Attacking Alzheimer's: The latest news on treatment and diagnosis

Though they may live in dread of it, most people will never develop it. "There's a 10 to 15 percent chance, if you live a normal life [span], you'll develop Alzheimer's disease," says Norman Relkin, associate professor of clinical neurology and neuroscience at New York Presbyterian Hospital and Weill Cornell Medical College. (To be sure, the prevalence in people over age 90 rises to nearly 1 in 2.) Relkin suspects the body has natural defenses—and several years ago, he and his colleagues set about finding them.