Is Histamine Intolerance Causing Your Fatigue, Headaches, Or Stomach Pain?

Registered Nutritionist & Dietitian By Nour Zibdeh, M.S., RDN
Registered Nutritionist & Dietitian
Nour Zibdeh is a functional and integrative dietitian and nutritionist, author, and speaker. She received a B.S. in Human Nutrition from Virginia Tech and an M.S. in Health Sciences from James Madison University.
Is Histamine Intolerance Causing Your Fatigue, Headaches, Or Stomach Pain?

Do you have headaches, flushing in your face, fatigue, sudden sweating and warmness, stomach pain, diarrhea, nasal congestion, and other symptoms that you can't explain or pinpoint? Do they get worse when you drink alcohol? These seemingly unrelated symptoms may all be caused by the very same thing: histamine.

What is histamine?

Histamine is a chemical produced by immune cells, especially mast cells, in response to injury or foreign invaders. It causes blood vessels to dilate so that white blood cells come to the rescue to heal and fight off pathogens, food, or allergens. It's why your skin swells and turns red when you get bitten by a mosquito or why you get a rash when exposed to an environmental allergen.

In addition to being an important part of the immune system's inflammatory protective response, histamine is needed for digestion and helps different parts of your body communicate with your brain. Some histamine is necessary, but when there's more than you can get rid of, your bucket overflows and you experience histamine intolerance symptoms.


What causes histamine intolerance?

Histamine levels increase when it's released by immune cells but also when you eat histamine-containing foods. Aged and fermented foods like hard cheeses, sauerkraut, cured meats, wine, and vinegars are rich in histamine. Citrus fruit, chocolate, fish, and a few others cause immune cells to release histamine. Food and environmental allergens, pathogens, gastrointestinal bleeding, mast cell problems, and even certain strains of healthy lactobacilli bacteria also increase histamine release. Inside your body, alcohol and histamine are metabolized using the same pathways, and histamine will accumulate when your body tries to detox alcohol.

Clearing out histamine requires two enzymes: diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT). The DAO enzyme is concentrated in the small and large intestines and metabolizes food histamine. It also works in the blood to clear histamine released from immune cells. The HNMT enzyme works on deactivating histamine inside the cells and tissues. DAO is the major histamine detoxifier as a deficiency in this enzyme specifically is related to histamine intolerance.

People with low DAO activity can develop histamine intolerance. There are several reasons this may happen: The DAO gene is responsible for expressing the DAO enzyme. If you're born with a genetic variation that causes you to make less DAO, you're more likely to develop histamine intolerance. However, one study found that other genes may also affect DAO activity.

Drinking alcohol blocks DAO function. Medications like certain diuretics, antibiotics, NSAIDs, and others block DAO activity and increase histamine release as well. In addition, digestive disorders, gut infections, leaky gut, and dysbiosis reduce DAO levels; in fact, people with inflammatory bowel disease like Crohn's and colitis have a 50 percent reduction in DAO activity.

Histamine intolerance symptoms.

If you visited an allergist, neurologist, dermatologist, gastroenterologist, and half a dozen other specialists, histamine may be the string connecting the dots between all your symptoms. It manifests in any part of your body as it can be released in every tissue and can travel through the blood to any organ. Histamine intolerance is difficult to identify, especially if your provider is not familiar with it. The symptoms may be delayed, depend on your overall histamine load, and are often confused with food allergies and sensitivities. 

Histamine intolerance symptoms include:

  • Flushing and rosy cheeks
  • Sweating and feeling warm suddenly
  • Low blood pressure
  • Rapid heartbeat
  • Asthma, exercise-induced asthma
  • Irritability, fatigue
  • Motion sickness, nausea, vomiting
  • Chest pain
  • Digestive issues like stomachache, gas, bloating, loose stool, diarrhea
  • Sinus and nasal issues like runny nose, nosebleeds, postnasal drip, sneezing
  • Skin issues like hives, rashes, eczema, psoriasis, itchy skin, dryness
  • Headaches and migraines
  • Vertigo, dizziness
  • Insomnia
  • Muscle and joint pain, fibromyalgia
  • Asthma, exercise-induced asthma

How to test if you have histamine intolerance.

If you have multiple symptoms that can't be explained by other labs or tests, it's possible that you have histamine intolerance. If they are worse after drinking alcohol, or if adding bone broth, fermented foods, and probiotics to heal your gut make you feel worse, histamine may be the culprit. The fastest and easiest way to confirm that is to follow a low-histamine diet.

A genetic test can help you identify variations in your DAO, HNMT, and other genes that affect DAO activity. Serum DAO can be measured and has been shown to help diagnose histamine intolerance.

A low-histamine diet.

Following a low-histamine diet will reduce your symptoms and may even increase DAO activity long-term. Symptoms may start improving in just one week, but I recommend that you try it for a month at least. To get started, avoid these high-histamine foods:

  • 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

You should also avoid or limit these foods that make your body release 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

And finally, avoid foods that block the DAO enzyme:

  • Alcohol
  • Energy drinks
  • Black and green tea

How to actually stick to a low-histamine diet.

You may be wondering if you need to stick to a low-histamine diet for the rest of your life. As an integrative dietitian and food lover, I look for root causes to fix, so my patients can enjoy a variety of foods with the least restrictions possible. Here are some suggestions for you.

Since most DAO is released in the gut, correcting dysbiosis, reducing gut inflammation, and healing your intestinal lining can increase your DAO level. Food sensitivities are immune reactions where histamine and other mediators are released after eating problem foods. Improving digestion, reducing intestinal permeability, and strengthening tight junctions will reduce food sensitivity reactions and histamine release. Balancing your gut flora with the right probiotics will reduce histamine load as certain bacteria produce histamine while others degrade it. This is something to work on with an integrative or functional medicine doctor.

It's possible that your genes are to blame for your histamine intolerance. You can't change the body you're born with, but you can support it with nutrients that boost DAO activity like calcium, magnesium, phosphorus, zinc, vitamin C, quercetin, and vitamin D help stabilize mast cells and reduce internal histamine release. Always consult with your health care provider before adding supplements. 

You can also take external DAO enzyme in capsule form to boost histamine breakdown when you want to eat histamine-rich foods. Keep in mind that DAO enzyme doesn't cross the gut barrier, so the pills won't help degrade the histamine produced internally by your immune cells. The only products available commercially have DAO extracted from pigs' kidneys, so it may not be an option if you're vegetarian or avoid pork for religious reasons.

It's important to remember that acute and chronic physical, mental, and emotional stress turns on your flight-or-flight response, which activates your immune system to release more histamine. To avoid this, shut down electronics and go to bed early, drop perfectionism and judgment, and surround yourself with people who make you feel great. Breathe and meditate. Do something you love. Exercise (but don't overdo it.) and support your adrenals if needed. Reduce allergen and dust in your environment by cleaning ducts, changing filters, opening windows, and swapping carpet with wood floors or tile.

You may always need to pay attention to your histamine load to avoid painful and disruptive symptoms, but don't let that frustrate you. You're now more knowledgeable and empowered to better understand your body, support it where you can, and choose smarter food and lifestyle habits.

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