Histamine, a  naturally occurring chemical present in body cells and plays a vital role in local immune responses, regulates various physiological processes in the gastrointestinal tract, and acts as a neurotransmitter within the central nervous system, including the brain, spinal cord, and uterus. Consequently, histamine is responsible for triggering numerous symptoms commonly observed in allergic reactions. For example, Whenever someone has an allergy to something, such as food or dust, their immune system incorrectly perceives this substance is harmful and develops allergic manifestations.

The Role of Histamine in Digestive Health

Histamine is a functionally important stimulus of gastric acid secretion. While treating ulcerative diseases of GIT, reflux esophagitis, etc, histamine receptors are the main treatment target. 

When histamine levels are imbalanced, gastrointestinal enzyme diamine oxidase (DAO) does not metabolise and degrade histamine properly, which causes histamine intolerance and leads to extraintestinal symptoms as well as functional, nonspecific, nonallergenic gastrointestinal complaints.  As a result of ingestion of histamine-containing foods and reduced enzyme activity, histamine levels in the body can rise, causing a variety of symptoms.

Common Symptoms of Histamine Sensitivity

Let us now understand some common symptoms people face due to high histamine levels.

  • Headaches
  • Nasal congestion
  • Vertigo
  • Dizziness 
  • Itching
  • Sneezing
  • Difficulty in breathing
  • Tiredness
  • Flushing
  • Disturbed sleep
  • Swelling
  • Low blood pressure
  • Irregular heart rate

According to the CDC's 2015 data, approximately 8% of US adults have hay fever, while 5% of children and 12 % of kids have food and skin allergies. The leading cause of these allergies is histamine, a signalling molecule produced by mast cells which acts via four receptors (H1R-H4R). It is involved in gastric acid secretion, inflammation, vasodilatation, bronchoconstriction and allergic diseases like dermatitis, rhinitis, and asthma. In short, it tells the stomach to make acid and the brain to stay awake by regulating the sleep-wake cycle.

Importance of balanced histamine levels for gut health.

Balancing histamine levels in the gut is crucial for overall digestive health. When histamine levels rise, it can lead to inflammation, bloating, and digestive problems. So, to prevent these digestive issues, one should aim to balance histamine levels by eating a low-histamine diet, taking supplements, etc.

5% of total histamine comes from food sources or gut bacteria. Fish, fermented foods, seafood, and microbiota increase histamine levels. The enzyme histidine decarboxylase produces histamine, which affects immune response. Due to high histamine levels during inflammation, when the body cannot break down histamine properly, gastrointestinal issues such as food allergies, intolerance, IBS, and IBD can occur.

Dietary Supplements for Histamine Sensitivity

In Western countries, nearly 20 % of the population is affected by the adverse reactions to ingested foods.

Are you looking for natural ways to address HIT? Many people try a low-histamine diet and incorporate lifestyle changes but still do not get considerable relief from HIT symptoms. Studies say that if you add supplements to dietary intervention, you may get relief from HIT symptoms. A supplement is like a support that provides your body with vitamins, minerals and enzymes to fight histamine sensitivity symptoms.

A supplement formulated for histamine sensitivity usually provides the following vital ingredients:

  • DAO enzyme: It is responsible for histamine breakdown in GIT. Its activity is reduced due to medicines, nutrient deficiency, genetic factors, etc.
  • Quercetin: It stabilises mast cells and controls histamine release. It also supports immune health.
  • Stinging Nettles Leaf:It promotes a balanced inflammatory response by controlling mast-cell degranulation and prostaglandin formation.
  • Vitamin C: It is an essential vitamin required for DAO production. This vitamin has immune-boosting properties that benefit individuals with seasonal discomfort by deactivating histamine.

TOP 4 DAO supplements to support healthy histamine levels

There are many supplements that can help with histamine insensitivity, but some are better than others. In this article, we will take a look at the  some of the best supplements for histamine intolerance that you can buy at Nutriessential.com

  • Omne Diem Histamine Digest

Taking Histamine Digest supplement before consuming high-histamine foods and beverages can help prevent digestive sensitivity to histamine and the accompanying reactions that may occur. This supplement formulation supplies Diamine Oxidase to neutralise excess dietary histamine in the digestive tract. DAO provided in this supplement is a highly convenient formula that promotes histamine degradation within 20 minutes of intake. 

