Oolong tea

Oolong is a partially oxidized tea, and like other teas it contains compounds that may interfere with DAO activity.

• DAO blocking — the caffeine in oolong may reduce DAO function, the enzyme your body uses to clear histamine; polyphenols are sometimes mentioned alongside caffeine in this context, though their specific role is not well established

• Oxidation level — oolong sits between green and black tea in terms of processing; it's generally considered moderate, though individual products vary widely in caffeine and polyphenol content

Lighter oolong varieties may be easier to tolerate than heavily roasted or aged ones.