The cognitive changes caused by deterioration of white matter are subtle, Buckner said. "The changes in the crosstalk of brain regions are correlated with mild cognitive changes," he said. "People who have these changes are aging gracefully."
These shifts affect people differently, and not all the older people showed the alterations, Buckner said. Interestingly, some networks, such as the visual system, remained intact.
It may be possible to slow even this normal process of aging, Buckner said. "Maybe we can find ways to age even more gracefully," he added.
Buckner believes living right may help. "There are indications that staying cardiovascularly fit and healthy helps our brains age gracefully," he said. "We now have a way to study aging and to understand the factors that might help all of us age optimally."
The study points out the differences between healthy brain aging and Alzheimer's, one expert said.
"It's interesting that the normal process of brain aging is different from what we see in pre-clinical Alzheimer's," said Paul Sanberg, director of the University of South Florida Center of Excellence for Aging and Brain Repair. "One can tease away what is related to aging, and what is related to a disease."
It's important in developing therapies for Alzheimer's to be able to tell the difference between normal aging and disease, Sanberg said, because "it helps us make sure that we are affecting the right problems."
In addition, knowing how the brain ages normally might make it possible to create cognitive enhancers, Sanberg said.
Another expert noted that Buckner's group looked for signs of Alzheimer's in fewer than 20 percent of the older adults in the study.
"Since one can expect 20 to 30 percent of people in their 80s to develop Alzheimer's and Alzheimer's takes decades to develop, 20 to 30 per
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