The DAO gene produces the main enzyme responsible for breaking down ingested histamine and needs vitamin B2 as a cofactor. Variants on this gene may decrease enzyme activity resulting in excess histamine and causing allergy-type symptoms including irritation to the GI tract, food allergies, gluten-sensitivity, Crohn's disease and ulcerative colitis, skin irritation, eczema and hives, and even anxiety and insomnia. Those with histamine sensitivities will experience symptoms after ingesting even small amounts of histamine.
If you carry the TT allele for this gene, you are among the 30-50% of the population likely to have genetically reduced DAO activity, and therefore increased the risk of histamine sensitivity. If you experience symptoms you should reduce consumption of histamine foods, alcohol, and black tea. Support DAO activity with vitamins B2, B6, quercetin, zinc and C.
Below is a list of high histamine foods to avoid:
- Fermented foods: Sauerkraut, pickles, vinegar, fermented soy, yeast, yoghurt, kefir. kombucha and aged cheese
- Cured Meats: Bacon, sausage, pepperoni, salami, smoked salmon, herring, sardines etc.
Here is a list of anti-histamine foods to include in your diet: