What is Histamine Intolerance, and what can I do about it?

Specific food and environmental allergies are now very common, and these can range from peanut and cow’s milk protein allergies to grass and pollen allergies. However, some people have a more generalised sensitivity to a chemical that naturally occurs in everyday foods called histamine. Ingesting low levels of histamine will probably not hurt most people, but a build-up of histamine can lead to difficulty breathing, asthma, skin rashes, hives, itchy eyes and mouth as well as a runny nose and sneezing.

Too much histamine can also make you feel very tired with a foggy brain – and it can feel like the plug has been pulled on your energy levels. Histamine can also trigger headaches and it is closely linked to the onset of migraines. Many people experience breathlessness, wheezing and difficulty breathing when they have histamine issues.

In some cases, too much histamine can trigger an irregular heartbeat and can lead to symptoms of postural tachycardia syndrome (PoTS) such as dizziness and weakness from standing up too quickly. Many people with histamine intolerance have insomnia and get very hot at night. They can get very thirsty and urinate very frequently. It can also lead to menstrual cramps and hot flushes. Histamine can affect the gut too and some people experience nausea, vomiting, gut pain, diarrhoea or ongoing constipation.

Histamine intolerance tends to creep up slowly and many people get it very mildly for several months or years until the balance of histamine is tipped, and the symptoms start to become much more pronounced. At NatureDoc we have seen soft signs of histamine intolerance even in young babies and children and parents often report rashes, runny nose, wheezing, itching or irritability within a few hours of ingesting a high histamine meal such as tomato pasta with spinach.

Symptoms are often worse in the late evening and on waking as histamine builds up over the day and can remain active in the body overnight. The reaction can be pretty immediate but is more often delayed by a few hours. So, if your symptoms present several hours after eating lots of high histamine foods this is quite a normal response, and some people don’t get the symptoms until the next day.

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Histamine Intolerance vs Mast Cell Activation Syndrome

Histamine intolerance is a subset of mast cell activation syndrome (MCAS) which is a more complex systemic type of allergic response. The main trigger for MCAS is histamine, but MCAS can also be a broader reaction to multiple chemicals in the diet and the environment. There are over two hundred known signals (cytokines) that can fire up mast cell reactions and these can be made within the body or triggered by chemicals from the environment. They can lead to many of the same signs as high histamine and can come on much more quickly such as sudden hives all over the skin.

These triggers can be very far-reaching, to include infections, stress, emotional challenges, changes in heat, strenuous exercise, candles, air fresheners, fragrances and tobacco smoke. MCAS is hard to diagnose and there are only a handful of MCAS doctors in the UK who can run tests and offer medical treatments to include mast cell stabiliser medications.

The cornerstone to getting better control of MCAS is also a low histamine diet. It’s also important to identify other food or environmental triggers and avoiding exposure to these as much as possible. This can be tricky sometimes as some people have multiple chemical sensitivities and their reactions can wax and wane and change quite rapidly. For instance, you might react to an air freshener one day and then not again for a while. Many of the food supplement guidelines for histamine intolerance below can also help to manage MCAS.

Why does histamine intolerance develop?

There are several reasons why histamine builds up in some people more than in others. It is strongly genetic and there are several key genes responsible for regulating the level of histamine in the body. If you are atopic (eczema, asthma or hay fever) then histamine intolerance may be part of the picture. Histamine intolerance and mast cell activation syndrome are also much more common in people who are very flexible or have hypermobile joints as well as those diagnosed with collagen disorders such as Ehlers-Danlos syndromes (EDS). EDS can affect the connective tissues which support skin, tendons, ligaments, blood vessels, internal organs and bones. If the mast cells go rogue in any of the connective tissues then this can lead to a myriad of histaminic-type reactions.

The primary way our body breaks down the histamine in our food and to prevent this food from causing allergy-type symptoms is an enzyme called Diamine Oxidase, commonly known as DAO. We all produce this in varying amounts and the more you make in your gut, the less likely you will have a problem with histamine-rich foods. Again, much of this is dependent on genetics, but that is not the only reason why we don’t produce enough DAO.

