What is Histamine Intolerance?
Histamine is a crucial component of our immune system. It is released in response to injury or inflammation. Histamine plays many important roles in the body such as helping us stay alert, acts as a neurotransmitter, has a role in blood pressure maintenance and helps in the production of stomach acid.
Think of histamine like water filling a bucket. We need a certain amount of water (histamine) in our bucket. The problem comes when the bucket becomes overly full and spills over. This is when symptoms of histamine intolerance can start to appear. This process often builds over a period of time.
What Causes Histamine Intolerance?
There are often multiple reasons and mechanisms behind the cause of histamine intolerance. Our gut produces an enzyme called DAO which helps breakdown histamine in the gut, for example when we eat a high histamine food like a ripe banana or spinach. If there is damage to the gut lining it can be difficult for the gut to produce DAO enzyme leading to a build up of histamine. We have trillions of healthy microbes in our gut. Some gut microbes produce histamine. If these species are in higher quantities then histamine production will be too.
Woman who track their menstrual cycle may notice more histamine related symptoms when oestrogen is higher as oestrogen can down regulate the DAO enzyme required for histamine breakdown. Whereas progesterone can help up regulate the DAO enzyme. Times of hormone changes like during perimenopause or if a woman is taking the oral contraceptive pill can effect this balance too.
Certain nutrients are required for histamine breakdown in the gut and within the body such as B12, zinc, magnesium, B6, vitamin C and vitamin D. If these nutrients are lacking in the diet or not being absorbed properly it can contribute to an increase in histamine.
Viruses can also trigger a high histamine response. It is not uncommon for those with long covid to experience histamine intolerance.
Genetics also play a role. Some people have a slight mutation on their genes that regulate histamine, which makes it more challenging for that person to breakdown histamine.
What Are The Symptoms Of Histamine Intolerance?
Admittedly the list is very long! People can vary in how they present. If you have a history of asthma, hay fever and/or eczema it is more likely histamine is part of the picture. Common symptoms include chronic runny nose, watery eyes, fatigue and brain fog, palpitations, headaches, over reaction to insect bites, insomnia, hives, digestive issues, period cramps, itchy or flushed skin especially to high histamine foods like red wine and aged cheeses.
Sometimes in severe cases of histamine intolerance it is diagnosed as mast cell activation syndrome (MCAS). Mast cells are part of the immune system and produce histamine. In MCAS large amounts of histamine are released often in relation to stress, chemical exposure or toxins. Many people who have MCAS also have hypermobile joints and/or collagen disorders.
What Can You Do?
Fortunately a lot!! Ideally speak to a nutritional therapist or another health practitioner to try and understand the root cause. Many people find removing high histamine foods helpful, but ideally this should only be temporary until the underlying issue is resolved. High histamine foods include things such as spinach, fermented foods, tomatoes, alcohol, ages cheeses, vinegars, strawberries, avocado, and chocolate. After a few weeks of removing these foods and supporting histamine pathways in the body I would ideally start to reintroduce some of these foods.
In addition to being mindful of high histamine foods, I would recommend putting any batch cooking or leftover foods in the freezer otherwise they start to accumulate histamine. If you do have a high histamine food ideally don't combine it with another high histamine food. Eg if you have strawberries in a smoothie don't also add avocado.
Foods to include that can help counteract histamine are red onions, red apples, pomegranate seeds, ginger, turmeric, green tea with a slice of lemon, asparagus, capers, watercress, garlic, chamomile and nettle.
Supplements and gut repair work are often a crucial part of a histamine intolerance protocol, although recommendation are always unique to the individual. I often will run a stool test. Some supplements I often recommend are vitamin c, zinc/B6/magnesium, rutin, quercetin, vitamin D, black cumin oil and/or DAO enzyme. Also drink nettle and tulsi teas.