It’s allergy season again: those who are suffering from allergies are dreading this time of the year when trees and flowers start blooming… Allergies affect millions of people worldwide and can have a significant impact on your quality of life. While there are various types of allergies, one common factor is the release of histamine. Histamine is a chemical that plays a crucial role in your immune system, but when it's released in excessive amounts, it can trigger allergic reactions. In this blog post, we'll take a closer look at histamine and how it relates to allergies.
What is Histamine?
Histamine is a chemical that is naturally produced by your immune system. It's stored in a special type of white blood cell, called mast cell and is released in response to injury or allergens. When histamine is released, it causes a range of physiological responses, including inflammation, swelling, itching, redness, and increased mucus production.
Histamine is also found in various amounts in foods containing the amino acid histidine. Fermentation, curing, and slow cooking, convert histidine to histamine thereby increasing the food’s histamine content.
Histamine has several roles in the body. It helps to regulate various bodily functions, including digestion, blood pressure, and sleep. It also plays a crucial role in your immune system by helping to defend against pathogens and foreign substances.
While histamine is essential for your body's immune response, excessive amounts of histamine can trigger allergic reactions.
How does Histamine cause Allergies?
Allergies occur when our immune system overreacts to harmless substances like pollen, dust mites, or animal dander. When we come into contact with an allergen, our immune system produces antibodies called immunoglobulin E (IgE), which bind to mast cells and trigger the release of histamine. Allergy symptoms can range from mild to severe, depending on your sensitivity to the allergen and the amount of histamine released.
There are 3 main types of histamine problems:
Histamine intolerance: some people may experience symptoms similar to allergies, even when they're not exposed to an allergen. This can be due to histamine intolerance, which is a condition where the body is unable to break down histamine effectively.
Mastocytosis: this is a rare genetic condition caused by an excess of altered mast cells. And the more mast cells a person has, the more histamine the body will produce.
Mast Cell Activation Syndrome (MCAS). MCAS is different from an intolerance caused by histamine consumption: it refers to an immunologic condition where the mast cells set off a hyper response to a threat.
Some people may experience symptoms similar to allergies, even when they're not exposed to an allergen. This can be due to histamine intolerance, which is a condition where the body is unable to break down histamine effectively.
When histamine builds up in the body, it can cause symptoms such as headaches, hives, and digestive issues.
Foods that are high in histamine, such as aged cheese, fermented foods, and cured meats, can trigger symptoms in people with histamine intolerance.
Key guidelines to avoiding foods high in histamine:
Alcohol (especially red wine, champagne & beer)
Fermented & vinegar containing foods
Aged meats, cheeses (& leftovers)
Strawberries, citrus fruits, banana, avocado, tomatoes
Spinach & eggplant
Always rinse your meat and fish (and pad) dry before cooking them
The body is usually well-equipped to prevent the build-up of histamine. Usually, once histamine has done its job (or after consuming a histamine-rich food), this amine will be enzymatically degraded via 2 specific enzymes:
Oxidative deamination by diamine oxidase (DAO) into imidazole acetaldehyde and is produced in the small intestine.
Methylation by histamine N-methyltransferase (HNMT) into N4-methylhistamine helps break down and mop up excessive histamine.
When these enzymes are not present or when you are suffering from a metabolic issue that makes it hard to break down histamine, it can build up and contribute to health concerns.
Since histamine travels throughout your bloodstream, excess levels of histamine can affect physiological function in your gut, neurotransmitter levels in your brain, immune responses in your sinuses, lungs and skin, and your entire cardiovascular system, contributing to a wide range of symptoms, including:
Itchy skin, eyes, ears, nose
Difficulty falling asleep – Histamine from mast cells in the brain can promote wakefulness
Headaches or Migraines
Eczema or other types of dermatitis
Excess sweating during exercise
Fast resting heartbeat, heart palpitations or irregular heart beat
Super-itchy mosquito bites
Trouble regulating body temperature
Facial swelling or other tissue swelling
Tightness in the throat
Vertigo or dizziness – allergies affect the Eustachian tubes in your ears, which help regulate balance
Abnormal menstrual cycle
Hives or Rashes
Breathing issues like asthma
Anxiety or panic attacks – Histamine acts as a neurotransmitter in the brain and can contribute to anxiety, depression and other psychiatric conditions
Flushing or redness of skin
Depression or mood changes
Nasal and sinus congestion
Swelling and redness of eyes
Heartburn, reflux, indigestion, nausea or diarrhea
There are several factors that can contribute to histamine intolerance, including:
Genetics: Some people may be genetically predisposed to histamine intolerance, and may produce lower levels of DAO or HNMT or have altered activity of these enzymes.
