Thomas Perls has definitive proof that both mind and body can escape the decay of time. He's seen firsthand the brain of a deceased 100-year-old woman that showed no signs of the neurological wear-and-tear that usually accumulates in the aging brain. Not a hint, for example, of the plaques and tangles that accompany normal aging and are a hallmark of Alzheimer's disease. What's more, before her death, the donor had the cognitive abilities of a 60-year-old.

In 2005, Maria Esther Capovilla of Ecuador was confirmed as the oldest living person by Guinness World Records. At 116, she was still reading and walking without a cane. Researchers hope to understand how people like Capovilla live so long and remain so healthy. (Credit: Reuters)

As director of the New England Centenarian Study at Boston Medical Center, Perls has spent the last decade hunting for genetic and environmental clues to these ageless wonders. He hopes studies of very long-lived people will explain why some individuals succumb to diabetes, heart disease, or Alzheimer's at a relatively young age, while others live two decades beyond the average life expectancy and show remarkably few signs of the passage of time. (The extraordinary brain described above was donated by a participant in the study.)

Perls' study, made up of 800 centenarians, is the largest ever conducted of people who have lived to the age of 100 and beyond. Not only do these people live long, but many of them seem to escape the disability associated with diseases of aging or to compress that disability period into a short time span very late in life.

While researchers haven't yet found the source of centenarians' enviable passage into old age, they have published numerous studies showing that longevity runs in families.

Perls' team is now starting a new, larger study of long-lived families, which he hopes will bring better insight into the specific genetic and environmental factors that underlie longevity. His center will conduct one arm of the Long Life Family Study, funded by the National Institute on Aging, in which scientists at four different sites will recruit 1,000 families that show exceptional longevity. Eventually he hopes to be able to translate the findings from these families into broadly usable treatments for the diseases of aging.

Here Perls tells Technology Review what he's learned so far about aging -- and what he hopes to uncover.

Technology Review: What makes centenarians so interesting from a medical perspective?

Thomas Perls: These individuals have a remarkable potential for resilience. Forty percent of centenarians have diseases they've been living with 20 years, but they don't show disability from these diseases until their early-to-mid-nineties. What is this resilience that allows people to live with these diseases and not have problems until the relative end of their extremely long lives?

In addition, 13 percent of centenarians seem to escape the diseases of aging altogether. Some even do this despite some horrendous health habits. We want to figure out how to translate that into strategies for other people. Our goal is to get people to markedly delay or escape disability associated with aging. If we could do that, it would be a huge boon to the health system and our society.