How to Reduce Histamine Levels by Supporting a DAO Enzyme Deficiency

Supporting a DAO enzyme deficiency is one of the best ways to reduce histamine levels in the body. Using a DAO enzyme supplement such as Histamine Block is effective at metabolizing histamine in foods, thus improving histamine intolerance symptoms. Following a low histamine diet and improving gut health is crucial to reduce histamine levels in the body. 

Histamine intolerance can cause a wide variety of symptoms such as headaches, itchy skin, nasal congestion, and sneezing. Symptoms of histamine intolerance can leave you feeling frustrated and unsure how to pinpoint the cause of your symptoms.

One day you feel fine; the next day, you are not, depending on whether you have hit your histamine threshold and your body’s ability to metabolize histamine. Welcome to the annoying symptoms of histamine intolerance.

Anyone who has a DAO enzyme deficiency will struggle to metabolize histamine effectively and, as a result, are more likely to experience histamine symptoms, especially after eating high histamine foods.

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What is the DAO enzyme and its connection to histamine intolerance?

Histamine intolerance is the inability to process histamine from either internal or external sources, resulting in various symptoms.

Two main enzymes help break down histamine in the body, including the DAO enzyme, also known as diamine oxidase. The DAO enzyme is primarily responsible for breaking down ingested histamine and histamine found outside the cell while. For the DAO enzyme to work, it needs copper and zinc as cofactors to function.

The HNMT enzyme is primarily responsible for breaking down intracellular histamine found inside the cell. This enzyme requires SAMe as a cofactor to help metabolize histamine. Ensuring the methylation cycle is optimal is necessary to produce SAMe, a methyl donor needed to help break down histamine inside the cell.

If these enzymes are not functioning optimally or are overwhelmed with the amount of histamine to metabolize, then a wide variety of histamine-related symptoms may result.

If these two enzymes work optimally, you can most likely eat high histamine foods and not experience any symptoms. Yet another day, you may have hit your histamine threshold. You will experience symptoms even though you ate the same food, which is why histamine intolerance can be difficult to pinpoint if you don’t know about your histamine threshold.

The DOA enzyme is primarily located in the small intestine, kidney, and placenta and acts as a barrier against histamine in the gut, histamine originating from foods and intestinal microbes. If the gut lining is damaged, there can also be a loss of the DOA enzyme resulting in a decreased ability to metabolize histamine.

Symptoms of Histamine Intolerance:

Some of the most common histamine intolerance symptoms include: diarrhea

• heartburn
• bloating
• nasal congestion
• watery eyes
• asthma
• headaches
• racing heart
• itchy skin
• hives
• flushing
• eczema
• uterine cramping

Histamine plays essential roles in the body, contributing to microvascular dilation and permeability, stomach acid production, intestinal secretion, and motility, and triggers the immune and inflammatory pathways in response to pathogens and food allergies.

Histamine itself is not bad, but histamine becomes problematic if there is a DAO enzyme deficiency in the gut resulting in an inability to process the excess histamine.

One of the critical roles of histamine is to combat pathogens in the gut by stimulating the immune system to release killer chemicals that attack pathogens. Still, when the pathogens are never dealt with, they can be a constant source of histamine production that overwhelms the DAO enzyme in the gut.

Certain probiotics produce histamine, such as many lactobacillus species, which can grow in excess in the small intestine. Often people with SIBO have too much histamine-producing bacteria and thus concurrently suffer from symptoms of histamine intolerance.

Our body’s immune system also produces histamine in response to stress, pathogens, and sensitivities to foods. Yep, stress is always a factor!

One of the best ways to support a DOA enzyme deficiency and reduce histamine in the body is by optimizing a weak upper digestive system by supporting stomach acid production, bile flow, and digestive enzyme support.

Stomach acid is our first line of defense against pathogens. When stomach acid is common, pathogens can survive and set up home in the intestines, thus contributing to histamine production.

​Bile is our body’s natural antimicrobial that helps disinfect the small intestine and prevent SIBO that triggers histamine.

Pancreatic enzymes ensure that food is appropriately broken down and absorbed. Undigested starches and sugars can feed bacteria in the small intestine leading to SIBO and thus more symptoms of histamine intolerance.

Reducing histamine in the body through dietary means a person can support an overwhelmed DOA enzyme by reducing high histamine foods or fermented foods in which histamine is enhanced. Bacteria that live in particular food produce histamine, and these bacteria are enhanced in fermented, leftover, and aged foods.

High histamine foods include:

• Aged cheese
• Alcohol, especially red wine
• Bone broth
• Chocolate
• Coffee
• Citrus fruits and juices
• Cured meats such as salami, corned beef, pastrami, etc
• Dried fruits
• Fermented foods including yogurt, sauerkraut, kimchi, kefir, pickles, and fermented vegetables
• Fish especially when smoked
• Raw tomatoes
• Spinach
• Vinegar
• Some nuts

How to reduce histamine levels in the body

Suppose you notice that some of these foods increase histamine-related symptoms. In that case, you will want to limit your intake of high histamine foods (especially histamine-triggering foods). Eating a low histamine diet is one of the best ways to reduce histamine in the body naturally. 

To further reduce histamine levels in the body, it is helpful to support your digestion and balance your microbiome with probiotics such as ProBiota HistaminX. 

Directly supporting a DOA enzyme deficiency with A DAO enzyme supplement such as histamine block, which contains the enzyme diamine oxidase, provides your body with extra support to metabolize the excess histamine that comes from food.

Reducing/eliminating high histamine trigger foods and supporting your digestion are critical first steps to reduce histamine in the body. The DAO enzyme is one crucial enzyme that helps to metabolize extracellular histamine.

Still, there are other pathways in which histamine is metabolized, such as the HNMT enzyme, which may be struggling due to genetic SNP’s, poor methylation, and nutritional deficiencies that act as cofactors for these enzymes and pathways to function.

DAO enzyme test

Suppose you implement the initial steps and are still struggling with histamine symptoms. In that case, you may want to do genetic testing to find out where your susceptibilities lie in your genetics and unique ability to metabolize histamine or not.

You can order the s genetic Ancestry DNA testing kit online then upload your raw data to generate your strategene report to determine if you have SNP’s in your DAO enzyme or histamine pathways. Knowing where genetic SNP lies in the histamine pathways can help determine the cofactors required to support specific histamine metabolizing enzymes.

Someone struggling to process intracellular histamine through the HNMT enzyme will require additional support with optimizing methylation to ensure the production of SAMe to metabolize histamine further through the HNMT enzyme. SAMe is a methyl donor that is the cofactor HNMT enzyme. 

Everything is connected to the body. Optimizing your health can take some detective work to determine the root cause of blockage in the body.

The best place to start with reducing histamine in the body begins with the diet and reducing high histamine trigger foods while also identifying your trigger foods.

If you are looking for a DAO enzyme supplement to help break down high histamine foods, histamine block by seeking health is an excellent supplement with 5-star reviews.

Histamine Block contains diamine oxidase to help break down external sources of histamine from food. Anyone with a DAO enzyme deficiency and histamine intolerance symptoms can benefit from taking a DAO enzyme supplement with high histamine foods.

I highly recommend reading Dirty Genes by Dr. Ben Lynch for more information on histamine and the DOA enzyme. Especially the chapter on the DOA if you suspect histamine intolerance. Learn more about genetic testing and my genetic story here