Do you experience unexplained headaches or anxiety? What about irregular menstrual cycles? Does your face flush when you drink red wine? Do you get an itchy tongue or runny nose when you eat bananas, avocados, or eggplant? If you answered yes to any of these questions, then you could have histamine intolerance.

Histamine intolerance can be very frustrating because the symptoms often feel as though they come out of nowhere. Trust me, I understand! I had a histamine intolerance myself. I kept getting terrible headaches seemingly out of the blue. Fortunately, I was able to pinpoint histamine intolerance as the source of my headaches and determine the underlying cause.

To help you find your own answers to these questions, I’ll walk you through what histamine intolerance is, what causes it, the best diet for it, and how to combat it.

What is Histamine?

Histamine is a chemical involved in your immune system, your digestion, and your central nervous system. A neurotransmitter, it communicates important messages from your body to your brain. It is also a component of stomach acid, which helps you break down food.

You might be familiar with histamine in relation to your immune system. If you have seasonal or food allergies, you may notice that antihistamine medications including ZYRTEC®, Allegra®, or Benedryl® provide quick relief for your symptoms.

Histamine’s role in the body is to cause an immediate inflammatory response. It serves as a red flag in your immune system, telling your body about any potential attackers. Antihistamines prevent this inflammatory response.

How Does Histamine Affect Your Body?

Histamine causes your blood vessels to swell so that your white blood cells can quickly move in to resolve any problems. It’s part of the body’s natural immune response. Typically, enzymes will break down the histamine so that it doesn’t build up. If you don’t break down histamine properly, it builds up and you develop histamine intolerance.

As histamine travels throughout your bloodstream, it can affect your gut, lungs, skin, brain, and your entire cardiovascular system. Histamine can contribute to a wide range of symptoms. This can make histamine intolerance difficult to pinpoint and diagnose.

Common Symptoms of Histamine Intolerance

  • Abdominal cramps
  • Abnormal menstrual cycle
  • Anxiety
  • Arrhythmia, or accelerated heart rate
  • Difficulty falling asleep
  • Difficulty regulating body temperature
  • Fatigue
  • Flushing
  • Headaches/migraines
  • Hives
  • Hypertension
  • Nasal congestion, sneezing, difficulty breathing
  • Nausea, vomiting
  • Tissue swelling
  • Vertigo or dizziness

What Causes High Histamine Levels?

In addition to the histamine produced inside your body, there are also a variety of foods that naturally contain histamine, cause the release of histamine, or block the enzyme (diamine oxidase or DAO) that breaks down histamine. I’ll talk more about DAO and how you break down histamine in a bit.

If you have a histamine intolerance, I recommend avoiding the following foods until you have addressed the underlying cause of your histamine intolerance.

Foods to Avoid if You Have Histamine Intolerance

Histamine-Rich Foods

  • Aged cheeses including goat cheese
  • Cured meats: bacon, salami, pepperoni, luncheon meats, and hot dogs
  • Dried fruit: apricots, prunes, dates, figs, raisins
  • Fermented alcoholic beverages, especially wine, champagne, and beer
  • Fermented foods: sauerkraut, vinegar, soy sauce, kefir, yogurt, kombucha, etc.
  • Most citrus fruits
  • Nuts: walnuts, cashews
  • Peanuts
  • Soured foods: sour cream, sour milk, buttermilk, soured bread, etc.
  • Smoked fish and certain species of fish including mackerel, mahi-mahi, tuna, anchovies, sardines
  • Vegetables: avocados, eggplant, spinach, and tomatoes
  • Vinegar-containing foods: pickles, mayonnaise, olives

Histamine-Releasing Foods

  • Alcohol
  • Artificial preservatives and dyes
  • Bananas
  • Chocolate
  • Cow’s milk
  • Nuts
  • Papaya
  • Pineapple
  • Shellfish
  • Strawberries
  • Tomatoes
  • Wheat germ

DAO-Blocking Foods

  • Alcohol
  • Black tea
  • Energy drinks
  • Green tea
  • Mate tea

Foods to Enjoy if You Have Histamine Intolerance

That was a long list! Now you might be wondering what on earth you CAN eat, so I’ve made a list of low-histamine foods as well. Remember, freshness is key when you have histamine intolerance.

