What is it?: a natural chemical that is part of your immune system
Where is it?: found naturally in your body and in certain foods like smoked meats, mature cheeses, and eggplant
Is it a common trigger?: if histamine is building up in your system, then yes!
Histamine is a natural chemical found in your body. You’re probably most familiar with the immune functions of histamine and its role in allergies – when you encounter something you’re allergic to, your body releases histamine to try and keep you safe. As a result, you might experience itching, sneezing, diarrhea, rashes, or swelling based on where the reaction is occurring.
Histamine is a vasodilator, meaning it causes your blood vessels to widen and your blood pressure to lower. This vasodilation is also seen during a migraine episode.
In addition to being a natural part of your immune system, histamine can also be found in foods. There are also certain foods that encourage your body to release histamine. Some people have linked the consumption of histamine-rich foods with an increase in migraine symptoms.
Histamine is known as a biogenic amine and shares this title with other food chemicals like tyramine and phenylethylamine. Biogenic amines are relevant to migraineurs because they can play a role in the gut brain connection and interact with neurotransmitters (chemicals that allow your nerves to communicate with the rest of your body). In fact, histamine is considered a neurotransmitter itself and plays an important role in the inflammatory response.
Increased inflammation caused by higher histamine levels could have negative effects for migraine, including increased pain. Normally, your body does a good job of keeping histamine levels in check and gets rid of the excess you might get from eating certain foods.
Histamine in food can be an issue for migraineurs, however, when too much is allowed to build up in your body. This can happen if you have a deficiency of an enzyme called DAO, or diamine oxidase. A 2018 study found that people with migraine are much more likely to have a deficiency of the DAO enzyme than the general population … but 44% of non-migraineurs still had this deficiency and did not struggle with headaches.
So what does this mean? DAO deficiency might be part of the puzzle, but there’s likely other factors involved that would make histamine a migraine trigger.
Another piece of the histamine puzzle could be the gut microbiome, or the population of friendly bacteria that lives in your intestines. If you have too much of certain kinds of bacteria, it can cause an overproduction of histamine that even people with normal levels of the DAO enzyme may struggle to process. Testing for and correcting for these imbalances could greatly improve migraine and other symptoms in affected people.
It’s also good to talk to your doctor about the medications you’re taking if you suspect a histamine issue – some prescriptions like amitriptyline and morphine can interfere with histamine metabolism and potentially lead to increased headaches.
***Leftovers and food that’s been sitting tends to be higher in histamine than freshly prepared food. Sticking leftovers in the freezer as soon as you can helps prevent the build up of histamine.
To Avoid or Not to Avoid?
Many migraine diets avoid foods that contain or cause your body to release histamine. But do all of us need to avoid histamine for migraine?
There are some clues that may point to an issue with histamine. You might have “seasonal allergy symptoms”after eating certain foods like runny nose, hives, or itchiness, followed my migraine symptoms. You may also notice that taking an antihistamine improves your migraine pain. However, some people have issues with histamine and don’t find relief from antihistamines, nor do they experience allergy symptoms.
There are tests available that look at both your DAO levels as well as blood histamine levels, but these tests are not well proven and do not always correlate with symptoms. Right now, they best way to see if you have an issue with histamine is by keeping a food journal or completing an elimination/reintroduction diet.
There is an interesting connection between histamine and migraine, and it is very likely that migraineurs with higher than average levels of histamine or lower than average levels of DAO enzyme may find it harder to manage their symptoms.