If you found this post, you’re probably dealing with a number of seasonal allergy symptoms, even if you don’t actually have seasonal allergies. Maybe you’re even looking for how to clear histamine from the body without using antihistamines or H2 blockers, the typical medicines that doctors throw at a runny nose and a rash.
This article is focused on that very issue, particularly for those with a histamine intolerance— how can you lower histamine levels naturally and for good?
What is Histamine?
Histamine is an inflammatory nitrogen-containing biogenic amine, which just means that wherever it goes, it causes inflammation. To produce histamine, enzymes and co-factors must come together to convert the essential amino acid L-histidine via a process called “decarboxylation.”
The main co-factors necessary for the production of histamine are PLP (pyridoxal 5’-phosphate), vitamin C, iron, and vitamin B6. Some people with histamine issues end up deficient in one or more of those nutrients due to their body’s overproduction of histamine.
But histamine is necessary because it plays an important part in the body’s inflammatory and immune cells’ reactions to different allergens such as pollen, dust, certain foods, insect bites, and even certain medications.
Recently histamine has also been recognized as a neurotransmitter, due to its many body-wide effects. Histamine is mainly produced in granules in the basophils and mast cells (important parts of your immune system.
Normally, histamine is cleared from the body through a metabolism (breakdown) catalyzed by the enzymes diamine oxidase (DAO) and histamine methyltransferase (HNMT).
Causes of High Histamine Levels
Histamine intolerance itself is a symptom of the root cause(s) and should NOT be listed as a cause by itself. Some of the most common causes include SIBO, mastocytosis, mast cell activation diseases, heavy metal poisoning, some inflammation-causing viruses, and mold toxicity or other infections.
Some sources I’ve read over the years have mentioned nutrient deficiencies, specifically vitamin B12, as playing a role in developing histamine intolerance that can be reversed. Now that we understand what histamine is and why it’s important, let’s look at the many potential causes of high histamine levels.
A condition known as Histamine Toxicity occurs when histamine accumulates in the body, and eventually rises to toxic levels which can lead to potentially dangerous physical symptoms, including anaphylaxis.
The fact is that chronic histamine toxicity— i.e. histamine intolerance— is still widely unknown to modern doctors, and that seems to be the main reason why it still goes widely undiagnosed.
8 Potential Causes of Histamine Toxicity
- Poorly refrigerated or spoiled fish, such as tuna or anchovy, which develop an overgrowth of histamine-producing bacteria. When this bacteria is consumed, it can cause elevated and eventually toxic levels of histamine, in a condition is known as Scombroid Poisoning. Certain types of fish are more prone to causing histamine toxicity, including mackerel, herring, tuna, mahi-mahi, anchovies, bluefish, marlin, and amberjack.
- Low DAO: a deficiency of the enzyme diamine oxidase (DAO), which metabolizes and eliminates histamine from the body, can lead to elevated histamine levels in the body and eventual overload. Causes of DAO Deficiency include the excess use of alcohol, overgrowth of certain intestinal bacteria, as well as DAO blockers (a group which includes medicines as well as foods). Other causes of DAO Deficiency include hormonal imbalances and gastrointestinal disorders such as Irritable Bowel Diseases, of which Ulcerative Colitis and Crohn’s Disease are the most common.
- Mastocytosis is another cause of histamine toxicity. It occurs when the number of mast cells increases in the body’s tissues, even in places where they shouldn’t be. As the number of mast cells increases, so does the amount of histamine produced within the cells, leading eventually to histamine overload if left untreated.
- Small Intestinal Bacterial Overgrowth (SIBO) is a histamine liberator in which there is an overgrowth of bacteria in the small intestines usually due to complications of surgery or intestinal disease, which then leads to elevated histamine levels.
- Mast Cell Activation Diseases are rare, but seem to be increasing in the general population. They’re characterized by abnormal mast cell activation by patient-specific triggers, which cause them to release unnecessary histamine. Continual and untreated triggering of the mast cells leads to extremely high levels of histamine, causing many of the symptoms of a severe allergic attack including hives, shortness of breath, and abnormally low blood pressure. This is different from Mastocytosis.
