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Histamine, Health and Hormones

Updated: Apr 13

Histamine affecting your health?

We typically relate histamine to allergies in the summer. A runny nose, itchy eyes and multiple sneezes. This pesky molecule can indeed reek havoc on our bodies in more ways than you may know. Infact, it may be at the root cause of many period related pains and problems, as well as a barrier to conception. Below we will uncover the role of histamine, how it can become dyregulated and what this means for your health and wellbeing. I will also give you some ideas on how to test and address high histamine levels.

Histamine is an important signalling molecule that has many positive functions:

  1. Neurotransmitter: Histamine acts as a neurotransmitter in the brain, where it helps regulate important functions such as wakefulness, attention, learning, and memory. Proper histamine signaling is essential for maintaining cognitive function and overall mental wellbeing.

  2. Immune response: Histamine is released by immune cells in response to allergens, pathogens, or tissue damage. It plays a key role in triggering inflammatory responses that help the body fight off infections and heal injuries.

  3. Histmaine and Fertility: Histamine is an important molecule for conception. It regulates the mesntrual cycle and positively supports implantation. It is when histamine is produced in excess that issues arise.

However, it also has some well known negative functions when produced in excess:

  1. Allergies: In individuals with allergies, histamine can be released in excess in response to harmless substances like pollen, pet dander, or certain foods. This can lead to symptoms such as itching, hives, nasal congestion, sneezing, and in severe cases, anaphylaxis.

  2. Histamine intolerance can cause a range of symptoms, including headaches, digestive issues (such as bloating, diarrhea, or abdominal pain), skin problems (like eczema or urticaria), and fatigue. Causation is multifactorial but at times it is a deficinecy in the DAO enzyme that works to break down histamine. This is where gut health becomes important!

  3. Histamine and PMS/PMDD: Histmaine negatively affects the GABA receptors in the brain. This can lead to increased feelings of anxiety,low mood and much more at certain times in the cycle, often pre-ovulatory and/or just before menstruation. It can be a cause for painful periods, breasts and aggrevated skin at ovulation or in the luteal phase.

  4. Histamine and Endometriosis: Excess histamine leads to an upregulated immune response. This is a driver for endometriosis. Mast cells (the cell that releases histmaine) are found in much higher quantities in the endometrial tissue of those with endometriosis. Symptoms and the proliferation of endometriosis can often be reduced by avoiding histamine triggers.

What are the signs and symptoms of high histamine?

  • Difficulty Sleeping

  • Irregular Cycles

  • Anxiety and rapid heartbeat

  • headaches and migraines (often premenstrual or pre-ovulatory)

  • Inflamed or itchy vulva or vaginal tissue

  • loose stools

  • sneezing, runny nose and seasonal allergies

  • itching, hives, eczema

Histamine, Estrogen and the Menstrual cycle:

Estrogen and Histamine have the ability to work in complete harmoney and not cause you any issues. However, if you are histamine intollerant OR you have high histamine levels Estrogen, and its fluctuating levels through the cycle can leave you feeling rotten.

When your estrogen levels rise, you release more of your own histamine. Histamine then stimulates your ovaries to release more estrogen - thus setting off a vicious cycle. Moreover, estrogen stops your DAO enzyme from working as well. This combination of factors can become particularly prominent mid-cycle, pre-period and in those who are estrogen dominant.

Often, women who have been through IVF treatment or egg collection will start to feel rotten after treatment. They may also notice changes to their cycles and heightened levels of anxiety, digestive struggles and poor sleep. This can be linked to the high doses of estrogen administered during treatment triggering histmamine intollerance or simply causing transient elevations in histamine levels and DAO dysfucntion.

Histmaine and Fertility-Is this the hidden cuase of miscarriages, implantation failure and infertility you have been looking for?

Histamine is involved in the regulation of the female reproductive system, where it plays a role in the menstrual cycle, ovulation, and implantation of the embryo. Additionally, as we have discussed, it has a relevant effect on estrogen levels and inflammmation.

Although more research is needed, high histamine levels or sensitivity may potentially impact fertility due to its affect on ovulation, fertilisation and implantation. In addition, the inflammatory effects of histamine in excess has a negative effect on the reproductive system as a whole.

In optomising Fertility the key is to lower inflammation. Therefore, if we can deduce that histamine intollerance or excess is present this is an obvious issue to address to promote conception.

What causes high histamine?

  1. Alcohol: Alcohol can inhibit the enzyme DAO, which helps break down histamine, leading to elevated histamine levels in some individuals.

  2. Histamine-rich foods: Consuming foods that are high in histamine, such as aged cheeses, fermented foods, and certain types of fish, can lead to increased histamine levels in the body. This can be tricky, as often these foods are promoted as postive for fertility. That is why a personalised approach to food is important.

  3. DAO enzyme deficiency: Can be caused by: Genetic variants, SIBO, Candida and parasties, Leaky gut, Crohns/IBD.

  4. Stress: Stress and emotional factors can also play a role in histamine release, as stress can trigger the activation of mast cells and the release of histamine.

  5. Certain medications: Some medications, such as opioids, muscle relaxants, and certain antibiotics, can trigger the release of histamine in the body or interfere with the breakdown of histamine, leading to high levels.

  6. Mast cell activation syndrome (MCAS):

  7. Allergies: Allergic reactions trigger the release of histamine in the body, leading to symptoms such as sneezing, itching, and swelling


  1. Elimination/Food Diary/Low Histamine Diet for 2 weeks: This is the best way. Remove high histamine foods, keep a food diary and try to assess and look for changes in symptoms. After a 2-4 week break, you re-introduce trigger foods and assess for response.

  2. THAK blood testing- Available at certain laboratories.

If you feel like you need some help in uncovering why your hormones, health and fertility may be in jeopardy or you believe histamine may be causing you to feel crappy. Book in to have a free 15 minute call with us to see how we can help you.

Until next time,

Dr Lizzie


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