Histamine Intolerance

man old depressed headache
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This is commonly called histamine ‘intolerance’, but is actually a condition of histamine excess or sensitivity really. It is also known as Histaminosis and is shortened to HIT.

There are some estimates that up to 10% of the population suffer from some degree of histamine sensitivity and possibly 2% who have severe histamine excess. Basically, we need histamine. It’s just that some people can have too much in their system and they overload, triggering the classic histamine symptoms that include mood changes, head pain, hives, sensitivity reactions etc. Commonly, excess histamine is also involved in wakefulness and insomnia and gut problems, so not just the allergy symptoms we mostly think of.

Here is a list of common HIT symptoms. Recognise yourself?

  • Headaches and migraines
  • Itching and irritation – especially eyes, ears, nose, skin; hives, urticaria, prickly heat
  • Eczema, psoriasis
  • Chills/shivers
  • Fatigue – HIT and adrenal fatigue are often found together
  • Dizziness
  • Facial/neck flushing
  • Nausea/vomiting, motion sickness
  • Fast heart rate and blood pressure changes, sometimes nose bleeds
  • Large bites when bitten
  • Anxiety, panic attacks, sudden mood changes, blackouts
  • Swelling (inflammation) esp in face, mouth and throat – histamine is linked to rheumatoid arthritis too
  • Insomnia, sleep difficulties, waking etc
  • Sneezing and sinus congestion, dry mouth, runny nose
  • Irregular periods and worse symptoms before periods and in perimenopause because oestrogen releases histamine and histamine triggers oestrogen
  • IBS symptoms including abdominal pain, constipation, diarrhoea, bloating, feeling of fullness
  • Heartburn, indigestion
  • Asthma and exercise-induced asthma, chest tightness, constricted breathing
  • Chest pains
  • Thyroid problems – histamine helps control the release of TSH
  • Weight problems – low or high, because histamine is involved in appetite control and leptin levels
  • Light sensitivity, even not being able to go out because of reactions

Histamine has a dual role in the body, which is why people are often confused by it. It acts as a neurotransmitter and as an immune system modulator. It increases metabolism and suppresses appetite, is involved in the sleep-wake cycle and in inflammatory processes in the body. You can read more about histamine imbalance and how it relates to food on my Histamine Imbalance factsheet.

Diagnosing and treating histamine intolerance is quite complex. However, I will normally start by trying to confirm a high level of histamine in the blood and checking for a low level of the DAO enzyme that helps us to break it down. It can be as simple as boosting DAO levels to bring the histamine down. It’s not always easy to do because the body regulates levels throughout the day with need, but often you can get an overall high level result or people test when they are in a reaction to see if it is histamine-related. Histamine will rise after a meal as it is needed to release gastric acid into the stomach so best to take your sample in between meals. You can see the histamine and DAO test here.

In essence, there are two main enzyme pathways we use to break histamine down to stop high levels in the body; one is the diamine oxidase (DAO) pathway and the other is the methyltransferase pathway. The basis of treatment is partly to ensure those pathways are working optimally and I advise specific protocols to help that.

Both of these pathways need specific nutrients in place in the right amounts to operate effectively, so treatment partly involves making sure you have enough of those.

What causes high histamine?

That’s the key question, isn’t it?! Most people will normally be fine with these kind of things but if you tend to have a high histamine level anyway and/or low enzyme activity, it doesn’t take much to tip you over the edge into histamine excess. Symptoms are quite difficult to track because a histamine reaction often takes hours to develop. For example, if you have symptoms towards the end of the day, you’ve probably built up over the day and tipped into excess then. If your symptoms are early morning, this might be because we know that histamine tends to be highest in the early hours. At other times, if your general level is OK – say your stress has been low today – you might not react in the same way to the exact same food as you did before on a different day.  It’s all about the bucket!

Histamine Diet

Blimey, I wish I had a pound for every histamine diet list I’ve seen over the years – and all the lists differ, don’t they?! The best Histamine Foods List we have come across – voted by my Facebook groups – is this one from a Swiss source: Histamine & Mast Cell Food List. You can see their website histaminintoleranz too here. There are more good ones in the Histamine Factsheet below too.

I tend to say to people that it is not all about the diet – do what you can, but bear in mind there is only so much you can do. The stress of trying to stick to lists is somewhat counterproductive – especially since we know stress causes histamine release! In fact, no-one tends to believe us but myself and a colleague have controlled our histamine release at various stages by using relaxation methods and brain neuroplasticity – it CAN be done. See my Healing Plan here for more on how I went about this.

Treating High Histamine

To lower histamine, the main option is the diet and optimising the pathways. On top of that, you need to lower stress, don’t do the wrong exercise (a known histamine-releaser) and sort out the histamine causes including your gut.

Symptom-wise, you could try some zeolites such as Toxaprevent or another binder to bind the histamine. It won’t stop the histamine being produced, but it can make less hang around to cause problems. A mix of sodium and potassium bicarb can also help relieve the symptoms of excess histamine. You can use the powders (2tbsp sodium to 1 tbsp potassium bicarb, then mix half a tsp of that in half a cup of water and drink, repeat after 20 mins if you need more, don’t use excessively), or you can take a capsule.

Of course, it can be a lot more complex than that and I ended up writing a whole Histamine Factsheet for you which you can get here. In it, I have given you tons of tips and info as well as my clinical protocols cos I’m nice like that 😉

Histamine 2D


Welcome and Housekeeping 4

Introduction 6

Neurological Histamine Imbalance 9

What Causes High Histamine? 11

Testing for Histamine Intolerance 16

The HIT Diet Guidelines 18

Treating Histamine Intolerance 19

Histamine and Genetics 22

A First-Line Treatment? 24

The HIT Protocol 26

Boosting DAO 29

Probiotics 32

Symptom Support 36

Getting Support 39

Resources 41

I hope that helps and that your future is far less histameanie than the present!