With hay fever season around the corner, you may be dreading the onset of symptoms such as itchy eyes, rashes and a blocked nose.
Many of us reach for over-the-counter medication to cope with the pollen onslaught each year, and some of us need to use them more routinely due to year-round allergies and related symptoms.
But not only do these medications fail to address the underlying imbalances causing symptoms, many cause unwanted side effects and may even be harmful to health. Understanding the mechanism behind these reactions can help us to figure out what's going on, and in turn reduce our reaction to external allergens, or even find more permanent relief from symptoms.
What is histamine?
When we react in this way to pollens and allergens, our bodies are producing a natural substance called histamine - hence the relevance and popularity of anti-histamine medication. Many who suffer with seasonal allergies only become aware of histamine's irritating properties for a limited time each year, but others deal with histamine-related symptoms on a more continual basis. But what is histamine, and how can we manage it?
Histamine is a chemical that plays a part in your digestion, immune system, and central nervous system. It is also one of your neurotransmitters, which communicates important messages between the cells of your brain.
Histamine promotes the allergic symptoms we are familiar with because it causes an immediate inflammatory response, during which your blood vessels swell, or dilate, so that your white blood cells can quickly find and attack the infection or problem. Histamine release is part of the body’s natural immune response, but if you don’t break it down properly, levels can elevate and you can develop histamine intolerance. This may cause symptoms such as headache, chest pain, rashes, itching and flushing. Because histamine travels throughout your bloodstream, it can affect your gut, lungs, skin, brain, and entire cardiovascular system, contributing to a diverse range of problems in different parts of the body, such as...
· Difficulty falling asleep, easily arousal
· Vertigo or dizziness
· Arrhythmia, or accelerated heart rate
· Difficulty regulating body temperature
· Nausea, vomiting
· Abdominal cramps
· Nasal congestion, sneezing, difficulty breathing
· Abnormal menstrual cycle
· Chest pain
· Tissue swelling
Causes of high histamine
There are many possible causes of high histamine, including genetic factors or increased exposure to allergens, but often the crux of the problem is an inability to break the histamine down, leading to elevated levels. Histamine in the digestive system is primarily broken down by an enzyme called diamine oxidase (DAO). Diamine oxidase is produced by cells within the lining of the digestive tract. And so very often, the lining of our digestive tracts can become damaged thanks to stress, alcohol, antibiotic use, poor diets and many other factors. When the gut lining becomes damaged, we are less able to manufacture the DAO needed to break down histamine, and when this happens, you may develop histamine excess and intolerance.
Causes of low DAO or high histamine
· Leaky gut (where the lining of the gut becomes porous and damaged)
· SIBO (small intestinal bacterial overgrowth)
· Inflammatory bowel conditions such as colitis and Crohn’s disease
· Ingestion of too many high histamine foods or alcohol
· Pollen or pets
· Allergies that involve the IgE response
· Gluten intolerance
· Foods that block DAO such as alcohol and tea
· Medications such as Nurofen, aspirin, antidepressants, even antihistamines
How to overcome histamine excess and intolerance
The first thing to try is a low histamine diet. This can help manage symptoms temporarily while you try to find out the root cause of the problem, such as digestive dysfunction.
Some foods are either rich in histamine, or can cause the body to release its own histamine from the mast cells that contain it. In certain people, eating these foods can trigger headaches and 'allergy-like' symptoms; or worsen existing allergic and inflammatory conditions.
Examples of high histamine foods include alcohol, vinegar, chocolate, fish, shellfish, sausages, cured and smoked meats, cheese, yoghurt, chickpeas, red beans, certain nuts and seeds, and even some fruits and vegetables like tomatoes, bananas, aubergine and citrus fruits. In addition, the histamine level in food increases as it ages, so it's best to cook and eat food when it's very fresh, and any leftovers will be higher in histamine than freshly cooked meals.
Certain nutrients have anti-histamine qualities, such a vitamin C and quercetin, which can be found in various fruits and vegetables. It may be difficult, however, to take in the levels needed to achieve their anti-histamine benefits through diet alone, and supplements may be necessary. Some probiotics have been been shown to possess anti-histamine properties, while others can instead increase it, so careful management of digestive balance can be helpful. Supplements of DAO itself are now available too, and can be taken before meals to minimise the risk of symptoms stemming from the histamine within foods.
Special diets and anti-histamine supplements are helpful, but it's a bit like putting a plaster over a wound that never heals. For long term relief, it's key to look deeper and correct any digestive imbalance such as leaky gut and imbalanced flora within the large and small intestine, that may be contributing to the overall problem. It may be worthwhile and even necessary to seek out a qualified nutritional therapist or functional medicine practitioner who can guide and support you through targeted diet, supplement and lifestyle strategies that help get to the bottom of why your histamine level may be elevated in the first place.