Understanding Histamine Intolerance and Why It Matters

By Dr Alain Sanua

Many people struggle with symptoms such as allergies, skin rashes, headaches, digestive problems, anxiety, poor sleep, or unexplained fatigue without ever finding a clear cause. One possible explanation is an imbalance involving a natural substance in the body called histamine.

What Is Histamine?

Histamine is a chemical naturally produced by the body. It plays an important role in helping us respond to infections, injuries, allergens, and other environmental challenges. Histamine is released by immune cells called mast cells and helps coordinate the body’s defence system.

Histamine also has several other important functions. It helps regulate:

• The immune system
• Digestion and stomach acid production
• Sleep and wakefulness
• Brain function and mood
• Blood vessel function
• Hormonal balance

Under normal circumstances, histamine is carefully controlled and broken down by enzymes in the body. Problems arise when histamine is produced faster than it can be removed.

What Is Histamine Intolerance?

Histamine intolerance occurs when histamine accumulates in the body because it is not being broken down efficiently.

This may happen because:

• The body is producing too much histamine
• Histamine-releasing cells are overactive
• The digestive system is unable to break down histamine effectively
• Gut health problems interfere with histamine metabolism
• Certain foods, medications, hormones, or environmental factors trigger excess histamine release

Importantly, histamine intolerance is not the same as a food allergy. In many cases, symptoms develop gradually and only appear when histamine levels reach a certain threshold.

Common Symptoms of Histamine Excess

Histamine can affect many different systems in the body, leading to a wide variety of symptoms, including:

Nervous System

• Anxiety
• Depression
• Panic symptoms
• Brain fog
• Poor concentration
• Insomnia
• Dizziness or vertigo
• Motion sickness
• Migraines

Digestive System

• Bloating
• Abdominal pain
• Diarrhoea
• Cramping
• Heartburn
• Food sensitivities

Skin and Allergies

• Hives
• Itching
• Eczema
• Rosacea
• Skin rashes
• Hay fever
• Sinus congestion
• Dermatographia (skin writing)

Cardiovascular System

• Palpitations
• Irregular heartbeat
• Low blood pressure
• Flushing

Hormonal and Women’s Health

• Painful periods
• Heavy menstrual bleeding
• Water retention
• Symptoms that worsen before menstruation

The Gut-Histamine Connection

One of the most important areas of research involves the relationship between histamine and gut health.

The digestive tract contains large amounts of histamine and many of the cells that produce it. When the gut becomes inflamed or imbalanced, histamine-related symptoms can increase significantly.

Conditions that may contribute to histamine overload include:

• Gut dysbiosis (imbalance of gut bacteria)
• Small Intestinal Bacterial Overgrowth (SIBO)
• Small Intestinal Fungal Overgrowth (SIFO)
• Candida overgrowth
• Parasite infections
• Chronic gastrointestinal inflammation

In many cases, treating underlying digestive issues is a key part of managing histamine-related symptoms.

Foods That May Increase Histamine

Certain foods naturally contain higher amounts of histamine or may trigger histamine release.

Examples include:

• Aged cheeses
• Fermented foods
• Processed and cured meats
• Alcohol
• Vinegar-containing foods
• Tomatoes
• Spinach
• Eggplant
• Certain legumes
• Some seafood products

Because every individual is different, identifying personal triggers is often more effective than following a highly restrictive diet long term.

Histamine and Hormones

Histamine and oestrogen influence each other.

As oestrogen levels rise, histamine activity may increase. Histamine can also stimulate additional oestrogen activity, creating a cycle that may worsen symptoms.

This may explain why some women experience:

• Migraines before their periods
• Skin flare-ups
• Allergy-like symptoms
• Mood changes
• Increased sensitivity around menstruation

Histamine and Mental Health

Histamine also functions as a neurotransmitter in the brain.

When histamine balance is disrupted, some people may experience:

• Anxiety
• Restlessness
• Difficulty sleeping
• Mood disturbances
• Increased stress sensitivity

Although histamine is not the sole cause of these symptoms, it may contribute significantly in susceptible individuals.

Mast Cell Activation Syndrome (MCAS)

In some people, mast cells become excessively reactive and release histamine too easily. This condition is known as Mast Cell Activation Syndrome (MCAS).

MCAS can produce many of the symptoms associated with histamine intolerance but often in a more severe and persistent form.

Patients with MCAS may experience recurrent allergic-type reactions, unexplained inflammation, skin problems, digestive symptoms, and episodes that appear disproportionate to the trigger involved.

Managing Histamine Intolerance

Treatment should always be individualised and based on the underlying cause.

Management may include:

• Identifying and reducing trigger foods
• Improving gut health
• Treating bacterial or fungal overgrowth
• Addressing mould exposure where relevant
• Supporting normal histamine breakdown pathways
• Correcting nutritional deficiencies
• Managing hormone imbalances
• Using appropriate supplements or medications when indicated

Because symptoms can overlap with many other conditions, a comprehensive assessment is often required.

When Should You Seek Help?

If you suffer from recurring symptoms such as:

• Unexplained allergies
• Chronic skin conditions
• Digestive complaints
• Migraines
• Anxiety or sleep disturbances
• Reactions to multiple foods
• Persistent fatigue

it may be worth investigating whether histamine imbalance is playing a role.

Consult Dr Alain Sanua

Histamine intolerance and Mast Cell Activation Syndrome can be complex conditions that often go unrecognised. Proper assessment requires careful evaluation of symptoms, medical history, diet, gut health, environmental exposures, and possible contributing factors.

Dr Alain Sanua offers consultations for patients experiencing symptoms that may be related to histamine intolerance, mast cell activation, gut dysbiosis, food sensitivities, and related health concerns.

If you suspect histamine imbalance may be affecting your health, a personalised consultation can help identify possible causes and develop an appropriate management plan tailored to your individual needs.

If you would like help with your condition and symptoms, contact Dr Alain Sanua for an appointment.