Histamine and Digestion

Most of the common understanding on histamine comes from our own experiences or of those around us who have suffered with allergies. Most of us are familiar with antihistamines, medicines that block the action of histamine in our body. These help reduce the symptoms of sneezing, runny nose, and itchy eyes associated with seasonal allergies like ragweed and pollens. But the actions of histamine run much deeper than hayfever, food allergies and mosquito bites. In fact, they have far-reaching effects in the gut itself.

As you’ll see, histamine and poor digestion are connected more often than you’d think. In today’s article I break down the role of histamine in the gut and the ways histamine shows up in different digestive issues. We’ll discuss who’s at risk for histamine issues and some signs to watch out for. Finally, we’ll explore some practical solutions if you suspect your digestive issues may be related to histamine.

So What Does Histamine Do?

Before we dive into the specific ways histamine impacts digestion it’s important you understand a few of the important roles it plays in the body. Here are a few of its key functions:

1. Allergic Response: When you come into contact with an allergen, such as pollen or pet dander, histamine is released in response. It causes symptoms like sneezing, itching, and watery eyes.
2. Immune Response: Histamine plays a role in this response by increasing blood flow and permeability. This allows immune cells to travel to the affected area and fight infections.
3. Inflammation regulation: Histamine is a signaling molecule that helps to regulate the body’s inflammatory response. It can cause blood vessels to dilate and increase blood flow to the affected area, promoting healing and delivering immune cells.
4. Neurotransmission: In the brain, histamine acts as a chemical messenger. It helps control how awake, alert, and hungry we feel. Medicines that work on histamine receptors are used to manage problems like allergies, trouble sleeping, and eating disorders. This is why some antihistamines can make you feel drowsy. This is also in part, why some individuals with histamine issues may struggle with anxiety or insomnia.
5. Stomach Acid Production: Stomach acid is, in part, produced by the action of histamine on our acid-producing cells. This aligns with histamine’s functions in defense. After all, stomach acid helps neutralize pathogens. Some heartburn medicines target histamine receptors in the stomach.

How is Histamine Produced & Processed?

Histamine is both produced within our bodies and ingested through foods and beverages. Let’s break this down a bit further. Generally speaking, we develop symptoms from histamine when we:

• Release or produce too much of it
• Consume excessive amounts
• Can’t break it down effectively

The body releases histamine from white blood cells known as mast cells. The cells in the stomach also produce histamine. Certain activities and substances can trigger an increase in histamine levels in the body. Here are some examples:

1. Allergies: Exposure to allergens such as pollen, dust mites, animal dander, or certain foods can stimulate the release of histamine.
2. Alcohol consumption: Alcoholic beverages, particularly red wine, beer, and champagne, can lead to an increase in histamine levels.
3. Certain foods: Some foods naturally contain histamine or trigger its release. See below for examples
4. Physical exertion: Intense exercise or strenuous physical activity can cause a release of histamine in the body.
5. Stress: Emotional or physical stress can contribute to increased histamine levels.
6. Medications: Certain drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and some antibiotics, can interfere with the breakdown of histamine, leading to higher levels in the body.

High histamine foods and beverages that may contribute to digestive issues:

• Fermented foods: Sauerkraut, kimchi, kefir, yogurt, kombucha
• Aged cheeses: Cheddar, gouda, parmesan, Swiss, blue cheese
• Smoked and cured meats: Salami, sausages, bacon, ham
• Shellfish: Shrimp, crab, lobster
• Tomatoes and tomato products: Tomato sauce, ketchup, canned tomatoes
• Spinach
• Chocolate and cocoa products
• Citrus fruits: Oranges, lemons, grapefruits
• Strawberries
• Pineapple
• Avocado
• Black & green tea
• Fermented soy products: Soy sauce, miso, tempeh
• Vinegar and foods containing vinegar: Pickles, mustard, mayonnaise
• Alcohol: Especially red wine, beer, champagne

Finally, there are two ways that histamine is broken down in the body. The first is through an enzyme called diamine oxidase (DAO). The second is through an enzyme called Histamine-N-methyltransferase (HNMT). DAO breaks down most of the histamine in the gut – we’ll keep our focus on it. DAO’s ability to handle histamine levels hinges on certain factors like genetics, gut microbes, medications, and foods. More on this shortly.

How does histamine affect digestion?

Now let’s turn our attention to how histamine impacts digestion.

Symptoms of too much histamine in the gut include:

• Heartburn/acid reflux
• Nausea
• Abdominal pain
• Indigestion
• Vomiting
• Diarrhea
• Bloating

Histamine can directly cause theses digestive symptoms through the following ways:

1. Increasing stomach acid – worsening heartburn and indigestion
2. Altering gut motility – things moving too fast or too slowly which can lead to nausea and diarrhea
3. Irritating gut nerves – many of the immune cells lie in nerve rich areas in the gut
4. Causing/worsening leaky gut
5. Increasing fluid levels in the bowels – This results in bloating and diarrhea

Digestive disorders connected with Histamine intolerance

• IBS
• GERD
• Eosinophilic esophagitis (EoE)
• Functional Dyspepsia
• Ulcerative colitis
• Anal fissures

Who’s at Risk for Histamine Issues?

Those With Histamine Genes

Typically you’ll know if you have histamine genes. A sibling, a parent or perhaps the whole family will suffer with allergies (including food and seasonal), asthma or eczema.

Histamine regulation involves several genes. The main ones control for the creation, breakdown of histamine and how strongly the histamine receptors respond.

