Follow on

Natural Ways to Increase DAO Enzyme Activity When You Suffer With Histamine Intolerance and MCAS

One way to improve the symptoms of histamine intolerance and MCAS is by increasing DAO enzyme activity. If you remember DAO is the enzyme that prevents the accumulation of histamine in the body. The great news is that you can increase DAO activity naturally. If you are DAO deficient you will develop symptoms such as allergies, headaches, low blood pressure, migraines, depression, GI problems, hives, eczema, anxiety, bad menstrual cramps and many other histamine intolerance symptoms.

Increasing DAO Enzyme Activity Naturally with Vitamins.

So one of the ways you can ensure your body doesn’t have a histamine build up is by making sure your body has the necessary cofactors for DAO to work properly. Cofactors are vitamins and minerals that activate the DAO enzyme.

So in this video, I’m talking about how you can

  1. Increase DAO enzyme activity naturally.
  2. Vitamins that are good for Histamine Intolerance and DAO activity
  3. Some very practical tips on How to get started with a low histamine diet

If you take a look at this illustration, you will notice that at the very top we have histamine, histamine is broken down by HNMT on the left and DAO on the right.

Auto Draft 37

In green letters you are going to see SAMe on the left and Iron, B6, B12, copper and vitamin C on the right. What this means is that if you are deficient in any of these vitamin cofactors, the DAO enzyme or HNMT enzyme won’t work properly, in turn, histamine will not be broken down and ultimately, you will experience excess histamine or histamine intolerance.

Common Ways Nutritional Deficiencies Can Interfere with DAO enzyme Activity

So things I want you to consider, if you are woman, and you have a heavy menstrual cycle for whatever reason, you have fibroids, you have endometriosis, there is a good change you are deficient in iron. This could in turn cause DAO deficiency and consequently excess histamine to build up.

Adrenal Fatigue, Stress and How It Affects Histamine Intolerance/MCAS 1

If you have hemorrhoids, Ulcers, H.pylori infection, you have been on proton pump inhibitors, you are taking birth control pills, these medications and these health problems can cause a B12 deficiency, B6 deficiency and a deficiency of vitamin C.

If you have been pounding down zinc (more than 60mg per day and you have been doing this for longer than 6 momths) like many patients do when they have gut issues, you might also be low in copper- because there is a very important relationship between copper and zinc.

So, if any of these sound like you, consider supplementing with everything I just mentioned.

To support the HNMT enzyme pathway, you also can support your methylation pathways. This is where things like SAMe and other sulfur based donors supplements perhaps thigs like MSM, taurine can help with that

Herbs and Supplements to Help Histamine Intolerance and Naturally Raise DAO levels

Let’s talk about some other strategies or supplements that can help with histamine intolerance and improve DAO activity.

  1. Quercetin: When you intake Quercetin, you’re helping your body to calm the inflammation. It also blocks the releases of histamine from your mast cells. Quercetin has strong antioxidant activity and has been shown to support immune health by influencing other inflammatory agents like leukotrienes and prostaglandins. Quercetin is known for its ability to stabilize mast cells, inhibit the release of histamine.
  2. DAO™ supplementation has been clinically tested and found to break down food-derived histamine in the digestive tract. DAO is found in the small intestine, in two sections called the jejunum and ileum. When foods high in histamine enter the small intestine, DAO breaks it down and prevents it from being absorbed. When you have sufficient DAO, nearly all of the histamine that passes through your digestive tract is broken down and therefore doesn’t cause any issue. Since it is impossible to completely eliminate all sources of histamine from the food we eat, supplementation with DAO can certainly help mop up some of the extra histamine when their is either injury in the small intestines or if we ingest too much from a meal. Taking DAO does not give you free reign to splurge and eat high histamine foods- BUT when you combine this with a low histamine diet- it can have a profound impact on histamine intolerance symptoms.
  3. Stinging Nettles Leaf Extract– Studies have shown that the extract of stinging nettles leaf balances a variety of inflammatory activities that affect respiratory health. If you are someone sinus infections, sinus pressure, histamine induced asthma, stinging nettles leaf extract would be something to add to your arsenal.
  4. Bromelain– comes from pineapples. Proteolytic means that it is (protein-digesting) in that it aids in in the breakdown of large protein complexes. Studies show that is helps break down allergenic proteins. So it makes sense that this can be important for people with allergies and hyper-sensitive immune responses.
  5. Omega-3 is another important one, Omega 3 essential Fatty acids like EPA, and alpha-linolenic acid have been shown to help with allergic reactions.
  6. And lastly Green tea- Studies show many benefits of green tea for inflammation, as well as being a mast cell stabilizer. Anything that stabilizes the mast cells can help prevent them from rupturing and releasing all the inflammatory chemicals contained with mast cells.

