(Lisa F. Young/iStockphoto)
No, it's not just about doing sudoku—though puzzles do fall into the category. The brain's ability to reorganize neural pathways with new information or experiences means it's regularly changing; we can even generate new brain cells. But you need to work it. The general guideline, says Neil Buckholtz, chief of the dementias of aging branch at the National Institute on Aging, is regularly engaging in "some kind of new learning that challenges you." No one knows exactly what works, though population research has shown that having more years of formal education seems to be protective. Folks with lots of schooling can still get Alzheimer's, but the disease may appear later. From that, some extrapolate that lifelong curiosity and learning may have benefits.
Next: 4. Social connections