What is histamine intolerance?

While many people are unaffected by eating histamine-forming foods, if you have a histamine intolerance it can trigger uncomfortable symptoms – from hay fever, digestive issues to even triggering migraines.

We’ve pulled together a simple guide to help you navigate what histamine intolerance is and the foods that are best to avoid.

What is histamine?

Histamine is a compound involved in the local immune response and inflammatory responses in your body. Immune cells and mast cells, cells that are part of typical allergic responses, produce histamine. Once released, histamine can produce a variety of effects in the body, including the contraction of muscle tissues of the lungs, uterus and stomach, and the dilation of blood vessels. The increased permeability of capillaries allows white blood cells to get to work on any unwanted pathogens and toxins.

An example of a histamine response is what you might notice from a bee sting or after a mosquito bite. The swelling and redness is histamine regulated. Additionally, the reactions of hay fever – including itchy eyes and skin – are allergic responses mediated by histamine.

What is a histamine intolerance?

Histamine intolerance happens when the excess production of histamine or the inability to breakdown histamine effectively causes symptoms in your body. The large proportion of sufferers (80%) are female. These symptoms are often very similar to an allergic reaction and can range from mild to severe depending on the individual.

Symptoms can include:

  • Seasonal allergies (such as hay fever)
  • Migraines
  • IBS
  • Low blood pressure
  • Painful joints
  • Itching
  • Swelling
  • Blocked/runny nose,
  • Symptoms that resemble an anxiety attack
  • Painful periods
  • Increased heart rate
  • Conjunctivitis

The problem with histamine isn’t histamine itself – we need it to effectively attack pathogens and toxins. Issues arise when we overproduce histamine or if we have problems breaking it down.

The first issue that could cause histamine intolerance is overproduction. There are a few possibilities of what can cause this. Either it can be the bacteria in your gut overproducing histamine, or it can be mast cell activation syndrome. This is where your mast cells are overactive and produce excess histamine.

The second issue is if your body is unable to effectively break histamine down using the enzyme diamine oxidase. If your body is deficient in this enzyme, the levels of histamine can build to a ‘toxic’ level and produces such reactions. The production and breakdown of histamine is particularly notable in the gut, which is why histamine intolerance can lead to noticeable gut issues.

Histamine and diet

Having a low histamine diet can be very helpful with relieving symptoms and treatment, however for long-term healing you would need treatment from a doctor to cure the underlying reason for the intolerance.  Histamine is derived from the amino acid histidine, which is common in many foods.

One of the biggest histamine-forming foods is fermented foods, as the bacteria produces histamine in the fermentation process. For those with a histamine intolerance the first point of call is to limit (or cut out if you are very intolerant) your intake of wine, cheese, live yoghurt, kefir, kimchi, kombucha and vinegar. Seafood is also a histamine-forming food, including shellfish, fin fish, fresh and particularly smoked or canned seafood.

Other histamine-forming foods include:

  • Eggs
  • Cured, smoked or processed meats
  • All fermented products – see below for links to non-histamine forming probiotics 
  • Citrus fruits
  • Avocados
  • Banana
  • Walnuts, peanuts
  • Berries and dried fruit
  • Spinach
  • Aubergine
  • Seaweed
  • Mushrooms
  • Tomatoes
  • Artificial food colouring and preservatives
  • Certain spices (see the full list below)
  • Green and black teas
  • Alcohol
  • Chocolate and cocoa
  • Vinegar (and foods that contain it)

While this list may seem extensive, cutting out some of these foods can greatly reduce any symptoms. Not everyone with a histamine intolerance reacts the same to each food. For example, you may be intolerant to red wine and chocolate, but fine with others.

To find out which histamine-forming foods cause your intolerance, it will be a case of testing the foods that affect you, and what you benefit from cutting out. To do this, you need to cut out all histamine-forming foods and then slowly add each one back into your diet one by one. Over time, you’ll be able to figure out which foods cause you problems.

Once the underlying cause (e.g. overproduction or inability to breakdown histamine) is addressed and treated by your doctor, most people are able to add some of these foods back into their diet without any pesky symptoms.

For a full list of histamine-forming foods click here.

Non-histamine forming probiotics available from Amazon

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