Histamine is an important compound made by various specialty cells throughout the body and is critically involved in local immune responses, as well as regulating physiological function in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus.

Many will be familiar with the powerful, acute, short term impact of histamine when they are exposed to an allergen; hives, swelling, hay fever, etc.  What is less known is that there can be physiological, genetic and biochemical factors at play, which result in chronically elevated histamine levels and a poor ability to ‘clear’ or metabolise dietary histamine; this can create a state called Histamine intolerance.

The causative factors generally include some combination of genetic susceptibility (MTHFR, DAO, MAO, HNMT, PEMT), microbial pathogens (a number of which produce histamine or block clearance), nutrient deficiencies medications (antibiotics, antacids and even antihistamines -long term), Stress, anxiety, lack of sleep, hormonal insufficiency (adrenal fatigue), hormonal excess (oestrogen especially), Lifestyle (excessive exercise & alcohol esp.), diet, environment (mould, mildew, especially)and associated conditions (leaky gut, IBD, IBS).

Signs and symptoms will vary from person to person, but can include headaches or migraines, chronic, persisting nasal congestion or sinus issues, fatigue, especially with associated body pain, recurring hives, chronic digestive issues, including pain & IBS like symptoms, irregular menstrual cycle, cardiac issues, including high blood pressure, irregular heart rate and dizziness, anxiety and difficulty regulating body temperature.

Normalising histamine levels and improving capacity to clear effectively from the body can be achieved, but can take time, professional support and an understanding of all the factors involved. Meanwhile, limiting histamine intake can be helpful: