Those people who live a very long time are typically much healthier than their peers, and spend a shorter period of their lives suffering from age-related disease and disability. Aging is a process of accumulating cell and tissue damage, and those people who are more resilient to damage, or who have suffered less of it though simple happenstance, will be less impacted in all aspects of aging. This is exactly what we'd like to achieve through the development of rejuvenation therapies that can repair this damage, which even in their early stages should produce a much greater difference in outcomes than the naturally occurring gap between long-lived and short-lived people.

Research has shown that the human lifespan has the potential to be extended. But would this merely mean people living longer in poor health? The upbeat findings from a new study indicate that those extra years could well be healthy ones. In a study of nearly 3,000 people, the onset of illness came decades later in life for centenarians than for their younger counterparts. "Most people struggle with an ever-increasing burden of disease and disability as they age. But we found that those who live exceptionally long lives have the additional benefit of shorter periods of illness - sometimes just weeks or months - before death."

The researchers looked at the health status of centenarians and near-centenarians enrolled in two ongoing studies: the Longevity Genes Project (LGP) and the New England Centenarian Study (NECS). The LGP recruits healthy, independently living Ashkenazi Jewish people 95 and older from the northeastern United States. For comparison, the LGP includes a group of Ashkenazi Jewish individuals who do not have a parental history of longevity. The NECS began in 1994 as a study of all centenarians living in eight towns near Boston and was later expanded to include participants from North America generally as well as England, Ireland, Australia and New Zealand. The NECS comparison group consisted of people aged 58 to 95.

This study compared (1) the health status of 483 long-lived LGP participants with 696 LGP comparison individuals 60-94 years old, and (2) the health status of 1,498 long-lived NECS participants with 302 NECS comparison subjects aged 58-95. For both sets of comparisons, the researchers looked at the ages at which individuals developed five major age-related health problems: cancer, cardiovascular disease, hypertension, osteoporosis and stroke. Analysis revealed a consistent pattern of delayed onset of illness in the LGP and NECS centenarian groups compared to their respective comparison groups. For example, for the long-lived NECS individuals, cancer didn't afflict 20 percent of men until age 97 and women until 99. In contrast, 20 percent of NECS comparison participants had developed cancer by age 67 in men and 74 in women. Results were similar for the LGP: for the long-lived LGP participants, the age at which 20 percent had developed cancer was delayed to 96 for both sexes. But cancer had affected 20 percent of LGP control-group males by age 78 and control-group females by 74.

Despite their genetic, social and cultural differences, the long-lived LGP and NECS participants proved markedly similar with respect to major illness: Compared to younger comparison groups, their onset of major age-related disease was delayed, with serious illness essentially compressed into a few years very late in life. The findings suggest that discoveries made in one group of centenarians can be generalized to diverse populations. And they contradict the notion that the older people get, the sicker they become and the greater the cost of taking care of them.