• Dr. Tania Dempsey

Everything You Need to Know About the Low Histamine Diet



The foods we eat lay the foundation for our health or lack thereof. Choosing a healthy, whole food diet that is low in sugar and processed foods is the way I encourage all my patients to eat.


However, a simply healthy diet may not be enough for some people, especially those with MCAS or histamine intolerance. When there are deeper things at work, a targeted diet may be necessary.


This is where a low histamine diet can help.


A low histamine diet differs from other eating patterns in that foods are evaluated based on either their amount of histamine or their potential to induce histamine release or prevent its breakdown. Eating this way is probably unlike any other diet you’ve tried.


When I recommend this type of diet to patients that I believe can benefit from it, there is usually a learning curve as they shift to new habits. It’s a normal part of learning a new way of eating, and I’m committed to helping my patients on this journey.


Today I want to share the essential things you need to know about a low histamine diet. I’ll touch on:


  • A brief look at the role of histamine in the body and when it’s a problem

  • When a low histamine diet might be recommended

  • Pros and cons of a low histamine diet

  • Principles of a low histamine diet

  • Foods to eat and foods to avoid

  • How to know if the diet is working


How Histamine Works

Histamine is a signaling molecule produced by many cells in the body, including mast cells, basophils, other white blood cells like neutrophils and lymphocytes, ECL cells (enterochromaffin-like cells) in the stomach, and central nervous system neurons. Mast cells and basophils are the major source of histamine stored in granules and histamine is released from these granules when these cells receive certain signals. Histamine then sends signals to other cells alerting them to perform certain functions.


Here are just a few of the other functions of histamine:


  • Involved in the secretion of gastric acid

  • Smooth muscle contraction

  • Immune modulator

  • Neuromodulator, regulates the release of other neurotransmitters.

  • Allergic and inflammatory reactions


Many essential bodily functions would not be possible without histamine, so histamine is not all bad news. However, trouble arises when there is either an overproduction and/or release of histamine or an imbalance in the system that regulates the breakdown and removal of histamine.


When Histamine Becomes a Problem

Regular exposure to high levels of histamine is a major problem. Since histamine is released by so many cells in so many locations in the body, it can certainly overwhelm the body if the mechanisms to control and balance histamine are impaired.


While mast cells are one of the primary sources of histamine in the body, some foods also contain histamine, which may be absorbed during digestion or cause the body to release more histamine. Too much histamine from food will also contribute to excessive histamine exposure.


The body has systems in place to regulate histamine balance under normal conditions. There are two primary ways that histamine is metabolized in the body. First, in the intestines, is the enzyme, Diamine Oxidase (DAO) that is responsible for the breakdown of histamine consumed from food or released from mast cells. DAO levels can be reduced in some people due to certain medications, supplements, medical conditions, and genetics.


Second, we have another enzyme,Histamine N-Methyl-Transferase (HNMT), which converts histamine into a compound called methylhistamine that the body can get rid of through the detoxification pathways. There are things that can impair this enzyme as well, and one of the main causes is a genetic mutation in the gene that codes for the HNMT enzyme. Nutritional deficiencies and other genes that affect methylation can also impact the function of this enzyme since it is an enzyme that requires methyl groups.


These two enzymes are essential to maintaining histamine balance. Any disruption to these enzymes' production or action may result in imbalanced histamine levels.

Factors that influence the effectiveness of these histamine regulating enzymes include:

  • Genetics

  • Mast cell activation syndrome

  • Altered histamine receptors

  • Nutritional deficiencies

  • A diet high in histamine containing foods

  • Certain medications and supplements

If the amount of histamine in the body outpaces its ability to clear it, then histamine intolerance may develop.


