For a quick health quiz, consider whether you suffer from any of the following symptoms:

  • Rashes / hives / eczema / psoriasis
  • Chronic headaches / migraines
  • Itchy eyes / runny nose / congestion
  • Premenstrual cramping or headaches
  • Profuse sweating
  • Food sensitivities / food allergies
  • Seasonal allergies
  • Asthma
  • Nausea / vomiting
  • Abdominal pain / chronic digestive disorders / loose stools
  • Irregular menstrual cycle / sever menstrual cramps
  • Chest tightness / rapid heart rate
  • Anxiety / irritability

These are very general symptoms and have many potential causes. One potential cause which isn’t discussed often is a condition called Histamine Intolerance (HIT)

Instead, many patients with a combination of such symptoms are routinely referred to a variety of different doctors, each focusing on a piece of the puzzle:

  • Dermatologist
  • Gastroenterologist
  • Pulmonologist
  • Gynecologist
  • Endocrinologist
  • Psychiatrist
  • Cardiologist

Then, each doctor, in turn, prescribes a variety of medications:

  • Anti-inflammatories (cortisone, NSAID’s)
  • Antihistamines
  • Proton pump inhibitors
  • SSRI’s
  • Calcium-channel blockers
  • Hormones
  • Pain meds
  • Antibiotics

These medications suppress and mask the symptoms and not one of them addresses the underlying cause. In fact, some of them exacerbate the actual cause!

DID YOU KNOW: the World Allergy Organization estimates that approximately 1% of the world’s population suffers from histamine intolerance, of which 80% are women and most of them are over the age of 40. Sadly, even after years of painstaking research and excellent peer-reviewed publications by very reputable clinicians and scientists, many conventional medical practitioners deny the existence of histamine intolerance as a medical condition.

What is Histamine?

Histamine is a natural chemical responsible for a few major functions. It is both made by the body and found naturally in certain foods. It conveys messages between cells and our nervous system. It is involved in the regulation of stomach acid, the permeability of blood vessels, muscle contraction and brain function and is essential to fight against disease-causing agents such as bacteria and viruses.

What is Histamine Intolerance?

Histamine only becomes a problem when we have metabolic disturbances that do not allow us to effectively metabolize it properly. In our body, histamine is broken down by the enzymes diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT).

HNMT is responsible for breaking down histamine in the central nervous system, skin, lungs and other organs while DAO is the major enzyme involved in histamine metabolism in the digestive tract and is responsible for ensuring a steady histamine level required for the balance of numerous chemical reactions taking place in the body.

DAO is the key enzyme responsible for the degradation of extracellular histamine, regardless of whether the histamine originates from allergy-induced processes in the body or is consumed with food. If DAO is inhibited, histamine will accumulate in the blood and would result in intolerance.

“Think of histamine intolerance like a bucket filling up with water. Everything is fine while the water is below the top of the bucket; however, as soon as the bucket overflows, serious problems can occur. Every person has a different sized “bucket”; the point ofoverflow and the appearance of symptoms is called a person’s limit of tolerance, and this level varies between individuals. So, why does the bucket overflow at all? It is because, for various reasons, histamine levels in the body can increase to a point that exceeds the body’s ability to remove the excess.”

The onset and severity of histamine intolerance symptoms vary greatly between individuals, but common complaints are:

Truly, there are not many issues that can cause so many adverse problems in virtually every area of the body like histamine intolerance.

It’s not a Food Allergy!

With histamine intolerance, symptoms can be triggered by certain foods, but the mechanism is different than a food allergy.

  • Allergies are an IgE mediated, histamine response to an allergen, i.e., pollen or cat dander.
  • Histamine Intolerance is a toxic response by the body due to an excessive accumulation of histamine rather than an over-release of histamine. Thus, symptoms may not be immediate but may be triggered any time your “threshold” is reached and it may be difficult to pinpoint a particular food as the culprit.

It’s important to note that some of the symptoms mimic a true allergic reaction, but since histamine intolerance is not mediated by IgE, skin testing and blood allergy tests will be negative.

