Histamine (+liberators / DAO inhibitors)

What is it?

Histamine intolerance is a deficiency of the DAO enzyme that normally breaks down dietary histamine. Symptoms: flushing, headache, hives, digestive upset, sometimes hypotension. Three categories matter: (1) histamine-rich foods — aged cheeses, cured meats, fermented foods, fish, alcohol; (2) liberators that trigger endogenous release — strawberries, tomatoes, citrus, chocolate; (3) DAO inhibitors that block clearance — alcohol, black tea, energy drinks. Important: the ratings here assume the food is consumed ultra-fresh. Histamine accumulates rapidly in protein-rich foods (fish, meat, leftovers, ripe cheese) as they sit — a safely-rated food can become risky within hours of cooking or a few days in the fridge. As a rule of thumb, avoid all fermented, aged or long-stored foods, freeze fish and meat immediately if not eaten the same day, and consume any prepared dish within 24h.

Source: Maintz & Novak 2007, American Journal of Clinical Nutrition

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