Is Histamine Intolerance the Hidden Reason You Feel Unwell?

Is Histamine Intolerance the Hidden Reason You Feel Unwell?

Do you get flushed after wine? Headaches before your period? Itchy skin after strawberries or a weird reaction to avocado or chocolate?

Histamine intolerance (HIT) is a growing issue that affects many people, especially women, and often flies under the radar. Let’s explore what it is, why it happens, and what you can do about it.

What is Histamine, and Why Do We Need It?

Histamine is a natural chemical your body produces. It plays an essential role in:

• Immune system response (e.g., allergies and inflammation)

• Gut function and motility (helps move waste through the bowel)

• Stomach acid production (helps digest proteins)

• Brain function (influences sleep, mood, focus, and alertness)

• Hormonal balance (especially estrogen)

It’s produced by immune cells (especially mast cells) and works through special receptors (H1, H2, H3, and H4) located throughout the gut, brain, lungs, skin, and reproductive system.

What is Histamine Intolerance (HIT)?

Histamine intolerance happens when you have too much histamine and your body can't clear it fast enough.

It’s not about your body making too much histamine (although it can) it’s usually that your breakdown systems aren’t working properly, and it builds up over time.

Signs & Symptoms of Histamine Intolerance

Histamine intolerance can look like many things because it affects multiple systems in the body.

You may experience:

• Headaches or migraines (especially before your period)

• Flushing, itching, rashes, or hives

• Anxiety, dizziness, or heart palpitations

• Bloating, nausea, cramps, or loose stools

• Insomnia or trouble staying asleep

• PMS, heavy periods, painful cycles, endometriosis

• Asthma, nasal congestion, sneezing

• Fatigue, low energy, or brain fog

• Histamine symptoms worsen with fermented foods, leftovers, or alcohol

Why Does Histamine Build Up in the First Place?

Histamine levels in your body are dynamic, they change depending on your diet, hormones, gut health, genetics, and environment.

Common causes of high histamine include:

• Poor histamine breakdown due to low levels of DAO and HNMT enzymes

• Gut infections or overgrowths (e.g., SIBO, E. coli, Citrobacter, Klebsiella, Candida)

• Mould exposure, parasites, or inflammation

• Estrogen dominance (especially around ovulation or PMS)

• Nutrient deficiencies (B6, C, copper, zinc, folate, B12)

• Genetic mutations (like MTHFR, COMT, HNMT, DAO)

• Medications that block DAO (antihistamines, NSAIDs, antidepressants, PPIs)

• Stress and poor sleep

• Leaky gut and poor detox pathways

The Hormone Connection – Especially for Women

Estrogen stimulates histamine release, and histamine stimulates estrogen production. It’s a cycle. That’s why many women feel worse around ovulation and just before their period, when estrogen naturally peaks.

Histamine also impacts ovulation, mood, and period pain. It’s been linked to:

• Endometriosis

• PMS and PMDD

• Heavy or irregular periods

• Mood swings, anxiety, and sleep disturbances

During pregnancy, the placenta produces up to 500 times more DAO enzyme to protect you from high histamine levels—showing how sensitive the uterus is to histamine.

What Foods Contain or Trigger Histamine?

Histamine is found in many everyday foods, especially if they’re aged, fermented, or leftover.

High Histamine Foods:

• Alcohol (wine, beer, cider)

• Aged cheeses

• Smoked meats

• Fermented foods (sauerkraut, kombucha, vinegar, soy sauce)

• Leftovers

• Canned or smoked fish

• Tomatoes, spinach, eggplant, avocado

• Strawberries, pineapple, banana, mango

• Chocolate, nuts, sourdough bread

DAO-Blocking Foods:

• Black tea, green tea, mate tea

• Alcohol

• Energy drinks

• Some probiotics (especially L. casei, L. bulgaricus, L. acidophilus)

So, What Can You Do About It?

Step 1: Find the Root Cause

If you’re reacting to foods or experiencing chronic symptoms, don’t just eliminate foods forever; get testing and support to uncover what’s underneath.

A GI Map stool test can identify:

• Histamine-producing bacteria

• Leaky gut

• Gut inflammation

• Pathogens like Klebsiella, Citrobacter, or Candida

We also assess nutrient levels, hormone metabolism, MTHFR, and other methylation genes.

Step 2: Support Histamine Breakdown

Support the enzymes that break histamine down:

• DAO (in the gut): Needs B6, B12, vitamin C, copper, and calcium

• HNMT (in the brain): Needs SAMe, B12, methyl folate, magnesium

DAO and HNMT enzymes can’t function if you're inflamed, depleted, or lacking nutrients.

Step 3: Use Nutrients, Herbs and Supplements

These help stabilise histamine levels and reduce inflammation:

• Quercetin – natural antihistamine

• Vitamin C – supports DAO and immune function

• B6 and B12 – essential for DAO and methylation

• Magnesium and SAMe – support detoxification and nervous system

• Copper and Zinc – needed for enzyme function and immune health

• Glutathione – protects cells and supports detox

• Probiotics – use strains like L. rhamnosus GG or B. infantis (avoid histamine producers)

Herbs like nettle, turmeric, and albizia are also helpful for calming histamine reactions.

Ready to Get to the Root Cause of Your Symptoms?

You don’t need to live with headaches, bloating, rashes, or painful periods. Histamine intolerance can feel overwhelming, but once you understand what’s driving your symptoms, there are natural and effective ways to bring your body back into balance.

Book a consult to explore how we can support your histamine pathways, hormones, and gut health.

Appointments available in-person in Melbourne or via Telehealth across Australia.

Let’s work together to figure out what your body is trying to tell you.