So, What Triggers Histamine Overload?

There are four major factors that contribute to excessive accumulation of histamine in the body:

 1. Diminished ability of the body to clear histamine:

  • Genetic susceptibility (MTHFR, DAO, MAO, HNMT, PEMT)
  • Mast cell activation disorder – MCAD or MCAS (this may be caused by any of the factors listed here)
  • DAO enzyme deficiency (low enzyme activity leads food-derived histamine to enter the bloodstream increasing its plasma concentration and once located in blood it spreads throughout the body)
  • Inflammatory rheumatic diseases, rheumatoid arthritis, soft-tissue rheumatism
  • Hormonal insufficiency (adrenal fatigue) or excess (estrogen)
  • Injury or trauma

2. Poor diet and lifestyle choices:

  • Chronic dehydration (water is undoubtedly the most important macro-nutrient and the only one whose absence will be lethal within days; water shortages can cause histamine to become excessively active in the body’s effort to restrict water loss in the brain, lungs, liver, kidneys and hormonal glands)
  • Over-the-counter and prescription medications that interfere with DAO and HMNT levels (including: antibiotics, antidepressants. antipsychotics, diuretics, muscle relaxants, pain meds, gastrointestinal meds, nausea and GERD meds,  malaria meds, tuberculosis meds, airway meds, heart meds, acetylsalicylic acid (aspirin), indomethacin (Indocin), diclofenac (Voltaren), and naproxen)
  • High-histamine diet (see next section for more details)
  • Nutrient deficiencies (B12, folate, B6, B2, B1, zinc, copper, C, methionine) and nutrient demands (stress, anxiety, lack of sleep)
  • Excessive alcohol consumption
  • Extreme or chronic stress
  • Excessive exercise, low oxygen states

3. Compromised digestive tract:

  • Bad gut bacteria – dysbiosis (many gut bacteria produce histamine or block methylation. If these strains are overrepresent in your gut, you may suffer negative symptoms from any extra histamine.)
  • Intestinal conditions (leaky gut, SIBO, IBD, IBS) or injuries that compromise the gut lining and affect digestion
  • Food sensitivities 

4. Environmental toxins and allergens

  • High pollen counts, mold, mildew, dust mites, natural gas leaks, etc.
Note, that the three biggest factors involved with histamine intolerance include: leaky gut syndrome (or related disorders such as Crohn’s disease, Irritable bowel, celiac, gluten intolerance);  a genetic polymorphism with the DAO enzyme; and heavy alcohol and/or medication usage.

How Does Diet Play a Role?

Most people associate histamine with immune responses in the body. But almost all foods and drinks contain some level of histamine, and these usually increase as the food ages, spoils, or ferments.

Some foods and drinks also contain compounds that help release histamine in the body or block the production or effectiveness of the enzymes DAO and HMNT. Researchers are still working out how much histamine is in most foods and drinks, as well as precisely how some nutrients impair DAO and HMNT activities.

According to the current research, everyday foods and drinks rich in histamine include:

  • Fermented alcoholic beverages, especially wine, champagne and beer
  • Fermented cow and goat dairy products such as cheese (especially aged), yogurt, sour cream, buttermilk, and kefir
  • Vinegar and vinegar-containing foods such as pickles, mayonnaise
  • Fermented soy products: miso, tempeh and soy sauce
  • Fermented grains such as sourdough bread
  • Cured or processed meats such as bacon, sausages, salami, pepperoni, luncheon meats and hot dogs
  • Smoked, salted, or canned fish and certain species of fish: mackerel, mahi-mahi, tuna, anchovies, sardines
  • Green tea, matcha tea, coffee, cocoa
  • Seeds: pumpkin seeds
  • Nuts: walnuts, cashews
  • Vegetables: avocados, eggplant, spinach, and tomatoes
  • Dried fruit: apricots, prunes, dates, figs, raisins
  • Junk foods and processed foods of all types – Preservatives are high in histamines
  • Kombucha

