Histamine is produced by animals and by plants, and is present in many foods. Excess histamine — whether produced within the body or consumed in histamine-containing foods — is usually cleared away by enzymatic action. When this fails, or when the body is flooded by more histamine than can be easily cleared, symptoms of histamine intolerance may result. In this article we’ll get into the details of what histamine is, causes and symptoms of histamine intolerance, and how a low histamine diet may help reduce intolerance symptoms.

What Is Histamine?

Histamine is an immune compound that plays a number of important roles in the body, from stimulating gastric juices for digestion to carrying signals between neurons in the brain. It’s best known for causing the uncomfortable symptoms we have during an allergic reaction: Histamine causes the itchy throat, watery eyes, and hives we experience in response to allergens like cat dander and pollen. Allergy medications such as Benadryl (diphenhydramine) and Claritin (loratadine) are antihistamines, meaning they block the effect of histamine in the body to alleviate these uncomfortable symptoms. (Source)

In an allergic reaction, histamine is released by specialized immune cells called mast cells. There are receptors for histamine all over the body, including in the gut lining, lungs, and brain. Histamine triggers vasodilation, or the relaxation of blood vessels, and increases the ability of immune cells to move in and out of blood vessels. These effects make it possible for white blood cells and other immune molecules to easily reach areas that are injured or under attack by foreign antigens. Histamine also can increase production of cell-signaling proteins called cytokines, and work as a neurotransmitter in the brain. (Source)

Although we need the inflammation mediated by histamine to protect the body from injury and harmful pathogens, having too much histamine contributes to chronic inflammation and is implicated in many inflammatory conditions such as asthma, autoimmune diseases, and inflammatory skin diseases.

How Does Your Body Regulate Histamine Levels?

How does your body get rid of histamine when there is too much? There are two enzymes, called diamine oxidase (DAO) and histamine N-methyltransferase (HNMT), that can break down histamine in your body.

DAO and HNMT are found in different regions of your body. HNMT is responsible for breaking down histamine inside your cells, whereas DAO is responsible for breaking down histamine in the area surrounding your cells. Both of these enzymes are important for regulating the histamine level in your body. (Source)

But What About Histamine Intolerance?

When DAO or HNMT are not functioning properly, you can develop histamine intolerance. Histamine intolerance is a disorder in which your body has impaired ability to break down histamine.

Histamine intolerance makes you hypersensitive to dietary histamine. However, it is important to note that histamine intolerance, like any intolerance to specific foods, is different from an allergy.

Histamine intolerance has two main causes:

• overproduction of histamine: Environmental allergies and increased consumption of histamine through food or alcohol can result in too much histamine circulating in your body. This high level of histamine can cause you to develop symptoms of histamine intolerance.
• impaired histamine degradation: If DAO or HNMT are not functioning properly, they won’t be able to break down histamine in your body. Impaired enzyme action is the more common cause of histamine intolerance.

(Source)

There are also certain medications that are thought to either prevent DAO from breaking down histamine or cause histamine intolerance directly as a drug side effect. Some of these include:

• chloroquine (antimalarial)
• verapamil and clonidine (antihypertensives)
• amitriptyline (antidepressant)
• clavulanic acid (antibiotic)

(Source)

Do I Have Histamine Intolerance?

Histamine Intolerance Symptoms

Symptoms of histamine intolerance usually occur when you consume foods that are rich in histamine, such as wine or aged cheese. These symptoms are usually gastrointestinal symptoms such as:

• abdominal pain
• gas
• diarrhea
• nausea
• feeling extremely and uncomfortably full after eating
• constipation

You may also experience:

• runny or stuffy nose
• headache
• dizziness
• sneezing
• swelling of the skin
• eczema

(Source, Source)

Am I At Risk For Histamine Intolerance?

About 1% of the population has histamine intolerance, making it an uncommon condition. Histamine intolerance is more common in middle-aged people and, in the case of histamine intolerance caused by impaired histamine degradation, is often genetic. For example, if one of your parents has histamine intolerance caused by faulty DAO or HNMT, you could be at higher risk of having this same type of histamine intolerance.

Histamine intolerance is also associated with inflammatory and gastrointestinal diseases such as Crohn’s disease, food allergies, and ulcerative colitis. If you have one of these conditions, you may be at higher risk for histamine intolerance. (Source)

How Is Histamine Intolerance Treated?