Symptoms of Histamine Intolerance

Identifying histamine intolerance can be tricky. Common symptoms of histamine intolerance include:

  • Itching

  • Redness

  • Hives

  • Swelling

  • Sneezing and/or coughing

  • Asthmatic symptoms

  • Blood pressure changes

  • Palpitations

  • Headache or migraine

  • Dizziness

  • Chronic fatigue

  • Sleep disturbances

  • Anxiety and/or depression

  • Cramps

  • Bloating

  • Flatulence

  • Diarrhea and/or constipation

One aspect of histamine intolerance that can be frustrating is that it may come and go. Symptoms may resolve and then flare, and I often hear from my patients that they are not sure what is causing them. When we dig deeper into their medical, family, and symptom history, it becomes clearer that there are triggers that are driving their symptoms. Whether these are triggers that are directly affecting their mast cells or whether these are triggers that are affecting histamine levels specifically is important to piece apart. While there is often other work that needs to be done to understand the root cause of a patient’s issues, sometimes just starting with the diet is a simple and effective place to start.


Pros of a Low Histamine Diet

Some of my patients who try a low histamine diet are pleasantly surprised. Getting relief from those pesky symptoms is freeing and a huge opportunity to experience freedom from debilitating symptoms. I love it when this happens.


While a low histamine diet is not usually a miracle cure, it can be a factor in improving how someone feels. Treating histamine intolerance or MCAS takes an approach that works from many different angles, and diet is an important one.


I like a low histamine diet for a few reasons:


It can provide a clear diagnosis. If symptoms improve on a low-histamine diet, we know we are on the right track.


It’s inexpensive. Quality self-care can be pricey. It’s worth it to care for yourself, but it’s also nice to find low-cost solutions. Switching up what you eat to avoid high histamine foods doesn’t require expensive ingredients or hard-to-find foods.


It works relatively quickly. We usually know within the first few days to weeks if the diet provides any benefits.


Cons of a Low Histamine Diet

A low histamine diet isn’t right for everyone. Each patient has unique needs, and effective treatment must meet the patient where they are at.


A low histamine diet may not be the solution in every case. Some people with histamine intolerance react differently than we expect to high or low histamine foods. Sometimes there are additional factors at play that make a low histamine diet less effective.


As always, treatment must be individualized to each patient. When I work with someone with MCAS and/or histamine issues, we do a lot of troubleshooting to find out what works for them. There is no one-size-fits-all approach.


Here are some drawbacks to a low-histamine diet.


The amount of histamine in certain foods is variable. Histamine is present in many foods; however, the amount of histamine present when you actually eat it is influenced by many factors. How long you store the food, cooking method, and preservation techniques may alter histamine levels.


The diet may be challenging to stick with long-term. Because histamine is present in so many foods, the list of foods to avoid on this diet can feel overwhelming.


It takes effort to achieve a balanced diet. With so many foods off the table, patients following a low-histamine diet need to put in a certain amount of effort to get an adequate balance in their diet. If you’re not careful, you may end up low in certain nutrients.


Histamine may not be the problem. From a mast cell perspective, there are over 1,000 mediators that mast cells can make and release, so symptoms in the gut that resemble histamine intolerance could certainly be due to some other inflammatory chemical released from mast cells. Avoiding high histamine foods or trying to lower histamine levels, may not actually control the symptoms if another mediator is at play.


Principles of a Low Histamine Diet

Completely eliminating histamine from your diet is not possible. And that’s ok. You don’t have to achieve perfection to feel better. For some people, avoiding the highest histamine foods will bring relief.


If I start a patient on a low histamine diet, we review what they are currently eating and analyze what the culprits might be. I also discuss with the patient the options for eliminating some of the more obvious foods first vs. starting a strict elimination diet. There is no right answer. It’s about finding the path that helps the patient feel better.


Usually, once my patients feel the benefits, they can tune into how their body responds to specific foods and optimize the diet for themselves.


High-Histamine Foods:

  • Fish: Shellfish, canned fish, anchovies, and smoked fish.

  • Meats: Processed, smoked, or grilled meat, especially bacon, sausage, lunch meat, and hot dogs.

