Finally, personality seems to play an important role in protecting our mental prowess. A sense of self-efficacy may protect our brain, buffering it from the harmful effects of stress. According to Albert, there's evidence that elevated levels of stress hormones may harm brain cells and cause the hippocampus—a small seahorse-shaped organ that's a crucial moderator of memory—to atrophy. A sense that we can effectively chart our own course in the world may retard the release of stress hormones and protect us as we age. "It's not a matter of whether you experience stress or not," Albert concludes, "it's your attitude toward it."
Reducing stress by meditating on a regular basis may buffer the brain as well. It also increases the activity of the brain's pineal gland, the source of the antioxidant hormone melatonin, which regulates sleep and may retard the aging process. Studies at the University of Massachusetts Medical Center and the University of Western Ontario found that people who meditated regularly had higher levels of melatonin than those who took 5-milligram supplements. Another study, conducted jointly by Maharishi International University, Harvard University, and the University of Maryland, found that seniors who meditated for three months experienced dramatic improvements in their psychological well-being, compared to their non-meditative peers.
