What is Histamine Intolerance?
Histamine intolerance is where excess histamine activity is occurring in your body which leads to a wide range of symptoms, from headaches to stomach upset, facial flushing, itchy skin and hives, just to name a few. What makes it complicated is that it can occur for different reasons, such as nutrient deficiencies, excess production, or a reduced ability to break histamine down, which could be genetic. Histamine intolerance can also be classified under the general umbrella of food intolerance, which is different from food allergy.
The Genetics Of Histamine Intolerance vs Mast Cell Activation Syndrome (MCAS)
Histamine Intolerance and Mast Cell Activation Syndrome (MCAS) can result in histamine symptoms, though the underlying causes of each are different. There are also other factors affecting histamine levels in the body, which will be discussed below.
Histamine Intolerance is where your body is deficient in the enzymes that break down histamine, which can mean that histamine can accumulate. The enzymes involved are DAO (diamine oxidase) and HNMT (histamine-N-methyltransferase).
Mast Cell Activation Syndrome (MCAS) is where your immune system is overactive (not an autoimmune disease) which causes an excessive amount of histamine to be released in the presence of inflammation.
Other genetic factors that can contribute to histamine symptoms are defects in histamine receptors (H1, H2, H3, and H4), which could mean that the receptor is triggered more easily, though more research in this area is required.
Histamine Triggered Mood Changes
As well as physical symptoms, histamine can also cross the blood brain barrier when levels are high enough, and can act as a neurotransmitter and hormone affecting mood and behaviour. When we are injured or in pain, our natural instinct is to go into fight or flight mode, and we can become more aggressive, less agreeable, and less tolerant of others. As a result, histamine is thought to help activate the fight or flight response [2] contributing to negative mood and mental states along with the possibility of aggressive behaviour changes as part of a natural self-protection mechanism.
Related Condition: Digestive issues (IBS)
Related Condition: Anaemia
Inflammation in the body decreases iron absorption. The reason for this is that inflammation is commonly associated with viral and bacterial infections which can be fuelled by iron as it increases the rate of growth, so to limit the risk of infection, iron absorption is decreased. (The body reduces iron absorption by increasing production of a molecule called hepcidin which blocks iron absorption). Therefore, histamine, which increases inflammation by regulating the immune system can result in low iron absorption and anaemia [3].
Histamine Symptoms
The symptoms of histamine intolerance are wide ranging, with different people experiencing varying degrees of severity. The following are some of the more common symptoms that people can experience.
Headaches & Fatigue
Digestive Issues – bloating, cramps, pain, diarrhoea
Dizziness / Low blood pressure
Itchy skin / Hives / Urticaria
Mood / Behaviour changes / Anger / Irritability
Nasal congestion or runny/stuffy nose
Rapid heartbeat
Redness of the skin
Shortness of breath
Common Histamine Sources
Top Foods Sources of Histamine (mg/100g)
Parmesan Cheese (aged), (10–200+)
Cheddar Cheese (aged), (2–100)
Swiss Cheese (aged), (2–40)
Anchovies (canned), (30–400)
Salami, (10–50)
Pepperoni, (20–100)
Red wine, (2–20)
Yeast extract (e.g., Vegemite), (20–70)
Note: Some foods have low levels of histamine, but can trigger the release of histamine. These are known as “histamine liberators”.
Testing Available
Urine testing is available for Histamine levels. I can order these tests during a consultation, or you can order them through your GP. If you already have your test results, please email them through to [email protected] when making an appointment.
I can help you interpret the results in light of what the optimum values should be, instead of just the standard reference ranges which is more of a reflection of the range of values found in the general population.
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Help is at Hand
One way to help reduce your histamine levels is to increase your vitamin C intake. Research shows that as vitamin C levels increase in your blood, histamine levels decrease. Inflammation can trigger the release of histamine from your immune system (mast cells) which then results in the release of more histamine – in a chain reaction. Vitamin C can reduce inflammation (as an antioxidant, it neutralises free-radicals that cause damage), which slows or stops the histamine chain reaction [1].
This is just one option that can help people whose vitamin C intake is inadequate. There are many other ways to reduce total histamine load depending on your unique biochemistry.
Your Personalised Roadmap
When you make a booking, I will do a deep-dive into your lifestyle, diet, personal symptoms, as well as examine your current supplements and medications, and blood tests where available, to guide the creation of a personalised, evidence-based treatment plan to help reduce your histamine load based on your unique physiology.
Book A Free Discovery Call To Learn More
Booking a free discovery call is the best first step to understand how a clinical nutrition consultation can support your health goals. This no-obligation call gives you a chance to ask questions, learn about the consultation process, and see if the approach aligns with your needs – without committing to a full appointment. You’ll gain clarity on what to expect, including how your health history, symptoms, and lifestyle factors are assessed to create a tailored nutrition plan. It also allows you to connect with the practitioner, ensuring you’re comfortable and confident moving forward.
Click the “Book” button above to schedule a free discovery call now.
Additional Resources
The following resources contain science-backed, evidence-based information to learn more about the condition.
Food allergy and intolerance | Better Health Channel (Victorian Government)
Histamine intolerance | Mayo Clinic Connect
Histamine Intolerance: Causes, Symptoms, and Diagnosis | Healthline
References
1. Impact of oral vitamin C on histamine levels and seasickness https://www.ncbi.nlm.nih.gov/pubmed/25095772
2. Histamine in the Nervous System | Physiological Reviews | American Physiological Society https://journals.physiology.org/doi/full/10.1152/physrev.00043.2007?links=false
3. Role of Histamine in Inflammatory Diseases | SpringerLink https://link.springer.com/chapter/10.1007/978-3-319-77658-3_4