  • Histamine Digest PureMax

Some people specifically require DAO and not added nutrients. This supplement is for these individuals and provides 40,000 HDU of DAO in a designed-release capsule that dissolves in the small intestine and acts on dietary histamine to support digestive health.

  •  Seeking Health Histamine Digest

This supplement helps digest histamine from 3 primary sources, including food and drink, the gut immune system and the microbiome. It is helpful for those who feel worse after eating and drinking, have problems with a leaky gut and want to maintain a healthy gut lining, have inconsistent bowel movements, etc.

  •  Histamine Block Plus

This supplement contains DAO, Vitamin C, copper, and other important vitamins that promote a healthy response to high-histamine foods due to its unique composition; it also contains cofactors and antioxidants for total histamine processing. When histamine is metabolised, toxic byproducts like ammonia, hydrogen peroxide, and acetaldehyde are created. These can cause damage to cells.   Histamine Block Plus has nutrient cofactors to support the normal breakdown of these toxic byproducts.

To manage histamine sensitivity, DAO plays an important role. These supplements work on DAO levels by restoring them and maintaining healthy levels. 

DAO supplements: what is the scientific evidence?

According to a study, dietary treatment of HIT also considers supplementation with exogenous DAO enzymes to enhance intestinal histamine degradation. This study evaluated the microbiota composition of patients along nine months receiving a low-histamine diet, and DAO supplementation.3 out of 5 histamine intolerant patients had microbial species closely resembling healthy individuals.

This study supported the hypothesis that reducing histamine-secreting bacteria could diminish histamine's accumulation and absorption at the intestinal level and prevent the onset of discomforting symptoms.

This study also found that an increase in Roseburia species bacteria was associated with an improvement in the inflammation of intestinal mucosa. This was observed throughout the dietary treatment. This species produces SCFA that maintains intestinal homeostasis and inhibits pro-inflammatory status.

Oral supplementation of the enzyme DAO before meals improves HIT-related symptoms.

A study included 28 patients with HIT who were instructed to take DAO capsules before meals. During the follow-up period, these patients did not take the DAO. The questionnaire, which included 22 symptoms, was divided into four categories and a symptom severity score. Researchers reported symptom improvement following DAO supplementation. The symptom intensity score was reduced for all symptoms due to enhanced DAO's ability to degrade intestinal histamine. Do you know how a histamine-reduced diet (mostly plant based) can complement DAO supplements? This study also found elevated serum DAO two months after following such a diet.

Strategies for promoting gut healing

It's essential to get to the root cause of high histamine levels to treat them. Taking antihistamines relieves symptoms but provides short-term results. With a healthy lifestyle, food choices and supplements, it may be possible to heal the gut from stress caused by high histamine levels.

  • Know these high-histamine foods and avoid them.

Alcohol, processed food, fermented food, fish, vinegar, and shellfish trigger histamine release. 

  • Avoid DAO enzyme Blockers.

Alcohol, green and Black tea, and energy drinks block DAO enzymes, so avoid them.

  • Enjoy a healthy lifestyle.

Avoiding stress, Sleeping for 7-8 hours daily, exercising, spending time in nature, self-care, meditation, yoga, and cycling are some of the best ways to enjoy a healthy life. 

  • Reduce toxic load

Prefer organic, natural, or homemade products. Invest in a high-quality air purifying system and a water filtration system.

Final Thoughts 

Histamine intolerance occurs due to excess histamine in the body, leading to various digestive issues. DAO breaks down histamine in the gut and helps maintain healthy histamine levels, preventing digestive problems like bloating, gas, and diarrhoea. 

Managing histamine sensitivity is vital for a healthy digestive system. It involves two research-based strategies. This included avoiding high-histamine foods and taking histamine supplements. Diamine oxidase (DAO) provided by high-quality supplements breaks down histamine in the gut and reduces sensitivity symptoms. With dietary adjustments and supplements in such cases,  one can improve their gut health. 


  • https://medlineplus.gov/medlineplus-videos/histamine-the-stuff-allergies-are-made-of/
  • Sánchez-Pérez et al. The dietary treatment of histamine intolerance reduces the abundance of some histamine-secreting bacteria of the gut microbiota in histamine intolerant women. A pilot study. Frontiers in Nutrition, 9. https://doi.org/10.3389/fnut.2022.1018463
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