Histamine Intolerance: A Helpful Healing Overview

Updated: Nov 16, 2020

When I first heard the term "histamine intolerance" I'll admit, I went "huh'?

In discovering that my then-infant daughter may not just been dealing with multiple food allergies but also potentially reacting to foods high in histamine, I was stumped. I thought about it a bit more and realised that of course I'd heard of antihistamines for seasonal allergies, but that was it. Which led me to researching it further so I could refine our gut healing protocol.

Understanding histamine intolerance is key, because many nutrient dense foods are actually high in histamine which helps to explain why some individuals don't do as well with certain gut healing protocols. It's a fairly serious and complex topic so I'll try to break it down into easy to understand language!

What is Histamine?

Histamine is a chemical found throughout the animal kingdom and is also present in many plants, bacteria and insect venom. In us humans, histamine is found in nearly all of our tissues where it is stored primarily in our mast cells. It serves as a neurotransmitter, regulates stomach acid and is a key player in an allergic reaction.

An allergic reaction is where your immune system reacts to a foreign substance called an allergen or antigen which it has decided is a threat. Things kick into gear because our immune system is designed to keep us safe so it responds as such. When an antigen enters the body, a chain reaction occurs. First a signal is sent to our mast cells (concentrated in our skin, lungs, nose, gut, mouth and blood) to release stored histamine in significant amounts and this boosts blood flow to that area of the body - a highly inflammatory response, meaning other immune agents are bought in to support the target > attack > repair process.

Immune system proteins called antibodies bind to the antigen to remove them while histamine binds to receptors on your cells. Together they make up a big part of our defense strategy. The best description I can think of is that histamine is the bouncer at the club - it's job is to work with antibodies (the soldiers) to get rid of something that is threatening you and it does that by making the exit doors easier to open. They're keeping you safe but that doesn't stop them from being annoying, especially if they get a bit heavy handed... but what they want is for the 'bad guy' to get out and they'll make it easier for that to happen any way they can: increased mucus production, dilating blood vessels, increased stomach acid production, increased heart rate, watery eyes, sneezing, itching tissue swelling and more.

What is a Histamine Intolerance?

Once this overflows, we'll soon notice!

There is always some amount of histamine circulating in our bloodstream because it plays an important role in many processes. A histamine intolerance is when our accumulated histamine levels become greater than the amount of histamine we are able to eliminate.

Our individual tolerance levels can be described using a bucket analogy. Once levels build and our buckets overflow, we see the symptoms of 'too much' but that doesn't mean you're allergic or sensitive to histamine as such - just that you have more than what you can metabolise or degrade at any one time.

The reason antihistamine medication is often suggested is that it blocks the binding of histamine to those receptors, which can tame observable symptoms, however it doesn't address the original release, which is key considering it's main job is to increase inflammation as described above.

So not only do we have to deal with our own stored and circulating levels of histamine, many foods we eat either contain histamine (generally the older the food, the more histamine it contains) or stimulates additional release of our stores.


  • 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 disorders include Mast Cell Activation Disorder, Allergies, Gut Dysbiosis, Crohn's, Coeliac Disease, Multiple Sclerosis, Fibromyalgia, Pre-Menstrual syndrome, Bacterial digestive imbalances (such as SIBO or H.pylori as they can damage the gut lining), irritable bowel syndrome and migraines.

My daughter's histamine intolerance symptoms were: a red rash around her mouth after eating foods high in histamines (especially sauerkraut) which didn't bother her but lasted around 15 minutes before self-resolving, enlarged lymph nodes and I suspect it had a part to play with her having trouble both falling asleep and staying asleep. Once our gut healing journey had been going for a while, all these symptoms cleared.

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'.

Clearing Histamine

A lot of people presume that with a histamine intolerance, their only option is to follow a low histamine diet but in my opinion that is a very limited approach as many of those foods are also extremely nourishing and easy to digest, so that leaves us with supporting our body to degrade (break down or clear histamine) better.

Our bodies have ways to break down histamine in the food we eat. In the lining of our intestines, we have an enzyme called diamine oxidase (DAO) - it's job is to clear histamine before it can hit our blood stream. However for some of us that enzyme doesn't work so well, there are low levels, the DAO gene is 'dirty' (methylation is often a factor here that results in poor enzyme function) or our gut walls are less than optimal. Once in the blood, histamine can be broken down by another enzyme called N-methyltransferase (HNMT) so when both of these clearing agents don't function so well, or where just have too much histamine being ingested, we need to look at what else we can do.

Interestingly mothers often report their symptoms of allergies clear up while pregnant, and it's thought because this is because the body up-regulates DAO production to protect the growing fetus from potential histamine toxicity. On the other side, many women report severe symptoms at the time of ovulation and in the days leading up to their periods, as estrogen is thought to down-regulate DAO, so if you're dealing with estrogen excess or progesterone deficiency, histamine is one aspect worth investigating.

Foods that are naturally high in histamine include:

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

  • Aged and mouldy (blue) cheeses.

  • Aged, processed and cured meats (bacon, salami etc)

  • Avocado.

  • Dried fruits.

  • Yeast and foods/supplements that contain such as sourdough or nutritional yeast.

  • Vinegar and condiments that contain vinegar (ketchup, mustard, mayo).

  • Bone broths (the longer the cook time, the more histamine)

  • 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

So, What to Do?

  • If you suspect histamine intolerance, a short term low-histamine diet can help confirm (or rule out). Focus on lower histamine foods such as fresh meat and fish, fresh fruits and vegetables (with a close eye on the ones above), egg yolks, peanut butter, coconut/hemp milk, and fresh herbs.

  • Leftovers or slow cookers may not be your friend as the longer food ages or cooks, the higher the histamine content. Pressure cookers like the Instant Pot are fantastic to shorten cooking time without losing flavour (especially when stainless steel rather than non-stick)

  • Appropriate testing - this is something I talk clients through.

  • Investigate methylation barriers to histamine management. The Dirty Genes book is a great read.

  • Address gut health to ensure foods stay in the digestive tract rather than cross into the bloodstream.

  • Take a histamine-safe probiotic to balance gut bacteria. My preferred product probiotic is GutPro (or GutPro Infant for young/sensitive systems)

  • Increase supportive nutrients such as: magnesium to support increased DAO levels, zinc, Vitamins C, A, and E as well as essential fatty acids. Quercetin and Aloe Vera Juice can help reduce the release of histamine from mast cells, and Black Cumin Seed Oil and Apple Cider Vinegar are considered natural antihistamines.

  • Products like this one can help manage the discomfort from higher histamine foods.

  • Reduce inflammation and support your exit doors (aka organs), and more...

If you would like some support in navigating histamine intolerance naturally, you can make a booking with myself here.