- Environmental poisoning: both mold poisoning and heavy metal poisoning, such as that with mercury or copper, have been found to lead to inflammatory reactions involving high levels of histamine.
- Viral infection: inflammation-causing viruses such as SARS-CoV-2 have been found to cause increased histamine levels and result in chronically high histamine states if left untreated. Other viruses and bacteria have also been found to increase histamine production and levels, especially in children.
- Vitamin B12 deficiency has also been associated with reversible but persistent histamine intolerance, thought to be due to issues with the body’s ability to break down the histamine quickly enough.
How to Reduce Histamine in the Body Naturally
1. Decrease Stress. Chronically high stress has been found to increase the release of many hormones, use up calming neurotransmitters, and release inflammatory substances such as histamine. Therefore reducing or managing physical and emotional stress can decrease histamine levels in the body. This should be one of your top priorities.
2. Eat a low histamine diet. There are many approaches to starting a low histamine diet, but the first step is to avoid all high histamine foods, as this can also help to decrease the amount of histamine in the body without requiring you to overhaul your diet in one go.
High histamine foods include any fermented foods such as sauerkraut, wine and beer, aged meats and cheeses, olives, tomatoes, vinegars, kombucha, most seafood, and spinach.
This may sound like a lot of foods to cut out, and if that’s the case, for you it may just be easier to jump into following a low histamine diet that outlines only what you can eat.
But rest assured, after just 3-4 weeks eating low histamine, your symptoms should subside— and if not, you’ll need to talk to your doctor about other potential causes for your allergy symptoms.
3. Fight inflammation with food. There are numerous anti-inflammatory and natural antihistamine foods you can & should add to your diet to naturally decrease the amount of histamine in your body. Some anti-histamine foods include garlic, basil, and olive oil, which all together make for a delicious pesto sauce, though there are dozens of options.
Each of these foods contains a combination of mast cell stabilizers and DAO supporters such as bromelain, a natural anti-histamine plant enzyme found in apples, onions, parsley, and blueberries.
4. Utilize natural antihistamines. While whole foods are the ideal form of nutrition, sometimes they’re just not enough. This is where mast-cell stabilizers such as quercetin, stinging nettle, and astragalus come in. Quercetin, which is a polyphenol antioxidant found in pears and apples, has been found to stabilize mast cell membranes and thus decrease the level of histamine in the body, especially when combined with Vitamin C.
5. Digest more slowly. Another way to decrease histamine in the body is to slow its release, thereby giving the body more time to break it down. This means incorporating more sources of low histamine fiber, fat, and protein so that you digest food more slowly, decreasing the rate of further histamine release and giving your body more time to break it down.
Low histamine proteins include nut butters and fresh-frozen meats, and low histamine fats include avocado oil, olive oil, coconut oil, and fats from low histamine meats. Some low histamine fibers to add into meals include hemp, chia, and flax seeds.
6. Increase your DAO. Diamine oxidase, or DAO, is an enzyme produced in the kidneys, the lining of the intestines, and the thymus. As mentioned above, DAO’s main function is to metabolize and break down excess amounts of ingested histamine in the body, along with the enzyme histamine methyltransferase (HNMT).
Increasing DAO production can be accomplished by “eating the building blocks” needed for our bodies to produce our own DAO, which includes the materials needed to make DAO and well as the co-factors needed for its production.
These building blocks are foods that enhance DAO function and production, and they include fresh organic proteins, grass-fed meats, and omega-9 fatty acids, such as those found in fresh eggs, coconuts, and olive oil.
Additional helpful nutrients are found in most types of fresh fruit and various grains, such as quinoa, rice, corn, and millet. Fresh pea sprouts are a vegan source of DAO, but even non-meat eaters should do their best to help their bodies produce DAO rather than consume it directly.
7. Correct systemic imbalances. Being deficient in any one nutrient can have a cascading effect, as can having too much of one. For example, high estrogen has been linked to high histamine levels, and low zinc or copper can impair the production of DAO.
