Boston, Massachusetts, 1985. Dr Joe Upton is struggling to reattach a severed ear onto a little boy. Using incredible skill and the best in modern equipment he re-attaches the arteries, but the veins are proving difficult. Blood keeps getting congested and the little ear is turning black. Just when it looks like all is lost, Joe remembers leeches.

Once used to treat every malady imaginable, the vampiric worms fell out of favour when we gained a better understanding of how the body works. But, Matthew Syed wonders, did the medical backlash against leeches go too far, squandering the ancient wisdom contained in the worm?

In seeking to find out what other potentially useful cures have been consigned to history, Matthew learns about an Anglo Saxon recipe for an eye balm which uses garlic and bovine bile and may have MRSA busting qualities. He learns how the chants and charms accompanying such potions had incredibly practical purposes but why the newly professional doctors of The Enlightenment were keen to deride homespun medicine as quackery.

Matthew draws out why we dismiss certain knowledge and experience in favour of modernity and progress and asks what we risk losing as a result.

With Microsurgeon Dr Joe Upton, Carl Peters-Bond of Biopharm Leeches, Micro-biologist Dr Freya Harrison of Warwick University, Nottingham University Anglo Saxon expert Dr Christina Lee and 18th Century Medical historian Dr Kathryn Woods of Goldsmith’s University.

Presenter: Matthew Syed Producer: Marilyn Rust Series Editor/Exec: Katherine Godfrey Researcher: Nadia Mehdi Music Sound, Design & Mix: Rob Speight Additional mixing: Alex Portfelix Theme Music: Seventy Times Seven by Iona Selaru A Novel production for BBC Radio 4