Histamine – what is it and what are its effects?

What role does histamine play in allergies?



S.A.C. Dip (Diet, Exercise & Fitness), Advanced Human Anatomy & Physiology Level 3
@ActiveLouise
Ask Louise


14 December 2020

What is histamine?

Histamine is found naturally in the tissues of all living beings. It is synthesised from an amino acid called histidine and is then stored in certain blood cells, as well as mast cells.

To get a better understanding of histamine and the effect it can have on the body, this blog answers some key questions:

  • What role does histamine play in allergies?
  • What symptoms does too much histamine cause?
  • How does histamine affect the body?
  • What foods are high in histamine?
  • What foods are low in histamine?
  • What else affects histamine levels?
  • How can I reduce histamine naturally?

What role does histamine play in allergies?

Mast cells are part of the immune system and help to fight infection. When mast cells detect an allergen, they will release histamine (alongside other chemicals) into the bloodstream.

After being released from mast cells and basophils, histamine exerts its biological activities by activating histamine receptors (of which there are 4), with H1 and H2 being the ones most associated with allergic responses.

Histamine-1 receptors are found in the walls of blood vessels, particularly in the respiratory system and cardiovascular system. When they are activated by histamine, they set off reactions that include increasing the permeability of blood vessels, promoting the movement of immune cells, and upping the sensitivity of the sensory nerves in the respiratory tract. This makes the whole respiratory system more likely to react to anything it encounters – the cells are more sensitive and ready to 'fire'.

Tryptase is an enzyme that is released alongside histamine and which promotes its effects. Inhibiting it is therefore useful in reducing allergic responses.

What symptoms does too much histamine cause?

Excess histamine that is sometimes triggered by the presence of allergens can cause several symptoms:


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How does histamine affect the body?

As well as influencing allergic processes, histamine plays various roles in the body, including:

  • Mucus secretion
  • Tissue healing
  • Mediating itching
  • Production of stomach acid
  • Contraction and relaxation of smooth muscles and blood vessels
  • Regulation of local blood circulation.

What foods are high in histamine?

The other main source of histamine is food. There are a number of histamine-rich foods such as alcohol, fermented food and drinks (cheeses, sauerkraut, vinegar), dried fruit, processed or smoked meat, shellfish, tomatoes and aubergine. Leftover food that accumulates bacteria and overripe fruits can also be a source of histamine.

On top of this, some foods can actually trigger the release of histamine in the body. These include bananas, wheat germ, papaya and walnuts. Food dyes and other additives can also be problematic.

What foods are low in histamine?

It may seem as though there are a lot of histamine-rich foods about but, fortunately, there are actually plenty to choose from that are low in histamine too. Some options are fresh meat and fish, non-citrus fruits, eggs, quinoa, rice, coconut milk, almond milk and fresh vegetables (omitting tomatoes, avocadoes, spinach and aubergine).

What else affects histamine levels?

An enzyme called DAO is responsible for breaking down histamine from food; however, this can be affected by various factors, causing histamine to become more of a problem.

DAO enzyme levels could be affected by medications that block DAO functions or prevent its production, for example. Gastrointestinal disorders, such as leaky gut syndrome and inflammatory bowel disease, can also be problematic. Moreover, histamine-rich foods may cause DAO enzymes to function improperly, whilst other foods can block DAO enzymes or trigger histamine release.

So, what is a helpful solution? Well, vitamin B6, vitamin C and copper are essential cofactors for DAO activity and these are things we can all get in our diets through foods like fish, potatoes, brussels sprouts and shiitake mushrooms.

My Self-Care Tip: Get some vitamin C to help allergies

Find out more about the link between vitamin C and allergies.

How can I reduce histamine naturally?

To help manage allergy symptoms, it can be helpful to get histamine production under control. There are a few ways you can attempt this.

First, as mentioned, diet is something to focus on. As well as making some changes to the type of foods you eat following the guidance above, you may want to hone in on some particular nutrients and ingredients.

Inflammation is a particular problem among allergy sufferers (as you'll be all too aware, I am sure!), leading to issues like congestion and irritated skin. To help manage this, there are a few food constituents that offer anti-inflammatory benefits, such as bromelain and quercetin. These are found in everyday ingredients like garlic, pineapple and onions. In addition, quercetin may help to inhibit the release of histamine by mast cells.

Curcumin (found in turmeric) and ellagic-acid (found in pomegranate) are also anti-inflammatory, as is nettle. The latter can easily be consumed via a natural herbal tea.

Bioflavonoids associated with vitamin C (found in foods such as broccoli, peppers, etc.), are also efficient at helping to lower histamine blood levels. They also help to prevent the secretion of histamine by white blood cells in the immune system.

Some other tactics that may help to control histamine levels are:

  • Looking after your gut health. Most immune cells are found in the gut, so, keeping this area functioning well can have a direct impact on allergy symptoms.
  • Identify medications that may cause a problem and speak to your doctor about this. The likes of antibiotics and diuretics may influence histamine levels.
  • Identify things that trigger histamine production in your body and take steps to reduce their impact.
  • Tackling stress – it can affect the health of the gut and immune system.
  • Excess oestrogen and low progesterone can affect histamine levels so managing this can be useful. Our expert Eileen can offer further advice on this topic.

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