Here are some of the other key factors that can affect how much DAO is produced:

High Histamine Diet – If we are eating too many foods rich in histamine then this can in itself overwhelm our DAO reserves. Some so-called healthy foods such as spinach, tomato, avocado, strawberries and banana contain quite a bit of histamine. Some alcoholic drinks can also drive up histamine, especially red wine. One of the first signs an adult is starting to get the histamine/DAO balance wrong is when you start to become sensitive to red wine, especially the more mature aged wines. This can manifest in headaches, night waking, bad hangovers, sneezing and hot flushes.
Balance Of Gut Bugs – An overgrowth of bacteria in the small intestine (known as SIBO) can also hamper the effectiveness of the DAO enzyme. SIBO can present in several ways but most experience considerable bloating and irritable bowel alongside fatigue. Once the SIBO has been addressed then the DAO is often able to do its job more easily. Gastroenteritis, vomiting or diarrhoea may also lead to a depletion of DAO and may make you temporarily histamine intolerant until the DAO has a chance to build back up again.

N.B. Many probiotics and fermented foods like yoghurt and kefir can drive up excess histamine. A qualified practitioner with an interest in histamine intolerance can advise on the best histamine degrading prebiotic and probiotic strains to take and which ones to avoid.

Vitamin Deficiencies – Vitamin B6 is a key nutrient co-factor for making DAO and if a person is deficient in Vitamin B6 they might have more pronounced histamine reactions. Both Vitamin D and Vitamin C help to stabilise mast cells. Magnesium is key mineral that can help with histamine intolerance and mast cell activation and most people find that upping their magnesium intake can help with oral and gastric tolerance and reduce symptoms.
Imbalanced Hormones – Interestingly too much oestrogen can down-regulate DAO, leading to more histamine-related issues whereas on the other hand, progesterone can up-regulate DAO and helps to stabilise mast cells. Many women experience higher histamine symptoms in the build up to their period during the luteal stage. The contraceptive pill may be part of the picture too, skewing a woman’s hormonal balance to oestrogen dominance and lower progesterone. Puberty and menopause can disrupt the delicate of balance of oestrogen and progesterone, and this may be why histamine intolerance can be worse during these times of a woman’s life. On the flip side of this, a mother’s placenta makes DAO in abundance, which is probably why mast cell activation and histamine intolerance can greatly improve with pregnancy.
Infections – Viruses as well as bacterial, parasitic and fungal infections are also known to trigger histamine intolerance and mast cell activation. Again, these may in part disrupt the DAO reserves in the gut, as well drive mast cell activity. Epstein Barr Virus (glandular fever), herpes simplex virus and Helicobacter pylori have all been identified as specific mast cell triggers.

The heightened histamine symptoms and mast cell activity also seem to have become quite a common pattern in those that have contracted coronavirus over the past year. Many of the symptoms of Long Covid cross over with histamine intolerance, and several Long Covid sufferers report that they feel much better on a low histamine diet in conjunction with food supplements with antihistamine properties. A few doctors are now aware of this link and are prescribing antihistamine medication to help manage the Long Covid symptoms better. Children with Long Covid seem to be very susceptible to histamine reactions and rashes that wax and wane as well as nausea, extreme fatigue and weakness are common symptoms reported.

Existing Allergies & Mould – If you have pre-existing environmental allergens or have had significant mould exposure from living in a damp house, then again, your histamine levels can be more elevated. People with hay fever and summer allergies are more prone to more significant reactions in the summer months and those with mould sensitivity seem to have more symptoms during wet weather and in the autumn and winter months. However, this can change from day to day too.
First Signs of Autoimmunity – A key sign that a person is on the road to developing an autoimmune condition is a rise in food and environmental allergies to include a more marked histamine response. When we experience chronic inflammation through poor diet, an imbalanced gut microbiome, stress, dehydration, infection or toxic exposure our immune system becomes more TH2 dominant (this is the type-2 immune pathway called “humoral immunity”) and this can manifest in increased allergies, asthma and chronic infections in our empty cavities such as our gut, urinary tract, lungs, ears and throat. These people often present with reoccurring infections and histamine intolerance symptoms at the same time.

How to restore a better equilibrium?

The first step to reducing your histamine load is to adopt a low histamine diet until you are able to work out what else is driving your high histamine related health challenges. Ideally you would cut back as much as you can on the higher histamine foods as possible for 30 days and then slowly build them in one by one so you can work out the levels of histamine in food your body can handle.

