Histamine – The Elephant in the Room?

As a naturopath as well as an acupuncturist, it’s my job to assess the full landscape...and there something that’s become a problem child for lots of people, especially in the last few years...and its HISTAMINE.

What Are Histamines?

Histamines are natural chemical compounds that play a key role in the body’s immune system, digestion, and communication between cells. They are stored mainly in mast cells—a type of immune cell—and are released in response to triggers such as allergens, infections, or injury.When histamines are released, they cause blood vessels to widen, smooth muscles to contract, and tissues to become more permeable. This helps the body fight infection but can also cause symptoms like itching, swelling, runny nose, or flushing.

They are important, but they seems to be going a bit feral lately, and that is not a good thing...let’s discuss...

What Is Histamine Intolerance?

Histamine intolerance occurs when the body accumulates too much histamine—either because of excessive release or because it can’t break it down efficiently. Normally, enzymes like DAO (diamine oxidase) and HNMT (histamine-N-methyltransferase) help clear histamine. When these enzymes are sluggish or overwhelmed, histamine levels rise and can cause a wide range of symptoms, some quite debilitating, including:

• Headaches or migraines

• Nasal congestion or runny nose

• Flushing, hives, or itching

• Digestive upset (bloating, nausea, loose stools)

• Irregular heart rate or blood pressure changes

• Fatigue, anxiety, or “brain fog”

  
  

What Is MCAS (Mast Cell Activation Syndrome)?

MCAS is a condition in which mast cells release histamine and other inflammatory chemicals too easily and too often. Unlike classic allergies, MCAS may not always be triggered by specific allergens—it can be provoked by heat, stress, certain foods, or infections.Symptoms often overlap with histamine intolerance but may also include low blood pressure, dizziness, shortness of breath, or abdominal pain.

The Nervous System and Histamine

The nervous system and the histamine system are closely linked. When the body is in a state of stress or “fight-or-flight,” the sympathetic nervous system becomes activated. This activation signals mast cells to release more histamine and other inflammatory chemicals. For some people, even subtle or long-term stress can keep the nervous system on high alert, leading to ongoing histamine release and heightened sensitivity.

The Role of Oestrogen

Oestrogen and histamine influence each other closely. Oestrogen can increase histamine release and at the same time reduce DAO enzyme activity, which slows histamine breakdown. This is why some people notice their symptoms worsen around ovulation or just before menstruation when oestrogen levels are higher. Balancing hormones naturally can therefore be an important part of managing histamine intolerance.

Naturopathic Approach

Histamine issues aren't just annoying allergy blips, they represent systemic imbalance, having a major impact on our long-term physical and mental health. A naturopathic approach focuses on identifying triggers, supporting the body’s detoxification and enzyme systems, balancing hormones, and calming the overactive immune response.

1. Reduce histamine load:

• Limit high-histamine foods (aged cheeses, fermented foods, alcohol, smoked meats, tomatoes, spinach, vinegar).

• Eat fresh foods—leftovers can accumulate histamine.

  
  

2. Support histamine breakdown:

• Ensure adequate intake of vitamin C, vitamin B6, and copper, all of which are needed for DAO activity.

• Support gut health, as the majority of DAO is made in the intestinal lining.

  
  

3. Calm mast cells and inflammation:

• Manage stress, get restorative sleep, and avoid known triggers (heat, alcohol, certain medications) – DO YOUR NERVOUS SYSTEM WORK!

  
  

Helpful Supplements

Whilst it may be tempting to reach for OTC antihistamines, and they may be useful for short term support, long term regular use is linked to cognitive decline. Here’s some natural alternatives:

1. Vitamin C (500–1000 mg/day) – Whole Food Vitamin C (not ascorbic acid) - Natural antihistamine; helps degrade histamine.

2. Quercetin (250–500 mg twice daily) – A bioflavonoid that stabilizes mast cells and reduces histamine release.

3. DAO Enzyme Support (before meals) – Helps break down histamine from food for those with low DAO activity.

4. Luteolin & Rutin – well researched natural histamine regulators

5. Magnesium (200–400 mg/day) – Hydroxide or Glycinate. Supports nervous system balance and may calm mast cell reactivity.

   
   

Histamine plays a vital role in the body but can cause problems when not properly regulated. Both histamine intolerance and MCAS involve excessive histamine activity, leading to a variety of systemic symptoms. Oestrogen can further aggravate this by promoting histamine release and slowing its breakdown. It’s no coincidence our bodies are more reactive in recent decades – chemicals, stress, processed foods, plastics, and lots of other things we can’t mention (*cough cough*).

But there is hope - through dietary adjustments, stress support, hormone balance, and natural anti-inflammatory nutrients, it’s possible to restore balance and reduce reactivity over time. The histamines are the messenger, we should listen.

Fiona O'Farrell is an acupuncturist and naturopath with over 20 years working in Newtownmountkennedy, Co Wicklow. With over 20 years experience, she specialises in women's health, fertility, pregnancy, menopause and nervous system regulation.

For more information see www.acupuncturewithfiona.com or contact 087 929 0807