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Histamine Intolerance: Linking Confusing Uncomfortable Symptoms

Histamine Intolerance: Linking Confusing Uncomfortable Symptoms

Histamine Intolerance may be the link between your confusing and uncomfortable symptoms. If you have headaches, migraines, anxiety, skin itchiness, eczema, congestion, post nasal drip, sudden sweating, stomach pain, diarrhea, or others that you or your doctors haven’t been able to resolve, it’s possible that histamine is the problem.

What is Histamine

Histamine is a compound released by mast cells and other types of white blood cells as an immune and inflammatory response to injuries and foreign invaders. It’s needed for many important functions such digestion by stimulating hydrochloric acid release from the stomach and  female reproductive health by stimulating estrogen release. It stimulates smooth muscle contractions like the ones in the intestine and uterus. When your body is faced with a pathogen or any foreign substance (like pollen and other triggers), mast cells release histamine which dilates and swells the blood vessels, allowing more white blood cells to come to site and fight the pathogen or threat. Histamine also acts as neurotransmitter, sending signals to the brain to help control body temperature, digestion, heart rate, and others.

Histamine Intolerance

Histamine is an important chemical. However, too much histamine means too much stimulation of everything.

Those muscle contractions? Have too much histamine and these contractions in the intestine will cause stomach pain, nausea, vomiting, and diarrhea. If you’re a female, these muscle contractions will happen in the uterus and cause menstrual pain and cramping.

Dilating vessels to allow white blood cells to fight invaders? Have too much dilation and you will experience low blood pressure, flushing, and rosy cheeks.

Stimulating hydrochloric acid for proper digestion? Have too much HCL and you will experience heartburn and reflux (and potentially even coughing and trouble swallowing as a symptom of silent acid reflux).

Histamine Intolerance Causes

Histamine will go out of balance when your body obtains too much histamine from food or produces too much histamine while not being able to get rid of the excess.

There are 2 major enzymes that break down histamine:

  1. DAO enzyme: it stands for diamine oxidase enzyme. It’s responsible for breaking down external histamine in the gut (the histamine you get from food). It’s produced mostly in the small intestine, ascending colon, placenta, and kidneys.
  2. HNMT enzyme: it stands for Histamine N-Methyltransferase enzyme. It’s responsible for breaking down internally-produced histamine in the intracellular space (in between the cells). It’s mostly found in the kidney, liver, spleen, colon, spinal cord, prostate, ovary, and bronchi.

Impairment in DAO enzyme seems to be a bigger contributor to histamine intolerance that impairment in HNMT enzyme.

Histamine Intolerance Treatment

With histamine intolerance, you can reduce and mange your symptoms by doing 3 things;

  1. Follow a low histamine diet
  2. Support DAO function with the right nutrients (vitamin C, B6, copper). People with genetic variations that cause them to make less DAO may benefit from external DAO enzymes tablets (derived from pork)
  3. Stabilize mast cells (stinging nettle, quercetin, vitamin C)

However, all of these are still short-term solutions.

As an integrative and functional dietitian, I want to find the root causes for the intolerances and imbalances my patients are experiencing.


Hiatamine Intolerance Root Causes

The best long-term solution to getting rid of histamine intolerance is to fix your gut, immune, and inflammatory problems from their root.

If you have food sensitivities, your body will continue to release histamine as a response to foods–even healthy ones. Since DAO is produced and works in the gut, problems in the small or large intestine, such as dysbiosis, leaky gut, and SIBO, can lead to impairment in DAO and histamine intolerance. If you have those, your immune cells are going to constantly fight pathogens and foods, releasing histamine. Certain types of bacteria will make histamine while other degrade it, so you have to make sure you balance your gut flora properly. I find that following a personalized food sensitivity plan along with a low histamine plan gets my patients the fastest results (in 10-30 days). You can learn more about my process for healing the gut in this free online training.

The bottomline is: you have to identify the underlying root causes of your histamine intolerance or fix them if you want to be able to enjoy a variety of foods and reduce your discomfort (and potential complications) of histamine excess.



Book a strategy call to understand how my Eat to Thrive integrative and functional nutrition program can help you reach your goals faster. .

