This booklet summarizes what scientists have learned so far and where research is headed. There is no definitive evidence yet about what can prevent Alzheimer's or age-related cognitive decline. What we do know is that a healthy lifestyle-one that includes a healthy diet, physical activity, appropriate weight, and no smoking-can maintain and improve overall health and well-being. Making healthy choices can also lower the risk of certain chronic diseases, like heart disease and diabetes, and scientists are very interested in the possibility that a healthy lifestyle might have a beneficial...