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| Jay Olshansky: Hitting a dead end |
Will people live ever longer and longer? Will life expectancy
keep pushing towards 100 and beyond?
No chance, says Jay Olshanksy, a demographer specializing in longevity, who today upended for
me this widely held notion.
Olshanksy, a professor at the University of Illinois at Chicago's School
of Public Health, was speaking to journalists at the Age Boom Academy –a
gathering of aging experts pulled together by Columbia University’s Graduate School of Journalism and its Mailman School of Public health.
Worse yet, he believes that life expectancy is about to
reverse course. Japan, he said, is on the verge of decline. And the same could
be true of other Western countries.
How is this possible?
“Every generation,” he explained, “carries its own set of
mortality and morbidity risks.” We should not forecast the future based on the
longevity we’re seeing now.
He cites research out of the United Kingdom that found that
people born between 1925 and 1934, who grew up during the difficult years of
Depression and World War II, are living longer than those born before them –and
after them.
Why? It’s not known but one theory, he said, is that this
group, known as the “golden cohort,”
experienced “caloric restriction” during critical years in their youth. Food rationing might have extended their lifespans, much as some dietary experiments
with mice have done. (A study of long-lived Okinawans offered a similar explanation.)
Olshanksy guesses that the generations of obese children
that followed carry a different, and likely shorter, life expectancy. “The
obesity epidemic that swept the globe will carry those effects for
generations,” he predicted, citing his 2005 study.
Another reason humanity might well have reached a lifespan
limit is because we’ve found ways to push back age-related diseases such as
heart disease and cancer. That leaves us face to face with what kills us all in
the end – “senescence” – the body’s natural aging process.
“We’ve reached a point of limited returns,” Olshansky said. 'We may have reached
the biological limitations of our bodies."
But living longer should not necessarily be the goal. Rather than “life extension,” science, medicine and public policy should be working toward “health extension” –- trying to increase the
number of years that we live in good health before the grim reaper does us all in.