Low-Histamine Foods

  • Cooked eggs
  • Cooking oils: olive oil, coconut oil
  • Dairy substitutes: coconut milk, rice milk, hemp milk, almond milk*
  • Fresh fruits: mango, pear, watermelon, apple, kiwi, cantaloupe, grapes
  • Fresh vegetables (except tomatoes, spinach, and eggplant)
  • Freshly caught fish
  • Freshly cooked meat or poultry
  • Gluten-free grains*: rice, quinoa, corn, millet, amaranth, teff
  • Herbal teas
  • Leafy herbs
  • Pure peanut butter*

*If you have an autoimmune disease and are following The Myers Way® Autoimmune Solution, avoid all grains, legumes, and nuts until you are able to successfully reintroduce them.

How Do You Break Down Histamine?

Once formed, histamine is either stored or broken down by an enzyme. Histamine in the central nervous system is broken down primarily by histamine N-methyltransferase (HMT). Histamine in the digestive tract is broken down primarily by diamine oxidase (DAO).

Though both enzymes play an important role in histamine break down, the American Society for Clinical Nutrition found that DAO is the main enzyme responsible for breaking down ingested histamine. If you’re deficient in DAO, you likely have symptoms of histamine intolerance.

Causes of Low DAO

  • Gluten intolerance
  • Leaky gut
  • SIBO
  • DAO-blocking foods: alcohol, energy drinks, and tea
  • Genetic mutations (common in people of Asian-descent)
  • Inflammation from Crohn’s, ulcerative colitis, and inflammatory bowel disease.
  • Medications:
    • Non-steroidal anti-inflammatory drugs (ibuprofen, aspirin)
    • Antidepressants (Cymbalta, Effexor, Prozac, Zoloft)
    • Immune modulators (Humira, Enbrel, Plaquenil)
    • Antiarrhythmics (propanolol, metaprolol, Cardizem, Norvasc)
    • Antihistamines (Allegra, Zyrtec, Benadryl)
    • Histamine (H2) blockers (Tagamet, Pepcid, Zantac)

Although histamine blockers, a class of acid-reducing drugs, seem like they would help prevent histamine intolerance, these medications can actually deplete DAO levels in your body.

How to Test for Histamine Intolerance

Elimination/Reintroduction

Remove high histamine foods for 30 days. Reintroduce them one at a time by following the guidelines in this comprehensive article.

Blood Testing

I use a test through Dunwoody labs to test for histamine levels and DAO levels. A high ratio of histamine to DAO signifies that you are ingesting too much histamine and that you don’t have enough DAO to break it down.

Trial of DAO

If testing is unavailable to you, you could try a diet low in histamine and add a DAO supplement at each meal (see more on this below). If your symptoms resolve, you could have low DAO.

How Do You Treat Histamine Intolerance?

After years of working with patients in my clinic, I found there are simple actions anyone can take to address the symptoms of histamine intolerance.

Relieve Your Symptoms Through Diet and Supplements

If you have histamine intolerance, step one is to minimize your dietary histamine. Do this by eating a low-histamine diet and avoiding foods that block DAO. I also recommend taking a DAO supplement such as Histazyme for immediate relief.

When I was battling histamine intolerance, this supplement was a life-saver for me. I wouldn’t have a meal without it! One or two capsules no more than 15 minutes before you eat will help your body respond to symptoms of histamine intolerance.

Address the Root Cause of Your Histamine Intolerance

The key to overcoming histamine intolerance is to identify the root cause of the issue. In my experience, I found that histamine intolerance is often caused by a gut health issue, particularly one called SIBO. In fact, SIBO was behind my own histamine intolerance. Other common culprits behind histamine intolerance are leaky gut and gluten intolerance.

If you think the state of your gut is affecting your body’s histamine response, I recommend completing my Leaky Gut Breakthrough® Program. It includes diagnostic quizzes, meal plans, supplements, and handy tools to help you address your gut concerns from the comfort of your home.