Although it is not clear whether histamine intolerance can be cured, there are ways to improve symptoms. The most common treatment involves following a low histamine diet. Your WellTheory team can help you identify the root cause of your symptoms, and help you manage your symptoms through therapeutic diets and targeted supplements to get your histamine levels in check. (Source, Source, Source)

DAO Supplementation for Histamine Intolerance

Small studies of supplementation with DAO of both animal and plant origin have had some promising results. Research continues into the best sources of the enzyme, optimal dosing, and how to protect it from being broken down in the intestines before it can work. (Source)

Antihistamines for Histamine Intolerance

Antihistamines work by blocking histamine receptors found on cells throughout the body. They might provide some temporary relief from symptoms of histamine intolerance but haven’t been well-studied for this purpose. Because histamine also performs important beneficial functions in the body, blocking it with antihistamines can cause unwanted side effects. Currently antihistamines don’t provide a long-term solution for histamine intolerance. (Source)

The Low Histamine Diet for Histamine Intolerance

You can follow a low histamine diet as either a lifestyle or as an elimination diet. Studies show that eliminating histamine foods from your diet for 3 to 4 weeks can resolve symptoms, and adequately lower histamine levels in the body so that you may be able to reintroduce histamine foods without flare ups. Individuals with more severe histamine intolerance often find that sticking to a low histamine diet suits their body best. (Source)

Avoid High Histamine Foods

If you have histamine intolerance, it can help to avoid or limit consumption of foods that are high in histamine. Some of these histamine-rich foods include:

• aged cheese such as gouda and Swiss
• eggplant
• avocado
• soy sauce
• ketchup
• bananas
• red wine
• fermented foods such as kimchi and sauerkraut
• processed meat such as salami
• chickpeas
• fish such as mackerel and tuna
• beer

(Source, Source)

‍

Avoid Histamine Liberators

There are also groups of foods referred to as histamine liberators. Histamine liberators do not contain high levels of histamine, but there is evidence they may cause mast cells to release their histamine.

It is a good idea to limit your consumption of histamine liberators if you have histamine intolerance. Some of these histamine liberators include:

• citrus fruits such as oranges
• tomatoes
• nuts
• strawberries
• spinach
• papaya
• pineapple
• chocolate

(Source)

Low Histamine Diet Recipes

1. Easy Low Histamine Blender Blueberry Muffins

Source: Mast Cell 360

These blueberry muffins are free of high histamine foods and are easy to whip up for breakfast. This recipe calls for a special type of flour called cassava flour, which is made from the root of the cassava plant. Cassava flour is nut free, grain free, gluten free, not fermented, and is a great flour substitute if you are allergic to nuts or sensitive to gluten. This recipe also uses anti-inflammatory foods such as coconut milk and coconut oil, which could help alleviate symptoms of histamine intolerance. (Source)

2. Low Histamine Pizza

Source: Mast Cell 360

Although many diets can feel restrictive, the low histamine diet has a plethora of recipes to provide for your guilty pleasures. This low histamine pizza recipe is versatile and suggests swaps you can make for each ingredient. This recipe also uses cassava flour and doesn’t include tomatoes or pepperoni, which are both high histamine foods. The low histamine pesto is a great substitution for tomato sauce because pesto contains basil, which has anti-inflammatory effects. (Source)

3. Turmeric Chicken Stir Fry

Source: Randa Nutrition

This turmeric chicken stir fry dish provides a great anti-inflammatory boost. This recipe is gluten and dairy free and contains turmeric, which is an anti-inflammatory spice. Anti-inflammatory foods are a great way to counter the effects of histamine in your body. (Source)

Make it AIP: To make this recipe AIP, swap another vegetable such as peas or shredded carrots for the red pepper, and omit the sesame seed garnish and almond butter.

The Bottom Line on the Low Histamine Diet

There’s no one size that fits all. Like many diets, the low histamine diet needs to be personalized to you. If you have histamine intolerance it’s important to learn what foods are high in histamine and try to limit your exposure to them, replacing them with low histamine alternatives. Our Care Team at WellTheory can help guide you through this process — explore our high-touch coaching membership.

If you have histamine intolerance due to impaired DAO function, it’s possible taking enzyme supplements in addition to following a low histamine diet will help your body break down histamine after an inflammatory reaction. In some cases, antihistamines may provide temporary relief from symptoms of histamine intolerance.

‍