TUESDAY, Aug. 19 (HealthDay News) -- Living longer, even past the 100-year mark, doesn't necessarily mean that a person's last years will be spent in sickness or disability, Danish researchers report. That's because the very old typically enjoy healthy, independent lives despite their advanced age, the study found.
"This finding is not surprising," said Dr. James S. Goodwin, a professor of geriatrics and director of the Sealy Center on Aging at the University of Texas Medical Branch in Galveston. "Because when you think about it logically, the reason we're living longer is because we're healthier. And if we're healthier at any given age, then we're less likely to be disabled."
The new finding is based on assessments of the physical and mental health of Danish citizens in their 90s. These elderly were tested periodically on their ability to take care of themselves as they approached their 100th year.
Goodwin -- who was not involved in the study -- believes it also refutes the prevalent notion that an aging population will bring about skyrocketing health care expenditures. Such theories hold that, "all the nursing homes will choke, as more and more people spend much more time disabled," Goodwin said. "But in reality, that hasn't really worked out to be the case."
The new study was led by Dr. Kaare Christensen of The Danish Aging Research Center at the University of Southern Denmark in Odense. The team reported its findings in the Aug. 18-22 issue of the Proceedings of the National Academy of Sciences.
To gauge recent quality of life trends among the so-called "super-elderly", Christensen's team launched mental and physical health surveys in 1998 that focused on an initial group of almost 2,300 Danish men and women, all of whom had been born in 1905.
The researchers did not exclude anyone on the basis of prior health issues or cognitive status at the start of the study. In all, four surveys were conducted -- one approximately every two years-- and all tracked the same group of individuals as they aged from 92 to 100.
By the time of the last survey in 2005, just 166 of the participants were still alive. However, the study authors observed that among those super-elderly still alive at the time of each survey, the percentage that was still able to maintain a functionally independent lifestyle remained nearly constant.
Across surveys, those deemed to be mentally and physically "independent" -- able to perform basic tasks on their own, while remaining free of serious and disabling cognitive, sensory, or physical impairment -- declined only "very modestly" from 39 percent at age 92 to 33 percent by age 100, the researchers reported.
According to the researchers, those patients who made it to 100 were, by definition, healthy enough to do so, whereas those who weren't as healthy passed away at an earlier age. This finding, they said, meant that any boom in the numbers of super-elderly would not necessarily translate into a steep rise in health care expeditures.
"This is very good news that I can give to some very old people," noted Goodwin. "I can tell my elderly patients that their chances of being able to take care of themselves 10 years from now is the same as it is now."
For his part, Dr. Thomas Perls, an associate professor of medicine and geriatrics at Boston Medical Center, shared Goodwin's optimistic reading of the findings, while describing the independence-with-age dynamic as a geriatric "survival of the fittest."
"As I like to say, the older you get, the healthier you've been," he said. "So getting to 100 really is a survival phenomenon. And people who get there necessarily have to have been disability-free -- not only in their early 90's, but pretty much for the vast majority of their lives."
For more on healthy aging, visit the National Institute on Aging.
SOURCES: James S. Goodwin, M.D., professor, geriatrics, director, Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas; Thomas Perls, M.D., associate professor, medicine and geriatrics, Boston Medical Center, Boston; Aug. 18-22, 2008 Proceedings of the National Academy of Sciences