Low Histamine Diet

If you want to do something about your symptoms today, start a low histamine diet. If you feel better after 14-30 days, then it’s very possible that you have a histamine problem. Many people, unfortunately, make the mistake of stopping there. They think that they need to stay on a low histamine diet forever. Some people may have to avoid large portions of the worst offenders (such as alcohol), but my philosophy is to help my patients fix the underlying problems so they can worry less about what they can or can’t eat. Use a low histamine diet as a short-term crutch until you find the answers for fixing your gut and immune system.

Avoid these foods that contain histamine: 

  • Fermented foods like sauerkraut, kimchi, and kefir
  • Aged cheeses, yogurt, sour cream, buttermilk
  • Alcohol, especially red wine
  • Processed, aged, cured, or smoked meats
  • Bone broth, bone broth powders
  • Tomato, spinach, eggplant, avocado, mushroom
  • Dried fruit like raisins, dates, apricots, prunes, figs
  • Sardines, tuna, herring, mackerel
  • Soybeans, chickpeas, and lentils
  • Vinegars or vinegar-containing condiments like salad dressing, ketchup, mustard, mayonnaise
  • Foods that are moldy or starting to go bad
  • Yeast-containing foods and supplements, including sourdough bread and kombucha

Avoid these foods that stimulate your body to make more histamine: 

  • Citrus fruit (orange, grapefruit, lemon, lime, kiwi)
  • Papaya, strawberry, pineapple, banana, avocado
  • Nuts, especially peanuts and walnuts
  • Chocolate
  • Tomatoes, spinach, eggplant
  • Fish and shellfish
  • Pork
  • Egg whites

Avoid these foods that block DAO enzyme: 

  • Alcohol
  • Energy drinks
  • Black and green tea

Need help identifying the root causes of your problems so you can fix them–correctly–once and for all? Learn more about my comprehensive integrative and functional gut healing program and book a strategy call to see if you’re a good fit.

Histamine Intolerance Summary Video

If you’d like to learn more, watch this video I posted summarized what histamine intolerance is and what to eat to alleviate the symptoms.

Histamine Intolerance Q&A

Can you test for histamine intolerance? 

Yes. There are some tests that measure blood histamine level and DAO enzyme level. However, I find that the fastest way to getting some answers is following a low histamine diet. Because dysbiosis, leaky gut, and SIBO are linked to histamine intolerance, I prefer to use my patient’s resources to get these tests done to identify the real triggers so we can eliminate and correct them. If all of these come back negative and I still doubt histamine issue, I order a histamine/DAO panel.

How can you test for DAO gene? 

You can get this done with 23 and Me or other genetic tests. Also understand that having MTHFR morphism is going to affect your DAO enzyme.

Histamine and estrogen, is there a link? 

Yes! Histamine make your produce more estrogen, and estrogen makes you produce more histamine. That’s why histamine tends to be more common in women. During the phases of your menstrual cycle where your estrogen level is high, you’re more likely to notice worsening of your symptoms. Women with histamine issues, such as asthma, experience fluctuations in their symptoms based on the time of the month. Period cramps and PMS are worse during ovulation and right before your period starts, times when histamine tends to peak. Personally, with all my 3 pregnancies, I had constant congestion and runny nose, and my doctors never knew how to explain it to me. My guess (I can’t test at this point) is that my body was producing more histamine as my estrogen levels were high. You can read more about histamine and estrogen in my second article in MindBodyGreen.

Is histamine the same as food allergies or sensitivities?

No. Food allergies are IgE-mediated immune reactions. In food sensitivities, mediators are released from antibodies and directly from cells (cell-mediated), in response to food. While histamine is one of the mediators that may be released, there are others involved. I find that it’s common to have both histamine intolerance and food sensitivities at the same time, and helping reduce ALL immune reactions (both histamine release and other mediators) is the fastest way to resolved the uncomfortable symptoms.

Nour’s guidance and expertise was the key to dramatically halting our son’s [Crohn’s] disease progression! His pediatric gastroenterologist is now in agreement of our choice to treat solely with diet and supplements. All his labs have improved and his inflammatory markers are so low they are practically nonexistent.

Before working with Nour, I experienced intestinal pain off and on for for 54 years with minimal success on medications. I have benefited 100% from Nour’s program as I am now pain free!

A lot of time and money was wasted on foods that I thought would help my digestive struggles [diarrhea, bloating, hunger], but in fact I was making it worse. The main benefit is getting a handle on what negatively affects my digestive symptom. Doing a total 180 to my eating habits has been pretty amazing.