People who consider themselves self-disciplined, organized achievers live longer and have up to an 89% lower risk of developing Alzheimer's than the less conscientious, according to two studies. When you're good at focusing your attention, you use more brainpower, says the lead researcher in both studies, Robert S. Wilson, PhD, a professor of neurological sciences and psychology at Rush University Medical Center in Chicago.

Set personal or career goals, and challenge yourself to meet them by a certain time. Also, try new things to stimulate your brain: If you always read fiction, pick up an autobiography instead. The next day, try to recall three facts you learned from the reading.