Updated: Oct 25
Most of you are probably familiar with histamines in relation to seasonal allergies and histamine blockers that are used to mask the allergy symptoms. Also, many migraineurs are prescribed histamine blockers as part of their treatment plan (read further down to see why that’s not a good idea). But what’s the connection between histamine and migraines? Let’s first have a look at what histamines actually do in our body…
What are histamines?
Histamines are chemicals your immune system makes to defend yourself. They help your body get rid of something that's bothering you.
But histamines also act as messengers between your body and brain and are responsible for promoting stomach acid production which is essential for healthy digestion and defense against bacterial overgrowth.
How do histamines work?
Your histamines are stored in your mast cells, which is a type of immune cell or white blood cell in your body, especially found under the skin, near blood vessels and lymph vessels, in nerves, and in the lungs and intestines.
In order to release histamine, your immune system sends a chemical signal to the "mast cells". When the histamines leave the mast cells, they boost blood flow in the area of your body that was affected by the allergen. This causes inflammation (via cytokine generation), which lets other chemicals from your immune system step in to do repair work. This could look like a build up of mucus in your nose to make you sneeze, but also show up as redness, eczema, migraines, IBS, diarrhea, constipation or other digestive symptoms.
Research has found that people with chronic migraines have higher levels of histamine in their blood and increased histamine-releasing brain mast cells. Scientists have found in one study that 87% of migraine patients have a deficiency in DAO.
DAO (Diamine Oxidase) is an enzyme in your body that breaks down histamine. Some people are born with deficiency in this enzyme and some people develop it over time linked to their lifestyle. The good news is that you can manage both with the right tools!
Histamine is present in many foods, especially anything aged and fermented, but your body is also producing its own histamine. When exercising for instance, your body is producing histamine. So when you notice skin reactions, runny nose or headaches/migraines coming up with or just after exercising, that might be your histamine at play. People with histamine intolerance have too much histamine: they either create it in excess or they can’t break it down quickly enough due to abnormally low levels of DAO, (another enzyme called HNMT), or both. (Source)
Studies also indicate that DAO deficiency may increase the risk of migraines, while DAO supplementation may decrease the length of migraine attacks. So you might be thinking: why not take Benadryl for migraines (and I know many of you do…) Let me explain why that’s not a good idea:
Why Benadryl (or Zyrtec) is not a solution: they don’t LOWER your histamine levels, they will only block your histamine receptors for the time the drug remains efficient. Once the drug wears off: you get the full blast of histamine and your symptoms are worse than before. It’s like all other drugs: just a band aid that can provide temporary symptom relief.
While researchers have found that eating high-histamine foods can trigger migraines in both chronic migraine patients and in those who normally don’t have migraines, a low histamine diet can help migraineurs.
Symptoms of DAO deficiency:
Often feeling irritable, hot or itchy after eating
Often getting migraines or headaches
Sensitivity to red wine or alcohol
Can’t tolerate shellfish
Can’t tolerate citrus fruit, fish, wine or cheese
Can’t tolerate sauerkraut, kimchi, kefir or other
Often suffering from heartburn
Getting diarrhea at times without any reason
Ringing in ears at times, especially after eating
Sensitivity to many foods or leaky gut syndrome
Frequent runny or congested nose
Getting carsick, seasick or generally feel dizzy
I have not tested for this, but I know that I’ve had issues with foods high in histamine in the past. But since going through gut healing I can tolerate them again!
You might be thinking: what does a healthy gut have to do with histamine tolerance? Well if you consider that your main immune defense resides in your gut and that your microbiome hosts histamine producing bacteria, it’s not that far fetched is it?
A strong, diverse and robust microbiome that includes a variety of bacteria in the right proportions is your base for resilience. If your bacterial balance is disrupted, you may end up with excess histamine in your gut. As a result, your immune system will produce too many chemicals and a bunch of unpleasant symptoms. When any part of the digestive process gets disrupted, your DAO gene is likely to be overwhelmed.
Leaky gut is often a factor here too: when the walls of your intestines become leaky, your body is in a chronic state of inflammation and generating extra histamine with the intention to calm down the ongoing inflammatory process created by the food particles leaking into your bloodstream and causing an immune reaction. You should also know that your DAO enzyme (the one that decomposes your histamine) lives in the cells of your gut lining. So if that wall is damaged, it also means that you have less of the DAO enzyme to process histamine.
The histamine - hormone connection - a rise in estrogen also causes a rise in histamine
As described in my article about estrogen dominance, an excess of estrogen can also be linked to how efficiently you are breaking down and excreting your excess estrogen, causing it to build up in our system.
Your cells have many different types of receptors that the chemical messengers, or hormones, like estrogen, will recognize and attach to. Interestingly, histamine and estrogen attach to the same receptors (H1) in your cells. Because of this, estrogen will cause the release of histamine from the mast cells present in the reproductive organs of both men and women. The more estrogen you have, the more histamine will be released into the bloodstream. It’s a vicious cycle: more histamine results in more estrogen and more estrogen will increase histamine. In these cases it’s very important to address both issues as you can guess…
Now what can you do to manage histamine intolerance?
Heal your gut: get a detailed stool panel
Identify food allergies and sensitivities
Adopt a low histamine diet
Support your liver to help flush out excess toxins & hormones
Work with a skilled practitioner to:
rebalance your microbiome, restore your gut lining and remove pathogens (identifying and eliminating gut pathogens is essential, as the pathogens cause histamine release and inflammation)
improve your digestion: a lack of stomach acid, pancreatic enzymes or bile flow will impact your nutrient absorption and allow pathogens again to settle in your intestines
Key guidelines to avoid foods high in histamine:
Alcohol (especially red wine, champagne & beer)
Fermented & vinegar containing foods
Aged meats, cheeses (& leftovers)
Strawberries, citrus fruits, banana, avocado, tomatoes
Spinach & eggplant
Always rinse your meat and fish under water (and pad) dry before cooking them