Three women at risk of developing Alzheimer's join a groundbreaking study to prevent the disease while sharing their ups and downs, anxiously watching for symptoms, and hoping they can make a difference. Barb, Sigrid, and Karen all had mothers with Alzheimer's and witnessed firsthand the devastation wrought by the disease, not only on the mind and body but on patients' families. Now, they are all participating in a major study that tracks the health and memory of thousands of people over many years, as researchers hunt for lifestyle changes and medicines that could improve all our chances and ultimately protect the brain and body from one of the world's deadliest diseases.