Histamine and Your Thyroid


Histamine is an organic compound produced by the body and also present in many foods. Histamine is necessary for the maintenance of life and is involved in immune response. It is released by cells in response to injury and allergic or inflammatory reactions. There are four types of histamine receptor cells (H1R, H2R, H3R, and H4R). Each receptor influences different systems of the body.

H1R — Correlates with the heart, the skin, respiratory tract and uterus. It affects estrogen, mucus secretion, and vasodilation. Symptoms of histamine responses in HR1 receptors include: tachycardia, arrhythmias, hypo- and hypertension, pruritus (itching), red skin-flushing, urticarial (rash), sinus congestion and rhinorrhea.

H2R — Correlates with the cardiovascular system and the gastrointestinal system. Symptoms of histamine responses in H2R receptors include: stomach cramps, diarrhea and leaky blood vessels.

HR3 — Correlates with the central nervous system. Common symptoms of histamine responses in HR3 receptors include: headache, ear ringing, vertigo, nausea, vomiting, insomnia and interrupted sleep, arousal, learning and memory.

HR4 — Correlates with bone marrow, immune cells and mast cell secretion. Mast cells are found in numbers in connective tissue and release histamine and other substances during inflammatory and allergic reactions.

Histamine Foods

Foods that are high in histamine levels include:
• Alcohol
• Pickled or canned foods
• Sauerkrauts
• Matured cheeses
• Smoked meat products
• Shellfish
• Beans
• Nuts
• Chocolates and cocoa based products
• Vinegar
• Ready meals
• Salty snacks or sweets with preservatives and artificial colorings

Histamine Intolerance

A histamine intolerance may signal a thyroid problem. Low thyroid levels can cause an increase in histamine production, whereas high thyroid levels can cause increased histamine receptors and a heightened histamine response.

Histamine intolerance is the result of an imbalance in the body system resulting in a build up of histamine due to the body’s inability to break it down. A healthy person can rapidly detoxify histamine by the enzyme amine oxidases, but in unhealthy or immune-compromised people with low amine oxidase enzymes, the aftereffect is a toxic overload of histamine.

Individuals who have histamine intolerance have diminished diamine oxidase (DAO), the enzyme responsible for breaking down histamine-rich foods. Alcohol and drugs can release histamine into the body and completely block the main enzyme, DAO from doing its job metabolizing histamine, causing symptoms such as diarrhea, headache, hypotension, and arrhythmia. Hives and other skin issues, nasal congestion, and, in extreme cases, asthma attacks may also occur.

DAO enzyme products such as HistDAO from Xymogen, taken with each meal, additional pepsin, vitamin C and B6 can increase the DAO activity and help degrade histamine.

Histamine intolerance causes a condition that many people with autoimmune disease have that’s called “low stomach acid.” Although the symptoms of heartburn and poor digestion are the same as high stomach acid, low stomach acid is a dangerous condition that can contribute to poor vitamin absorption and can lead to very serious problems later on.