WHAT IS HISTAMINE?

Histamine is a chemical compound made and used everywhere in our body. It is mainly stored in basophils and mast cells. Histamine plays three critical roles, among others: in the stomach to aid the production of gastric acid, which helps to break down and digest food effectively; as a neurotransmitter communicating important messages between neurons in the nervous system; and as an inflammatory response mechanism released among other compounds from mast cells to neutralize offending organisms, including allergens, viruses, and bacteria.

We also consume histamine from foods and beverages and have histamine produced by some of our gut bacteria.

HOW DO WE BREAK DOWN HISTAMINE?

Excess histamine is broken down by two enzymes: diamine oxidase (DAO) in the digestive tract and histamine n-methyltransferase (HNMT) in the central nervous system and cells of diverse tissues throughout the body.

WHAT CAUSES HISTAMINE INTOLERANCE?

Histamine intolerance happens when there are excess levels of histamine in the body due to a deficiency in the production of DAO and HNMT, the two enzymes that break down histamine. Apart from these enzyme deficiencies, other medical conditions can increase histamine levels in the body, such as MCAS (mast cell activation syndrome), allergies, food sensitivities, leaky gut, SIBO, and genetic predisposition. Exposure to environmental toxins and allergens, mold, pollution, volatile organic compounds (VOCs) from air fresheners or paints, and any scented product worsen histamine intolerance, as they can trigger the release of histamine from storage cells like mast cells. Stress can also prompt the release of histamine into the body. Consuming foods and drinks naturally high in histamine, such as wine, fermented foods, aged cheeses, and food leftovers, can contribute to elevated histamine levels in people with histamine intolerance.

Histamine Intolerance can be seen alongside Mast Cell Activation Syndrome because when mast cells are triggered, they can release histamine. Constant mast cell activation can lead to a steady stream of histamine in the body. If the body can’t keep up with eliminating this histamine, you can end up with histamine intolerance.

FACTORS CONTRIBUTING TO HIGH HISTAMINE LEVELS

    • Allergies (IgE reactions)/Food and Environmental Sensitivities

    • DAO and HNMT Deficiencies (genetic polymorphisms)

    • High Histamine-Rich Foods

    • Leaky Gut (increased intestinal permeability)

    • Mast Cell Activation Syndrome (MCAS)

    • SIBO (small intestinal bacterial overgrowth)

COMMON SYMPTOMS OF HISTAMINE INTOLERANCE

This excess of histamine in the body brings uncomfortable symptoms ranging from mild to very disruptive. At the core of all symptoms of histamine intolerance is inflammation. Because histamine and histamine receptors are found throughout the body, symptoms vary depending on which receptors are activated and in which tissues. Symptoms of high histamine levels or histamine intolerance may include:

   • Abdominal Pain

   • Acid Reflux

   • Acne

   • Anxiety

   • Bloating

   • Brain Fog

   • Constipation or Diarrhea

   • Crawling Skin Sensations

   • Dizziness or Vertigo

   • Eczema

   • Fatigue     

   • Flushing

   • Headaches/Migraines

   • Heart Palpitations     

   • Hives (Urticaria)

   • High Blood Pressure

   • Irregular Menstrual Cycles

   • Itchy Eyes, Tearing

   • Low Blood Pressure

   • Mood Swings

   • Nasal Congestion

   • Nausea

   • PMS

   • Rashes

   • Rosacea

   • Seasonal Allergies

   • Sleep Disturbances

   • Sneezing, Runny Nose

   • Symptoms of Asthma

   • Tinnitus (Ringing in the Ears)