Histamine intolerance

Often times, histamine intolerance and MCAS go hand in hand.

Histamine intolerance is having an issue clearing histamine from the body, which results in a build up leading to that histamine bucket overflowing, resulting in symptoms.

MCAS, or Mast Cell Activation Syndrome, is when our body has over active mast cells that have become “trigger” happy, so they are releasing excess mediators constantly, resulting in symptoms due to this.

If both conditions are in the picture, you can see how this over activity of mast cells without efficiently clearing them can feed into each other.

So… what works? The key is understanding why this is happening: utilizing proper testing, getting a good history to see root causes (s), then using the right supports. The following is not medical advice and should always be discussed with your doctor!

Histamine intolerance

Underlying causes include

• Immune system dysregulation

• Gut dysbiosis (SIBO is a big one!)

• Immune system dysregulation

• Nutrient deficiencies

• Nervous system dysregulation

Now there’s a variety of underlying causes that can contribute to the above: antibiotic use, chronic stress, trauma, large viral load (think COVID), history of processed foods and…. environmental toxicity (mold is one of the biggest root triggers here).

There are two main ways that histamine get’s broken down, by enzymes DAO and HNMT.

DAO: this is within the gut and can be inhibited by dysbiosis. This enzyme also needs certain nutrients/ co factors to effectively work. So let’s paint a picture…

Before histamine is histamine, it starts out as compounds called histidine and through a series of necessary co factors and enzymes, can either become histamine or glutamic acid. When there are missing co factors/nutrients to support the conversion to glutamic acid, this is where we see histamine rise.

For histamine itself to even breakdown properly after it’s been converted, it uses acetaldehyde, and for that to work we need aldehyde dehydrogenase to work which needs b3 and molybdenum. It’s all about understanding the pathway that histamine breakdown takes! And if there are deficiencies, that will contribute a lot.

Now let’s talk about the other enzyme that break down histamine: HNMT, this occurs outside the gut and is involved in methylation. If someone has impaired methylation, it means they are unable to breakdown histamine well. Labs need to check for B6, folate, B12 and methyl donor availability for this methylation pathway,

So knowing all this about histamine intolerance, what do we do?

1. Stressors: Reduce what is causing stress to the body: which is what causes excess histamine. This includes: processed foods, actual stress, environmental toxins…

2. Testing: Utilize testing to understand the why. Genova’s Metabolomix panel is a great one to use to understand histamine issues and detox pathways. Other testing: real time labs mycotoxin urine panel, traditional lab work ups, HTMA (hair tissue mineral analysis),

3. Stabilize: Support the gut, add histamine stabilizers, limbic/nervous system regulation, assess environment for mold and high EMF. If needed, support: adrenals, thyroid, blood sugar regulation.

4. Address root cause: whether it ended up being nutrient deficiencies, a weak gut, toxins, stress etc, these ultimately need addressing and teh body needs rebuilding to create a stronger terrain.

What to do about diet?

Reduce inputs of what is triggering you. This is the key. There are so many types of diets, and this can get very overwhelming to identify what to do.

Keep a food diary, and notice which foods bother you and which you can tolerate. And stick with what isn’t creating excess histamine issues. You may be able to tolerate some high histamine foods and not others.

Reduce processed foods. Eat real, whole foods.

Monitor your symptoms

Start monitoring if your symptoms are improving. They should never be getting worse!

🧠 Brain: Headaches, brain fog, irritability
🌡️ Skin: Flushing, hives, itching
💓 Heart: Racing heart after meals
🤢 Gut: Bloating, nausea, diarrhea
👃 Nose: Congestion, sneezing
🌙 Sleep: Trouble falling asleep

What’s new on the pod

Holistic Hub Podcast

My latest episode with Justin Carlson of Mold Map was so informative. Learn about how this incredible app is currently helping people find great air quality environments for hotels, and what else is on the horizon here.

Check this out

Vital Reset Retreat

Mark your calendars: November 15th-21st, 2026. You can come join me on a retreat I am hosting! The goal of this retreat is to step outside of what societal norms look like, and to take control of your health and well being by not following the status quo. But instead: eat whole foods, regulate your nervous system, immerse yourself in nature, be in a community of like minded people, and so much more.

You can follow the Instagram account here to keep up with the latest info: Vital Reset Retreat.

Tickets going on sale soon.

If you are looking to work 1:1 with me, you can add yourself to the waitlist or email us here at [email protected].

Until next time,

Happiness and health

Dr. Steph