Nutrient deficiencies: can be caused by suboptimal digestive function, higher nutrient demands (such as in cases of stress, anxiety, or poor sleep quality), and a nutrient-poor diet. Sufficient vitamin B6 and copper are required for DAO production. HNMT activity can also be impacted by micronutrient deficiencies (such as deficiencies of vitamins B1, B2, B12, B6, and minerals like folate, zinc, and copper). These nutritional deficiencies impact the methylation pathway via which HNMT degrades histamine.
Dietary factors: Certain foods are naturally high in histamine or can trigger the release of histamine in the body. Foods that are high in histamine include aged cheese, fermented foods, cured meats, and alcohol. Other dietary factors that can contribute to histamine intolerance include a deficiency in nutrients such as vitamin B6 or copper, or consuming foods that block DAO activity, such as tea or coffee.
Medications: Some medications, such as non-steroidal anti-inflammatory drugs (NSAIDs) aka ibuprofen, tylenol, exedrin, paracetamol, aspirin or steroids, can interfere with DAO activity, leading to elevated histamine levels.
Gut health: Histamine intolerance has been linked to imbalances in gut bacteria, as well as conditions such as leaky gut syndrome and irritable bowel syndrome (IBS). Increased intestinal permeability or leaky gut can cause a DAO deficiency which could then lead to histamine buildup in the body. Moreover, histamine can be produced by pathogens and beneficial bacteria. Pathogens can also produce phenols – usually, the body is able to metabolize excess phenols. However, if someone has gut issues or inadequate levels of sulfate and liver enzymes, excess phenols can trigger histamine release.
Hormonal imbalances: Hormonal fluctuations, such as those that occur during menstruation or menopause, can trigger histamine intolerance symptoms in some women.
It's important to note that histamine intolerance is not the same as a histamine allergy or a histamine intolerance caused by mast cell activation syndrome (MCAS). Histamine intolerance is a separate condition in which the body is unable to properly break down histamine, leading to symptoms that can be similar to those of allergies or MCAS.
What is Mast Cell Activation Syndrome?
Mast cell activation syndrome (MCAS) is a rare condition in which mast cells, a type of immune cell, are overactive and release excessive amounts of chemicals such as histamine, leading to a range of symptoms. Mast cells play an important role in the immune system, protecting the body from foreign substances and infections. However, in MCAS, the mast cells can become dysfunctional and release too many chemicals, causing inflammation and tissue damage.
Symptoms of MCAS can vary widely from person to person and may include:
Headaches and migraines
Anxiety and/ or depression
GI distress, heartburn, diarrhea
Redness, flushing or hives
Wheezing or shortness of breath
Nasal congestion or drip
Hypotonia and hypertension
Circadian rhythm imbalance (sleep issues)
Food and chemical sensitivities
The symptoms of MCAS can be similar to those of allergies, but in MCAS, the triggers may not be clear or specific. In some cases, patients may have a genetic predisposition to MCAS or may develop it as a result of an underlying medical condition, such as autoimmune disorders, infections, or cancer.
What can trigger MCAS?
Mast cells can become overactive due to:
Any type of inflammation
IgE and IgG antibodies – Any type of food allergens and food sensitivities can trigger MCAS.
Gut dysbiosis or infections caused by bacteria, viruses, fungi, Lyme, and mold. Source. The toxins released by these bacteria can cause severe symptoms by triggering MCAS, inflammation and oxidative stress.
