Understanding Dietary Histamine Intolerance and DAO Deficiency

Histamine intolerance is a condition in which the body struggles to break down excess histamine from food, leading to symptoms that mimic allergies, digestive disorders, and even neurological issues. The primary cause of this intolerance is a deficiency or dysfunction of Diamine Oxidase (DAO), the enzyme responsible for metabolizing dietary histamine.

What is Histamine?

Histamine is a naturally occurring compound involved in immune response, digestion, and brain function. It is found in various foods, especially fermented, aged, or processed products such as:

• Aged cheeses
• Fermented foods (kimchi, sauerkraut, kombucha)
• Alcohol (especially wine, beer, and champagne)
• Cured meats (salami, ham, bacon)
• Vinegar and vinegar-based products
• Dried fruits
• Certain vegetables (tomatoes, eggplants, spinach)
• Certain fish (tuna, mackerel, sardines, if not fresh)

For most people, the body regulates histamine levels efficiently. However, in individuals with histamine intolerance, histamine accumulates in the body, leading to symptoms.

Common Symptoms of Histamine Intolerance

Histamine intolerance affects multiple systems in the body, resulting in a range of symptoms, including:

• Skin Reactions – Flushing, itching, hives, swelling
• Digestive Issues – Bloating, diarrhea, nausea, stomach pain
• Neurological Symptoms – Headaches, migraines, dizziness, anxiety
• Respiratory Problems – Nasal congestion, runny nose, asthma-like symptoms
• Cardiovascular Effects – Rapid heart rate, low blood pressure

Because these symptoms can overlap with other conditions (like food allergies, IBS, or mast cell disorders), histamine intolerance is often misdiagnosed or overlooked.

DAO Deficiency: The Root Cause of Histamine Intolerance

DAO (Diamine Oxidase) is the primary enzyme responsible for breaking down histamine in the digestive tract. It is produced in the small intestine and serves as the body's first line of defense against dietary histamine.

What Causes DAO Deficiency?

1. Genetics – Some people naturally produce lower levels of DAO due to genetic factors.
2. Gut Health Issues – Conditions like leaky gut, IBS, Crohn’s disease, and SIBO can damage the intestinal lining, reducing DAO production.
3. Nutrient Deficiencies – DAO enzyme function depends on vitamin B6, copper, and vitamin C. Deficiencies in these nutrients can impair histamine breakdown.
4. Medications – Certain drugs can block DAO activity, including:
   • NSAIDs (ibuprofen, aspirin)
   • Antidepressants (SSRIs, MAOIs)
   • Antihistamines (which can paradoxically worsen symptoms over time)
   • Blood pressure medications (beta-blockers, ACE inhibitors)
5. Hormonal Imbalances – Estrogen dominance (from pregnancy, birth control, or hormone therapy) can increase histamine levels while reducing DAO function.
6. Alcohol Consumption – Alcohol blocks DAO activity and increases histamine levels, making symptoms worse.

Managing Histamine Intolerance with DAO Supplementation

Since DAO deficiency is the leading cause of histamine intolerance, supplementing with OmneDiem® Histamine Digest® provides the enzyme needed to break down histamine before it enters the bloodstream.

By taking one capsule before meals, individuals can prevent histamine buildup, reducing symptoms like headaches, flushing, and digestive distress.

Other Ways to Reduce Histamine Intolerance

While DAO supplementation is the most effective approach, additional strategies can help manage histamine intolerance:

✅ Follow a Low-Histamine Diet – Limit high-histamine foods and focus on fresh, unprocessed meals.
✅ Support Gut Health – Repair the intestinal lining with probiotics, prebiotics, and gut-healing nutrients like L-glutamine and quercetin.
✅ Increase DAO-Supporting Nutrients – Ensure adequate intake of vitamin B6, copper, and vitamin C to enhance DAO function.
✅ Avoid DAO-Blocking Medications – If possible, work with a healthcare provider to find alternatives.
✅ Stay Hydrated – Proper hydration helps flush excess histamine from the body.

By combining DAO supplementation with these lifestyle adjustments, individuals with histamine intolerance can enjoy a more diverse diet without discomfort.

Would you like additional information on testing for histamine intolerance or low-histamine meal plans?