Some fortunate folks stay mentally sharp well into their 90s. Scientists are learning their secrets in hopes of helping the rest of us keep our minds fit as we age.Irving Kahn works 8 hours a day, 5 days a week, at his Madison Avenue investment advisory firm. This would hardly be noteworthy except for his age: 99. When scientists gave him a mental fitness exam 2 years ago, Kahn showed no signs of cognitive decline. “I don’t seem to have that problem,” Kahn says.
Kahn has the good fortune to be intellectually spry as he approaches his 100th birthday. But he is not alone. Although only one in 10,000 people lives to be 100, studies suggest that up to a third of centenarians are doing well cognitively, and most of the rest have dodged any mental impairment until well into their 90s. Contrary to popular belief, “there is not an inexorable decline in mental function in older people,” says neurologist David Bennett, who runs two longitudinal studies of aging at Rush University Medical Center in Chicago, Illinois. “If you follow [older] people over time, a lot do get worse, but most stay the same–and some get better.”
A growing body of research is geared toward determining what keeps some people’s minds nimble into old age, and how to reproduce that success in the rest of us. Some scientists have identified genes that are associated with successful aging of the brain and hope to find drugs with similar effects. Others have discovered that simpler solutions like mental exercises also might prevent dementia, including the most devastating sort that accompanies Alzheimer’s disease. Buttressed by these findings, Bennett speculates: “Cognitive, physical, and social factors may delay the onset of Alzheimer’s disease.”
