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Histamine Intolerance: A Helpful Overview

Updated: Mar 4, 2023

Have you ever heard of histamine intolerance?

When I first heard of the term, I had no idea what it meant until after I discovered that my infant daughter was reacting to certain foods with a bright red rash around her mouth, even though these were often foods recommended for gut healing, like sauerkraut and broth. As I researched further, I realized that a focus on histamine was going to be key to resolving her issues with eczema and allergies.

Histamine intolerance is becoming increasingly common, and it's something that many of my clients are dealing with. But what exactly is histamine? Most of us have heard of antihistamines for things like seasonal allergies, but we don't actually know what histamine is.

In simple terms, histamine is a chemical that is released by our cells in response to injury, allergies, or other triggers. It plays a key role in the immune system, helping to defend our bodies against invaders like bacteria and viruses but when there is too much histamine in the body, it can cause a range of symptoms.

Why do some people have too much histamine in their bodies? There are a few different reasons. One is that they may have an overactive immune system, which causes them to release more histamine than is necessary or they may not be able to break down histamine efficiently, leading to a buildup and some foods are naturally high in histamine or can trigger the release contributing to an excess.

Understanding histamine intolerance helps to explain why some individuals don't do as well with certain protocols or foods. It's a fairly complex topic so I'm breaking it down into easy-to-understand language to help you learn more about what it is and how to manage it.

What is Histamine?

Histamine is a naturally occurring chemical that is found throughout the animal kingdom, and in many plants, bacteria, and insect venom.

In humans, histamine is present in nearly all of our tissues, where it is primarily stored in our mast cells. It plays several key roles in our bodies, including serving as a neurotransmitter and regulating stomach acid, but perhaps most importantly, it is a critical initial component of our immune system's response to foreign substances.

When our immune system encounters a foreign substance that it deems a threat, it initiates an allergic reaction. This triggers a chain reaction in which mast cells are instructed to instantly release large amounts of stored histamine. This causes blood flow to increase in the affected area, leading to inflammation and the recruitment of other immune agents to help combat the perceived threat.

During this process, immune system proteins called antibodies bind to the foreign substance to remove it, while histamine binds to receptors on our cells. Together, they form a critical part of our body's defense strategy. Histamine can be thought of as the bouncer at the club, working with antibodies (the soldiers) to remove the threat by making the exit doors easier to open.

While their job is to help keep us safe, their methods can be irritating particularly if they get a bit heavy-handed. Histamine can cause a range of symptoms, including increased mucus production, dilated blood vessels, increased stomach acid production, increased heart rate, watery eyes, sneezing, itching, tissue swelling, and more.

What is a Histamine Intolerance?

Histamine intolerance occurs when the amount of histamine in our body exceeds the amount that we can efficiently eliminate.

To understand histamine intolerance, we can use the bucket analogy. Just like a bucket can overflow when filled beyond its capacity, our accumulated histamine levels can exceed our individual tolerance level, leading to symptoms of excess

It's important to note that histamine intolerance does not necessarily mean that someone is 'intolerant' to histamine but rather that they have more than what they can metabolize or degrade at any one time.

While antihistamine medications can help alleviate symptoms by blocking the binding of histamine to receptors, it doesn't address the original release and circulation of histamine, which is a key factor considering its role in increasing inflammation as described earlier and may actually trigger the body to produce even more histamine.

In addition to dealing with our own stored and circulating levels of histamine, many foods we eat either contain histamine or stimulate additional histamine release. Generally, the older the food or longer it is stored, the more histamine it contains. This is why it's important for people with histamine intolerance to be mindful of their diet and identify trigger foods that can worsen symptoms.

potential symptoms of histamine intolerance

  • Hives, spots, rashes, itching, flushing.

  • Joint and bone pain.

  • Headaches and migraines.

  • Unexplained and persistent fatigue.

  • Numbness and tingling.

  • Chest pain and irregular heart rate.

  • Dry eyes.

  • Ovulation pain, menstrual cramps, PMS and estrogen imbalances.

  • Enlarged lymph nodes.

  • Recurring infections.

