Histamine Intolerance

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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.

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. In addition Vitamin D, probiotics (more on these below as some can make you better, others worse) and fish oils also help as they are generally anti-inflammatory and modulate neurotransmitter production.

What causes high histamine?

Obviously, it is not all about those pathways and nutrients. You also have to try and work out what is making the histamine go high in the first place. That could be microbes in an upset gut, allergy or inflammation from something or stress. Hormone change is a big one: progesterone and testosterone drop and times of main hormone change like starting periods and menopause, for example, make us more histameanie, as I call it, so balancing hormones may well help if those are an issue. Although, because DAO is produced more in pregnancy, often histameanies suffer less then!

Some people could have a mast cell disorder so it is histamine plus other triggers causing the issue. In this case, a tryptase test can be helpful so you can establish baseline and see if the level rises to meet the MCAS criteria (20% increase + 2ng/ml). You can read more about MCAS/mastocytosis here.

Most commonly, though, histamine is raised because of diet, and some medications (inc common NSAIDs, aspirin etc) may well exacerbate it as some common ones are histamine-releasers. There is a handy list of these in Dr Joneja’s book below.

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 is also one in Janice’s book below in resources.

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.

For more on my histamine approach, read this article that I wrote for FoodsMatter a good few years ago now (I am so old…!)

Could it be histamine?

Nutritionist Micki Rose looks at the symptoms, possible causes and ways to diagnose and treat histamine ‘intolerance’/excess

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 excess exercise (a known histamine-releaser) and you could try some zeolites such as Toxaprevent or another binder to bind the histamine to help symptoms. It won’t stop the histamine being produced, but it can make less hang around to cause problems. Finally, 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.

You can also see a blog post I wrote here about natural anti-histamines which, incidentally are all TGF safe – grain and dairy free. And for more ideas, download my free Bringing Down A Reaction factsheet.

Another part of treatment is probiotics, but some can help and others make you worse. If in doubt, leave them out, but since we know that some microorganisms in the gut help create histamine, it’s probably a good idea to sort your gut out. Check the Gut Plan out here for a start. If you are TGF, use the TGF Detox instead.

So, let’s delve a bit more into the tricky subject of histamine-safe probiotics…

Histamine Probiotics

This is a bit of a minefield and Christine (my supplement wonder-woman assistant) has done some research on it for us. This will probably change as it is an evolving science, but this should give you a good starter. Note, our recommended products are in the TGF Supplements Master List here (more on this below), simply because we only have one place then to update when they inevitably change!

Just be aware this is only a guide and lots of factors come into play; everyone is different and you have to find what suits you best.

Probiotics can either lower histamine, raise histamine or have no effect on it, depending on the species contained within them. When we eat food containing histidine, certain types of bacteria within the gut can convert this into histamine, thereby increasing internal histamine levels even if the food eaten was not classed as a high histamine food. Therefore, it is important to try to avoid the histamine-raising species. Within each species, there are different strains and some of them can oppose each other, so it is important to also know the strains if you can.

Note also, whilst we’re on the subject of bacteria: you could have large numbers of pathogenic bacteria in the gut which increase histamine, such as Citrobacter Freundii, so sorting your gut out is also important in any histamine treatment. Use a gut test to check the state of your microbiome and you can see a list of the microorganisms that could create histamine in Janice’s book below.

Species that are thought to INCREASE histamine and so are probably best avoided:

Lactobacillus casei

Lactobacillus Bulgaricus

Streptococcus thermophilus

Lactobacillus delbrueckii

Lactobacillus helveticus


Species that are thought to REDUCE histamine and so should be good ones to take:

Bifidobacterium infantis (especially 35624) – this is often the best one to start with as many people need to build their baby bacteria back up before others will seed, plus it is usually the most gentle.

Lactobacillus gasseri

Bifidobacterium breve

Bifidobacterium bifidum

Lactobacillus rhamnosus (especially GG)

Bifidobacterium longum (especially BB536)

Bifidobacterium lactis

Lactobacillus Salivarius

Lactobacillus Sporogenes (also called Bacillus Coagulans) (soil based spore forming)

Lactobacillus Plantarum – This has been shown to degrade histamine in wine, but this doesn’t necessarily mean that it will degrade it in the gut. However, most lists include it as being okay to take. Some places say that it does not appear to have an effect on histamine, but lowers/inhibits tyramine and putrescine.

Don’t worry too much about the strain with the Bifido bacteria, as they are mostly thought to have a beneficial effect. In fact, I most often advise you at least start with a Bifidobacteria product, especially the baby one as I’ve said above.

Additional Strains of Importance:

Lactobacillus reuteri MM53 (otherwise known as DSM 17938, ATCC 55730, and SD 2112) – This one is thought to increase histamine. However, as well as raising histamine, it is also supposed to raise cAMP which is a good thing and kills inflammation.

Saccharomyces-Boulardii – also helps to regulate digestive issues, especially diarrhoea.

Lactobacillus lactis – debate exists over whether helpful, harmful or neutral for histamine intolerance (this may be due to different strains acting differently perhaps?)

Lactococcus Lactis – used in producing some high-histamine foods but, other studies have suggested this strain to be histamine-neutral.

Lactobacillus acidophilus – debate exists over whether helpful, harmful or neutral for histamine intolerance. (this may be due to different strains acting differently perhaps?)  It is one of the two most key bacteria for your health so i tend to advise it if people are OK with it.

Many histamine-sensitives are also grain and dairy sensitive or have a gluten-related disorder so we have also come up with some suggestions for TGF (trulyglutenfree) histamine-safe probiotics. You can find that list in the TGF Supplements Master List here. Most people should be safest with these.

Phew – there’s a lot of info there, isn’t there; I got a bit carried away! For some more, here are some…


I have written a few articles on this subject and been interviewed about it. See:

Could it be Histamine? An article I wrote for FoodsMatter, who also have a great round-up on histamine intolerance here. They have also set up a Q&A on histamine intolerance with Dr Janice Joneja, which is very useful too, and you can see her books for laypeople and professionals here.

Treating and Diagnosing Histamine Intolerance, an interview I gave to the Yasmina of Healinghistamine.com, a site where you can find a ton of info on this subject.

There is also a really good factsheet on Histamine Intolerance from Nutrigold here too.

I hope that helps!