FRIDAY, Oct. 2, 2009 (HealthDay News) -- If current life expectancy trends continue, more than half of babies born in rich nations since 2000 will live to 100 years of age, and they'll have less disability than elderly people in previous generations.
That's the conclusion of researchers who found that increases in life expectancy evident in rich nations since 1840 show no signs of slowing.
"The linear increase in record life expectancy for more than 165 years does not suggest a looming limit to human lifespan. If life expectancy were approaching a limit, some deceleration of progress would probably occur. Continued progress in the longest living populations suggests that we are not close to a limit, and further rise in life expectancy seems likely," Kaare Christensen, of the Danish Aging Research Center at the University of Southern Denmark, and colleagues wrote. Their study appears online Oct. 1 in The Lancet.
During the 20th century, huge increases in life expectancy (30 years or more) occurred in developed nations. Even if health conditions don't improve, 75 percent of babies born in rich nations since 2000 can expect to live to 75, the researchers concluded.
Their analysis of data from more than 30 developed countries revealed that death rates among people older than 80 are still falling. In 1950, the likelihood of survival from age 80 to 90 was 15 percent to 16 percent for women and 12 percent for men, compared with 37 percent and 25 percent, respectively, in 2002.
While longer life expectancy is good on one hand, it presents major personal and societal challenges in health care and other areas.
The researchers suggested that shortening work weeks and extending people's working lives might further extend increases in life expectancy and health, and help nations cope with the economic implications of many more people living longer lives.
"If people in their 60s and early 70s worked much more than they do nowadays, then most people could work fewer hours per week than is currently common -- if they worked correspondingly more years of their longer lives," the authors stated.
"Preliminary evidence suggests that shortened working weeks over extended working lives might further contribute to increases in life expectancy and health. Redistribution of work will, however, not be sufficient to meet the coming challenges. Even if the health of individuals at any particular age improves, there could be an increased total burden if the number of individuals at that age rises sufficiently," the researchers concluded.
Strokes are among the health problems that may become more common as human life expectancy increases, because people over 80 are particularly susceptible to stroke. Despite that increased risk, routine stroke interventions are underused in the very elderly, even though such interventions could be very effective in this age group, Dr. Nerses Sanossian, of the University of Southern California, and Dr. Bruce Ovbiagele, who's with the UCLA Stroke Center and Department of Neurology at UCLA, explained in an article that appears online and in the November print issue of The Lancet Neurology.
"With the rapidly growing population of individuals above 80 years, future stroke trials need to include the very elderly to facilitate ready generalizability of results and to convince skeptical clinicians that all patients with stroke should benefit from prompt evidence-based treatment, regardless of age," they wrote.
The U.S. Centers for Disease Control and Prevention has more about life expectancy in the United States.