Toxicity of heavy metals such as aluminum and mercury (Source). But also environmental toxins.
Salicylates (one type of phenol) – It is estimated that 0.6 to 2.5% of the population is sensitive to salicylates which can over-activate mast cells. (Read more about salicylates and oxalates here)
Oxalates – Oxalates appear to also trigger MCAS
Diagnosis of MCAS can be challenging, as there is no specific test that can definitively diagnose the condition. Instead, doctors rely on a combination of symptoms, medical history, and laboratory tests to make a diagnosis. This may involve testing for the presence of specific chemicals in the blood or urine, as well as performing allergy testing or other diagnostic tests to rule out other conditions.
Why histamine issues/ allergy symptoms can get worse during perimenopause:
In women who are perimenopausal, hormonal fluctuations can affect the body's ability to regulate histamine levels. When entering perimenopause, many women suffer from estrogen dominance due to the decline of progesterone levels that create a hormonal imbalance.
Histamine is involved in the regulation of the menstrual cycle and can influence the production of estrogen. Elevated histamine levels can increase estrogen production, which in turn can exacerbate symptoms of estrogen dominance. Your cells have many different types of receptors that the chemical messengers, or hormones, like estrogen, will recognize and attach to. Interestingly, histamine and estrogen attach to the same receptors (H1) in your cells. Because of this, estrogen will cause the release of histamine from the mast cells present in the reproductive organs of both men and women. So excess estrogen exacerbates histamine symptoms and vice versa.
Additionally, estrogen can inhibit the production of the enzyme diamine oxidase (DAO), which is responsible for breaking down histamine in the body. Therefore, estrogen dominance may lead to decreased DAO activity, resulting in an increase in histamine levels.
This explains why some women suffer from itchy skin in perimenopause (among others).
But also progesterone can also affect histamine levels. Progesterone has anti-inflammatory properties and can help to stabilize mast cells, so when your progesterone levels decline, you may experience pronounced allergy symptoms due to increased inflammation.
Overall, the hormonal changes that occur during perimenopause can exacerbate histamine issues, making it more challenging for the body to regulate histamine levels and leading to symptoms such as allergies, food sensitivities, and digestive issues.
In these situations it’s key to get your hormone levels checked and work on balancing them either with natural remedies or bio-identical hormone therapy.
What can you do to manage allergy symptoms?
If you have allergies or allergy-type symptoms as described above, antihistamines are the most commonly used medication.
Using pharmaceutical antihistamines long-term has a negative impact on your gut health and liver. You can imagine that if your detox organs are doing overtime, your gut microbiome is frail and your immune system constantly being triggered, it leads to chronic inflammation, allergies (food, environmental and seasonal), but also hormone imbalance and thyroid issues as a side effect.
This explains why many people stop responding to antihistamines and anti-allergy medications. Addressing the underlying causes of allergies is the only long-term solution.
Another thing you should know about antihistamines: they don’t lower your histamine levels, they only block your histamine receptors for the time the drug remains efficient. Once the drug wears off, you’re getting the full blast of built up histamine and your symptoms are getting worse unless you take another Benadryl.
Here is my approach to dealing with allergy symptoms:
Heal your gut: get a detailed stool panel and work on balancing your microbiome by removing pathogens and building up good bacteria and your gut lining
Address nutrient deficiencies by improving your diet and/or your digestion to make sure you are absorbing your nutrients
Identify food allergies and sensitivities
Adopt a low histamine diet
Support your liver to help flush out excess toxins & hormones
Balance your hormones: that may mean to detox excess estrogen or to increase progesterone production or to support your hormone levels overall
Identify genetic deficiency and address with appropriate supplements
Contact me or work with your practitioner to manage your allergy symptoms.
If you are not ready to do the groundwork, but need a short-term relief for this allergy season, here is a great product that I can recommend:
Allernat from Copmed (you’ll need to start this in February-March and take 1 capsule before each meal (3 per day)). If you want to order this, you need to indicate BEABE803 at checkout.