When you hear the word histamine, drugs like Benadryl probably come to mind. It’s common to use antihistamines in the face so strong allergic reactions.
If histamine hasn’t given you much trouble other than a few runny noses in the spring, you probably haven’t given it as much thought.
On the other hand, if you suffer from severe allergies, histamine intolerance, mast cell activation syndrome (MCAS) or any other condition that causes your histamine levels to be higher or your body to less tolerant – then you know firsthand how powerfully histamine can rule over your life.
With chronic illness on the rise, I’m seeing higher incidences of histamine intolerance and mast cell activation syndrome in my practice. Though these conditions can have overwhelming symptoms, there’s a lot that can be done to keep them in check.
First, let’s take a step back and understand three critical concepts:
- How histamine affects the body.
- What you can do to reduce the impact of histamine over your life.
- How to boost DAO enzyme levels, which is responsible for breaking histamine down.
What is Histamine?
Histamine is an important part of your immune system because it causes necessary inflammation during times of injury and healing. Histamine is released from your mast cells, which are present in every tissue in your body. Mast cells release multiple chemical inflammatory mediators as part of your immune system response. Histamine is only one of these hundreds of chemicals your mast cells can release – though it gets a lot of attention.
Histamine is incredibly powerful. For example, in the case of someone who’s severely allergic to peanuts, the smallest taste can trigger a strong histamine response. When histamine is unleashed, it sends inflammatory signals throughout your body – to your gut, nose, throat, mouth, skin, and lungs. Histamine is the chemical that’s largely responsible for the trademark allergic reaction.
When histamine runs rampant and unchecked, it can cause health complications like histamine intolerance and mast cell activation syndrome. A buildup in the body can happen because of excess histamine but also insufficient DAO levels.
If you want more on the effects of histamine, you can read more in my article, Mast Cell Activation Syndrome: When Histamine Goes Haywire.
The Mighty DAO Enzyme
Diamine oxidase (DAO) is an enzyme that’s responsible for breaking down histamine. Another enzyme responsible for breaking histamine down is called histamine N-methyltransferase (HNMH), but we are going to mostly focus on DAO because it’s much more effective.
DAO is mostly found in the kidneys and thymus. In pregnant women, DAO levels rise significantly and are found in the placenta. In the body, DAO breaks down histamine, which is then excreted through your kidneys and urine.
DAO is also found in the small intestine, in two sections called the jejunum and ileum. When foods high in histamine pass by this part of the small intestine, DAO breaks it down and prevents it from entering the body. 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 issues.
If you don’t have enough DAO, it can cause histamine levels to rise. If this goes on long enough, it can cause histamine sensitivity, chronic inflammation or mast cell activation syndrome.
If you suspect you have too much histamine or not enough DAO enzyme there are a couple of things you can do:
- Reduce the histamine in your diet
- Boost DAO enzyme
- Avoiding DAO blocking foods
In general, avoiding histamine means avoiding old or aged food. This includes vinegar, alcohol, cured meats, smoked meats, fermented foods, canned foods, and leftovers. However, this is just a general rule of thumb and there are other foods that contain histamine.
There’s a lot of helpful information online about low histamine diets. One of my favorite resources for this is Healing Histamine. There you can find extensive food lists that show you how to reduce your histamine intake, which is very effective overall.
I want to more talk about boosting your DAO enzyme levels, let’s take a closer look.
Boosting Your DAO Enzyme Levels
You can take DAO supplements, which will increase your levels in your digestive tract and enhance histamine breakdown of anything that’s eaten. However, DAO supplements do not get into your bloodstream and cannot increase your DAO levels internally. This means that supplementing with the DAO enzyme only helps you break histamine down that you’re  consuming.
DAO enzyme supplements will not break down histamine that’s created by your mast cells – though this is still an effective treatment. This also means that DAO supplements cannot cure histamine intolerance or mast cell activation syndrome. Now you’re probably wondering how we can boost DAO naturally, within the body.
