A low histamine diet is needed for those who have a histamine intolerance. This condition is when your body cannot break down histamines, which can lead to a variety of symptoms.
This post outlines the condition and who needs to be following a low histamine diet.
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Table of Contents
What is a histamine?
Histamine is a substance produced by cells during an infection. It signals the immune system to start an inflammatory response, which helps the body fight infection.
In allergies, histamine is incorrectly released by the body in response to something, e.g. nuts. It is this histamine that leads to the symptoms you see in a food allergy.
Histamine is also found naturally occurring in some foods (2, 3, 4).
Histamine intolerance occurs due to the inability to break down histamine in the body. This leads to a build-up of the substance, causing symptoms.
It is thought that around 1-3% of people have histamine intolerance (1). However, the actual number of people may be higher due to the potential undiagnosed numbers.
Check out our Histamine Intolerance E Book
What causes a histamine intolerance?
It is thought that histamine intolerance is caused by previous digestive diseases and/or genetic problems (5).
Usually, histamine is broken down by two different enzymes: diamine oxidase enzyme (DAO) and/or histamine N-methyltransferase (HNMT) (6, 7).
When these enzymes are not working correctly, it leads to a build of histamine, and you start experiencing symptoms (5).
The symptoms of a histamine intolerance
The symptoms of histamine intolerance are not life-threatening but can reduce your wellbeing. Simple things like eating out can become an issue.
Symptoms vary depending on the level of histamine you have built up in your body and are very similar to an allergic reaction. The more histamine you have, the more severe your symptoms will be.
Symptoms can occur between hours or days after eating trigger foods (8).
Histamine intolerance symptom list (12);
- Runny or blocked nose
- Asthma-related wheezing
- Low blood pressure
- Severe skin itching
- Bladder irritation
- Persistent urinary tract infections
How to Diagnose Histamine Intolerance
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Symptoms alone can not diagnose histamine intolerance, and there are no specific tests available either.
Instead, histamine intolerance is diagnosed by ruling out other conditions first. For example, if you are experiencing digestive problems, your doctor will likely test you for conditions such as coeliac disease.
After you receive negative testing, then the ‘gold standard’ for diagnosis of a histamine intolerance is (12);
- A 4 week low histamine diet under the supervision of a registered dietitian.
- A double-blinded placebo-controlled provocation test with histamine.
How to Treat Histamine Intolerance
Histamine intolerance is treated by avoiding high histamine foods and foods that stop histamine’s breakdown.
People with histamine intolerance do not need to follow a low histamine diet 100% of the time. They need to find out their tolerance level.
The low histamine diet
The information available about foods and histamine is confusing. There doesn’t seem to be a very clear-cut path to what you should be doing. However, we know a low histamine diet has improved symptoms in 80% of people (9).
There seems to be a consensus on ‘best practise’ among experts (10). This is based on scientific studies and what medical experts have seen in their own practises.
The experts say that you should be approaching this in a series of ‘stages.’ This is because everyone has a different level of sensitivity, so going into a very restrictive diet may not be required.
The below stages outline the process, and you only need to work through each one if you find that your symptoms are still troublesome.
As we have already mentioned, this condition is an intolerance. However, your tolerance to histamine may differ depending on hormones, stress and other factors (10). Therefore, foods you tolerate one day may become a problem a couple of weeks later.
This diet is complicated and should be done with a registered dietitian to avoid malnutrition complications.
Low histamine food list
- Oils and fats
- Fresh meat and poultry
- Unfermented dairy
High histamine food list
- Fermented food
- Citrus fruits
- Yeast containing products
- Beans and pulses
For a full comprehensive list of low histamine foods, check out this guide by The Swiss Interest Group.
Foods and Medications That Block Histamine Breakdown
Alcohol and caffeine can stop your body from breaking down histamine. If you have histamine intolerance, then you may need to avoid these ingredients.
Some medications can also prevent histamine from being broken down. Speak to your pharmacist for advice on this.
Pros and cons of a low histamine diet
The benefit of a low histamine diet is to manage symptoms of histamine intolerance.
The low histamine diet is very restrictive and so there is a high risk of nutritional deficiencies. This is why it is recommended to do only with a registered dietitian.
Tips to help manage a low histamine diet
We have helped 1000’s of people to manage their histamine intolerance with a low histamine diet. These are the main tips we routinely use;
- Plan your meals out
- Base meals on low histamine carbohydrates such as rice, pasta and quinoa
- Stock up on low histamine fruits for snacks
- Work with a registered dietitian to guide you
- Find out your tolerance level so that your diet is as least restrictive as possible
DAO Enzymes on The Low Histamine Diet
DOA enzymes are oral supplements that you can take before each meal to break down the histamine in your food.
Before you get excited, these enzymes have not been proven to be that useful. There has been 1 study looking at taking a DAO enzyme (7% DAO with an enzymatic activity of 10,000 HDU/ml) 20 minutes before a meal (13).
The study showed that the enzymes helped reduce the pain of headaches related to the condition, but that is it.
It is also important to note that these enzymes are extracted from pig’s kidneys and are not suitable for vegans or Muslims.
Check out our Histamine Intolerance E Book . This book will take you through how to get a diagnosis and manage this condition.
Histamine intolerance is a common condition impacting up to 3% of people. Diagnosis is made through a doctor’s assessment, tests to rule out other conditions and symptom improvement on histamine avoidance.
A low histamine diet is highly restrictive and it is not recommended to follow without registered dietitian guidance.
Kirsten Jackson is a UK registered Consultant Gastroenterology Dietitian and founder of The Food Treatment Clinic. She has undergone many qualifications to get where she is today, including a UK BSc Honours Degree in Dietetics and Post-Graduate Certificate in Advanced Dietetics. In addition to this, she has FODMAP Training from Kings College London University. Kirsten set up The Food Treatment Clinic in 2015 after first experiencing digestive problems herself. She felt that the NHS was unable to provide the support individuals needed and went on to specialise in this area before opening a bespoke IBS service. Kirsten also participates in charity work as an Expert Advisor for the IBS Network. In addition, she can be seen in publications such as Cosmopolitan and The Telegraph discussing IBS as an Official Media Spokesperson to the IBS Network.
Julie Ann Azadegan says
Reading the high tolerance to histamine I feel that is me,I’ve also got IBS,and diverticulitis,so thinking 🤔 when I think it could be IBS,I could be high tolerance to acid foods,that’s when I usually get flare up
Serena Bansal says
Hu Julie! Sounds like you have a lot going on and it is difficult to pinpoint things when this is the case! Please do reach out to us and get in contact if you feel you need support with this. We would be more than happy to help you. You can contact us via the website or email us on email@example.com
Whenever I eat onion an hour or so later I have severe itching on my legs to the point I end up taking paracetamol. Now I believe it to be a histamine intolerance so I avoid or take an anti-histamine. This is all self diagnosed though 🧐. Additionally, EVERY TIME I have a virus I come out in a rash in my chest, neck and face. I’m wondering if this is related to histamine as well?
Serena Bansal Registered Dietitian BSc Hons says
Hi Kate. Onions are actually low histamine. Histamine intolerance can be quite complex so I highly recommend you get an accurate diagnosis first and work with a Registered Dietitian to control it. If you would like further help with this please do reach out to us and email on firstname.lastname@example.org 🙂