Suspected histamine liberating and DAO blocking foods include:

  • All legumes (including peanuts) 
  • Citrus fruit, such as oranges, limes, lemons, and grapefruit
  • Berries: raspberries, cranberries, strawberries
  • Pineapples, papaya, bananas
  • Egg whites
  • Shellfish
  • Chocolate
  • Alcohol
  • Energy drinks
  • Black tea
  • Mate tea
  • Green tea

People who are looking to reduce or reverse the condition will often need to go on a low-histamine diet. Note, that I said ‘low-histamine’ not ‘free-histamine’ diet. The goal is to decrease your histamine load rather than follow a histamine-free diet. That will ensure that you have more room for error when it comes to food, and you are not starving and stressing yourself to no end.    

Foods and drinks low in histamine include:

  • Freshly cooked meat & poultry
  • Freshly caught fish
  • Extra virgin olive oil
  • Pasture-raised eggs
  • Most leafy greens except spinach
  • Most fresh vegetables (see exceptions above)
  • Most fresh fruits and berries (see exceptions above)
  • Gluten-free grains
  • Coconut and rice milk
  • Coconut oil, grass-fed butter, ghee, almond butter
  • Leafy herbs
  • Herbal teas 

Scientists have found a number of nutrients that are effective at boosting DAO enzyme levels. These nutrients include:

  • Omega-3 and saturated fats
  • Vitamin B-6 (helps DAO break down histamine)
  • Vitamin C (helps lower histamine blood levels and help DAO break down histamine)
  • Copper (helps raise DAO blood levels slightly and helps DAO break down histamine)
  • Manganese (enhances DAO activity)
  • Zinc (helps DAO break down histamine)
  • Magnesium 
  • Calcium 
  • Phosphorus
  • Iron
  • Vitamin B-1
  • Vitamin B-12

Remember: a low-histamine diet is a structured program that’s best done under the supervision of a nutritionist or a naturopath specializing in food intolerance.

Diagnosing Histamine Intolerance

Histamine intolerance is poorly understood in the medical world. Most health professionals are not trained on the topic, diagnosis is flaky at best, and the condition itself is difficult to treat.

In fact, many practitioners typically recommend a diet high in histamine containing foods.  This includes fermented foods which have incredible health benefits for those with adequate histamine metabolism.

You may want to discuss the following tests with your health practitioner:

  1. Advanced Intestinal Barrier Assessment (or AIBA).
  2. Genetic Test (MTHFR, MAO, HNMT, PEMT).

Treating Histamine Intolerance

Aside from dietary changes, there is no set treatment for people with histamine intolerance. Depending on their symptoms or the cause of the condition, most people benefit from the following functional approaches:

  • Following a low-histamine diet
  • Avoiding DAO blocking foods (such as alcohol, energy drinks, black tea, mate tea, and green tea)
  • Taking DAO enzyme supplements (note: DAO supplements do not get into your bloodstream and cannot increase your DAO levels internally. This means that supplementing with the DAO enzyme only helps you break downhistamine that you’re consuming.) 
  • Taking targeted vitamin and mineral supplementation
  • Switching prescription medications
  • Avoiding medicines associated with histamine intolerance, such as most anti-inflammatory and pain drugs
REMEMBER: Suppressing a symptom may ease your suffering and help in the immediate moment, but it never gets to the underlying cause; this approach does not take into account your body’s natural self-healing mechanisms and causes long-term dysfunction; thus, it is best to think WHY, HOW and MECHANISM of various conditions rather than focusing on the ‘condition’ itself. 
Ronit Mor, ND

Ronit Mor, ND

Ronit Mor, ND, is the founder of My Wellbeing Compass and Mor Wellness Concepts. As a naturopath and a clinical aromatherapist, her greatest passion is educating, empowering and inspiring people on their path to regaining optimal vitality and wellbeing. She is also an author, regularly contributes articles to different publications, and is a local and an international speaker. read more...