Ask your doctor about getting a full blood panel to check for deficiencies or an overabundance of any given nutrient, though the blood will generally be the last place that a deficiency is revealed, as the body works very hard to keep it in homeostasis, sometimes to your own deficit.
8. Sweat more. This may sound strange if you’ve found that exercise seems to aggravate your symptoms, but sweat is one of the main ways in which your body eliminates toxins. Some people enjoy doing this in a sauna, but personally I prefer an evening bath in warm water, as I find that it also lowers my stress levels.
In this two-for-one approach, helping yourself sweat more will help your body eliminate any heavy metals or mold that may be contributing to your illness, as well as any excess nutrients.
Aim for 15 minutes a day, as any longer in the bath and your body may start reabsorbing all that you just released. Adding epsom salt or baking soda can help further calm your system.
9. Address gut health. This should by no means be the last thing you try or a one-off attempt. Your gut is where much of your body’s histamine ends up, so making sure that it’s in balance should be a top priority.
Low stomach acid levels can contribute to high histamine levels by leaving your gut vulnerable to opportunistic bacteria that either themselves produce histamine or deteriorate DAO, so it’s important for your gut microbiome to keep it neither too high nor too low.
This means checking your stomach acid levels, as well as asking your doctor about a SIBO breath test and a stool test to check for parasites, pathogens, and imbalances in gut flora. Based on the results and your symptoms, your doctor may prescribe you a probiotic or a course of natural antivirals.
One example is mastic gum and oil of oregano (which I took to get rid of my h. pylori). Alternatively, they may pronounce your gut healthy, which is itself an important clue.
I hope this post has helped you figure out a few new ways to support your body’s natural histamine-clearing pathways, as well as fight inflammation in other ways. Do you have any more tips for clearing histamine without antihistamines or H2 blockers?
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Sunday 12th of February 2023
Olive oil is mentioned many times in this article and I have also seen it mentioned in other articles on histamine intolerance. It seems that nothing bad can be said about olive oil. I have histamine intolerance and I react very badly to olive oil. Olive oil has histamine in it. If it helps at all, it's not enough to overcome the reaction. I caution anyone with histamine intolerance against ingesting olive oil.
Saturday 6th of May 2023
@Max, Olive oil is very high in Salicylates. Perhaps that is what u are reacting to.
Sunday 12th of February 2023
I don't think people hail olive oil as a fully-tolerated oil for all, but it's certainly well-tolerated by most people, from what readers and research have told me over the years. I do use it in a lot of my recipes, along with coconut oil, but if you have a sensitivity to olive oil then you should definitely avoid it and just use a different oil— it's all about figuring out why and in which forms you react to certain foods, and configuring your diet around that. If you have very low DAO levels, you may not tolerate olive oil very well initially, but that doesn't mean it's high in histamine or should be avoided by all, and I'd caution against fear-mongering specific foods that are otherwise healthy only because you've reacted to it.
Monday 7th of November 2022
I think that there might be mold behind the paneling in the rental I live in I am all of a sudden so sensitive to anything and everything been living here for 4 years and have been getting sicker and sicker don't know where to start as moving isn't an option right now
Wednesday 9th of November 2022
I highly recommend checking out the book 'Through the Shadowlands' by Julie Rehmeyer. She's a science writer dealing with debilitating mold illness, but I can summarize it for you, as someone who's lived with mold: you can't escape until you leave, and I mean escape. Think of it like an abusive relationship that you just need to flee from, because it colonizes in everything and on everything it can, so if mold is truly making you ill, you need to get away from it and anything it's been in contact with. Mold has been evolving for millions of years and we can't even see the spores, so even if something looks safe, it probably isn't. I don't want to be the bearer of bad news or make anyone more worried, but as someone who's been medically brushed-off or not told the full story too many times to count over the last half decade, I'd rather you not think (like me) that you can spend 3 years living in mold and just leave it behind when you move. Maybe you have people you care for, finance issues, or any of the above, but if you live with mold and it is making you sick, the ONLY first step is to leave and leave all the fabrics and other absorbent things behind. Buy new clothes form a department store and leave every single thing you brought in with you behind. Go live somewhere else, somewhere verified mold-free for one week, and then see how you feel. Your health is everyhting, and I guarantee that even if they don't understand what's going on, your family doesn't want you dying just because they don't 'believe in' the reason you became ill. I'd also 100% consult an expert in mold illness, because they can explain all of this in much better detail and with much more scientific backing than I can. I'm sorry you're dealing with all this, Tina, and I wish you all the luck in the world.
