The history of the spice trade, and the human misery behind it, is explored by Katie Prescott.

Katie travels to the spice island of Zanzibar in the Indian Ocean, where cloves, turmeric, nutmeg and vanilla are still grown to this day. But it also supported a trade in African slaves who worked the spice plantations, as Katie discovers at what was once the local slave market.

Food historian Monica Askay recounts the cultural importance that these spices gained in Europe and the other markets where they ended up, while Rahul Tandon how they came to define Indian cuisine.

(Picture: Spices; Credit: Whitestorm/Getty Images)