Understanding MAOA, Histamine, and Tyramine: What Your Genotype Means for Symptoms and Lifestyle
Histamine is a natural compound that helps the immune system and supports brain signaling. Tyramine is a related compound commonly found in aged and fermented foods. Both are normally broken down by enzymes in the body. The MAOA gene encodes the MAO-A enzyme, which primarily degrades tyramine and also helps as a backup pathway for histamine breakdown. Variations at the rs909525 location in the MAOA gene can change how well the MAO-A enzyme works, which can influence sensitivity to foods and environmental triggers that raise histamine or tyramine levels.
How this can affect you
- Reduced MAO-A activity can allow histamine and tyramine to accumulate, which may cause symptoms such as headaches or migraines, flushing, itching, nasal congestion, digestive upset, and other allergy-like reactions.
- Increased MAO-A activity supports more efficient clearance of these compounds, lowering the chance of buildup and related symptoms.
- Your diet, nutrient status, stress level, sleep, and environmental exposures can change how these pathways function, regardless of genotype.
Foods to be aware of
Foods that commonly contain higher levels of tyramine or histamine include:
- Aged cheeses (Parmesan, blue cheese)
- Cured and smoked meats (salami, pepperoni, prosciutto)
- Fermented foods and condiments (sauerkraut, kimchi, soy sauce)
- Certain alcoholic beverages (red wine, beer, some spirits)
- Some fish and leftovers that have been stored improperly
Practical testing and monitoring
- Keep a food and symptom diary to link specific foods or drinks with symptoms.
- Basic labs to discuss with your healthcare provider may include nutrient panels for B vitamins, especially riboflavin, and tests for markers of inflammation or allergy when appropriate.
- Work with your healthcare provider before starting new supplements or making major diet changes.
Genetic Interpretation
Two effect alleles (TT at rs909525)
You carry two copies of the effect allele (TT). This genotype is associated with reduced MAO-A enzyme activity. With lower MAO-A function, your ability to break down tyramine and the backup breakdown of histamine may be diminished. This can increase the likelihood of accumulation of these compounds after eating aged, cured, or fermented foods and certain alcoholic beverages. Possible symptoms include headaches or migraines, flushing, itching, nasal congestion, digestive upset, and other allergy-like reactions.
Actionable considerations:
- Limit or avoid high-tyramine and high-histamine foods and drinks listed above.
- Use a structured elimination trial with food and symptom tracking to identify triggers.
- Consider discussing riboflavin (Vitamin B2) supplementation with your provider, as it can support enzyme cofactors.
- Focus on stress reduction, regular exercise, good sleep, and avoiding environmental toxins to support overall enzyme function.
- If symptoms are frequent or severe, consult your healthcare provider for further evaluation and personalized testing.
One effect allele (CT at rs909525)
You carry one copy of the effect allele (CT). This genotype is associated with mildly reduced MAO-A activity. Your MAO-A enzyme may work less efficiently than someone with two non-effect copies, which can modestly increase the risk of histamine and tyramine buildup after certain foods. Typical symptoms to watch for include headaches, mild digestive discomfort, or occasional allergy-like reactions.
Actionable considerations:
- Be mindful of intake of aged cheeses, cured meats, fermented foods, and certain alcoholic beverages.
- Keep a food and symptom diary to spot patterns and limit the specific items that trigger symptoms.
- Discuss nutrient support such as riboflavin and a diet rich in flavonoid-containing fruits and vegetables with your healthcare provider.
- Adopt lifestyle habits that support enzyme function: consistent sleep, regular moderate exercise, stress management, and reduced exposure to cigarette smoke and environmental chemicals.
No effect alleles (CC at rs909525)
You carry two copies of the non-effect allele (CC). This genotype is associated with higher MAO-A activity. Your body is likely efficient at breaking down tyramine and, as a backup pathway, histamine. You are less likely to experience buildup of these compounds and related symptoms after consuming foods that are rich in tyramine or histamine compared with people who have reduced MAO-A activity.
Actionable considerations:
- While your genotype suggests lower risk, individual reactions still occur. Use a food and symptom journal if you notice issues.
- Maintain a balanced diet and adequate nutrient intake to keep enzyme systems functioning well.
- Continue healthy lifestyle practices: manage stress, exercise, prioritize sleep, and avoid environmental toxins.
Diet, Supplements, and Lifestyle Recommendations
Diet
- Reduce or avoid high-tyramine and high-histamine foods if you notice symptoms. Try fresh, minimally processed options instead of aged, cured, or fermented items.
- Favor fresh meats, freshly caught or properly stored fish, fresh vegetables, and non-fermented dairy when possible.
- Eat a wide variety of fruits and vegetables rich in flavonoids to support natural anti-inflammatory and enzyme-supportive pathways.
- Stay hydrated and avoid alcohol or limit types that trigger symptoms, such as red wine or beer.
Supplements to discuss with your healthcare provider
- Riboflavin (Vitamin B2): supports enzyme cofactor requirements and may help MAO-A function.
- Broad-spectrum antioxidant-rich foods or supplements containing flavonoids: may support detoxification and reduce inflammatory signaling.
- Probiotics or digestive support only under guidance if digestive symptoms are present, as some probiotic strains and fermented products can contain histamine.
Lifestyle
- Manage stress through breathing exercises, meditation, yoga, or other relaxation techniques. Chronic stress can impair metabolic and enzyme pathways.
- Exercise regularly with a mix of cardiovascular and resistance training to support circulation and metabolic health.
- Prioritize sleep hygiene: aim for regular sleep schedule and restorative sleep to support overall detoxification processes.
- Reduce exposure to environmental toxins such as cigarette smoke and unnecessary household chemicals that can burden detox pathways.
When to seek medical support
- Frequent or severe headaches, migraines, persistent digestive symptoms, or breathing difficulty should prompt evaluation.
- If an elimination diet or lifestyle changes do not improve symptoms, consult your healthcare provider for further testing and management.
- Always discuss starting supplements, major diet changes, or new medications with your clinician to avoid interactions and ensure safety.
PlexusDx provides educational information about genetic predispositions. This content is not medical advice. Always consult your healthcare provider for diagnosis, treatment, and before making changes to your diet, supplements, or lifestyle based on genetic information.

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Histamine | HNMT (rs11558538)
Histamine | HNMT (rs11558538)