Histamines and IBS


Erin Dwyer - Research Dietitian, 19 August 2020

We have recently been sent many questions asking about the relationship between IBS and histamines. This area of research has grown in the last few years, currently the association is weak but it will be interesting to see where it goes.

Histamines are a chemical compound found in every cell of the body, as well as naturally in many foods. Histamines are involved in the process of inflammation, immunity, and the neurological system. When histamines are released from mast cells (a type of cell that produces and stores histamines) they can elicit symptoms depending on what cells they bind to (Targeting)(1). If they bind to Diamine Oxidase (DAO) a histamine enzyme, they are broken down. Histamines released in the gut can alter gut movement, enhance gastric acid production and changes to mucus secretion, this can lead to cramping, gas and diarrhoea for some (2). 

Histamine intolerance occurs when a person has a low level of DAO meaning when they eat histamines or histamine-producing foods, there is not enough DAO enzyme to break the chemical down leading to a build-up in the body. It is thought that a history of GI disease such as IBD or IBS or a genetic predisposition can lead to this low level of DAO.

Histamine intolerance produces ‘allergy like’ symptoms but it is not a true allergy. Histamines build up in the body and so the reaction is not immediate like a nut allergy. Therefore, it can be harder to tell what food or foods have caused the reaction.

The effects of histamines are ‘dose-dependent’ meaning that eating small amounts of histamine-containing foods are unlikely to cause issues but the larger the quantity, the larger the reaction. 

Symptoms of histamine intolerance include (2):

  • Redness or 'flushing of skin'
  • Headaches
  • Respiratory problems including asthma, runny or blocked nose
  • Rashes, dermatitis, hives or eczema
  • Gastrointestinal symptoms: nausea, reflux, vomiting, abdominal pain, diarrhoea
  • Dizziness, low blood pressure and irregular heart beat
As you can see, some of the gastrointestinal symptoms are remarkably similar to that of IBS and therefore it can be difficult to tell if you have IBS or histamine intolerance without a thorough examination from your gastroenterologist. 

Diagnosis of histamine intolerance (3)

To be diagnosed with histamine intolerance you need to present with a combination of the following:

  • Having more than 2 typical histamine intolerance symptoms (see above)
  • Improvement of symptoms through histamine free diet
  • Improvement of symptoms through antihistamine medication

Pain and mast cells

The other interesting fact about histamines and mast cells is that people with IBS tend to have mast cells that are easily activated in the gut. When histamines are eaten or released in the body the mast cells in the gut are located very close to intestinal nerves and therefore when ‘activated’ they can trigger the pain response in the brain (4). It has been suggested that people with IBS had more masts cells than usual, however study results have been inconsistent (with one study showing evidence to support this suggestion but another study failing to show evidence) (4,5). A recent systematic review of all studies found that in fact it appeared no matter the number of mast cells found in the biopsies, they all had more activated mast cells than samples taken in those without IBS (6).

What foods contain high levels of histamines or increase histamine release?

The below list is not exhaustive, and it is important to note that we do not recommend undertaking this diet without medical guidance but the common high histamine foods are as follows (2): 

  • Fish (Mackeral, Herring, Sardines, Tuna)
  • Cheese (Gouda, Camembert, Cheddar, Swiss, Parmesan)
  • Processed meat (Fermented sausages and ham, salami)
  • Vegetables (Sauerkraut, spinach, eggplant)
  • Condiments (Red wine vinegar, tomato sauce/ketchup)
  • Alcohol (Red and white wine/beer)

Foods that release histamines:

  • Citrus fruit
  • Papaya
  • Strawberries
  • Pineapple
  • Nuts
  • Peanuts
  • Fish/Crustaceans
  • Pork
  • Egg whites

To summarise, the research around histamines in IBS is growing but we highly recommend working with a dietitian to help guide you through the various treatment options for medically diagnosed IBS. 

A dietitian will be able to use evidenced based interventions to create a treatment plan which may or may not include FODMAPs and low histamines.  


1.       Fabisiak A, Włodarczyk J, Fabisiak N, Storr M, Fichna J. Targeting Histamine Receptors in Irritable Bowel Syndrome: A Critical Appraisal. Journal of Neurogastroenterology and Motility. 2017; 23(3): 341–348

2.       Maintz L, Novak N. Histamine and histamine intolerance. The American Journal of Clinical Nutrition. 2007;85(5):  1185–1196

3.       Tuck C, Biesiekierski J, Schmin-Grendelmeier P, Pohl D. Food Intolerances. Nutrients. 2019; 11(7):1864

4.       Guy E. Boeckxstaens. The Emerging Role of Mast Cells in Irritable Bowel Syndrome. Gastroenterology & Hepatology (N Y). 2018; Apr; 14(4): 250–252.

5.       Barbara G, Stanghellini V, De Giorgio R, Cremon C, Cottrell G, Santini D, et al. Activated mast cells in proximity to colonic nerves correlate with abdominal pain in irritable bowel syndrome. Gastroenterology 2004;126(3):693-702.

6.       Bashashati M, Moossavi S, Cremon C, et al. Colonic immune cells in irritable bowel syndrome: a systematic review and meta-analysis. Neurogastroenterol Motil. 2018;30:01.

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