As you work on the underlying issues blocking the production of DAO you can probably start to introduce more histaminic foods without too many negative effects. We find that most people need to be strict with their diet and supplements for 30 days, and then they can broaden their diet a little after that.

Once they have got their gut microbes and hormones in better balance and optimised DAO production, then other than being mindful of eating too many high histamine foods, they should only experience mild reactions that can be managed by occasional supplements and/or medications.

The key is to cook fresh food from scratch as much as possible. Leftovers should be put in the fridge or freeze immediately as this reduces the build-up of bacteria in the food. Most fresh ready meals are very high in histamine, however well they have been stored. The frozen ones are better in terms of histamine and maybe a better option to try. Later on down the line when you start to reintroduce small amounts of avocado and banana, ensure they are just ripe rather than overripe to reduce histamine. If you make a rule of buying fresh food with the longest shelf life and use your freezer regularly then this helps too. The freshness and storage is just as important as which foods you consume.

Always remember this is about avoiding ingesting volume of histamine more than anything else, so if you cook a recipe with a squeeze of lemon juice in it or a little lime zest then you probably won’t get a histamine reaction, but if you drink a whole glass of orange juice you might well start to develop symptoms. Even though citrus fruits are not actually high in histamine themselves, they can trigger the release of histamine in your body.

High histamine & histamine trigger foods & drinks

Here is a list of foods/ingredients to avoid for the first 30 days. These are either high-histamine or can trigger the release of histamine. Slowly build back in again these foods one by one after the first 30 days and look out for any increase in symptoms. If histamine levels seem to be reigniting symptoms, then cut back on the higher histamine foods, increase the low-histamine foods and take the food supplements.

Yoghurt, milk kefir, probiotics, prebiotics
Soured foods: sour cream, sour milk, buttermilk
Sourdough bread
Fermented foods: sauerkraut, kimchi, kombucha, miso, soya sauce, tempeh, water kefir
Vinegar and vinegar-containing foods including pickles, mayonnaise, olives – apple cider vinegar is Ok in small quantities.
Aged and blue cheeses including mature Cheddar, Emmental, Gouda, Gruyere, Parmesan, Roquefort.
Smoked products, such as sausage, ham, bacon, or salami
Aged or leftover meat to include biltong and well-hung meat.
Tinned fish such as mackerel and tuna, sardines
Prawns unless deveined
Fermented soya beans – miso, soya sauce, tempeh
Raw egg white
Strawberries
Bananas
Raspberries (a first food to re-introduce after 30 days)
Cherries (a first food to re-introduce after 30 days)
Grapes
Excess dried fruit: apricots, prunes, dates, figs, raisins
Excess citrus fruit: lemons, limes, oranges, mandarins, clementine’s, tangerines. (lemon and lime are a first food to re-introduce after 30 days)
Kiwi
Pineapple
Plum
Tomatoes, ketchup, tomato puree, passata, baked beans (a first food to re-introduce after 30 days)
Avocado
Spinach
Aubergine
Mushrooms
Peanuts, Cashews, Walnuts
Chocolate and cocoa
Coffee, black tea and green tea
Wine, beer, cider
Cayenne Pepper
Chilli powder
Curry Powder
Cinnamon
Cloves
Nutmeg
Paprika
Star Anise

