If you regularly experience allergy-like symptoms outside of allergy season, you may have histamine intolerance. Unlike food intolerance, symptoms of histamine intolerance gradually present themselves over time instead of immediately after eating.
Diet is one way to counter histamine intolerance. Since many foods contain varying levels of histamine, it’s impossible to follow a histamine-free diet. Instead, consider a low histamine diet.
In this article, we’ll take a look at what a low histamine diet is and how it can support your overall gut health. We’ll also explore the role probiotics and other supplements may play in improving your body’s immune response.
What Is a Low Histamine Diet?
To fight threats to your immune system, mast cells release histamine into your bloodstream. Histamine dilates your blood vessels, creating inflammatory responses like sneezing, heart palpitations, and rashes.
Diamine oxidase (DAO) is an enzyme that breaks down histamine. Ingesting too many histamine-rich foods can block DAO enzymes from doing their job. Combined with a gradual rise in histamine levels, this leads to histamine intolerance .
An effective way to start lowering your histamine levels and improve symptoms is following a low histamine diet.
Low Histamine Diet Rules
The general structure of a low histamine diet is free of:
- Aged or fermented foods
- Ready-made meals and canned foods
- Reheated foods
- Perishables that are no longer fresh
Freshness is very important in a low histamine diet. The fresher the food, the lower the histamine levels, and the better it will be for you.
To lower histamine levels, choose foods that are low in histamine:
- Most fresh vegetables and fruits
- Dairy alternatives such as coconut milk and almond milk
- Fresh meat and poultry
- Olive oil and coconut oil
- Leafy herbs such as basil and rosemary
- Herbal tea
Meanwhile, the following foods are high-histamine foods:
- Avocados, eggplant, spinach, and tomatoes
- Most citrus fruits, dried fruits, and bananas, strawberries, papayas, and pineapples
- Fermented foods such as kimchi, sauerkraut, and kefir
- Aged cheeses and soured dairy products such as sour cream and buttermilk
- Cured meats such as salami and bacon, shellfish, and smoked fish
- Nuts such as cashews, walnuts, and peanuts
- Seasonings such as soy sauce, miso, and ketchup
- Kombucha, energy drinks, and alcoholic beverages
How to Follow a Low Histamine Diet
Most people who follow a low histamine diet notice a difference in about a week. If your symptoms don’t go away after a week, you may not have histamine intolerance but rather a food allergy or a digestive issue.
If you do feel better after a week, keep following a low histamine diet until improvements plateau. From there, you can slowly reintroduce foods from outside of the low histamine diet.
As with any elimination diet, keeping a food diary can help you identify which foods are your worst triggers. You can also work with a dietitian or health coach to come up with a sustainable eating plan.
What Is Histamine Intolerance?
Histamine intolerance is often mistaken for a food or seasonal allergy. However, with allergies, an inflammatory response takes place immediately after exposure. With histamine intolerance, the response is delayed, as histamine levels in the blood rise to a certain level for reactions to take place.
Symptoms of Histamine Intolerance
Common symptoms of histamine intolerance look a lot like seasonal allergies. You may experience sneezing fits and congestion, among other symptoms.
Other symptoms of histamine intolerance may be:
- Neurological: Irritability, depression, brain fog, insomnia, and fatigue
- Dermatological: Rash, flushing, hives, and runny nose
- Rheumatological: Joint pain
- Cardiac: Racing heart and palpitations
- Gastrointestinal: Altered bowel function, abdominal pain, non-celiac gluten sensitivity, gastrointestinal reflux disease, and heartburn
Causes of High Histamine Levels
Histamine-rich foods lead to a buildup of histamine that can’t be easily broken down by the DAO enzymes. While diet is a major contributor to the development of histamine intolerance, there are other factors to consider.
Gut dysbiosis is an imbalance of gut bacteria and fungi. This disruption of the GI tract can be the result of many environmental and lifestyle factors, including a poor diet, antibiotics, and physical and psychological stress .
Gut dysbiosis leads to a build-up of histamine, both directly and indirectly, when:
- Bad bacteria in the gut produce excess histamine.
