HISTAMINE INTOLERANCE: SYMPTOMS, CAUSE, AND TREATMENT

​Histamine intolerance symptoms are experienced by many people, although it still remains relatively misunderstood (that being said - research on the topic is quickly expanding). Its severity ranges from more severe IgE-mediated symptoms to milder intolerances to fermented or aged foods containing high histamine levels.

Here, we’ll examine more about this condition, its causes, and what you can do to alleviate symptoms.

​Allergies form when the immune system improperly identifies an otherwise harmless molecule like a dust particle or pollen as a danger, mounting an immune response and producing the symptoms we’ve come to recognize as ‘allergies”. 

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What Is Histamine Intolerance?

Histamine intolerance is when the body has trouble with histamine clearance, either from excessive production or difficulty breaking it down. Since major of mast cells line our skin and mucous membranes, most symptoms include congestion, itching, and gastrointestinal disturbances.

Since the disorder is driven by excessive histamine in the body, the cause could be as simple as consuming too many histamine-rich foods like alcohol, fermented foods, and dried/aged food, or in more complicated cases it could due to trauma to the intestinal lining and/or downregulation in the enzymes diamine oxidase (DAO) and histamine N-methyltransferase (HNMT) in the gut that assistance in histamine clearance.
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How is a Histamine Intolerance Diagnosed

The simple answer is - clinically. While appropriate testing for histamine intolerances can be helpful to not only isolate the cause of the issue but support recovery long term, negative tests cannot always rule out an intolerance. This is where an experienced diagnostician can come in handy. It's also important to note that histamine intolerance is not an allergic reaction or food allergy, so traditional skin-scratch and allergy tests will be negative.

What makes histamine intolerance so insidious is that it can manifest in many different ways. Common symptoms of histamine intolerance include:

● Wheezing/shortness of breath
● Hives or dermatographia
● Eczema
● Fatigue
● Bloating
● Diarrhea
● Heartburn/Reflux 
● Irregular/painful menstrual cycle
● Headaches
● Nasal congestion/itchy eyes and nose
● Increased anxiety 

An elimination diet and challenge remain one of the best ways to know if you have histamine intolerance. Physicians may also check the levels of histamine in your bloodstream or take a skin biopsy, but this type of testing is more effective for conditions like mast cell activation syndrome. The DAO enzyme can also be measured, however as mentioned previously, normal results do not rule out an intolerance. Lastly, secondary histamine intolerances are more common in individuals with Irritable bowel syndrome, inflammatory bowel syndrome, dysbiosis or an overgrowth of bacteria in the gut. This is where SIBO testing and stool testing should be considered. 

Treatment with a Low Histamine Diet Regimens
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Since histamine intolerances are a by-product of how your body processes dietary and internal histamine, eliminating dietary intake can keep your levels below symptomatic thresholds. However, while eliminating high-histamine foods from your diet may seem like a simple solution, it can also be an overwhelming and restrictive process.

As foods age, they increase in histamine content. This makes foods like smoked and aged meats, cheeses, vinegar, wine and fermented foods naturally high in histamine. Also, longer shelf life foods, previously frozen, and ever leftovers will also typically have higher histamine contents. Also, as you can see, the list can grow quite large, and whether or not we can achieve an absolute histamine-free diet becomes debatable. 

This is where I often recommend exploring why a histamine intolerance occurred in the first place. Since we know histamine intolerances are more common in people with gastrointestinal issues, this is often where I start. 

Furthermore, probiotics, antioxidants and vitamin C have all been shown to have favourable impacts on mast cell stabilization, which can expedite recovery over the long term. 

To learn more about histamine intolerances, proper diagnostic assessments, and treatment options, please contact Toronto Naturopathic Doctor, Dr. Courtney Holmberg at 647-351-7282 to schedule your appointment today.