What is Histamine?
Histamine is a natural compound (biogenic amine) present in small amounts in nearly all foods, which typically cause no issues for most people. It circulates in the plasma (the liquid part of the blood) throughout the day, with levels fluctuating—highest during the day and lowest during deep sleep.
Histamine plays multiple roles in the body. It acts as a neurotransmitter modulator in the brain, helping to keep you alert and awake. If your child struggles to fall asleep, high histamine levels could be a contributing factor. Another key function of histamine is to stimulate the production of stomach acid, which is vital for proper digestion and nutrient absorption.
Histamine also acts as a defender against harmful invaders like insect bites, toxins, and allergens. In these situations, the body releases a surge of histamine to widen blood vessels, allowing white blood cells to reach the affected area more quickly. This response can cause localised swelling and fluid production (e.g., a runny nose) to help expel the offending substance.
If there’s excessive histamine in the gut, it may result in mucous in stools, which is part of the body’s histamine response.
How is Histamine Produced?
Histamine is produced and stored in certain cells, especially mast cells, which are found in tissues like the skin, lungs, and mucous membranes. Mast cells can be activated by stress, releasing Corticotropin-Releasing Hormone (CRH), which triggers histamine release.
In theory, cortisol, the body’s stress hormone, helps reduce histamine levels. However, in cases of prolonged stress—commonly seen in individuals with autism—cortisol levels may drop, leaving CRH levels elevated. This can lead to inflammation due to the release of cytokines like IL6 and IL8. Infections (bacterial, viral, or parasitic) and toxin exposure can also cause histamine release.
When the body releases large amounts of histamine, it attempts to counterbalance this by producing adrenaline, which lowers histamine levels. However, chronic infections can lead to persistently high adrenaline, disrupting mood, sleep, and even cognitive development. It’s important to understand that both chronic stress and infections can raise histamine levels, even if your diet is low in histamine. Take this quick Adrenal Fatigue Questionnaire to assess your stress levels and get clear next steps to start feeling more energised and in control again.
How is Histamine Broken Down?
In the central nervous system (CNS), histamine is broken down by the HMT enzyme (Histamine Methyltransferase). Impaired methylation can contribute to high histamine levels, which is why methylated B vitamins such as PCH B Complex can help in some cases.
In the digestive tract, histamine is broken down by the DAO enzyme (Diamine Oxidase), which tends to be low in those with allergies or autoimmune conditions. Research has shown that consuming oleic acid, found in olive oil, can significantly increase DAO levels.
Interestingly, during pregnancy, DAO production in the placenta can increase by 500 to 1000 times to create a protective barrier for the baby. This rise in DAO may explain why some women experience a reduction in migraines or allergies during pregnancy. However, low DAO levels during pregnancy can lead to complications such as premature birth, severe nausea (hyperemesis gravidarum), or gestational diabetes.
How to Normalise Histamine Levels
1. Remove Problem Foods
Histamine is produced through microbial activity during the fermentation or rotting of food. Foods like cheese, cured meats, vinegar, alcohol, and fermented items like sauerkraut are particularly high in histamine. Even leftovers can accumulate histamine quickly. Keep in mind that histamine levels can rise long before food spoils.
Certain foods are naturally high in histamine, and cosmetics or toiletries may also contain histamine-releasing ingredients such as cinnamaldehyde, Balsam of Peru, and sulfites. A bad reaction to fermented foods is a key sign of histamine intolerance.
2. Foods and Supplements to Manage Histamine
Certain foods and supplements can help regulate histamine levels. Quercetin, a bioflavonoid found in foods like ginger, garlic, onions, elderberries, and fennel, can lower histamine by stabilising mast cells. See Pippa Loves. Copper is essential for DAO to function, so be cautious of excessive zinc supplementation, which can deplete copper levels.
Supplements like DAOsin can help break down dietary histamine, but they won’t increase your body’s DAO levels. Carnosine, a naturally occurring dipeptide, can protect against histamine release. Supporting adrenal health is crucial, as the adrenal glands produce adrenaline, which helps neutralise histamine.
Other supplements that may help lower histamine include black seed oil, nettle tincture, and frequent doses of vitamin C (Vitamin C and L Glutamine is a natural antihistamine. Consider taking PCH Gut Repair and Vitamin C Complex supplements). In clinic we find that mot clients with histamine intolerance have leaky gut and/or dysbosis. Probiotics are also important, but you’ll want to choose strains that reduce histamine, such as Lactobacillus rhamnosus, Bifidobacterium infantis, and Lactobacillus plantarum all of which can be found in PCH Repopulate. Take my PCH Digest supplement. Those who are histamine intolerant need help digesting foods, so that it does not linger in the gut fermenting and producing bacteria and histamine.
By addressing diet, stress, and supporting the body’s ability to break down histamine, you can help bring histamine levels back into balance.
