You’re likely familiar with seasonal allergies and your body’s histamine response. Sneezing, itching, watery eyes –antihistamines anyone?
However, many people don’t realize that this chemical can also be found in your food supply. For people who are sensitive, following a low-histamine diet may help combat some of the symptoms of histamine release.
Depending on the severity of the sensitivity, some people may even develop food intolerance to high histamine foods.
But the story with histamine is a little more complicated than a simple immune reaction. So let’s dive in to learn more about this immune modulating chemical, and if it’s something you should be wary of.
Histamine is a chemical that can either be made by your immune system (mast cells release histamine), or consumed in foods that contain histamines.
Although it’s most well-known for causing allergic reactions like runny nose and mucus, histamine actually has a number of roles in your body.
It acts as a neurotransmitter, impacts wound healing, affects day and night rhythms, and is involved in angiogenesis — the development of new blood cells[*].
As a neurotransmitter, histamine has a significant impact on your central nervous system. It’s even being studied for its potential impact on neurological diseases like Alzheimer’s disease, multiple sclerosis, and Wernicke’s encephalopathy[*].
In the arena of wound healing, animal studies have shown that the absence of histamine results in a delayed healing process. When histamine is administered, however, healing is accelerated. Histamines wound healing potential likely results from a combination of immune cell signaling, and its role in angiogenesis[*].
Histamine and Allergies
In your immune system, histamine acts to alert your body that a foreign invader has approached. This is how it gets its role in immune reactions.
For instance, if you have seasonal allergies, when Spring comes and you breathe in that first bloom of pollen, (a common allergen), histamine will become active. The pollen serves as an alert to histamine, and histamine then responds by alerting the rest of your immune system that an invader (pollen) is attacking your body.
This response is only going to happen if you’re allergic to pollen, in other words — if your body doesn’t recognize pollen as harmless.
The same response will take place in the case of food allergies. In fact, three out of the four histamine receptors in your body are located in your gut.
Histamine released from your immune system has a role in a wide range of conditions including:
- Allergic rhinitis
- Crohn’s disease
- Ulcerative colitis
- Food allergy
- Atopic dermatitis
- Drug allergies
While an allergic reaction isn’t always pleasant, it’s your bodies way of trying to protect you from something potentially dangerous[*].
Histamine and Food
In addition to being an essential component of your immune system, some foods also contain histamine. These foods often fall into the aged or fermented category.
Your body is a delicate and intricate system of checks and balances. It’s maintained by feedback loops and messengers. Histamine is one of these messengers that allows your immune system to respond when substances from the outside world make it into your body.
Problems with histamine occur when the level of histamine in your body builds up. This build-up creates histamine intolerance resulting from either an impaired breakdown of histamine or excessive availability of histamine[*].
An impaired breakdown can happen via three mechanisms:
Three Possible Causes of Histamine Intolerance
#1 DAO Enzyme (Diamine Oxidase) Deficiency
DAO is an enzyme that breaks down histamine in your body. It’s known for breaking down ingested histamine that you take in when you consume high histamine foods. However, it may also have a role in breaking down immune-mediated histamine as well[*].
The primary issue with DAO deficiency is the accumulation of histamine in your gut that eventually gets absorbed into your circulation instead of being broken down and eliminated[*].
DAO deficiency can occur due to certain pharmaceutical drugs, diseases, and or genetic disorders. Symptoms associated with DAO deficiency vary greatly, but often include[*]:
- Nasal congestion
- Pain (fibromyalgia)
- Chronic fatigue
- Bronchial asthma
- ADHD (Attention Deficit Hyperactivity Disorder
- Hypo or hypertension
#2 HNMT (histamine-N-methyltransferase) Deficiency
HNMT is responsible for breaking down histamine within the cells of your body. This enzyme focuses on histamine that’s been released from your immune system.
It can be found throughout the tissues of your body but is mainly accumulated in your kidneys, liver, spleen, prostate, ovaries, and bronchi. HNMT deficiency can be caused by genetics or environmental factors[*].
#3 Digestive Issues
Dysbiosis, otherwise known as abnormal gut bacteria, may be another cause of histamine intolerance. With three out of the four histamine receptors being located in your gut, this should come as no surprise.
Researchers have found elevated numbers of harmful bacteria, with decreased numbers of beneficial bacteria in the stool of patients with histamine intolerance[*].
Your gut bacteria play a vital role in maintaining the integrity of your intestinal lining. When you experience dysbiosis, issues like leaky gut and inflammatory bowel diseases may occur. These conditions allow particles (like histamine) to pass through your gut and into circulation that would typically be eliminated in your waste.
However, it’s a bit of a chicken-egg situation. Does your gut bacteria cause leaky gut, or does the presence of leaky gut cause dysbiosis[*]?
Regardless of the mechanism, there seems to be a strong correlation between gastrointestinal conditions and histamine imbalance[*].
Symptoms of histamine intolerance are incredibly wide-ranging. Due to histamines many roles in your body, different systems can be activated or deactivated when your histamine becomes imbalanced.
Approximately 1% of the population has histamine intolerance, which may not sound like a lot — but that’s one in one hundred people[*].
