How to naturally boost production of the histamine degrading DAO enzyme

Variety of dietary supplements, including capsules of Garlic, Evening Primrose Oil; Artichoke Leaf; Olive Leaf; Magnesium and Omega 3 Fish Oil. Selective focus. Taken in daylight.

We’re told that diamine oxidase’s (DAO) job is to make sure histamine is broken down when it’s no longer needed for things like healing, digestion, and wakefulness. Studies show its activity varies more in women that men, possibly due in part to histamine’s role in causing uterine contractions and miscarriage. While DAO production does decline as we age (especially in women), there are nutrients proven to give it a boost. Read on to find out what they are and how we can get them from whole foods rather than supplements. 

Research tells us that DAO is highest during the luteal phase that is right after ovulation and up to menstruation, which is why low serum DAO levels in post menopausal women “should be interpreted with caution”.

While there remains some controversy as to how diamine oxidase is linked to excess histamine, for the purposes of this post I’m just looking at studies speaking of how we can boost this enzyme.

A recent study confirmed what I’ve been writing about for the last few years regarding DAO and nutrients,

and because I’m a fan of getting as many nutrients as possible as food rather than supplements, I created my nutrient and antioxidant dense histamine reset.

DAO boosting nutrients

Please bear in mind that some foods are only high histamine because of bacteria contamination or spoilage. Any kind of virus or bacteria will stimulate an inflammatory release of histamine. This is why fermented foods are so problematic for us. 

Vitamin B12

Liver (I also suggest grass fed – this appears as high histamine on some lists)

Salmon (fresh gutted fish or flash frozen at sea is not considered high histamine)

Grass fed beef (you can do regular beef but that would be inflammatory, the grass provides the animal with omega 3 fatty acid)

Eggs (duck and chicken, but they can also be inflammatory. I buy flax seed or pastured chicken eggs only)

Chicken (inflammatory so I don’t eat it, pastured may be less so)


Sunflower seeds (some websites list these as high histamine)

White beans

Mung beans

Grass fed beef


Brown rice


Eggs (uncooked egg white is a histamine/mast cell trigger. Ask your doctor if duck eggs might be alright for you)

Long chain/Omega fatty acids

Olive oil is an excellent source of long chain fatty acids. It’s also higher in the monounsaturated fat than vegetable oils, which means it’s less prone to oxidation (we don’t want that which is why we eat antioxidant foods like blueberries).

I eat about a pound of salmon a week for the omega 3 fatty acids. I prefer not to take supplements due to the oxidation of the oil. If you take them, make sure to add in an antioxidant or buy one that comes with it in the capsule.


I’ve left out dairy because it’s highly inflammatory and casein is a mast cell trigger

Sesame seeds (listed on some sites as high histamine)

Collared greens

Mustard greens

Beet greens



Salmon (wild caught is best if possible because farmers sometimes use antibiotics and food dye pellets to colour the salmon)

Sardines (I eat them fresh only, and I mean really fresh because they are rarely gutted)


Grass fed meats and poultry (if you can find it)

White beans





White fish




Read the histamine magnesium post here.


Pumpkin seeds

Kefir (fermented foods are considered high histamine)

Black beans


Banana (high histamine, never had a problem with them myself but always be careful please)

Cacao (not high histamine but can liberate histamine from mast cells)

Take the hassle out of meal planning and healing histamine with this four week meal planner and stress relieving program. 


Miyoshi, Makoto, Manami Ueno, Mari Matsuo, Yasuhiro Hamada, Michiko Takahashi, Masashi Yamamoto, Ikuko Yamamoto, Reiko Mikajiri, Satoko Tabuchi, Kumiko Wakida, Misa Yamanishi, Midori Hirai, and Makoto Usami. “Effect of dietary fatty acid and micronutrient intake/energy ratio on serum diamine oxidase activity in healthy women.” Nutrition 39-40 (2017): 67-70. Web.

“Phosphorus Helps Your Body Detox & Strengthen.” Dr. Axe. N.p., 09 May 2016. Web. 20 June 2017.

Publications, Harvard Health. “The A list of B12 foods.” Harvard Health. N.p., n.d. Web. 20 June 2017.

Calcium. N.p., n.d. Web. 20 June 2017.

“The histamine-(in)fertlity link | Healing Histamine.” Healing Histamine | Histamine Intolerance Diet Foods Recipes. N.p., 11 Dec. 2014. Web. 20 June 2017.

Hamada, Yasuhiro, Yurika Shinohara, Miyuki Yano, Mari Yamamoto, Misa Yoshio, Kumiko Satake, Akiyo Toda, Midori Hirai, and Makoto Usami. “Effect of the menstrual cycle on serum diamine oxidase levels in healthy women.” Clinical Biochemistry 46.1-2 (2013): 99-102. Web.

“Functional Foods Fact Sheet: Omega-3 Fatty Acids.” N.p., n.d. Web. 20 June 2017.


Check out these other Healing Histamine blog posts


Yasmina was an award-winning broadcast journalist with a decade of experience covering war zones for CNN and the BBC. She devoted her journalism skills to researching and writing about histamine. Click here to learn about her. Each post is carefully and fully referenced with the latest scientific research. Not sure where to start? Here’s a four week meal plan and overall Histamine Reset.

4 Week Histamine Reset

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