- A damaged intestinal lining (also known as leaky gut) cannot process histamine into other compounds.
- Damage to the intestinal lining also leads to immune system activation and reactivity, producing more histamine.
Small intestinal bacterial overgrowth (SIBO) is an excess of bacteria in the small intestine. This type of gut dysbiosis may develop as a complication of abdominal surgery or the result of structural damage to the small intestine.
SIBO increases the development of histamines in the body. Here’s what happens:
- Undigested food leads to an overgrowth of bad bacteria, creating excess histamine.
- Mast cell activation syndrome (MCAS) has been linked to SIBO and irritable bowel syndrome (IBS) .
Certain medications can raise histamine levels by either blocking DAO enzyme production or releasing excess histamine . In the case of antibiotics, overuse can kill off too much good bacteria, creating an imbalance that leads to more inflammation .
A number of over-the-counter and prescription drugs can directly or indirectly contribute to histamine buildup, including:
- Opioid analgesics [6, 7]
- Non-steroidal anti-inflammatories (NSAIDs) [8, 9]
- Tricyclic antidepressants [10, 11]
Other Ways To Lower Histamine Levels
While a low histamine diet can be helpful for quickly decreasing symptoms, improving your gut health is also important for reducing histamine levels.
Probiotics and Histamine Intolerance
Probiotics can likely lower histamine, although some disagree. While we don’t have any direct research to support this, we can make some conclusions based on three areas of research:
1. Studies make a direct connection between histamine intolerance and gut conditions:
- One study found that 30-55% of patients with digestive symptoms may also have histamine intolerance .
- In this study, patients with histamine intolerance were more likely to test positive for gut bacteria imbalances and leaky gut when compared with controls .
2. Research clearly shows that probiotics are effective against gut conditions, including:
- SIBO [14, 15, 16, 17]
- H. Pylori, fungus, protozoa and parasitic infections [18, 19, 20, 21]
- Leaky gut [22, 23, 24, 25, 26]
3. Preliminary evidence suggests probiotics can be effective against histamine symptoms:
- A meta-analysis and a more recent clinical trial concluded probiotics significantly reduced symptoms and clinical markers in patients with allergic rhinitis [27, 28].
- While probiotic bacteria for the prevention and/or treatment of allergic disease has shown promising results, further randomized controlled trials are needed to confirm the findings.
The above research indirectly suggests probiotics may help treat histamine intolerance.
Some practitioners recommend taking a low-histamine probiotic product. However, this recommendation overlooks the net benefits of probiotics on the gut ecosystem. Any quality probiotic supplement may help reduce histamine levels.
Supplements and Histamine Intolerance
A daily vitamin supplement may help lower histamine levels.
Studies show vitamins C and D may also decrease histamine levels:
- Vitamin C (ascorbic acid) is considered a natural antihistamine that can help reduce inflammation and other allergic reactions [29, 30, 31].
- Vitamin D contributes to the stabilization of the mast cells that produce histamine [32, 33].
Note that over-the-counter antihistamine medications might help to relieve symptoms of histamine intolerance. However, they’re unnecessary once you have improved your diet and gut health.
Should You Follow a Low Histamine Diet?
Research shows a low histamine diet can help improve your DAO enzyme levels . Thus, reductions in histamine levels may contribute to healing your intestinal lining. A healthier intestinal lining secretes more DAO, which will help lower your histamine further.
There isn’t a reliable lab test for diagnosing histamine intolerance. Following an elimination diet, tracking your progress in a food diary, and consulting your nutritionist and gastroenterologist are among the best ways you can get to the root of the issue.
A two- to three-week trial of a low histamine diet is the best way to evaluate if this approach is helpful for your symptoms.
Gut health plays a major role in histamine intolerance. A combination of mindful eating, diet, and high-quality supplements may help improve your gut health and reduce your symptoms of histamine intolerance.
Remember that elimination diets are not meant to be long-term solutions, as they can deprive your body of key nutrients. You can reintroduce foods back into your diet once your symptoms subside.