because of its ability to deactivate histamine.  This new product is beneficial for both the gut histamine reaction and respiratory symptoms from more typical allergies, including pollen. Additionally, since we are discussing inflammation, while not a “cure” for COVID 19, its use, if infected, can help reduce the inflammatory symptoms induced by the virus.

The Good News

Over time and with proper treatment for mold- and mycotoxin-induced illness, histamine reactivity does get much better. Then, the abovementioned products may be used on an “as needed” regimen if and when symptoms arise.  Even if the avoidance of high histamine foods is helpful initially, over time many of these foods may be added back to the diet without consequence when the overall inflammation is lowered.  And, for those of you wondering about fermented foods, which for the gut microbiome can be very helpful, if there are no overt signs of histamine excess, they may be used straight away.  However, when following a low histamine diet, at least initially, I have patients avoid fermented foods so as not to muddy the waters.  I do find that once the system has calmed down probiotic-rich foods are helpful to add back in for healthy bacterial support.  This all brings in the fact that every patient is an individual and there are no hard-fast rules without knowing specific history and manifestations.

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