DAO enzyme according to its origin: animal or vegetable?

(An article written in August 2022 and updated in April 2024)

We know that the Diamine Oxidase (DAO) enzyme is the main responsible for metabolizing a molecule that we ingest through the diet called histamine. This biogenic amine that we find in many foods has not any functions in our body (unlike the one we generate ourselves) and, for this reason, we eliminate it thanks to DAO. The process begins in the small intestine, but there are people who do not have enough DAO or it is not very active at the intestinal level and that is when different symptoms can appear.

The most frequent symptoms, which we had been mentioned in different articles, appear because of an accumulation of histamine in tissues due to the activation of different histamine receptors. These symptoms can be very diverse, such as: migraine, swelling, diarrhea and/or constipation, hives, rhinitis and muscle and/or joint pain, among others.

In the last 17 years, it has been shown that the most appropriate treatment for these patients with DAO deficiency is to follow a low-histamine diet prescribed by a specialized dietitian and supplemented with DAO enzyme of animal origin, more specifically from pig kidney protein extract. However, in countries like Spain, Germany or France, vegetal origin DAO enzyme is already a reality. It represents a step forward to be able to recommend this enzyme to people who follow a vegetarian/vegan diet or who for sociocultural reasons do not consume pork.

Currently, the main differences between the two origins are:


Animal origin DAO enzyme

Vegetal origin DAO enzyme

Pork kidney extract

Organic pea shoots

Good enzymatic activity and greater stability at temperature. Refrigeration recommended

Same enzymatic activity as the animal, but it is more sensitive to temperature. Requires refrigeration

More knowledge, both scientific and empirical (so far, human studies have only been conducted using animal DAO)

Promising alternative with in vitro research carried out so far

Contains catalase naturally

Contains catalase naturally

Available in the EU, USA and some countries in LATAM

Available in Spain, Germany and France

Not suitable for vegetarians nor vegans

Suitable for vegetarians and vegans

Gluten-free, lactose-free and low-FODMAP

Gluten-free, lactose-free and low-FODMAP

Dosage: 3 tablets/day 20 minutes before each meal (1-1-1)

Dosage: 3 tablets/day 20 minutes before each meal (1-1-1)


The researcher PhD Oriol Comas-Basté carried out a study on lyophilised legume sprouts as a functional ingredient for the supplementation of the diamine oxidase enzyme in the year 2020. It was concluded that certain edible legumes proved to be a source of DAO enzyme, which confirms the potential suitability of this food for the formulation of DAO supplements for the treatment of DAO deficiency. As a result, it was shown that the germination of legume seeds for 6 days in the dark provided the plant matrix with the maximum histamine-degrading capacity. Specifically, the raw legumes that showed histamine-degrading activity were alfalfa, broad bean, common bean, lentil and white lupine. Among them, the highest enzyme activity was detected in dry lentil seeds. On the other hand, lyophilised legume sprouts, practically all the samples analyzed showed histamine-degrading capacity in vitro, although with great variability between the different legume species. Bean and mung bean sprouts did not show this enzyme activity. Lyophilized green pea and grass pea sprouts showed the highest DAO activity, followed by lentils, soybeans and chickpeas. In contrast, lyophilized alfalfa, broad bean and white lupine sprouts showed the lowest enzymatic activity values.

In this sense, although the lyophilization of legume seedlings can be considered a suitable process to obtain a plant tissue ready to formulate, the storage stability of its enzymatic activity is still limited to the freezing or refrigeration of the product.

There is still research to find the optimal formulation to guarantee the shelf-life stability of the DAO activity of plant origin. However, we must not forget that we have in our hands good dietary management accompanied by supplementation, always customizing in each case and situation with the help of a health professional.

The International Institute of DAO deficiency has designed a new product rich in DAO enzyme called GoDAO®. Based on our extensive experience, we identified a requirement to create a new format containing 90 mini tablets protected in a blister for improved preservation. The main ingredient is the same as Daofood®. Available here! (Ask your nutritionist for a personal Discount Code!)

If you want us to advise you in a personalized way, either in our Barcelona nutrition centre or by video conference from anywhere in the world, contact us and we will help you


Comas-Basté, O., Latorre-Moratalla, M.L., Rabell-González, J., Veciana- Nogués, M.T., Vidal-Carou, M.C., Lyophilised legume sprouts as a functional ingredient for diamine oxidase enzyme supplementation in histamine intolerance, LWT – Food Science and Technology (2020), doi: https://doi.org/10.1016/j.lwt.2020.109201.

Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, Latorre-Moratalla M, Vidal-Carou MDC. Histamine Intolerance: The Current State of the Art. Biomolecules. 2020 Aug 14;10(8):1181. doi: 10.3390/biom10081181. PMID: 32824107; PMCID: PMC7463562.

Intolerancia a la Histamina, de los indicios a la evidencia – FESNAD 2020 | AD Dietistas. [online] Adrianaduelo.com. Available at: https://www.adrianaduelo.com/intolerancia-a-la-histamina-de-los-indicios-a-la-evidencia-fesnad-2020/

4 thoughts on “DAO enzyme according to its origin: animal or vegetable?

  1. Frederic

    Dear Adriana Duelo,

    in this article you wrote about this vegetal origin DAO that is already available in Germany and France.
    I live in Germany and searched for some time, but I could only find products with active agents that support natural DAO activity but none that include vegetal DAO.
    Could you please specify which product(s) you are talking about and how one could purchase them.

    Thank you in advance,

    1. Adriana Duelo Post author

      Hi Frederic,

      The name of this product is “Daofood Veg”. And you are right. In this moment the product is out of stock in Amazon, although we have some units in our clinical center (Barcelona). If you are interested email us to info@adrianaduelo.com and we will send them to you.

      Take care!

  2. AE O’Brien

    Thank you so much for your article! I have just been prescribed HistDAO by a naturopath, and as a vegan, am struggling with the animal origin of the enzyme.

    I had just been searching for a plant-based alternative when I came across your article.

    The brand you mention “DAOfood Veg” and another called “NaturDAO” (also legume origin) are both available in Canada, and I found NaturDAO at Amazon.com.

    Thanks again!
    Anne O’Brien

    1. Adriana Duelo Post author

      Thank you Anne!

      At the moment the most active DAO enzyme is DAOfood veg. In this link you can see the comparison of different brands.



Leave a Reply

Your email address will not be published. Required fields are marked *

Uso de cookies

Este sitio web utiliza cookies para que usted tenga la mejor experiencia de usuario. Si continúa navegando está dando su consentimiento para la aceptación de las mencionadas cookies y la aceptación de nuestra política de cookies, pinche el enlace para mayor información. ACEPTAR

Aviso de cookies