Scientists have found a number of nutrients that are effective at boosting DAO enzyme levels. These nutrients include:
- Omega-3 fatty acids
- Saturated fat
- Phosphorus
- Calcium
- Zinc
- Magnesium
- Iron
- Vitamin B12
DAO Boosting Foods
Foods that help boost DAO levels in your body and are also less likely to trigger histamine response include:
Omega-3 is an important one, they have been shown to release DAO and in women. Eat more:
- Olive oil
- Wild caught salmon
- Mackerel
- Walnuts
*Be wary of fish oil supplements, which are very susceptible to oxidation.
Healthy saturated fats:
- Grass-fed butter
- Avocado
- Fatty fresh fish
- Pasture-raised chicken eggs (unless it’s a sensitivity)
Phosphorus:
- Almonds
- Broccoli
- White beans
- Pasture-raised chicken eggs (unless it’s a sensitivity)
Calcium:
- Dark leafy greens
- Broccoli
- Beans
- Lentils
Zinc:
- Grass-fed meat
- Almonds
- Lentils
- Spinach
Magnesium
- Dark leafy greens
- Pumpkin
- Almonds
- Cashews
Vitamin B12:
- Grass-fed beef liver
- Grass-fed beef
- Wild caught salmon
- Fresh tuna
Iron:
- Lentils
- Pumpkin seeds
- Grass-fed beef
- Broccoli
Avoiding DAO Blocking Foods
If you’re having trouble with histamine, the number one thing you should avoid is alcohol. Histamine and alcohol share metabolic pathways that use the enzymes, aldehyde dehydrogenase and aldehyde oxidase.
Alcohol always releases histamine from your mast cells but if you develop to histamine sensitivity, this reaction become more prominent. You’ve probably seen this reaction before, it’s what makes a person’s face become flushed from drinking too much. Not only does alcohol release histamine, it also blocks to DAO. This histamine release in response to alcohol can get worse and worse.
The available information on histamine related issues has exploded in just the last two to three years. We are learning a lot more about histamine and DAO at a fast rate and this will only continue to get better.
Resources:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3625874/
https://www.ncbi.nlm.nih.gov/pubmed/12113214
https://www.ncbi.nlm.nih.gov/pubmed/17490952
https://www.ncbi.nlm.nih.gov/pubmed/28606572
Thank you so much for the list of foods that help with DAO production. I’m confused, though. Avocados and spinach are on all the lists as very high in histamines, yet they are on your list for DAO producing foods. I’ve been avoiding them along with quite a few others, like strawberries. Should I be trying to slip avocado in when I think my bucket is low?
If you are sensitive to histamine, you may need to use caution with high histamine foods
what? your comment does not address joanna’s question, which is also my question. isn’t your whole article about histamine sensitivity? the question is about the foods you list in which categories. in general, i am finding different functional docs list same foods in opposite categories. this is very confusing!
No, this article is exclusively about DAO levels and what foods may increase DAO. It says nothing about high histamine or foods that contain high histamine, nor should it be read as such – you can read more about MCAS and histamine here
Great summary, thank you!
Hello ! I read your “DAO Boosting Foods” list,,,And I see some items you have listed, that are on other lists by other people that are said to contain high histamine levels. These food items are, ALL NUTS, SPINACH and AVOCADO. BUT, you have them listed on your “DAO Boosting Foods” list as a boost to your DAO levels… So,,, how can these foods boost DAO, if other people have listed them as high histamine food items ??? I don’t get it ! Please respond, Thank You Very Much !! R. J. Hafer Benton Harbor, Michigan 09-20-2018
Yes i would like to hear a response to this too!!! thanks
Also wondering the same thing over here…some foods are on both lists and contradicting? Very confused
PS Hello again,,, It would be nice if ALL the food industries would list the HISTAMINE CONTENT of their product on their food container labels. It should be law…R. J. Hafer Benton Harbor, Michigan 09-20-2018
Dr. Jill,
I have read that Coq10 supplements can help histamine issues, but I have also read that they can make it worse due to the fermentation process to make the supplements? What about ubiquinol? Any certain brand of these if they ARE helpful? Also, how to test for histamine and DAO issues? Thank you
Hi Chelsea,
Any product or food from fermentation should be avoided if you have mast cell issues
warmly
Dr Jill
If you have mast cell issues as well as Sifo ,Sibo and Candida that has resulted in leaky gut and compromised biome needing probiotic replacement and intestinal lining repair what is the balance. Candida has biproduct of grain alcohol which can release histines apparently. It seems like one hand slaps the other. I have had extreme chronic inflammation and histine symptoms as well. The foods that treat one issue exasperates the other. Not sure what to do. I am also dealing with mold recovery.
