Michael Mosley and the doctors undertake the most ambitious experiment yet on the series - testing whether the spice turmeric could help protect us against cancer, with the help of nearly 100 volunteers, several UK universities and some brand new technology. Gabriel Weston learns how one of these methods, based on a new understanding of the very beginnings of cancer, could soon provide us all with personalised cancer tests. Dr Chris van Tulleken investigates whether glucosamine pills really help with joint pain, and Dr Saleyha Ahsan looks at whether cheap painkillers are as good as expensive brands. Guest Dr Zoe Williams, meanwhile, tries out home cholesterol test kits.