Adrenal Fatigue, Stress and How It Affects Those of Us With Histamine Intolerance/MCAS 6

How To Start A Low Histamine Diet –Practical Tips and Reminders When You First Start

#1 Avoid or reduce eating canned foods as well as carbonated beverages- many times foods that are found in cans or carbonated beverages… They have preservatives, they have sulphites, they have nitrites, they contain yeast and benzoic acid- these are known as histamine liberators. So, you want to avoid these as much as possible.

#2 Avoid or reduce fermented foods (cheeses, beer, wine, Relish, pickles, bone broth, vinegar and products containing yeast)

#3 Keep in mind that the Histamine levels in foods vary- depending on they are prepared how ripe they are, etc #4 try to purchase only fresh products. Less packaged foods, while this is a general rule to clean eating, eliminating packaged foods is especially relevant when you have histamine intolerance.

#5 When you start on a low histamine diet- try to make this the only change. Don’t start a low histamine diet, if you have an appointment with your doctor and you think he or she may change one or more of the medications you are taking. The key here is to minimize variabilities. Try to keep to your “normal routine” as much as possible.

#6 Avoid reheating foods especially proteins like meat. When you reheat meat, you increase the concentration of histamines in that food- sometimes by a factor of 10. This would not be a good thing.

#7 It’s easy to feel overwhelmed by all the foods you can’t eat I want you to focus on all the foods you can eat! This is one of those things called perspective! Your glass is not half empty- lets look at the glass as half full. Again, I want you to focus on all the foods you CAN eat

#8 Work with functional medicine practitioner who can identify some of the other root causes behind your histamine intolerance and one who will pair you up with a nutritionist. Tackling histamine intolerance often requires a team approach.

#9 Don’t beat yourself up if you relapse! Everyone has their own threshold and things that are filling up their histamine bucket; you and your doctor will need to find out what’s filling up your histamine bucket and how to empty it. Diet is starting point but there is much more going on then just diet.

#10 Have fun experimenting with new foods. Let’s face it, most people don’t like change and we often meet change with opposition. Here’s what I will say to that, after a few weeks, what seemed so difficult at first is now falling into place.

#11-There is no better time than Now to get started! Don’t procrastinate! To help you get started and make these changes, I have put together a free low histamine guide- you can download.

Download my free low histamine starter guide here This guide will help you get off to a good start when implementing a low histamine diet.


Ways to Increase DAO Enzyme Activity When You Suffer With Histamine Intolerance and MCAS



  1. How To Get Started on a Low Histamine Diet – Part I
  2. How to Get Started on a Low Histamine Diet-Part II
  3. Supplements to help Support Histamine Intolerances 
  4. Histamine Intolerance and Gut Health SIBO and Leaky Gut
  5. Best Tips To address Histamine Intolerance When you have SIBO
  6. DAO deficiency- The enzyme that breaks down Histamine- How to Activate this enzyme when you have Histamine Intolerance/MCAS
  7. Dr Hagmeyer’s Youtube Channel and Playlist for Histamine Intolerance/MCAS
  8. Histamine and MCAS Quiz- Assess your Risk for Histamine intolerance and MCAS 


See Other Recent Post!

Creating health doesn't have to be a guessing game!

Our Team will help you harness your health so you can trust your body and feel like YOU again. We can help find your Root Cause.