1. The HDC gene is in charge of making histamine from the amino acid histidine.
2. DAO (Diamine Oxidase) Genes: These genes influence the enzyme diamine oxidase. It is important because it helps break down histamine.
3. The Histamine N-Methyltransferase gene produces an enzyme that changes histamine into another form that is not active.

Genes don’t have the final say though! Learning to identify your triggers and improve your histamine responses can go a long way to reduce digestive suffering.

Recent Gut Infection

An infection like a stomach bug or food poisoning event can set off a cascade of histamine production that can affect digestion. In fact, if you were to look at the digestive lining under a microscope following a gut infection, you would see an increase in size and number of mast cells. These defense cells “stick around” and monitor the surroundings for dangers well after the infection has resolved. However, the alarm is often set off by things like spicy foods, stress, and caffeine instead of real threats. Even exercise can cause the body to produce histamine.

This is particularly true in functional dyspepsia, a chronic meal-related disorder of indigestion. Mast cells often concentrate in the first part of the small bowel in functional dyspepsia. When they spill their contents this results in upper abdominal pain, burning, fullness and bloating.

Check out a podcast episode I was featured on discussing functional dyspepsia

Imbalanced Gut Bugs & Leaky Guts?

Studies suggest that the microbes in our gut are linked with histamine and digestive issues. In fact, some studies have shown that those with histamine issues have a completely different make up of microbes in their gut. What’s worse, these people have higher markers of leaky gut, setting up a vicious cycle of higher histamine levels and resulting gut permeability.

Check out a previous article I wrote on the topic of gut dysbiosis

Hormones/Pregnancy

During times like menstruation, pregnancy, or menopause, hormonal changes can impact the way your body handles histamine. Estrogen can promote mast cell release of histamine. This can worsen digestive symptoms of histamine. It’s no wonder that antihistamines are often added to the treatment of nausea of pregnancy. It’s not all bad, however, as hormone fluctuations can also improve breakdown of histamine alleviating symptoms for some.

Signs You have Histamine Issues?

I’ll admit that the symptoms above are not overly specific. In order to figure out whether your digestion issues are related to histamine, consider whether the following statements apply to you:

• You have a past or present history of allergies, asthma or eczema
• Your gut symptoms worsen during hayfever season (beginning in the spring)
• Your digestive symptoms coincide with other classical histamine symptoms like flushing skin, hives, itchy skin, sneezing, and headaches
• You take antihistamines for seasonal allergies and they improve your gut symptoms
• Eating or drinking “gut healthy” fermented foods like yogurt, sauerkraut or kefir only makes your symptoms worse
• Non-classical food triggers like vinegar, avocados, bananas, tea, seafood, deli meats or left over foods aggravate your gut symptoms
• Pregnancy either aggravates or improves your symptoms

Balancing Histamine in the Gut

First of all, it’s important to reach out to a healthcare professional like a naturopathic doctor if you suspect histamine intolerance is impacting your digestion. Treatment of histamine intolerance can be tricky at best and a bit like navigating a never-ending maze at worst. So you’ll want to make sure you have an expert guide along your way. Ok, with that being said, I’d like to share some of the strategies that might prove helpful in your journey.

Herbal Remedies

Herbal remedies can have specific benefits by stabilizing mast cells, having antihistamine effects or by nudging the immune system to be less reactive. Here are some of the herbs I use commonly for improving histamine and digestion:

• Chinese skullcap – Has both anti-inflammatory and antihistamine properties
• Reishi – Helps balance the part of the immune system which promotes allergies
• Nettle Leaf – Has direct antihistamine effects. Great option as an herbal tea
• Black Seed – Contains Thymoquinone which reduces mast cell histamine release. Particularly useful with asthma
• Ginger Root – Particularly useful in nausea and indigestion

Nutrients/Supplements

Like herbal remedies, nutrients and supplements may be helpful

• Quercetin, Luteolin – These polyphenols can stabilize mast cells and reduce histamine levels
• Probiotics – Always a hot topic, the use of probiotics is challenging and not straight forward. Some probiotic strains increase histamine, whereas, others may decrease histamine levels
• DAO enzymes – These are typically taken like digestive enzymes before or with meals to improve the breakdown of histamine and to reduce the associated symptoms.

Medications:

At the end of the day some people will need antihistamine medications throughout their journey. If digestion issues are related to histamine, we would expect medications that block histamine receptors to be helpful for heartburn, abdominal pain, nausea and diarrhea. You may need medications that stabilize mast cells in the gut as well.

Always discuss medications, supplements and herbal products with your healthcare provider first

Summary

In short, histamine and digestive problems are often connected and can be tricky to manage. They are more likely to occur if you or your family has a history of allergies. Besides genetics, gut infections, certain foods, hormones, and even stress or exercise can affect how well your body handles histamine. Although this article provides some questions to help you figure out if your issues might be related to histamine, I recommend you seek advice from a healthcare professional such as a naturopath. This is particularly important if you are thinking of following a stricter diet to manage your symptoms.

References

Fabisiak, Adam, et al. “Targeting histamine receptors in irritable bowel syndrome: a critical appraisal.” Journal of neurogastroenterology and motility 23.3 (2017): 341.

Schink, M., et al. “Microbial patterns in patients with histamine intolerance.” J Physiol Pharmacol 69.4 (2018): 579-593.

Schnedl, Wolfgang J., and Dietmar Enko. “Histamine intolerance originates in the gut.” Nutrients 13.4 (2021): 1262.