Foods to enjoy

Cooked egg – in any form, try boiled, scrambled, poached or Spanish omelette
Fresh or flash-frozen meat, poultry and fish (buy with the longest shelf life and use frozen fish)
Chicken liver pate, calf’s liver
Rice, rice noodles, legume rice
Whole wheat pasta, spelt pasta, quinoa pasta as well as red lentil or chickpea pasta
Oats, barley, rye, spelt, kamut
Wholegrain breads, rye bread, pumpernickel bread, oatcakes, rice cakes, buckwheat crispbreads, amaranth crispbreads, corn crackers.
Quinoa, amaranth, millet, spelt, farro, buckwheat flakes or groats
Pulses & legumes: lentils, butter beans, black beans, kidney beans, borlotti beans, black eye beans, flageolet beans, yellow split peas.
Fresh, pasteurised milk (some people cannot tolerate this as it can release histamine in the gut)
Cream cheese, ricotta, mascarpone, feta, halloumi, buffalo mozzarella, fresh mozzarella balls, cottage cheese.
Butter, cream, ice cream
Fresh & Frozen Vegetables – broccoli, celeriac, celery courgette, mange tout, snap peas, peas, sweetcorn, spring cabbage, red cabbage, Savoy cabbage, Brussels sprouts, carrots, beetroot, cauliflower, leeks, red onion, spring onions, shallots, kale, chard
White potatoes, sweet potatoes, butternut squash, pumpkin, swede, parsnip.
Salads – lettuce, lamb’s lettuce, watercress, cucumber, red peppers, spring onion, chicory, cress
Fruits – apples, Cantaloupe melon, fresh figs, grapefruit, honeydew melon, mango, papaya, pears, pomegranate, redcurrants, rhubarb, watermelon. Fresh apricot, nectarines and peaches.
Almonds, chestnuts, pine kernels, brazil nuts, pecans, pistachio, hazelnuts, pumpkin seeds, sunflower seeds, chia seeds, flax seeds, hemp seeds.
Fresh coconut milk, tinned coconut milk and cream, rice milk, hemp milk, almond milk, oat milk, oat cream.
Most cooking oils – olive oil, coconut oil, cold-pressed rape, ghee
Fresh herbs: coriander, parsley, mint, rosemary, thyme, sage, basil, garlic, wild garlic.
Spices: turmeric, cumin, coriander, cardamom, fennel, lemongrass
Water – and lots of it – 1.5 to 2 litres daily
Most herbal teas – rooibos green tea or rooibos earl grey are both delicious. Try nettle, licorice and tulsi teas which are specific to helping histamine/POTS.

Here are some recipes from my blog that are naturally lower in histamine and can get you going on the diet. You can adapt these recipes depending on your own food sensitivities and dietary needs.

It’s ok to keep the diet simple at first which might mean porridge with blueberries, mixed seeds and honey at breakfast, a Spanish omelette with fresh soup and salad for lunch, and then fresh fish or chicken with buttery sweet potato mash and steamed vegetables at supper.

Food Supplements

These are nutritional food supplements and botanicals that can help to ameliorate a heightened histamine response. They can be taken alongside prescription antihistamines. Children can take these supplements too, but it is best to talk to a NatureDoc practitioner to ascertain appropriate dosages.

Key supplements

Diamine Oxidase (DAO) – many people find they can eat more histamine rich foods if they take a DAO supplement at the start of meal containing histamine-rich foods or drinks. This only works for some people where DAO production is the root cause of their histamine intolerance.
Quercetin – made from the Japonica tree and naturally occurring in red onions, red peppers and apples this is the most well documented plant in terms of its antihistaminic properties.
Magnesium – important for over 400 processes in the body and can help to rebalance a high histamine surge.
Epsom salts – either add a cupful to a warm foot bath or two cups to a warm bath and soak for at least 20 minutes. This can be helpful when hypersensitive to high histamine foods and other MCAS environmental triggers.
Vitamin C – super important for all mast cell and histamine related collagen disorders.

Additional supplements to try

Black Cumin Oil – also known as Nigella seeds, this spice from India has been used traditionally to help regulate histamine response.
Palmitoylethanolamide (PEA) – most research about PEA focuses on its potent pain-relieving properties, this is natural anti-inflammatory and mast cell stabiliser.
Herbal tea blends containing natural antihistaminic properties include nettle and tulsi.
Vitamin B6 – important for making DAO in the gut
Vitamin D – an all-round important nutrient that is important for a healthy immune response including stabilising mast cells.
Omega 3 – pure omega 3 fish oil can be helpful at reducing the inflammation triggered by histamine. Avoid fermented cod liver oil.
N Acetyl Cysteine (NAC) – helps to build up reserves of glutathione which is our master antioxidant that regulates immune response and inflammatory pathways
Anti-inflammatory polyphenols including Resveratrol and Turmeric which help to stabilise mast cells.

If you have read this article and feel this is the missing piece in the puzzle for you or a family member’s health, then please be in touch to book in to talk to one of our NatureDoc clinical team who specialise in histamine intolerance. Our nutrition coaches can also help you to create weekly low histamine menus working around your family’s food likes and dislikes.

What is Histamine Intolerance, and what can I do about it? - NatureDoc (2024)