The researchers believe theobromine acts on the sensory nerve endings of the vagus nerve, which runs through the airways in the lungs to the brain. Capsaicin stimulates these endings to provoke coughing.Persistent coughs melt away with chocolate (via Amanda Palmer)
The team explored their hypothesis by looking at theobromine's action on the vagus nerve in separate experiments involving guinea pigs and excised human trachea tissue.
Their results confirmed that theobromine does indeed inhibit the capsaicin-induced sensory nerve depolarisation in the vagus nerve.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.