Maybe you are experiencing symptoms such as sneezing, post-nasal drip, sinus pressure, rashes, hives, and itching and you are convinced that you are allergic to something, maybe food, but an allergy test was negative. Maybe your symptoms affect your head: You’re always tired, experience frequent headaches or dizziness. Something’s not right, and you feel that it is connected to food, but you can’t put your finger on it. It appears that something you can tolerate just fine one day causes problems on another. Maybe you’ve found that an anti-histamine drug helped! Then how can it not be an allergy?
If your allergy test was negative, it could be histamine intolerance. Histamine is a substance that occurs normally in our diet and is also a product of bacterial activity in our gut. You will have heard of it before in connection to allergies, because it is indeed produced during an allergic reaction. In healthy people, histamine is rapidly broken down and detoxified by gut enzymes and won’t cause any problems. It’s not a bad chemical as such: histamine is an important component of the immune system and nervous system and plays a role in the process of inflammation. However, if we produce or consume histamine faster than we can detoxify it or if the integrity of our intestinal lining is compromised, it can cause a variety of symptoms such as:
sneezing – post-nasal drip – sinus pressure – runny nose – congestion – rashes – urticarial – hives – an impaired sense of smell – asthma – eczema - arrhythmia (irregular heartbeat) – a racing heart – dizziness – brain fog – irritability – headaches – migraines – tiredness – flushing – hormonal imbalances (incl. PMS) – digestive symptoms (incl. nausea, diarrhoea) – low blood pressure – low sex drive …
If you are allergic to something, you will experience symptoms very quickly, between just seconds to up to 30 minutes after eating. Histamine reaction time is much slower and symptoms can take a few hours to appear.
Which foods are high in histamine?
Histamine is abundant in the sea, so fish and sea food can be high in histamine – which doesn’t mean that you have to avoid them: The histamine content of food varies as it depends very much on the freshness of foods. As food deteriorates (or simply matures, e. g. cheese), histamine content increases. Leftovers would be higher in histamine than the same food when it was fresh. This variability can explain why sufferers are confused about which foods cause a reaction. Some foods are not so much rich in histamine, but rather ‘histamine liberators’, triggering symptoms by releasing the body’s own histamine. So, which are the foods:
- anything aged, such as aged meats (ham), certain cheeses (parmesan, pecorino, gouda, Swiss cheese, cheddar, manchego, camembert), dried fruit
- anything fermented: sauerkraut, kimchi, pickles, relishes, soy sauce, yoghurt, kefir, buttermilk, sour cream, and fermented alcoholic drinks such as beer, wine, sherry, and champagne
- smoked meats or fish, salami, dry-cured sausages
- any fish that has been processed or stored too long
- bone broth
- strawberries, citrus fruit, grapes, bananas, pineapples
- aubergines, tomatoes and tomato products, spinach, cabbage
- chickpeas, soybeans, peanuts
- histamine liberators are crustaceans (seafood), citrus fruit, papaya, pineapple, nuts, strawberries, egg white, certain additives
- alcohol, black and green tea block on of the enzymes that detoxify histamine
The list is long, but by no means exhaustive. If you look around you may find slightly different lists as consistent data on the histamine content of foods is difficult to find, not least because it can vary so much depending on freshness, storage and processing. What most seem to agree upon is that the main culprits are fermented and matured foods.
Is there a test for histamine intolerance?
There are tests to measure histamine in the blood and urine, but levels do not seem to correlate very much with symptoms, i. e. some people get severe symptoms with fairly low levels of histamine, others have no symptoms with high levels of histamine. There is a test for diamide oxidase (DAO) activity, one of the enzymes that detoxifies histamine in the gut, but DAO is not the only enzyme involved and if you have a leaky gut, your histamine levels may be high even though your DAO is working well. An allergy test is not going to detect histamine intolerance as it is not IgE mediated. In allergy testing, blood is checked for IgE antibodies, but histamine does not trigger those.
The best way to find out whether you have histamine intolerance is an elimination diet. Eliminate histamine foods, keep a food diary and make a note of how you feel.
Eliminating histamine foods from your diet may make you feel a lot better. Unfortunately, some very healthy and nutritious foods are high in histamine and the diet is quite restricted. It is important to find the underlying reason for your intolerance. Once that is addressed, you may be able to reintroduce histamine foods.
Gut health plays a significant role, as it is here that the histamine detoxifying enzymes are produced and this is where they work. Gut bacteria are involved in the production of histamine from foods and ‘leaky gut’ allows histamine to enter the blood stream without passing through the gut cells were an enzyme would normally disarm it. Certain medications can affect the activity of the detoxifying enzymes; undiagnosed allergies can add to the histamine load; histamine intolerance can also be the result of a genetic mutation that affects DAO efficiency – it is more common in Caucasian people.
So, if you suspect that you may be intolerant to histamine, it may be worth finding a BANT registered nutritional therapist near you. They will look at your health history, medications, signs and symptoms, diet and lifestyle, probably suggest some tests to help find the reason for your intolerance and then advise and coach you while addressing the underlying problem so that hopefully in the long run you will be able to tolerate histamine foods again.