Histamine Intolerance is the excess accumulation of histamine in the body. About 1% of the world’s population is diagnosed with histamine intolerance.
What Is Histamine?
Histamine is an organic compound produced in the body. It is also obtained from certain foods you eat. Histamine has the following functions in the body:
- Releases stomach acid to help digestion
- Informs the brain in case of inflammation or allergy
- Helps in the contraction of smooth muscles of the stomach, lungs, and uterus
- Dilates blood vessels and reduces blood pressure
- Increases heart rate in case of physical or mental trauma or danger
Symptoms of Histamine Intolerance
Below are the symptoms of excess histamine accumulation in the body:
- Irritable Bowel Syndrome (IBS)
- Stomach pain and cramps
- Itchy skin and hives
- Congested or runny nose
- Itchy, watery, and red eyes
- Continuous sneezing and coughing
- Rapid heart rate and high blood pressure
- Difficulty in breathing
Food Allergy or Histamine Intolerance?
It is almost too easy to mistake the symptoms of histamine intolerance for those of a food allergy. This is because in both cases, the symptoms are a result of a surge in histamine levels. However, the reason for this surge is different in each case.
In food allergies, proteins in certain foods are seen as invaders, and our immune system releases histamine and other chemicals. These, in turn, cause symptoms like itching and hives.
In histamine intolerance, the symptoms are brought about by histamine-rich foods or foods that induce the excess release of histamine. Histamine intolerance is not sensitivity to histamine but an indication that too much of it has built up in your body. This occurs when your body cannot break down histamine effectively. Depending on the breakdown rate, different individuals can tolerate different levels of histamine.
How Does Genetics Influence Histamine Intolerance?
The amine oxidase copper containing 1 (AOC1) gene produces diamine oxidase (DAO) in the body. DAO helps breakdown histamine. Lowered levels of DAO leads to higher levels of histamine in the body.
Certain mutations in the AOC1 gene results in histamine intolerance. Certain SNPs in the AOC1 gene results in decreased DAO levels, thereby increasing the risk of histamine intolerance:
- rs10156191 - risk allele T
- rs1049742 - risk allele T
- rs2052129 - risk allele T
- rs1049793 - risk allele G
- rs2268999 - risk allele T
Non-Genetic Influences On Histamine Intolerance
When you are intolerant to histamine, it does not mean you are sensitive or allergic to histamine. It only means that your body has accumulated more histamine than what’s usually needed.
Bacterial infections - Bacterial infections lead to bacteria overgrowth in the body, and this can increase histamine levels. Normal levels of DAO cannot breakdown this excess histamine.
Excessive consumption of histamine-rich foods - Fermented foods, canned foods, alcohol, smoked meat, pickles, etc., are very high in histamine levels. Including these foods in your everyday diet can increase histamine accumulation in the body and lead to histamine intolerance.
Foods encouraging histamine release - While some foods can be low in histamine, they can encourage the release of histamine from the tissue mast cells. Few such food options that can lead to histamine intolerance are:
- Citrus fruits
- Egg white
- Crustaceans like crabs, lobsters, and shrimps
Certain drugs and long term medications - Certain drugs are known to increase histamine production in the body. Long term use of such medications can lead to histamine intolerance.
If you are taking one or more of the below drugs, talk to your doctor about their effects on your histamine levels.
- Muscle relaxants
- Tuberculosis medications
Atopic eczema - Studies show that people with severe atopic eczema end up having higher histamine levels in the plasma. This can, with time, lead to histamine intolerance.
Excess alcohol consumption - When you consume excess alcohol, it leads to histamine intolerance in the following ways:
1. Alcohol and histamine metabolic pathways release the same enzymes - aldehyde oxidase. This prevents histamine from getting fully broken down.
2. Alcohol encourages the tissue mast cells to release more histamine than what’s needed.
3. Alcohol reduces DAO production in the body leading to increased histamine levels. This can result in histamine intolerance.
Effects Of Histamine on the Body
- A concentration of histamine above 100 ng/mL can lead to cardiac arrest.
- Histamine levels between 7-12 ng/mL can lead to breathing difficulties, wheezing, cough, and airway spasm.
- A decrease in arterial pressure leading to dizziness occurs when the histamine levels are between 6-8 ng/mL.
- Headaches, flushes, hives, and skin itches are common when levels are between 3-5 ng/mL.
- Gastric acid secretion and a slight increase in heart rate are seen in people with histamine levels between 1-2 ng/mL.
Recommendations To Manage Histamine Intolerance
Diamine Oxidase (DAO) supplements - A 2019 study made use of DAO oral supplements in people with histamine intolerance. The study concluded that the symptoms of the condition reduced greatly with these supplements.
Histamine-elimination diet - Check the list of foods rich in histamine and eliminate them from your diet for at least 2-3 weeks. This is enough to eliminate stored histamine from the body. Start adding one food at a time and watch for the reappearance of the symptoms. This will help create your own food plan that keeps the symptoms of histamine intolerance controlled.
Choose fresher foods - Most packaged, canned, frozen, and pickled foods are high in histamine levels. You can control the symptoms when you choose fresher fruits, vegetables, greens, and grains.
Know your threshold for alcohol - Some people with severe histamine intolerance start stowing symptoms with very little alcohol in the body. Others can handle a certain limit before they reach their threshold. Drink moderately and watch your body for allergic flare-ups. You will know your alcohol limit over time.
- Histamine intolerance is the excess accumulation of histamine in the body. 1% of the entire global population is intolerant to histamine.
- Histamine helps in the normal functioning of the body and is needed for digestion. Histamine is released as a result of inflammation, allergy, and when the body is in physical or mental danger.
- Increased heart rate, diarrhea, Irritable Bowel Syndrome (IBS), breathing difficulties, dizziness, and allergic symptoms like hives, itchy skin, and watery eyes are some of the symptoms of histamine intolerance.
- One of the main causes of histamine intolerance is the decreased production of diamine oxidase (DAO) in the body.
Five different SNPs in the AOC1 gene causes decreased production of DAO and leads to an increased risk of histamine intolerance.
- Bacterial infections, consumption of histamine-rich foods, consuming drugs that can increase histamine levels in the body, and excess alcohol consumption can all lead to histamine intolerance.
- OTC antihistamine drugs, antihistamine prescription drugs, and DAO supplements all can keep symptoms of histamine intolerance controlled.
- Following a histamine-elimination diet also helps in preventing the flare-up of the condition.