Histamine Intolerance Symptoms Causes and Effects

Understanding Histamine Intolerance

We’ll be taking an in-depth look at histamine. What it is, how it affects you, and what you can do to manage it naturally.

Histamine intolerance is when the accumulation of histamine in the body is more than your body is able to break down. It overloads your system. To improve histamine intolerance long-term we must find the underlying causes and address them.

Hopefully, I’ll be able to give you an understanding of what is going on in your body. What to look out for when the doctor’s say "there’s nothing coming up in your blood results” when you still don't feel "quite right", and a few more tips on healthy eating.

What is Histamine?

Histamine is a chemical compound that is naturally produced in the body and plays a key role in the immune system and the regulation of many physiological processes. It is a neurotransmitter, which means it helps to transmit signals in the nervous system.

Histamine is involved in many functions, such as regulating blood vessel dilation, stomach acid secretion, and muscle contraction. It is also involved in the body's allergic response and helps to defend against harmful invaders like bacteria, viruses, and other pathogens.

However, in some cases, the body can produce too much histamine or have difficulty breaking it down, which can lead to a condition known as histamine intolerance.

What are Histamine Intolerance Symptoms?

There are many common symptoms of histamine intolerance. Perhaps you have experienced some of these yourself?

  • Skin reactions - Hives, itching, flushing, redness, heat, swelling and skin rash. Eczema, urticaria, rosacea & atopic dermatitis.
  • Allergic reactions, hay fever & asthma - sneezing, wheezing, shortness of breath, itchy eyes, red rash, congested nose, runny nose, watery nose, headache, general malaise.
  • Painful periods – heavy menstrual cycle, cramps, headaches.
  • Gastrointestinal symptoms - Irritable bowel syndrome symptoms (IBS) – nausea, vomiting, diarrhoea, flatulence, stomach ache, abdominal bloating, food intolerances, abdominal cramps, reflux or heartburn.
  • Central nervous system symptoms - Migraine or tension-type headaches, vertigo, insomnia, anxiety, irritability, depression.
  • Cardiovascular symptoms - Rapid heartbeat, palpitations, low blood pressure, high blood pressure, anaphylaxis and dizziness.
  • Musculoskeletal symptoms - Joint and muscle pain.

These symptoms can occur individually or in combination and can range from mild to severe. It's important to consult a healthcare professional to determine if the cause of these symptoms is histamine intolerance and rule out other conditions.

What are the Causes of Histamine Intolerance Symptoms?

Symptoms of a histamine intolerant person can occur in many parts of the body. Often, you might not even think they are related to an intolerance. One person’s reaction may be quite different to the next.

Histamine intolerance symptoms  occur when there is an excess of histamine in the body or when the body has difficulty breaking down histamine. This can be caused by a variety of factors, including:

  1. Reduced activity of enzymes that break down histamine, such as diamine oxidase (DAO), histamine N-methyltransferase (HNMT) and Monoamine Oxidase-B (MAO-B).
  2. Increased production of histamine due to allergies, inflammation, or immune responses.
  3. Consumption of histamine-rich foods, such as fermented dairy products, fermented vegetables, seafood that's been out of the water a long time, like canned tuna, anchovy and sardines and cured meats like bacon and salami.
  4. Consumption of foods that cause the release of histamine or block the activity of enzymes that break down histamine, such as alcohol, citrus fruits, and certain spices.
  5. Medications that can inhibit the activity of DAO or HNMT, or increase histamine release, such as nonsteroidal anti-inflammatory drugs (NSAIDs), antidepressants, and antibiotics.
  6. Gut issues, such as h.pylori, dysbiosis and poor gut health, leaky gut, gluten intolerance, small intestine fungal overgrowth (SIFO) or small intestine bacterial overgrowth (SIBO) and inflammation can impair histamine metabolism by reducing DAO enzyme production. Inflammatory bowel disease is also a contributing factor for some due to the inflammation and therefore reduction in DAO enzyme. It's important to test for these common underlying causes.
  7. Insufficiency of digestive enzymes, stomach acid and bile. These contribute to SIBO a major cause of histamine intolerance.
  8. Stress can increase histamine release and trigger symptoms. This is why in my Gut Fix Program we address stress management techniques to reduce digestive symptoms.
  9. Hormonal changes, such as during ovulation and menstrual cycles, can trigger histamine release and symptoms.
  10. Mast cell activation syndrome (MCAS). Where the mast cells over produce histamine and other chemicals that cause inflammation. Mould exposure is the main cause I've seen. MCAS is serious and needs to be dealt with by a specialist.

It's important to note that not everyone with histamine intolerance will have the same causes of their symptoms and it may take some trial and error to identify personal triggers and underlying drivers.

