A great article by Richard Powers,Instructor and dance historian, Stanford University Dance Division, Department of Drama.

For centuries, dance manuals and other writings have lauded the health benefits of dancing, usually as physical exercise.  More recently we've seen research on further health benefits of dancing, such as stress reduction and increased serotonin level, with its sense of well-being. Now we've heard of another benefit:  Frequent dancing apparently makes us smarter.  A major study has added to the growing evidence that stimulating one's mind can ward off Alzheimer's disease and other dementia, much as physical exercise can keep the body fit.  Dancing also increases cognitive acuity at all ages.