In 1900, the average American could expect to live 47 years. A century later that number had skyrocketed to 76 years — a 62 percent jump.
The question on everyone’s mind as they weigh their prospects on this earth: will that jump in longevity continue? What is the likelihood you and I will live into our 90s—or more?
Dr. James Vaupel, the Executive Director of the Max Planck Institute for Demographic Research is universally considered to be one of the greatest authorities on longevity. Vaupel speculated in a speech recently, “A baby girl born in 2000 in Japan, Western Europe, North America, Australia, or New Zealand has a 50-50 chance of seeing the 22nd Century.”
Said another way, life expectancy for females lucky to be born these days in those developed countries is now 100 years.
If life expectancy’s increase continues, equaling its jump between 1900-2000, how long will Americans be living by the year 2100 — 90 years from now? Do the math. That projection results in a life expectancy of 123 years for the average American. Today less that 1 percent of our society reaches the century mark. In 100 years, if that projection held, most everyone will pass 100 years and not look back.
But isn’t there a biologic maximum to aging? George Buffon, a French biologist of the early 19th Century, observed the close relationship between the duration for skeletal maturity and life span across a broad spectrum of animals. Buffon noted that large mammals live longer than small ones, and that animals tend to live six times the period needed to complete their growth, that is, gain “skeletal maturity.”
Humans reach skeletal maturity in 20 years, thus Buffon theorized that most humans should live about 120 years.
More recently Richard Cutler, of the Gerontology Research Division of the US National Institute of Health, has explored the rate of development, length of reproductive period, maximum caloric consumption, and brain size to compute the “mean lifetime potential” (MLP) of a number of animals. Mice live 3 years, dogs 20 years, elephants live 70 years, and whales live 100 years. Cutler’s calculations lead him to conclude that the MLP for humans is 110 years.
Walter M. Bortz, MD, and lecturer at Stanford Medical School and one of America’s foremost geriatric leaders, believes that if we don’t live to 100, we’re doing something wrong. His very readable two books “We Live too Short, and Die to Long” and “Dare to be 100” spell out why we should be living longer and how we can stop “shooting ourselves in the foot” geriatrically. No surprises here: More exercise. Better diet. More exercise. Staying engaged. More exercise. Finding meaning in what we do. And oh, did I mention “more exercise?”
Certainly our American healthcare researchers are doing their part these days. Ken Dychtwald, Ph.D., points out that more resources have been devoted to fighting disease and aging over the past 10 years than in the previous 10 centuries. Advances in tissue engineering, stem cell research, the human genome (gene mapping) project, bionic body parts, animal organ transplants, ever-improved public health advances, micro-nutrient research, and massive breakthroughs in diagnostic tools all bring that 100, or 110, or 120 life expectancy closer to each of us and faster, too.
Given the amazing work in bio-engineering of these past 10 years and the next 100, it may be that humans will be pushing the 150-year limit rather than the 120 ceiling. With replaceable body parts grown of our own DNA and without rejection, it’s possible, and maybe likely. Now if I can just learn to stay away from donuts and take longer walks every day.
Bill Morton has a Certificate in Gerontoly from the UW and is the author of “2H: The Official Second Half Handbook.” He’s lived on the Eastside for 20 years.