Some symptoms of histamine intolerance include:
- Skin rash
- Gastrointestinal inflammation (Crohn’s disease, irritable bowel disease)
- Irregular menstrual cycle
Whether your histamine intolerance is coming from an issue with enzymes, or digestion, one of the best ways to manage high histamine is through food. Avoiding foods rich in histamine, while focusing on low histamine foods is a key aspect of getting your histamine levels back down to normal.
In addition, some foods that are not necessarily high in histamine may trigger reactions or block the enzymes needed to break down histamine.
High Histamine Foods
High histamine foods are mostly foods that have been aged. Histamine accumulates over time, so in general, any food that is reserved is a potential high histamine culprit. With this in mind, try to avoid canned, jarred, or fermented foods[*].
High histamine foods[*]:
- Wine/ alcoholic beverages
- Canned fish
- Smoked meat (salami, ham sausage, prosciutto, pepperoni, etc.)
- Citrus fruits
- Foods with preservatives or artificial colorings
Low Histamine Foods
Low histamine foods will typically be any fresh foods. Fresh foods haven’t had the chance to accumulate histamine, so most of the time they’re a safe bet.
When hitting the grocery store focus on[*]:
- Fresh vegetables (except tomatoes, avocado, and eggplant)
- Fresh fruit (except strawberries and citrus)
- Cooking oils (coconut oil, olive oil)
- Grains like quinoa, rice, corn, teff, and millet
- Herbal teas
Another type of food to be careful with are histamine liberators. These foods don’t necessarily contain high levels of histamine themselves, but they help liberate histamine into your system – therefore contributing to the overall problem.
- Wheat germ
- Additives (nitrites, glutamate, sulfites, benzoate)
Diamine Oxidase Blockers
DAO is an incredibly important enzyme when it comes to the breakdown of histamine. In fact, inhibition or dysfunction of DAO is often the cause of histamine intolerance. While there are certain foods that can contribute to excess histamine, other foods may assist in histamine excess by blocking the function of DAO.
These foods are known as DAO blockers, and include[*]:
- Black tea
- Energy drinks
- Green tea
- Mate tea
If you’re having trouble with histamine, you can still follow a keto diet.
A balanced keto diet will focus on high-quality animal products and lots of low-carb vegetables. If you’re also working on reducing histamine, you’ll just want to keep a few things in mind.
Always choose fresh meat over smoked, preserved, or aged. Meat that’s been aged or preserved in any way will be higher in histamine. Think of it this way: the longer food has been on the shelf, the more likely it has accumulated histamine.
In addition, smoked or aged meat like sausage, pepperoni, smoked salmon, etc. also often contains additives or naturally occurring nitrates. Nitrates are histamine liberators, meaning they enhance the level of histamine in your body, even though they don’t contain histamine themselves.
Dairy holds a significant role in many keto diets. While dairy is not entirely off-limits if you have histamine intolerance, you’ll definitely want to watch your intake.
Focus on fresh dairy products, while staying away from aged products like aged or smoked cheese. And as always, choose high-quality dairy.
Fresh is always best when it comes to histamine. Therefore, avoid canned veggies and items like sauerkraut and kim chi. This doesn’t mean you can only eat salad but bake sure the vegetables you’re cooking with are as fresh as possible.
Frozen vegetables are often picked and frozen right away, so they serve as an excellent option for histamine sensitive people.
On a typical keto diet, there’s no problem with a little low-sugar wine or spirits here and there. However, if you’re dealing with histamine issues, you’ll want to cut the alcohol out as much as possible. Alcohol not only contributes to histamine in your body, but it also blocks the function of the enzyme DAO.
That’s a double whammy for your histamine levels.
Tea is another DAO blocker that you’ll want to cut down on. While most herbal teas are okay, black tea and green tea are a no-go. But the good news is – coffee is low in histamine. If you’re a big tea drinker, try switching over for a cup of coffee.
If you suspect that you might have issues with histamine, then you should consult your healthcare provider.
At this time there aren’t any tried and true tests to determine histamine intolerance, so doctors may ask you to keep a food journal.
If you feel that histamine may be an issue, one of the best ways to figure it out would be to cut out histamine rich foods. Try to avoid these foods for a few weeks and see if your symptoms subside.
Keep in mind that some foods also block the functionality of the enzyme DAO, or assist in the release of histamine. These foods should also be avoided.
Aside from its role in allergy symptoms, histamine plays a number of roles in your body.
Histamine intolerance can create a wide range of health issues. Whether you’re affected by digestive upset, migraines, skin rashes, or congestion, limiting the amount of histamine you get through diet could be incredibly helpful.
While there are certain foods that contribute to histamine intolerance, the good news is that many keto-friendly foods are safe. Avoiding aged products across the board should be your number one goal.
However, fresh vegetables and meat can take up the bulk of your diet – which are hallmarks of a balanced keto diet anyway.
If you think you may have a histamine issue talk to your health care practitioner. One of the best ways to tell if something is going on is to simply eliminate high histamine foods for a few weeks and track your symptoms.