Pathogenic Bacteria and Histamine Production

Some pathogenic bacteria have the ability to produce histamine by containing their own HDC (histamine decarboxylase) enzymes. These enzymes are responsible for converting the amino acid histidine into histamine. Examples of bacteria that possess this ability include Clostridium perfringens, E. Coli, Citrobacter, and Klebsiella species.

When these bacteria overgrow, they can lead to an excess of histamine in the body, which can trigger the typical histamine excess symptoms. Therefore, it is essential to address any underlying bacterial overgrowth, such as SIBO or dysbiosis, to alleviate histamine intolerance symptoms.

The Role of Pathogens in Histamine Production and Mast Cell Degranulation

Any organism that stimulates an immune response will result in mast cell degranulation and the subsequent release of histamine. This includes bacteria, viruses, parasites, fungi, candida, and mould. When histamine is released in response to these pathogens, it can trigger various symptoms such as itching, swelling, inflammation, and redness. Therefore, it is essential to identify and address any underlying infections or imbalances in the body that may be contributing to histamine intolerance to alleviate symptoms and promote overall well-being.

Gram-Negative Bacteria and Leaky Gut

Gram-negative bacteria that produce lipopolysaccharides (LPS) can contribute to the development of leaky gut syndrome, which is characterised by increased intestinal permeability. Some examples of Gram-negative bacteria that can produce LPS and cause leaky gut include E. coli and Klebsiella species. When these bacteria overgrow in the gut, they can release LPS, which can trigger inflammation and damage to the intestinal lining and DAO enzyme production.

Leaky gut syndrome, or increased intestinal permeability, is a condition where the gut lining becomes damaged and more porous, allowing undigested food particles, toxins, and microbes to pass into the bloodstream. Leaky gut can contribute to histamine intolerance in several ways. Firstly, the increased exposure of mast cells to antigens in the gut can lead to their degranulation and the release of histamine, triggering various digestive symptoms.

Secondly, the damaged enterocytes in the gut lining can result in reduced production and release of DAO enzymes, which are responsible for breaking down histamine. This leads to more histamine circulating in the body, which can trigger not only gut-related symptoms but also systemic symptoms such as eczema, allergies, and brain fog.

Finally, leaky gut can also increase reactivity to other foods, exacerbating histamine intolerance symptoms. Therefore, it is essential to identify and address these underlying drivers of histamine intolerance.

How to Diagnose Histamine Intolerance

There is no single definitive test to diagnose histamine intolerance, and diagnosis often involves a combination of clinical evaluation, symptom assessment, and laboratory tests.

Here are some common methods that may be used to diagnose histamine intolerance:

  1. Symptom assessment: A qualified healthcare professional may conduct a thorough evaluation of the individual's symptoms and medical history to determine if histamine intolerance is a likely cause.
  2. Elimination diet: An elimination diet involves removing foods that are high in histamine or that cause the release of histamine for a period of time to see if symptoms improve. After this period, foods are slowly reintroduced to identify which ones trigger symptoms.
  3. Blood tests: A blood test can measure the level of DAO (diamine oxidase) and histamine in the blood, which can help to determine if histamine intolerance is present. The problem with this test is it doesn't tell us what's causing the histamine intolerance. Generally we look for the underlying causes to fix to get improvement with histamine intolerance and rely on symptom picture and diet to confirm histamine issues.

It's important to note that these diagnostic methods are not foolproof, and it may take some time to identify the cause of the symptoms.

High Histamine Containing Foods

Certain foods are naturally high in histamine. As a result, this can aggravate any underlying health issues. Regularly eating foods with high levels can lead to a worsening of symptoms until underlying causes are dealt with. To follow a low histamine elimination diet we have to understand the histamine rich foods. The foods to monitor include:

  • Strawberries
  • Raspberries
  • Chickpeas
  • Kiwi
  • Tomato/tomato paste
  • Avocado
  • Soy beans
  • Banana
  • Most citrus fruit: Orange, lemon, lime
  • Smoked meats
  • Matured cheeses like gorgonzola, camembert, gouda)
  • Spinach
  • Peanuts
  • Fermented foods like kombucha, sauerkraut, soy sauce, vinegar, pickles, beer and wine
  • Pineapple
  • Papaya
  • Eggplant
  • Canned fish like tuna, sardines, salmon

What can You do to Prevent Histamine Taking Over Your life?

We've covered all of the background knowledge you need to understand histamine and the reactions it commonly causes. In our next article, we'll be talking about what you can do to control the levels within your body and reduce the symptoms of histamine intolerance. Following a low histamine diet should reduce symptoms and have you feeling better while we find the underlying causes relevant to you. An elimination diet takes around 4 weeks.

One of the main contributors to histamine intolerance is SIBO and both SIBO and a low histamine diet can be explored in my Gut Fix Program where I take you through my steps to healing your gut.

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