Documentary investigating scientific breakthroughs in research on Alzheimer's disease, which are bringing hope to millions of sufferers across the world. New scanning and gene technology is allowing scientists to identify the disease at its earliest stages, often 15 years before symptoms appear and brain cells are destroyed, with drug trials in Colombia, USA and Europe showing startling success. The programme also reveals the changes in lifestyle that can prevent the development of the disease, as well as the effects of a UK-wide trial.