Tuesday 20th of September 2022
A very well written and researched article which has given me all the information I need about how to lower my histamine levels. Thank you.
Wednesday 21st of September 2022
It's my pleasure, David! Always glad to be of help through science.
Tuesday 19th of April 2022
Wonderful article, thank you! I believe as we age DAO production naturally declines. Is this true?
Tuesday 19th of April 2022
Thanks, Laura! From what I've read, yes, this is true; DAO production declines along with most other functions, as we age. This is why older people tend to be more affected by HIT.
Friday 15th of April 2022
Yes, this seems valid info. I have been researching my dermatitis for decades and mostly food and stress seems to trigger. Over the years however my food has narrowed and I hit points of despair to enjoy food other than most but not all vegis! Nightshades, high acid, sugary fruits are a problem. Also most grains, nuts etc etc. I totally understand others suffering. I currently have a steady rash, crazy itching, after Covid booster end of Dec. It's relentless! I have to keep trying things tho, its not tolerable to be in a body rash. I've heard the gut is critical.. do you think leaky guy is legitimate?
Tuesday 15th of November 2022
@Deb, I totally understand your frustration. I never had any allergies, sensitivities, rash, hives, etc the majority of my life and then it started up about 12 yrs ago. And progressively got worse. I was diagnosed allergic to milk & egg yolks with intolerances to citrus, chocolate & such. And had to give up as many histamine releasing foods as I could. It is very sad to have to stop eating all the foods you enjoyed your whole life due to a condition that is hard to understand but makes life miserable. I even ended up with asthma & Roscea because of it. I take Allegra now which helps. Anything that is sedating helps, but I have to take sedatives at bedtime. No itching in the night due to that. I don't recommend this, but drinking alcohol (I drink domestic beer) calms my itching. I suspect because alcohol is considered sedating. I only drink alcohol in moderation and when I won't be driving or doing anything of importance; For me, it calms the itching.
Saturday 16th of April 2022
Stress can be a HUGE underlying factor for people, myself included. The body responds to the environments it's in the best it knows how, regardless of how you would want it to respond. I was reading a book for practitioners last year that was talking about allostasis, which is basically the name for process of the body responding to perceived stressors (foods, pollen, annoying people, etc.), and doing its best to maintain homeostasis. It reacts to what it perceives to be the "new normal." So when a person is dealing with too many stressors, often this can change the basic ways their body responds to things. Learning about this seriously changed the way I saw my body's reactions, and motivated me more to work with my body to understand its logic. I often randomly get contact dermatitis, and it seems to be merely from prolonged contact with anything, so I can relate... dermatitis sucks big time.
Sorry to have gone off on a tangent! But to answer your question, I do think leaky gut is a legitimate issue, but it seems more complex than it's usually explained. It seems to be related to more general inflammation of the gut leading to all sorts of things including higher intestinal permeability or even dysbiosis (imbalance of the bacteria in the gut). It sounds like your immune system is on high alert, as well as your gut being out of balance. I'm not a doctor so I can't give medical advice, but if I were you, my personal choice would be to look closer at my gut. Maybe ask your doctor about a stool test for parasites or dysbiosis, and about colostrum or other immune-regulating supplements. I've been on low-dose Naltrexone for about 10 weeks now and it's been life-changing for my joint pain, numbness, and most of my stomach issues. Sorry for the info dump, but I hope this help, and I'm so sorry you're dealing with this, Deb!