Histamine is a chemical produced in your immune system, which is involved in both our digestion, as a component of stomach acid, helping break down food in the stomach and in our central nervous system as a neurotransmitter, communicating important messages from your body to your brain.
Most of us are most familiar with histamine as it relates to the immune system; skin rashes and itching, unexplained headaches or anxiety, irregular menstrual cycles. Does your face flush when you drink red wine? Perhaps you suffer from an itchy tongue or runny nose when you eat bananas, avocados, or eggplants? If any of these affect you, then you could have a histamine intolerance.
Antihistamine medications like Piriton or Benadryl provide quick relief of your symptoms if you suffer from seasonal or food allergies. This is because histamine’s role in the body is to cause an immediate inflammatory response, resulting in your blood vessels swelling, or dilating, so that your white blood cells can quickly find and attack the infection or problem. The histamine build-up is what gives you a headache and leaves you feeling flushed, itchy and miserable and is part of the body’s natural immune response, but if you don’t break down histamine properly, you could develop histamine intolerance.
Once formed, histamine is either stored or broken down by enzymes. Histamine in the central nervous system is broken down primarily by histamine N-methyltransferase (HMT), while histamine in the digestive tract is broken down primarily by diamine oxidase (DAO). DAO is thought to be the main enzyme responsible for breaking down ingested histamine. So if you’re deficient in DAO, you are likely to have symptoms of histamine intolerance.
Causes of low DAO:
- Gluten intolerance
- Leaky gut
- Small Intestine Bacterial Overgrowth (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 such as:
- 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).
- Histamine travels throughout your bloodstream, and can therefore affect your gut, lungs, skin, brain, and entire cardiovascular system, contributing to a wide range of problems often making it difficult to pinpoint and diagnose.
Common symptoms of histamine intolerance include:
- Difficulty falling asleep, easy 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
- High histamine levels can be caused by many different things, such as:
- Allergies (IgE reactions)
- Small Intestine Bacteria Overgrowth (SIBO)
- Leaky gut
- Gastrointestinal bleeding
- Fermented alcohol like wine, champagne, and beer
- Diamine Oxidase (DAO) deficiency
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 production of diamine oxidase, the enzyme that breaks down histamine.
- Fermented alcoholic beverages, especially wine, champagne and beer
- Fermented foods: sauerkraut, vinegar, soy sauce, kefir, yogurt, kombucha, etc
- Vinegar-containing foods: pickles, mayonnaise, olives
- Cured meats: bacon, salami, pepperoni, luncheon meats and hot dogs
- Soured foods: sour cream, sour milk, buttermilk, soured bread, etc
- Dried fruit: apricots, prunes, dates, figs, raisins
- Most citrus fruits
- Aged cheese including goat cheese
- Nuts: walnuts, cashews, and peanuts
- Vegetables: avocados, eggplant, spinach, and tomatoes
- Smoked fish and certain species of fish: mackerel, mahi-mahi, tuna, anchovies, sardines
- Cow’s Milk
- Wheat Germ
- Many artificial preservatives and dyes
- DAO-Blocking Foods:
- Energy drinks
- Black tea
- Mate tea
- Green tea
Phew! It sounds as though there is nothing left! But there are low-histamine foods, which are many and varied and nutrient dense. These are easy to incorporate into a low histamine diet:
- Freshly cooked meat, poultry (frozen or fresh)
- Freshly caught fish
- Gluten-free grains: rice, quinoa
- Pure peanut butter
- Fresh fruits: mango, pear, watermelon, apple, kiwi, cantaloupe, grapes
- Fresh vegetables (except tomatoes, spinach, avocado, and eggplant)
- Dairy substitutes: coconut milk, rice milk, hemp milk, almond milk
- Cooking oils: olive oil, coconut oil
- Leafy herbs
- Herbal teas
Histamine intolerance can be treated by removing any high histamine foods for 1-3 months. Adding in a supplement of DAO can help to replace depleted stores. The most important factor is finding the root cause for the histamine intolerance. If you’re on a medication that is causing the intolerance, working with your physician to wean off of these medications is essential. If you’re currently suffering from histamine intolerance, you may not have to avoid these foods forever. It can be a short-term solution until your histamine or DAO levels return to their optimal ranges.
Resolving issues such as leaky gut, SIBO or food intolerances can help break through what feels like a quagmire of symptoms and may prove to be the root of the histamine intolerance.