Histamine Intolerance 101 (and How to Eat a Low Histamine Keto Diet)

Living with histamine intolerance can be frustrating. If you eat foods high in histamine, you provoke a variety of undesirable symptoms.

Avoiding histamine can help manage these symptoms, but the list of high histamine foods is long. Unfortunately, many of these foods—like seafood, leftovers, and spinach—are Keto staples. 

If you suffer from histamine intolerance, you probably won’t need to restrict these foods forever. But a low histamine diet is still the best first-line treatment option.[*]  

Today, you’ll learn about histamine intolerance with a special focus on a low histamine Keto diet. Read on. 

What Is Histamine?

Histamine may be the villain of this article, but at optimal levels, it’s a necessary immune chemical that supports many bodily functions. 

Secreted by a variety of immune cells, histamine mediates the immune response, including allergic reactions. It makes your nose stuffy, a bee sting swell, and your blood vessels dilate to allow immune factors (like white blood cells) to combat pathogens.[*] 

But it’s not just immune function. Histamine also regulates the secretion of gastric acid and other components of digestive health. And in the brain, histamine serves as a neurotransmitter to influence sleep, wakefulness, and the production of pain-relieving chemicals.[*] 

Where does the chemical histamine come from? It is:

• Produced by immune cells
• Produced by certain gut bacteria
• Ingested from dietary sources as histamine or the amino acid histidine (histidine is a precursor to histamine found in protein)

When histamine levels become too high, a person may experience histamine intolerance. 

What Is Histamine Intolerance?

Histamine intolerance is a catch-all term for a range of symptoms related to high histamine levels in the body. Many of these symptoms are similar to the symptoms of allergies. 

Histamine Intolerance Symptoms

• Itching of the skin or hives
• Watery or itchy eyes
• Nasal congestion, runny nose, or seasonal allergies
• Swelling of the face, mouth, or other tissues
• Throat tightness
• A drop in blood pressure (dizziness upon standing)
• Tachycardia (rapid heartbeat) or heart palpitations
• Digestive issues like heartburn or acid reflux
• Headaches
• Fatigue 
• Irritability
• Insomnia

Many clinicians are skeptical that excess histamine can cause these symptoms, but a growing body of literature suggests otherwise.[*][*] Conventional medicine is slowly catching up.

What Causes Histamine Intolerance?

Two overlapping factors can drive excess histamine levels and subsequent symptoms:

1. Overproduction of histamine
2. An inability to break down histamine

First, if you’re overproducing histamine, your gut bacteria might be to blame. Certain strains of bacteria produce histamine, while others degrade it.[*] 

It might also be your mast cells—the primary histamine-producing immune cells—producing too much histamine. This is called Mast Cell Activation Syndrome (MCAS), and researchers are still unraveling why it happens.[*]  

The second problem relates to breaking down histamine. Your body degrades excess histamine in several ways, including[*]:

• Histamine-degrading gut bacteria
• An enzyme called histamine N-methyltransferase 
• An enzyme called diamine oxidase (DAO)

Problems with any of these systems—for instance, a genetic tendency to underproduce DAO—can result in excess histamine and the symptoms of histamine intolerance. 

Managing Histamine Intolerance

As you just learned, histamine sensitivity is complex. It is well worth enlisting a functional (or integrative) medicine practitioner to help identify the root problem. 

There’s no established test for histamine intolerance, but you can measure histamine levels in the blood, along with testing DAO levels. Each of these may help inform your treatment plan.

For instance, you may have too many histamine-producing bacteria in your gut.[*] The fix could involve:

• Taking histamine-degrading probiotics (like L. plantarum)
• Avoiding histamine-producing probiotic strains (like L. casei)
• Dabbling with different gut protocols

There are also supplements (like quercetin and vitamin C) that may help regulate mast cell activity and inhibit histamine release.[*][*] DAO itself is also available in supplement form.  

But the gold standard for managing histamine intolerance is to avoid high histamine foods. Unfortunately, there are lots of foods to avoid.

High Histamine Foods

• All fermented foods (sauerkraut, kefir, kimchi, yogurt, etc.)
• Cheese
• Canned foods
• Seafood (especially canned seafood)
• Vinegar (and foods that contain vinegar like pickles, mustard, and ketchup)
• Wine
• Chocolate
• Processed or cured meat
• Leftover meat (histamine levels increase over time)
• Citrus fruits
• Tomatoes
• Spinach
• Spices like cinnamon, cloves, and curry
• Herbal tea

Also, certain compounds (including alcohol and some medications) can exacerbate histamine intolerance by blocking the activity of the DAO gene.[*] These compounds are called DAO blockers. 

