This week, we're talking about the human experience of aging. As more of us escape traumatic deaths, life expectancy has grown dramatically in our time. But what is a human lifespan?
According to genomic scientist J. Craig Venter, the key to slowing the process already exists in the smallest details of our genetic maps.
And we're asking you: Would you want to live to be 100-years-old, or even older? And if everyone could, what excites or worries you about what the future has in store?
We've received a lot of mixed reactions from listeners like you.
"I am 64 and recently retired. My Grandparents lived into their 80's, and they said the worst thing about living a long time was outliving all your friends," said Skip from Michigan. "They had 5 kids and watched them as they grew, married and had kids. I would like to be around as my kids have kids and watch them grow up. I think that as we live longer, we will start new careers several times, keeping each one for 20 to 30 years and then moving on to something new."
Debra from Emeryville, CA had similiar feelings: "I would love another 50 years! I am 62 now. If I had another 50-70 years, I would pursue a different career and do what I really should have been doing all along—art. You don't figure out what you want to in life, often until you are older."
But not all of you fell so optimistic. Gloria from Portland, OR says: "The global population is already way too large to be sustainable. I would only support longer life in countries like Russia with birth rates lower than replacement, and who would want a Putin in power for another 50-plus years?"
When did we get so fixated on life expectancy anyway?
S. Jay Olshansky, a professor in the school of public health the University of Illinois at Chicago, knows a lot about human aging through the centuries and what society stands to gain—or lose—from having a much larger, older human population. He joins The Takeaway to discuss the history of life expectancy and whether public and social infrastructure is equipped to handle an aging population.
"If you go back a couple thousand years, you have to realize that life expectancy was in the 20s and 30s," says Olshansky. "In the early part of the 20th century, life expectancy was about 50 for women and 45 for men. During the 20th century it rose about 30 years, primarily as a result of advances in public health, clean water, sanitation, hand-washing, refrigeration and the like. We're living much longer now because we reduced early age mortality."
Olshansky says that humans should not be surprised by age related diseases—like heart disease, cancer and stroke—because in a way, our society has created traded early age morality for old age morality, which naturally comes with such diseases. While life expectancy has been slowly creeping up, there have been times in history that it has slipped back.
"Throughout history there have been a lot of vacillations in life expectancy, primarily brought forth by influenza pandemics of one kind or another," he says. "The biggest one in the 20th century was the 1918 influenza pandemic; it dropped life expectancy by a couple of years. And then we had a drop in 1957 and 1968 due to influenza. Recently my colleagues and I just identified a drop in life expectancy among uneducated white men and women in the United States—about five years for women and three years for men."
On the whole, Olshansky says that society is not prepared for an inevitable demographic shift that has already started to occur and will continue—he says that both the United States and other developed countries should expect a very large, rapid increase of the number of people over 65, 85 and even 100-years-old. While populations are getting older, the professor suggests that societies begin looking toward early life to solve some of its unanswered questions.
"The human body changes with passage of time—those early life developmental events operate based on genetic clocks that influence growth, development and reproduction," says Olshansky. "But what happens later in the lifespan is not driven directly by genes, it is not by evolution, it's pretty much an inadvertent by product of these early life developmental events."
While there are clear differences between young and old, Olshanksy says recent research suggests that there are subgroups of the older population—including those that are 85-years-old or older—that are actually physically and mentally the same as people that are decades younger.
"We have to be real careful about how we consider age," he says. "In many instances, it's just a number and it's nothing more than that, and it should be completely ignored."
Olshansky says that it is time for society to take on a fundamentally new approach to aging—instead of fighting diseases as they arise, the professor says that the scientific and medical community should be refocusing on the underlying biological risk of aging itself.
"Aging is malleable—it means that there's something we can do, that there's something we can influence and we should be taking the opportunity to do so," he adds. "When you push most of the population after the age of 65, 75 and 85 as we've done now, you don't really get much in the way of additional longevity by attacking one disease at a time. However, you get huge advantages in public health with minor changes in slowing aging."