I have MCAS and while these articles are helpful, 50% of the foods you list I cannot eat so it’s dissapointing to read something that seems good and then I get to the bottom and have to disregard almost all of what is said. While every person with histamine issues have different tolerances, it sure would be great for health practitioners writing about histamine take a more conservative approach to their food recommendations so that those truly suffering can get some answers.
We practice individualized medicine in the clinic so there is no one size fits all as you well know Heather! Best to avoid foods that you know to be triggers.
Thanks for this article. I have been struggling with what I think is a histamine response and DAO insufficiency. After I eat, about 1-2 hours later, my nose runs and eyes water. The worst part though is the severe acid reflux in my throat. Recently I was feeling well and had some tea and this triggered me big time. The acid was horrible and my throat started to itch and I developed bumps on the back of my tongue. Then the diarrhea. This was days and nothing helped until I went on a liquid fast. 🙄 Prior to this I had been taking bovine kidney supplement as a source of DAO and had run out and forgot I ran out. Well, since starting to take it again, I am so much better. The acid in my throat is mostly gone and the diarrhea, watery eyes, etc. My goal is to heal my gut and fix the root cause. I’m glad doctors like you are writing about it. Between the bovine kidney supplement and quercetin with vitamin C I’m pretty stable. Have to avoid tea, bacon, lunch meat, canned tuna, and other things for sure though.
As a side note, I read about a study that Low FODMAP diet reduces histamine as well. Maybe getting rid of the excess bacteria? Not sure the mechanism but I’m trying to follow it.
yes, the low FODMAP diet treats SIBO and some of the SIBO organisms produce more histamine
would you care to share what bovine kidney supplement you are taking ? interested as I just found out about this thingy. I’ve eliminated all trigger-foods and drinks with leaky gut, fodmap and low-carb knowledge. but tanings have been plagueing me forever, until yesterday I had an eureka-moment. need to get my DAO-levels up until my gut is healed.
I was told that high doses of vitamin C is really good in boosting doa. Is this true?
Hi, I like your list of scientifically proven DAO boosters although I knew most of them already. However, I think you simplify lots of things too much. You are listing lots of foods which would have high levels of oxalates which bring up the histamines: nuts, seeds, many root veggies, greens, grains, potatoes, sweet potatoes etc. Olive oil, mackerel, avocados and more are full of histamines.
I started with co q10 last year and have found it extremely helpful. I stopped taking anti-histamines. Vitamin B6 foods help a lot with DAO formation.
I still have a problem with hydration and haven’t found a solution yet.
yes, of course Bridget! Diet must be personalized and in conjunction with your own needs… there is no one size fits all! 😊
Is there a DAO supplement brand you recommend?
Hi Steph,
I really like the Histamine Blocker here
Warmly
Dr Jill
Dear Jill,
I have MCAS and histamine intolerance – struggling in fact even on meds. and having read all the above, am quite keen to consult with you when back in UK (away with work right now). However, immediate query is Im taking Wiley’s Alaskan Fish oil – do you think this is risky? It’s meant to be very pure and freshly caught with no nasties in it. Look forward to your thoughts. Many thanks Mark
No, I think that is fine
I mean to say the fish is Pollack that they make it from
Dr. Jill,
Is there a brand of omega 3 that you know is pure? I use Nordic naturals because of their purity.
Dr Jill,
It would be great if you can clarify the following, I have terrible reactions to histamine and they are quite extreme, I was trying to determine if histamine is the cause or a symptom of a blocked lymphatic system because of like of bile to break down fats etc.. so I had a DAO test and it came back as 50U/ml concentration levels in the serum which is classed as good levels according to the test. But natural DAO takes away symptoms and Quercetin is really helpful to me.
How does DAO relate to mass cell activation syndrome? Could i still have histamine issues even though the DAO levels are ok?
And do you know a clear plan that we could take to resolve?
hi Don,
Yes, there are many pathways to histamine issues and MCAS and a normal DAO does not rule out other issues with histamine
warmly
Dr. Jill