What is Histamine Intolerance?

Are you wondering what histamine intolerance is and whether it has anything to do with GI issues like IBS, SIBO and and acid reflux?

Many of our clients have some degree of histamine intolerance and it’s likely one of the causes of their digestive symptoms, especially bloating. 

So what the hell is histamine intolerance and what do you do about it? 

There are two major players involved in histamine intolerance – histamine (obviously) and DAO enzyme. 

 What is Histamine?

  • Your immune system releases a bio-chemical called histamine as part of a normal inflammatory response.  It’s a neurotransmitter associated with allergic reactions.   It sends a signal to the immune system that it’s time to react to a perceived invader.  
  • We need histamine for proper immune function but sometimes our body can have too much or it can’t be cleared out of the body the way it should be. 
  • Histamine can also be found in food.  More on that below.

What is DAO Enzyme?

  • Your body produces the DAO enzyme, which breaks down histamine so it can be excreted from the body.

The Connection Between Histamine Intolerance and IBS, SIBO & IBD

  • Histamine intolerance results from increased levels of histamine and decreased production of DAO enzyme.  Guess where those DAO enzymes are produced.  Mostly in your gut.  Guess where histamine is produced.  Mostly in your gut.  So you can see how digestive health is so important for regulation of histamine in the body. 
  • Having GI conditions like IBS, SIBO or IBD may increase the levels of histamine in the body. 
  • When you eat foods that contain histamine and you can’t break them down efficiently because of a lack of DAO enzyme then histamine is produced in excess and not fully excreted by the body.  The result – your histamine levels increase and you may present with symptoms of histamine intolerance.
  • Keep in mind everyone has different histamine thresholds

Common Symptoms of Histamine Intolerance

Symptoms of histamine intolerance can be digestive or occur elsewhere in the body.  A study of those with histamine intolerance shows that the most common digestive symptom is bloating and most people have three or more of the following symptoms (1).   


Difficulty falling asleep, easily arousal


Vertigo or dizziness

Arrhythmia, or accelerated heart rate

Difficulty regulating body temperature


Nausea, vomiting


Abdominal cramps


Nasal congestion, sneezing, difficulty breathing

Abnormal menstrual cycle



Tissue swelling

How is Histamine Intolerance Diagnosed?

Determining if you have a level of histamine intolerance is tricky since there are no tests and symptoms don’t always appear immediately.  In fact, histamine symptoms appear after your body reaches its capacity to degrade histamine by the DAO enzyme.  So you may be able to tolerate some higher histamine foods until you reach your personal threshold.

Which Foods are High in Histamine?

This is the list of main offenders:

·      Aged foods – cheese, meats

·      Cured foods; canned meats/fish; deli meats

·      Fermented foods – yogurt, soy sauce, miso, kimchi, sauerkraut, wine, champagne, beer (sorry, folks)

·      Avocado

·      Banana

·      Dried fruit

·      Nuts

·      Lemon, Mandarin

·      Pineapple

·      Yeast (this includes leavened bread)

Sadly, the picture above featuring a gorgeous spread is full of high-histamine foods such as aged cheese, cured meat, red wine, olives. But not to worry, we can have you eating these foods again.

How to Resolve Histamine Intolerance?

Step 1:  Heal the Gut

Like Hippocrates said “All disease begins in the gut”.  So we start by resolving your GI issues like IBS, SIBO and IBD.  A gut-healing diet can help lower the amount of histamine produced by the gut and help repair the small intestine where the DAO enzyme is produced.  In fact, a study shows that the low-FODMAP diet can result in an eightfold decrease in histamine levels (2).   

Step 2:  Reduce High-Histamine Foods

If necessary, you may get even more relief by reducing the amount of high-histamine foods you are eating.    Take a look at the above list of high-histamine foods.  Are you eating them on a regular basis?  If so, try reducing your intake for a short amount of time.  Or spread them out throughout the day.  In the past, if I had too much avocado toast with smoked salmon, I would feel bloated later in the day from a double dose of high histamine food.  

If you fear having to give up your favorite foods for good, just remember that gut-healing diets are not forever diets.  As your gut heals, you should be able to tolerate more and more high histamine foods. 

Do you need help determining if you have histamine intolerance issues?  Contact me to develop a customized approach to get relief ASAP. 


1. Schnedl, W. J., Lackner, S., Enko, D., Schenk, M., Holasek, S. J., & Mangge, H. (2019). Evaluation of symptoms and symptom combinations in histamine intolerance. Intestinal Research. https://doi.org/10.5217/ir.2018.00152

2. McIntosh, K., et al., . (2017). FODMAPs alter symptoms and the metabolome of patients with IBS: a randomised controlled trial. Gut, 66(7), 1241–1251. https://doi.org/10.1136/gutjnl-2015-311339

Pin It on Pinterest

Share This