Building A Better Brain

But longevity is only part of the nuns' story. They also do not seem to suffer from dementia, Alzheimer's and other debilitating brain diseases as early or as severely as the general population. David Snowdon of the Sander's Brown Center on Aging at the University of Kentucky, the professor of preventative medicine who has been studying the nuns for several years, had found that those who earn college degrees, who teach, who constantly challenge their minds, live longer than less-educated nuns who clean rooms or work in the kitchen. He suspects the difference lies in how they use their heads.

Within the human brain each neuron contains at one end threadlike appendages called axons, which send signals to other nearby neurons. At the other end of the neuron are similar threadlike appendages called dendrites, which receive messages from nearby cells. Axons and dendrites tend to shrink with age, but experiments with rats have shown that intellectual exertion can spur neurons to branch like the roots of a growing tree, creating networks of new connections. Once a skill becomes automatic, the extra connections may fade, but the brain is so plastic that they can be tapped again if needed. Like the power grid of an electric company, the branching and connections provide surplus capacity in a brownout. Snowdon and some neuroscientists believe that people with such surplus who find their normal neural pathways blocked by the tangles that characterize Alzheimer's disease can reroute messages. To be sure, every brain is limited by genetic endowment, and flexibility does decrease with age. But new thinking in brain science suggests that whether someone hits that wall at age 65 or at age 102 may be partly up the the individual.

Professor Snowdon says the nuns of Mankato demonstrate this. He expects to prove that the better-educated sisters have significantly more cortex and more synaptic branching of neurons than their less-educated counterparts, which would allow the former to cope better with Alzheimer's disease, dementia and stroke. Brain exercising is a way of life at the nunnery, where the sisters live by the principle that an idle mind is the devil's plaything. They write spiritual meditations in their journals and letters to their congressmen about the blockade in Haiti, and do puzzles of all sorts....One 99 year-old, Sister Mary Esther Boor, takes advantage of slow minutes while working as the complex's receptionist to solve brainteasers -  some with words in Spanish.

What can the average person do to strengthen his or her mind? The important thing is to be actively involved in areas unfamiliar to you, says Steel, head of UCLA's Brain Research Institute. "Anything that's intellectually challenging can probably serve as a kind of stimulus for dendritic growth, which means it adds to the computational reserve in your brain."

So pick something that's diverting and, more important, unfamiliar. A computer programmer might try sculpture, a ballerina might try marine navigation. Here are some other stimulating suggestions from brain researchers: