Histamine | MAOB (rs3027452)

Understanding MAOB, Histamine, and What Your Genotype Means for You

Histamine is a natural chemical your body uses for immune responses, digestion, and brain communication. When histamine levels are balanced, these systems work well. If histamine builds up, it can cause symptoms such as headaches, itchy skin, flushing, nasal congestion, digestive upset, or general sensitivity to certain foods and environments.

The MAOB gene provides instructions for making the MAO-B enzyme. One job of MAO-B is to help break down histamine so it does not accumulate. Variations in the MAOB gene can change how well MAO-B works. That can influence how efficiently your body clears histamine and how sensitive you might be to histamine from foods or produced internally.

How to read this report

This report explains how different genotypes at rs3027452 affect MAO-B activity and histamine handling.
It offers practical, consumer-friendly steps you can consider to support healthy histamine balance through diet, supplements, and lifestyle.
PlexusDx does not provide medical advice. Use this information to guide conversations with your healthcare provider before making changes to medications, supplements, or major lifestyle habits.

Practical steps to support healthy histamine metabolism

Regardless of genotype, general strategies can help manage histamine levels and reduce symptoms if you are sensitive:

Choose fresh, minimally processed foods and limit high-histamine items such as aged cheeses, fermented foods and beverages, cured or smoked meats, sauerkraut, kombucha, and certain fish (especially if not very fresh).
Rotate or avoid known dietary triggers for you. Keep a food and symptom diary to learn patterns.
Support enzyme function with nutrients. Riboflavin (vitamin B2) is important for many metabolic enzymes and may support MAO-B activity. Flavonoids found in foods like apples, citrus, green tea, and onions can have supportive effects on oxidative balance and enzyme function.
Manage stress. Chronic stress increases inflammatory signals and can worsen histamine-related symptoms. Try breathing exercises, mindfulness, or other stress-reduction techniques.
Move regularly. Moderate exercise supports healthy circulation, immune regulation, and enzyme function. Avoid intense exercise if it reliably triggers symptoms for you; instead prioritize consistent moderate activity.
Sleep well. Regular, sufficient sleep supports immune and metabolic regulation, helping enzymes work optimally.
Work with your clinician before starting supplements, changing prescription medication, or making big dietary changes—especially if you have significant symptoms or medical conditions.

Diet and supplement considerations

Diet and targeted supplements can complement lifestyle changes. These suggestions are for education only. Discuss with your healthcare provider to confirm what is appropriate for your situation.

Focus on a whole-foods pattern: lean proteins, nonstarchy vegetables, fruits low in histamine risk (fresh berries, apples, pears), healthy fats, and whole grains if tolerated.
Limit or avoid high-histamine and histamine-releasing foods: aged cheeses, processed or fermented meats, fermented vegetables, kombucha, sauerkraut, certain canned or smoked fish, and alcohol, especially red wine and beer.
Consider fresh, frozen, or properly stored proteins to reduce bacterial histamine formation. Avoid leftovers that have been stored for long periods if you are sensitive.
Supplements that may be considered with clinician input: riboflavin (vitamin B2) to support enzyme systems, vitamin C and quercetin (a flavonoid) to help stabilize mast cells and support histamine breakdown, and magnesium to support stress regulation and sleep.
Monitor for interactions. MAO enzymes can interact with certain medications and dietary substances. Always review medications and supplements with your clinician or pharmacist.

Genetic interpretations

Two effect alleles — AA (reduced MAO-B activity)

If your genotype is AA at rs3027452, you carry two copies of the effect allele. This pattern is associated with reduced MAO-B activity. Lower MAO-B activity may make histamine breakdown less efficient, so histamine can linger longer in your body. That may raise the chance of experiencing histamine-related symptoms such as headaches, flushing, skin itching, nasal congestion, or digestive upset, especially after eating histamine-rich foods.

Consider these personalized strategies:

Adopt a low-histamine first approach: reduce or avoid aged, fermented, and processed foods and prioritize fresh foods prepared the day you eat them.
Try gentle mast cell stabilizing choices in diet and lifestyle: vitamin C rich foods, regular magnesium, and flavonoid-rich foods like apples and onions.
Work with a clinician on targeted supplementation such as riboflavin and possibly quercetin or vitamin C, and evaluate safety if you take other medications.
Prioritize stress reduction, consistent sleep, and moderate exercise to support overall enzyme and immune balance.
Keep a symptom and food diary to identify triggers and guide individualized adjustments.

One effect allele — AG (slightly reduced MAO-B activity)

If your genotype is AG at rs3027452, you have one copy of the effect allele. This is associated with a modest reduction in MAO-B activity. Your body may clear histamine a bit more slowly than someone with two non-effect alleles, which could increase sensitivity to histamine in certain situations but usually to a lesser degree than the AA genotype.

Practical recommendations:

Favor fresh, minimally processed foods and be mindful of common high-histamine items. You may not need as strict a restriction as someone with AA, but paying attention to timing and portions of high-histamine foods can help.
Support enzyme function through diet: include foods rich in riboflavin such as lean meats, eggs, and dairy if tolerated, and flavonoid-containing fruits and vegetables.
Use lifestyle strategies to reduce overall inflammatory load: good sleep, stress management, and consistent physical activity.
If you notice symptoms, try targeted measures like temporary reduction of high-histamine foods and discuss supplementation options with your clinician.

No effect alleles — GG (increased MAO-B activity)

If your genotype is GG at rs3027452, you carry two copies of the non-effect allele. This genotype is associated with higher MAO-B activity and more efficient histamine metabolism. That typically helps prevent histamine from accumulating, making you less likely to experience histamine intolerance symptoms compared with people who have reduced MAO-B activity.

Guidance for GG:

Most people with this genotype tolerate a broader range of foods without histamine-related reactions, but individual tolerance varies. Continue to follow general healthy eating principles.
Maintain lifestyle habits that support metabolic and immune health: adequate sleep, stress management, and regular exercise.
If you do experience symptoms, consider the common non-genetic causes first, such as food storage, food spoilage, infections, medication effects, or environmental triggers, and discuss these with your clinician.

When to talk with a healthcare provider

If you have frequent or severe symptoms such as chronic headaches, significant digestive problems, widespread hives, breathing difficulty, or other concerning signs, seek medical evaluation.
Before starting or stopping medications or beginning supplements, consult your healthcare provider or pharmacist. Some medications and supplements can interact with enzyme systems and change histamine handling.
Use this genetic information as one piece of the puzzle. Your symptoms, medical history, environment, and lifestyle all influence histamine balance.

PlexusDx provides educational information about genetic predispositions. This content is not medical advice. Always consult your healthcare provider to interpret genetic results in the full context of your health and before making medical, supplement, or major lifestyle changes.