Why Your New Diet May Be Making You Sick

Did you just recently start a Whole 30, Paleo, or Keto diet, only to find that now you’re feeling worse than you did before?! As it turns out, many of these “healthy” foods that are integral components of many of these diets are also very high in extrinsic histamines, which can cause a problem for someone with a “histamine intolerance.” But what exactly does this mean?

It is important to note that histamine is an integral and required part of a healthy immune system – the goal is never to rid your body of histamines entirely.  It is an important neurotransmitter and it creates necessary inflammation during any sort of immune system response, whether it’s related to injury, disease, or other foreign matter. Histamine levels of 0.3 to 1.0 nanograms per milliliter (ng/mL) in plasma are considered to be normal (1). Histamine, among many other chemical inflammatory mediators, is released from mast cells. Mast cells are located in connective tissue, like the lining of the gut, skin and other sites in the body. These cells play a very important role in helping defend these tissues from disease by releasing chemical “alarms”, like histamine, to areas of the body where they are needed. 

For example, if someone is extremely “allergic” to peanuts, the slightest taste can trigger an immense histamine response. This response results in systemic inflammatory signals – to your nose, throat, mouth, gut, skin, and lungs. This “allergic reaction” caused by histamine is likely why this inflammatory chemical gets such a bad reputation.

Like anything, too much of a good thing is a problem, and when we accumulate too many histamines and our bodies can’t break them down fast enough, that’s when we begin to see symptoms and are diagnosed as “histamine intolerant.” We all technically have some degree of  “histamine intolerance,” but it is important to remember that it is a dynamic process, affected by allergic reactions, diminished genetic ability to clear histamine (decreased Diamine oxidase AKA DAO, the enzyme that breaks down histamine, production), compromised gut health (leaky gut, gut infections, irritable bowel syndrome), lifestyle (stress and ingestion of substances that block DAO, like NSAIDS and alcohol), and food that is high in histamines (2,3).  Consider this quote from Chris Kresser:

Histamine intolerance is unlike other food allergies or sensitivities in that the response is cumulative, not immediate. Imagine it like a cup of water. When the cup is very full (high amounts of histamine in the diet), even a drop of additional water will cause the cup to overflow (symptoms activated). But when the cup is less full, it would take more water (histamine) to cause a response. This makes histamine intolerance tricky to recognize.


Think of your tolerance to histamine like a bucket.  When you’re stressed at work, taking NSAIDs (ie. Advil) to get rid of the headache you have to make it through the day, not sleeping well, and too tired to cook yourself a decent meal, you are more at risk for your “bucket” to overflow, resulting in the “allergic reaction-type” symptoms that you would expect (3).  We would label this as a histamine intolerance – you are not clearing the histamine in your body fast enough – but that doesn’t mean you’ll have these symptoms forever! I really like how this phenomena is described by Dr. Janice Joneja:

A person with histamine intolerance will typically experience a constant fluctuation in the signs and symptoms of histamine excess in response to changing conditions. For example, when a person is experiencing allergy to airborne allergens such as seasonal pollens, the histamine released in the allergic response alone might put them into the symptom range. In such a case, avoiding histamine-associated foods will no longer relieve their symptoms because their total level of histamine will remain above their limit of tolerance. This explains the observation that during their “pollen allergy season” many people find themselves reacting to foods (usually histamine-rich foods) that they could normally eat with impunity (1).

As mentioned by Kresser and Joneja, histamine intolerance is not so much of a diagnosis as it is a collection of a bunch of symptoms.  It is now believed that Mast Cell Activation Disorder (MCAD) is a more accurate depiction of what is happening in patients who have been diagnosed with “histamine intolerance.” Mast cells are located in most tissues of the human body, especially in connective tissue, skin, and the digestive, cardiovascular, nervous, and reproductive systems. When the body is exposed to perceived threats, mast cells quickly secrete chemicals, like histamine, interleukins, prostaglandins, cytokines, and other various chemicals stored in cells to address the issue. Both local and systemic effects are the result, such as increased permeability of blood vessels, that will cause increased inflammation and swelling, smooth muscle contractions that may lead to heart palpitations and stomach cramps, and increased mucous production that will cause increased sneezing and coughing. We initially only thought that mast cells were related to allergies, but now we know that they likely play a much larger role in over-activation of the immune system as well as the development of other autoimmune disorders, especially though involving antibodies, probably related to the presence of more environmental toxins and chemicals.  MCAS has been linked to the development of allergies, asthma, autism, autoimmune diseases (Hashimoto’s thyroiditis, lupus, multiple sclerosis, rheumatoid arthritis), eczema, Celiac disease, chronic fatigue syndrome, chronic inflammatory response syndrome (CIRS), fibromyalgia, food allergies, GERD, infertility, IBS, migraines, anxiety/depression, and postural orthostatic tachycardia syndrome (POTS) (4).

Overactive mast cells can cause a variety of symptoms including: skin rashes, swelling, flushed skin, itching, abdominal pain, nausea/vomiting, diarrhea, wheezing/shortness of breath, heart palpitations, anxiety, headaches, brain fog, low blood pressure, and fatigue.

