Histamine Imbalance – the Role of the Gut

If you suffer from unexplained, random symptoms which seem to appear out of nowhere, histamine imbalance could be to blame.

Symptoms such as unexplained headaches, facial flushing, digestive issues or itchy nose which come and go can have their roots in histamine imbalance. In this blog we’ll take a closer look at histamine and why it can become out of balance.

What is Histamine?

Histamine is produced by the body and it’s also found in some foods.

You may have heard of histamine with relation to allergies. When the body releases histamine, it provokes the classical allergic reactions of runny nose, hives and sneezing. This immediate inflammatory reaction is part of our immune response.

Histamine causes blood vessels to dilate and signals other cells to repair damage or fight infection. However, histamine is essential to the body because it also helps with brain communication and triggers the release of stomach acid.

Histamine should be broken down in the body so levels don’t climb too high. The body produces two enzymes to do this called DAO and HNMT. DAO is mainly responsible for breaking down the histamine we take in through food. If we don’t produce sufficient enzymes, histamine levels may rise.

Histamine only becomes a problem if it’s allowed to build up in the body. This could be because we’re producing too much, taking in large amounts in our diet or we’re inefficient in breaking it down. This is called histamine imbalance.

Symptoms of Histamine Imbalance

The frustrating aspect of histamine intolerance is the sheer variety of symptoms it can produce, which often mimic those produced by other health issues and come and go irregularly.

Histamine receptors are present throughout the body which is why an increase in histamine can cause so many diverse symptoms.

This makes it hard to diagnose from looking at symptoms alone.

Symptoms include:

  • Headache and migraine
  • Facial and chest flushing
  • Fatigue and brain fog
  • Anxiety
  • Hives, eczema and itchy skin
  • Runny nose and congestion
  • Itchy eyes
  • IBS symptoms
  • Menstrual irregularities and hormone imbalance
  • Racing heart

What Can Cause Histamine Imbalance?

  • Some people are genetically susceptible to producing less DAO.
  • Leaky Gut allows undigested food particles to enter the bloodstream, stimulating the immune system. If the intestinal lining is inflamed, this can impede the activity and release of DAO.
  • Imbalance in the microbiome. Some types of bacteria can produce histamine, whereas beneficial bacteria such as bifidobacteria suppress histamine release or reduce the sensitivity of histamine receptors.
  • Nutrient deficiencies. Magnesium, copper and vitamins B6 and C are necessary for proper DAO function. Increased intestinal permeability and microbiome imbalance frequently cause nutrient deficiencies.
  • NSAIDS cause gut inflammation, reducing DAO production, and aspirin can encourage the release of histamine. Anti-histamine drugs although they may alleviate allergic symptoms related to high histamine, can interfere with DAO release when taken long term.

How to Reduce Histamine Levels

Many foods naturally contain histamine or trigger the release of histamine in the body. Histamine is highest in foods which have been aged or fermented, although levels do naturally vary according to how long the food has been kept or left to sit, particularly if it’s not refrigerated.

High histamine foods include:

  • Alcohol
  • Fermented foods including sauerkraut, vinegar and yoghurt
  • Processed and smoked meats like bacon or salami
  • Aged cheeses
  • Dried fruit
  • Avocado
  • Aubergine
  • Pineapple
  • Shellfish
  • Spinach

Other foods although not themselves high in histamine can trigger its release:

  • Bananas and Strawberries
  • Nuts, especially walnuts, cashews and peanuts
  • Tomatoes
  • Citrus fruits
  • Food dyes and additives

Other foods, including alcohol, black and green tea and energy drinks can block DAO production and therefore indirectly contribute to a histamine imbalance.

Some symptoms only occur once histamine has reached a certain level in the body. That means you may be able to eat certain foods without experiencing symptoms, but not in combination with others or on two days running, for example.

How to Diagnose High Histamine Levels

Avoiding foods which raise histamine levels for a certain time period can be one way of determining if histamine is playing a role in your symptoms.

A blood test can determine if you suffer from leaky gut, while a stool test can examine the health of your microbiome.

Overcoming Histamine Imbalance

Avoiding foods high which contribute to histamine imbalance can only be seen as a short term measure, because they include plenty of nutrient-rich foods and simply restricting them can overly limit the diet.

In functional medicine, the goal is to always address the underlying cause. As we’ve seen the gut plays an important role in helping to balance histamine. So if we begin by healing the gut, we can naturally reduce high histamine levels.