  • Nausea and vomiting.

  • Nasal congestion, sneezing, shortness of breath.

  • Vertigo.

  • Insomnia or sleep disturbances.

Medical conditions thought to also be related to histamine include mast cell disorders, allergies, gut dysbiosis, crohns disease, coeliac disease, fibromyalgia, pre-menstrual syndrome, irritable bowel syndrome, bacterial digestive imbalances that can damage the gut lining (such as SIBO or h.pylori) and migraines.

There is probably a large percentage of the population dealing with histamine excess but it's hard to estimate because it's often overlooked and difficult to diagnose as it isn't an actual intolerance or sensitivity as such, just a case of 'too much'.

Interestingly, pregnant women often report relief from allergy symptoms, which is thought to be due to an increase in DAO production to protect the growing fetus from histamine toxicity. On the other hand, many women experience severe symptoms during ovulation and in the days leading up to their periods, as estrogen is believed to down-regulate DAO. Therefore, for those dealing with estrogen excess or progesterone deficiency, addressing histamine levels may be an important aspect to consider.

Managing Histamine

In the case of a histamine intolerance, it's common to assume that a low histamine diet is the only solution, but that approach can be overly restrictive. We can also help support our body to break down histamine more efficiently.

One important enzyme responsible for breaking down histamine is diamine oxidase (DAO), which is found in the lining of our intestines. However, in some people, DAO levels may be low or its function may be poor, leading to inefficient histamine clearance. In the bloodstream, another enzyme called N-methyltransferase (HNMT) can break down histamine, but if both DAO and HNMT aren't working optimally, or if too much histamine is being ingested, other solutions may be needed.

Foods that are naturally high in histamine include:

  • Fermented, cured and pickled foods (sauerkraut, kombucha, kefir, yogurt etc)

  • Aged and mouldy cheeses.

  • Aged, processed and cured meats such as bacon, salami etc.

  • Avocado.

  • Dried fruits.

  • Yeasts and foods/supplements that contain.

  • Condiments that contain vinegar (ketchup, mustard, mayo).

  • Long or slow cooked meals or broths.

  • Tinned foods.

Foods that help trigger the release of stored histamine include:

  • Alcohol.

  • Bananas, eggplant, pineapple, papaya, strawberries, tomatoes, spinach.

  • Cocoa/Cacao.

  • Citrus fruits.

  • Pasteurised dairy.

  • Pork.

  • Fish and shellfish.

  • Food additives.

Foods that block your production of DAO include:

  • Alcohol

  • Tannins (think teas)

  • Lectins

  • Energy drinks

How to Help Histamine

If you suspect histamine intolerance, a short term low-histamine diet can help confirm (or rule out) where you avoid foods that are high in histamine or that trigger the release of histamine in the body, as well as the following...

  • Support DAO production by consuming foods rich in copper, Vitamin C and Vitamin B6 such as liver, leafy greens, citrus and sunflower seeds.

  • Switch your slow cookers for a pressure cooker - I have an Instant Pot Duo Crisp due to it's stainless steel insert and ability to also act as an air fryer.

  • Switch to a quick broth - check out my recipes.

  • Support methylation by consuming foods rich in folate, Vitamin B12 and choline. The Dirty Genes book is a great read.

  • Take a histamine-safe probiotic to balance gut bacteria.

In a nutshell, histamine intolerance can be a symptom of underlying issues such as gut dysbiosis, nutrient deficiencies, or hormonal imbalances. Addressing these underlying issues can help to improve histamine intolerance symptoms.

I can provide guidance and support to help you manage and overcome your histamine intolerance. With my knowledge and expertise, we can work together to develop a tailored plan that includes dietary changes, lifestyle modifications, and targeted supplementation to help improve your digestion, reduce inflammation, and support your body's natural histamine clearing mechanisms. Book your session below.

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Content in this website for informational purposes only and is not considered medical advice. Please see your doctor before making any medical or lifestyle changes. I am not a doctor, this is not medical advice, none of these statements have been evaluated by any authority and and they are not intended to diagnose, treat, or cure any disease.



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