The good news is there are many foods that do act as natural antihistamines and mast cell stabilizers! Looking for foods that contain ascorbic acid, quercetin, vitamin B6, omega-3 fatty acids, and riboflavin can help reduce the amount of histamine you are producing.4

Sometimes, at least while you are experiencing a flare-up of your MCAS, it may be helpful to eliminate foods known to contain high histamine content. Foods may naturally have more histamine content, while others foods accumulate more histamine as they age. Please notice that many of the foods listed below are primary staples in any Whole 30, Paleo, or keto diet! Histamine-rich foods include:

  •      Fermented alcoholic beverages, like wine, champagne, and beer
  •      Fermented foods like sauerkraut, vinegar, soy sauce, kefir, yogurt, kombucha (don’t shoot the messenger!)
  •      Foods high in vinegar like pickles, mayonnaise, olives
  •      Cured meats like bacon, salami, pepperoni, deli meats, hot dogs
  •      Soured foods like sour cream, sour milk, buttermilk
  •      Dried and citrus fruits
  •      Aged cheeses
  •      Nuts
  •      Vegetables like avocados, eggplant, spinach, tomatoes
  •      Any smoked fish and certain fish species like mackerel, mahi-mahi, tuna, anchovies, sardines
  •      Any processed foods (preservatives contain high amounts of histamines).5

It is important to remember that ingesting histamine is not the only cause for an increase in histamine in your body.  Once an immune response is complete, there needs to be enzymes to break down the histamine and other chemical mediators that were released. Diamine oxidase is the enzyme that is primarily responsible for breaking down histamines.  Once broken down, they are excreted through your urine via the kidneys. Usually, sufficient DAO in the small intestines means that the histamine you ingest is broken down before it causes a problem. However, if you are DAO deficient, histamine isn’t being broken down as readily, resulting in an increase in histamine levels. If you experience this increase in histamine for a prolonged period of time, the result is Mast Cell Activation Disorder, chronic inflammatory, and histamine sensitivity.

To increase your DAO levels, an option is to take DAO supplements (Histamine Block from Seeking Health) with meals. However, keep in mind these supplements are not able to enter your bloodstream and will therefore only be able to break down histamines that you are consuming and not the histamine that is being produced by your mast cells. Including omega-3 fatty acids, saturated fats, phosphorus, calcium, zinc, magnesium, iron, and vitamin B12 in your diet are also way in which to naturally improve your DAO levels. See below for examples of food that will contain high levels of each of the above, I am only including low histamine sources in this list.

It is also important to avoid DAO-blocking foods. If you think you are having trouble with histamine, you should absolutely avoid alcohol.  Not only is it a histamine-rich food, but it also blocks your DAO pathways. If you continue to develop histamine sensitivity, the “flushed face” response will continue to get worse and worse with time!6,7


Another natural option I recommend to patients is a supplement called histo-relief, which includes quercetin (a mast cell stabilizer) as one of its primary ingredients. This supplement supports immune function, as well as the body’s response to food and environmental factors. I have seen many of my patients become a lot more tolerant to food when adding this supplement to their daily regimen. Certain probiotics also limit histamine production – look for items with Lactobacillus rhamnosus and bifidobacter.4


I think it is helpful for people to realize that they are not alone – histamine intolerance is not something that Western medicine typically recognizes. It is important to recognize these symptoms don’t have to be forever and are also not just about what you eat. Yes, you may just have started on a diet where you are eating a ton of new foods, many of them very histamine-rich, but you also have to take into consideration your environment? What season is it? Are you stressed? Have you been sick or been on antibiotics? All of these things can overflow your histamine “bucket” and make it so even if you are watching your foods, it may not be enough to control your histamine response if your “bucket” is also almost overflowing. Maybe instead of your high histamine diet, you try a low histamine reset diet while working on the underlying causes before reintroducing histamine-rich foods. Maybe you add in some yoga and meditation to help control your stress levels.  Figure out why your histamine may be elevated and then make the changes required. If you’ve already tried this and hit a roadblock, please feel free to set up a consultation with me. I would love to help you get a grip on your symptoms and take your life back!

Bye Bye avocado toast….at least for now!




  1. Dr. Janice Joneja. Histamine intolerance. https://www.histamine-sensitivity.com/histamine_joneja.html. Accessed 3/24/19.
  2. John O’Connor. Don’t fear the fridge! Histamine intolerance is bigger than food. https://www.mygenefood.com/dont-fear-fridge-histamine-intolerance-bigger-food/. Accessed 3/24/19.
  3. Chris Kresser. Could Your Histamine Intolerance Really Be Mast Cell Activation Disorder? https://chriskresser.com/could-your-histamine-intolerance-really-be-mast-cell-activation-disorder/. Accessed 3/31/19.
  4. Jill Carnahan. Mast Cell Activation Syndrome (MCAS): When Histamine When Histamine Goes Haywire. https://www.jillcarnahan.com/2016/10/31/mast-cell-activation-syndrome-mcas-when-histamine-goes-haywire/. Accessed 3/31/19.
  5. Dr. David Jockers. Are You Suffering From Histamine Intolerance? https://drjockers.com/suffering-histamine-intolerance/. Assessed 3/24/19.
  6. Jill Carnahan. Boost Your DAO Levels to Fight Histamine. https://www.jillcarnahan.com/2018/03/19/boost-your-dao-levels-to-fight-histamine/. Accessed 3/31/19.
  7. https://www.ncbi.nlm.nih.gov/pubmed/10344773
  8. http://www.mastcellaware.com/mast-cells/about-mast-cells.html

        * These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. If you are pregnant, nursing, taking medication, or have a medical condition, consult your physician before using this product.





Hi, I am Dr. Becky Campbell. I work with men and women who’ve had a health set back and are willing to do whatever it takes to reach optimal health so they can perform their best in their careers and be fully present with their family again.

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