  • Fermented vegetables: Sauerkraut, kombucha, pickles, relish, soy sauce, tamari, miso, tempeh, etc.

  • Fermented dairy: Yogurt, kefir, buttermilk, and most aged cheeses.

  • Fermented Grains: Sourdough

  • Vinegar-containing foods: Pickles, relishes, some olives, ketchup, mustard, etc.

  • Vegetables: Tomatoes, eggplant, avocado, and spinach.

  • Fruits: Bananas, grapes, strawberries, and citrus fruits.

  • Nuts: Walnuts, cashews, peanuts

  • Legumes: Chickpeas, soybeans

  • Cocoa and chocolate

  • Alcohol

Low Histamine Foods:

  • Fish: Only very fresh fish that has been cooked or frozen promptly after being caught.

  • Meats: All fresh or frozen unprocessed meats.

  • Eggs

  • Dairy: Butter, raw and fresh milk and cream, mozzarella cheese, cottage cheese, mascarpone cheese.

  • Fats: Coconut oil, flax oil, ghee, hemp oil, olive oil, rendered lard.

  • Gluten-free grains: Amaranth, corn, millet, oats, quinoa, rice, etc.

  • Fruits: All fresh fruits except bananas, grapes, strawberries, and citrus.

  • Vegetables: All fresh vegetables except spinach, tomatoes, avocados, and eggplant.

  • Seeds: Chia, flax, hemp, sesame, sprouted pumpkin, and sprouted sunflower seeds

  • Nuts: Macadamias and chestnuts

  • Sweeteners: Agave, maple syrup, raw honey, and stevia


Other Considerations

Avoiding high-histamine foods isn’t the only consideration for a low histamine diet. Not all foods have been tested for histamine, and the way food is handled, stored, processed, and prepared can contribute to more or less histamine.


Here are a few additional considerations.


Watch out for foods that interfere with DAO or HNMT enzymes. - Alcohol is a major culprit in this category. Consuming alcohol, especially wine, champagne, or spirits, blocks DAO and may release endogenous histamine. Other foods to be cautious of include any food with additives, certain spices, and black or green tea for some people.


Fresh foods are best - The longer a food is stored, the more histamine develops. Try to shop more frequently instead of holding food for long periods. Sourcing local food will ensure the freshest, low-histamine items.


Cooking methods matter - Some cooking methods such as grilling and smoking may increase the histamine content of food. Boiling may be a good choice as it lowers histamine.


Track your food intake and symptoms - Keep a detailed food and symptom diary to help identify patterns and pinpoint specific foods that may be causing problems.


A DAO supplement may help - Supplementing the enzyme may be appropriate for those with altered DAO enzyme level or function. I consider this for all my low-histamine patients, and many find it very helpful.


Consider additional vitamin/mineral supplements as needed - Nutrients such as vitamin C, Vitamin B6, and copper are essential co-factors for DAO. A deficiency of these nutrients may inhibit the actions of DAO and contribute to high histamine levels.


Getting The Most Out of a Low Histamine Diet

While this type of diet can be a challenge, it can also bring relief to people suffering from histamine intolerance. The best way to know if it’s working is to see if you feel better!


I don’t encourage people to self-treat if they believe they have histamine intolerance. You will get the best care and the most precise answers when you work with a qualified healthcare professional experienced in treating histamine intolerance and MCAS. There may be more going on than can be addressed with only a low-histamine diet.


In my clinic, we celebrate when a patient experiences a good outcome on a low-histamine diet. But, the journey doesn’t stop there. Once we know histamine intolerance is present, we keep digging to get at the root cause of why their body isn’t able to balance histamine levels. The goal is complete repair and recovery.


If you think you may have histamine intolerance, contact me to start the process of finding the answers you need. I hear all too often of people who struggle for years, unsure of why they feel the way they do. Solutions are out there. I’d love to partner with you on your journey.