There's good news and bad about Alzheimer's disease, which affects more than five million Americans. Current medications only minimally delay progression of the disease, says Lon S. Schneider, MD, who directs the Alzheimer's Disease Research and Clinical Center of California at USC. But evidence is piling up that you can lower your risk of Alzheimer's by making some simple changes in your life, researchers say. What matters most:Skip the chips. Eating too much fat and cholesterol seems to hasten