Histamine Intolerance: All You Need to Know

Do you experience unexplained headaches or anxiety? What about irregular menstrual cycles or gastrointestinal disorders? 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 histamine intolerance myself. I kept getting terrible headaches seemingly out of the blue. Fortunately, I discovered that allergic reactions from histamine intolerance was the source of my headaches. From there, I could determine the underlying root 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 histamine intolerance diet, and how to combat it.

What is Histamine Intolerance?

Let’s back up for a second and cover the basics of what histamine is and what histamine intolerance looks like.

What is Histamine?

Histamine is a chemical involved in your immune system, your digestion, and your central nervous system. As a neurotransmitter, it communicates important messages from your body to your brain. It is also a part 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 Benadryl® 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. On the other end of the spectrum, 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 entire cardiovascular system. Histamine can contribute to a wide range of symptoms.

Histamine Intolerance Symptoms

Symptoms resemble common allergic responses and symptoms. This can make it difficult to pinpoint or diagnose. Common symptoms are:

• 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

How Does the Body Break Down Histamine?

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

Once formed, histamine is either stored or broken down by an enzyme. In the central nervous system, histamine is mainly broken down by histamine N-methyltransferase (HMT). In the digestive tract, histamine is broken down by diamine oxidase (DAO).Though both enzymes play an important role in breaking down histamine, the American Society for Clinical Nutrition found that DAO is the main enzyme responsible.¹ If you’re deficient in DAO, you likely have symptoms of histamine intolerance symptoms.

Causes of Low DAO Enzymes

• 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 enzyme levels in your body.

What Causes High Histamine Levels?

We naturally produce histamine along with DAO. However, when outside factors interfere with how HMT and DAO work, their presence in your gut can decrease. Low levels of HMT or DAO enzymes means histamine can be produced without regulation.² Outside factors contributing to the overproduction of histamine include:

• Allergies (IgE reactions)
• SIBO, or Small Intestinal Bacterial Overgrowth
• GI bleeding
• Histamine-rich foods
• Leaky gut

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.

Foods to Avoid if You Have Histamine Intolerance

If you have histamine intolerance, I recommend avoiding the following foods until you have addressed the underlying cause of your histamine intolerance.³

Histamine-Rich Foods

Your diet should consist of foods with moderate to low levels of histamine. The high histamine foods list includes:

• 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
• Fruits: avocados and tomatoes
• Vegetables: eggplant and spinach
• Vinegar-containing foods: pickles, mayonnaise, olives

Histamine-Releasing Foods

Some foods, while not histamine-rich, can trigger your cells to release histamine, causing symptoms. Histamine-releasing foods include:

• Alcohol
• Artificial preservatives and dyes
• Bananas
• Chocolate
• Food containing dairy (cow’s milk)
• Nuts
• Papaya
• Pineapple
• Shellfish
• Strawberries
• Tomatoes
• Wheat germ

DAO-Blocking Foods

Some foods and drinks interfere with your body’s natural balance of HMT and DAO enzymes. As you consume more and more of these foods, the less your DAO enzymes will be able to keep your histamine intolerance symptoms in check. DAO-blocking foods to avoid while following a histamine intolerance diet include:

• 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 if you have histamine intolerance. Fortunately, there are plenty of foods you can enjoy on a low histamine diet. Remember, freshness is key when you have histamine intolerance and are following a histamine free diet.

Low-Histamine Foods

• Cooked eggs

• 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 or are following The Myers Way®, avoid all grains, legumes, and nuts until you are able to successfully reintroduce them to your histamine intolerance diet.

Following a low histamine diet is one of the best things you can do to manage your histamine intolerance. While a low histamine diet can feel strict, it will be worth it for the symptom management.

Elimination/Reintroduction

For optimal results, remove high histamine foods for 30 days. Then, reintroduce them one at a time by following my elimination diet guidelines.

How to Test for Histamine Intolerance

The Histamine Blood Test

My personal medical advice is to use a histamine blood test such as the one through Dunwoody labs to test for histamine levels and DAO enzyme levels and diagnose histamine intolerance. 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 a histamine blood test is unavailable to you, you could try a histamine intolerance diet and add a DAO supplement at each meal (see more on this below). If your symptoms resolve, you could have low DAO.

How to Treat Histamine Intolerance?

As a medical professional, after years of working with patients in my clinic, I found there are simple actions anyone can take to address their histamine intolerance symptoms.

Relieve Your Symptoms Through Diet and Supplements

For people with histamine intolerance symptoms, step one is to minimize 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. I’ve had so many members of my community tell me how Histazyme has provided them with the freedom of not having to worry about histamine intolerance when eating out.

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.

Address the Root Cause of Your Histamine Intolerance

The key tThe key to overcoming symptoms 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 Small Intestinal Bacterial Overgrowth (SIBO)⁴ In fact, SIBO was behind my own histamine intolerance. Other common culprits behind it are Candida overgrowth, leaky gut, and gluten intolerance.

If you think a gut infection is causing your body’s histamine intolerance, I recommend completing my Leaky Gut Breakthrough® Program. It includes diagnostic quizzes, meal plans, supplements, and handy tools to help you address your gut health and symptoms from the comfort of your home.

Additional Resources

For more information, check out my interview with Kara Fitzgerald, ND, where we discuss the overlap between allergic diseases and autoimmunity, and how our exposure to medications and environmental toxins plays a part.