Understanding Histamine Intolerance

Histamine is a natural chemical produced by our body. It plays a crucial role in helping various functions, such as supporting immune responses and acting as a messenger in our brain. However, histamine can be problematic for some of us, and not necessarily due to food allergies, but rather because our bodies have difficulty breaking it down, a condition referred to as histamine intolerance. Histamine intolerance has garnered a lot of attention from scientists over the past decade, despite being first defined at the beginning of this century. However, due to its wide variety of symptoms and difficulty in diagnosis, it continues to be a tough and occasionally controversial condition.

What Is Histamine?

Histamine is a biogenic amine, a small molecule generated from the amino acid known as histidine. Immune cells like mast cells and basophils are the primary locations for its natural production and storage. Additionally, histamine is also present in the brain, where it acts as a neurotransmitter, and in the stomach, where it stimulates acid secretion.

Histamine has a wide range of effects since it affects several organs, such as:

• Regulation of stomach acid

• Inflammation and immune responses

• Blood vessel dilation

• Muscle contraction

• Nerve signalling

How the Body Normally Handles Histamine

If histamine builds up in our body without breaking down, it can lead to harmful effects, and in order to prevent this from happening, our body relies on two main enzymes known as diamine oxidase (DAO) and histamine-N-methyltransferase (HNMT).

To break down the histamine we get from the food we consume, DAO plays a major role. It is found mainly in the small intestine and acts as a protective barrier to prevent dietary histamine from entering our bloodstream. The other enzyme, HNMT, works inside cells and breaks down histamine produced within the body.

The Role of DAO: The Enzyme Behind the Theory

If the activity of DAO is low, temporarily inhibited, or if histamine intake exceeds its capacity, this can lead to intolerance. Moreover, if you have inflammation in your gut or hormonal changes, take certain medications like NSAIDs and antidepressants, or consume alcohol, these can reduce the activity of DAO, thereby resulting in histamine intolerance.

When you have histamine intolerance, sometimes even tiny amounts of histamine that you consume through food can trigger symptoms. However, it is important to know that histamine intolerance is not a food allergy and is classified as a non-allergic food intolerance.

This condition can be challenging to treat because the symptoms can be nonspecific, highly variable, and can affect multiple body systems. For instance, nearly all of the patients in one research study who had been diagnosed with histamine intolerance had symptoms affecting multiple organs simultaneously, with an average of 11 distinct symptoms per individual.

Common Symptoms of Histamine Intolerance

So what are these symptoms that can appear if you have histamine intolerance? For instance, if it affects your digestive system, it can result in symptoms like bloating, diarrhoea, abdominal pain, nausea, and acid reflux. If the organ affected is the skin, symptoms may appear as flushing, itching, hives, and eczema-like rashes. You may experience headaches or migraines, dizziness, and brain fog if your nervous system is affected. Cardiovascular and respiratory symptoms manifest as a rapid heartbeat, low blood pressure, nasal congestion, and shortness of breath. These symptoms often appear after eating and may fluctuate from day to day.

Since the symptoms discussed above are broad and nonspecific, histamine intolerance may overlap with or be mistaken for other conditions. These include:

• Irritable bowel syndrome (IBS)

• Food intolerances

• Anxiety disorders

• Mast cell activation disorders

• Migraine disorders

• Perimenopause or hormonal imbalance

To exacerbate the situation, DAO testing is inconsistent, and results don’t always correlate with symptoms. Often, people get confused when their blood tests and scans come back normal, and symptoms fluctuate and don’t fit neatly into one diagnosis.

Why “Healthy” Foods Can Trigger Symptoms

One of the most frustrating aspects of histamine intolerance is that many of the foods that we consider healthy and wish to include in our diet regularly can be high in histamine or trigger histamine release. You may feel frustrated, confused, and guilty, thinking, “Why do I feel worse when I eat clean?” The common triggering food items include, but are not limited to:

• Fermented foods like dry-fermented sausages

• Raw milk cheese and pasteurised milk cheese (aged)

• Canned fish

• Cured meat

• Semipreserved fish

• Alcohol (especially red wine)

  
  
  
  

How Is Histamine Intolerance Managed?

Since there is no universally accepted treatment, management of this condition focuses on reducing symptoms. There are different approaches you could try, such as:

Dietary strategies

You could temporarily cut down on foods containing high histamine and try a low-histamine diet. However, it is important to discuss whether you cut down on highly nutritious foods for the long term because they are high in histamine, since this can affect your health. You could also eat fresh foods rather than leftovers, since histamine production may increase over time once food is cooked and stored, as certain bacteria can break down histidine in food.

Lifestyle approaches

Lifestyle modifications and specific supplements are frequently investigated to assist in treating histamine sensitivity, although their efficacy varies from person to person. Reducing stress is crucial because emotional and physical stress can trigger immune cells to produce histamine, which could exacerbate symptoms. Therefore, getting enough sleep, exercising gently, practising mindfulness, or engaging in relaxation techniques may help lessen symptom flare-ups. It is also important to support your gut health, as it plays a crucial role in breaking down histamine. This could be achieved by addressing underlying gut inflammation, avoiding overly restrictive diets, and maintaining regular eating patterns, which may improve tolerance over time.

It is also important to identify medication triggers, since certain drugs can interfere with histamine metabolism or DAO activity. Additionally, some people take antihistamines to inhibit the effects of histamine or DAO supplements to aid in the breakdown of histamine in the stomach. Vitamins B6 and C are occasionally used due to their involvement in enzymatic and antioxidant processes linked to histamine metabolism. Responses to these approaches, however, vary greatly, and what is effective for one individual may not be beneficial to another.

More research is needed to better understand histamine intolerance, and to diagnose and manage the condition. Until then, managing histamine intolerance can be made easier with more awareness, monitoring symptoms, supportive medical guidance, and a compassionate approach.

Sources

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