What is histamine intolerance

When I was told about the histamine intolerance I suffered from, I didn’t believe it at first, I was afraid it was some bogus disease or some well we don’t know what’s wrong, so let’s just call it so and so. Just like former diagnosis I had gotten like irritable bowel syndrome and chronic fatigue syndrome.

But a histamine intolerance is a very real thing. And it’s quite clear what the cause of it is.

Histamine

Histamine is an amino acid. A very small one even. One of the most well known functions of it is in the mediation of immunological responses. When harm is done to the body or intruders are noticed, histamine is released from specialized storage cells (mast cells) in the bloodstream to widen blood vessels and make their walls more permeable, so more blood and all handy things carried in the blood to fight of harm and intruders can go to the place of the disturbance.

Which is the reason a lot of the symptoms of histamine intolerance mimic allergic responses or real infections.  Mimic, since it isn’t an allergic response or a reaction to a threat at all.  Just a large amount of histamine can cause these responses.

The reason large amounts of histamine can build  up in the body

There are several reasons a large amount of histamine can come into existence in the human body and lead to annoying responses.

Histamine is not just active in the human body. It is also present in most other animal life, and even in plants. Which means that most of our foods contain histamine. So we consume histamine with almost everything we eat and drink. There are also certain substances that are able to aggravate the mast cells in which histamine is stored, so their contents get released  into the blood stream.

There are several enzymes that break down histamine. The main ones are histamine methyltransferase which mostly targets histamine within cells. And there is diamin oxidase (DAO) which is present in the walls of the bowels and within the bloodstream.

Most histamine intolerances are due to a lack of DAO. Ingested histamine is normally filtered within the walls of the bowels, so it doesn’t enter the bloodstream. And the histamine that has entered the bloodstream is filtered away with DAO as well. As the amount of DAO declines, the amount of free histamine in the body can grow rapidly, especially when foods high in histamine are eaten.

DOA can be low due to a genetic disorder. But the production of it can also be impaired when the bowels get damaged due to an infection but also different aggravations (antibiotics, crohn disease, gluten). A third reason the amount of DAO can be low is because it can be inactivated by several different substances, like certain medicines (morphine ) , but also alcohol impairs the working of it. Another reason a shortage of DAO can occur is when the components it is build out of aren’t present in large enough amounts, for example a shortage of copper and B6.

Since the levels of DAO can fluctuate with all these different reasons, the sensitivity to histamine can change depending on the circumstances. After a night of drinking I have to be much more careful with histamine rich foods. Stress can not only release histamine directly but also work against the working of DOA.

Since the response depends on the amount of histamine within the body, and this depends on it’s turn on the amount of DAO, the amount of histamine that can be taken before reactions occur is different for most people. And as most reactions only happen when a certain threshold is passed it will take a while for anyone to find out where that threshold is, and how certain things like stress affect this.

The amount of histamine in foods can also greatly vary, since the longer it is stored the more histamine is made by bacterial activity and other processes. That’s why certain foods like fish are okay if they are very fresh or never got defrosted. The same goes for any other food, like fruits and veggies.

The start of it all

Since information about histamine intolerance and the troubles histamine can cause in one’s body is scarce, I started this blog.

The first step

Summer 2009 I had a little operation done by me GP,  for which I got a local anaesthetic. Afterwards I got terrible allergic reactions, a runny nose so bad I stuck tissues in my nose, eyes that were tearing up, and I was constantly sneezing, which feels exceptionally wonderful if you just got your head stitched up. To be short I  was feeling really awful. And I noticed a lot of these problems got worse or started whenever I was outside.

Hay fever?

I had suspected I had hay fever for quite a while but never bothered to get tested,  I was a healthy girl who loved being outside and studied biology, so of course I couldn’t have hay fever. But after that horrid reaction I started to pay more attention to when and where my reactions started.

I had been suffering from strange reactions and illnesses for quite some years, and it once again had gotten worse that spring. One of those were terrible headaches that had plagued me for years, and that year they had gotten even worse, some days I could only lay down keeping my body very still,  as every movement of my head hurt like crazy.  I was deliberating if I should check myself into a mental hospital since the medical world thought I was either just making it up, as they couldn’t find any prove for my symptoms and thought they were psychosomatic, or just kill myself off or something. Those weird reactions of my body were driving me insane and withholding me from living my life the way I wanted to.

No hayfever?

So finally I got my blood tested for allergies, but I didn’t have any. Weird, since I was pretty sure I reacted badly to the outside air which pointed to a reaction to pollen. And the anti-histamines I squeezed out of my doctor, were really good with keeping certain symptoms in check. An acquaintance said I should visit an allergy specialist, she thought I could suffer from pseudo allergies, which weren’t widely recognized by most doctors but an allergy specialist should know more about this.
So I went. I got my arms splashed with droplets of all kinds of different possible allergens,  some kind of solution as control test as well, and a scratch test which consisted of just scratching my skin with some kind of pencil. Once again I didn’t test positive for any kind of allergy. Though I got quite an oversensitive reaction to control test  and the scratch that had been made on my back.
Once again I thought it was all for naught, and I would just be told it was all in my head, I was oversensitive and should learn to deal with it. Much to my surprise the first thing the doctor asked was if I needed more anti-histamines to help me. She explained I probably had an intolerance for histamine, which could give me bad reactions to even the slightest things like a breeze of fresh air. But also reactions to pollen, since those could lead to a histamine reaction in normal people as well, and with a high histamine load present those reactions could get quite severe and mimic hayfever She also directed me to a nutritionist to help me with a diet to control my intake of histamines.

Realisation

I was happy to get some recognition, but was very suspicion about the truth of it all. Was this really it? Just like that? As I’m a biology student with an interest in the molecular and neurosciences I read about every paper and site I could find on the internet and the university library. And still do. A world opened up for me, as I found out I wasn’t crazy at all, it wasn’t just in my head. I was suffering from something real.
The diet and anti-histamines turned my life upside down, had I always been feeling tired, sick, depressed and just right out awful I soon started to feel great. So great. I started to be afraid that I was suffering from some kind of manic episode. Luckily I didn’t.

Since there are many misconceptions about histamine and the problems it can cause, or things that can help I decided to start this blog, to keep myself informed by storing all useful information in one place, but also to inform others.