Other compounds may function as “histamine liberators,” triggering your cells to release more histamine. But at present, there isn’t enough data to support their connection to histamine intolerance.

The best approach may be to eliminate high histamine foods and re-introduce them one by one after your symptoms dissipate. A functional medicine practitioner can help to guide you through this process to ensure you are still meeting your nutritional needs. It’s not easy to give up your favorite munchies, but your long-term health and comfort are worth it. 

Is Keto Low Histamine?

Not by default, no. A Keto diet allows many high histamine foods—spinach, fermented foods, dark chocolate, etc.

If you’re dealing with histamine intolerance on Keto, try to avoid these foods:

Top 10 Keto Foods To Avoid With Histamine Intolerance

1. Seafood (especially canned)
2. Leftover meat
3. All fermented foods
4. Cheese
5. Spinach
6. Processed meat
7. Berries
8. High histamine spices, such as paprika, cayenne pepper, allspice, cinnamon and mace
9. Vinegar
10. Dark chocolate

It’s true. A Keto diet without seafood, vinegar, and leftovers doesn’t make your life any easier. But it’s not that bad. 

Eating a low-histamine Keto diet means consuming fresh meats, fresh vegetables, eggs, (most) nuts, and healthy fats. It’s just a clean Keto diet with a bunch of items removed. 

If your symptoms improve after a couple of weeks, try reintroducing forbidden foods one by one. Fresh seafood is a good one to try first since it’s so nutritious.

Living With Histamine Intolerance

Histamine intolerance isn’t necessarily a lifelong condition. You may only need to restrict high histamine foods temporarily or cycle on and off as needed. 

Or you may find that your symptoms improve when you address underlying gut issues or start a new supplement protocol. That’s where the support of a savvy medical professional can come in handy. 

All the while, think holistically. For instance, both sleep deprivation and stress affect your immune system, and therefore histamine intolerance.[*] Even if it doesn’t rectify your histamine problem, there’s no downside to being better rested and less stressed. 

So hang in there, and keep tinkering. That’s how you make progress.   

FAQs

1. What is histamine intolerance?

Histamine intolerance is a condition characterized by an accumulation of histamine in the body, leading to symptoms similar to allergic reactions. It typically occurs when the body either produces too much histamine or cannot break it down efficiently.

2. What are the symptoms of histamine intolerance?

Common symptoms include headaches, nasal congestion, hives, fatigue, digestive issues, rapid heartbeat, and low blood pressure. These symptoms can vary widely and often resemble seasonal allergies.

3. What causes histamine intolerance?

Histamine intolerance is primarily caused by two factors: overproduction of histamine, often linked to gut bacteria or mast cells, and an impaired ability to break it down, such as reduced diamine oxidase (DAO) activity. Both can lead to excess histamine levels in the body.

4. Is there a test for histamine intolerance?

There is no standardized diagnostic test for histamine intolerance. However, measuring blood histamine levels and DAO activity may provide useful information when considered alongside symptoms and dietary response.

5. What foods are high in histamine?

High-histamine foods include fermented foods such as kimchi, sauerkraut, and yogurt, as well as aged cheeses, canned or processed meats, seafood (especially canned), leftovers, vinegar, and alcohol. These foods can trigger or worsen symptoms in sensitive individuals.

6. Is a keto diet low in histamine?

A keto diet is not inherently low in histamine. Many commonly consumed keto foods, including spinach, fermented foods, processed meats, and dark chocolate, contain high levels of histamine, which may exacerbate symptoms.

7. What can you eat on a low-histamine keto diet?

A low-histamine keto diet emphasizes fresh meat and poultry, fresh vegetables, eggs, healthy fats, and certain nuts. Prioritizing freshness and avoiding aged, fermented, or leftover foods is essential to help minimize histamine exposure.

8. How do you manage histamine intolerance?

Managing histamine intolerance typically involves eliminating high-histamine foods and gradually reintroducing them to identify individual triggers. Supporting gut health, managing stress, and working with a healthcare professional may also help improve symptoms.

9. Is histamine intolerance permanent?

Histamine intolerance is not always permanent. In some cases, symptoms improve over time, particularly when underlying factors such as gut imbalances or enzyme deficiencies are addressed.