Medicine, history, and rare age disorders are reshaping the way researchers view the process of aging, and it may extend lives for decades.
Every four seconds, somewhere in the world, a baby is born. Babies grow, become toddlers, teens, adults. They age, they die. It’s only natural and quite straightforward. Or is it?
As it turns out, aging is not the inexorable, straightforward process we once thought it was. Our ideas of longevity and life expectancy have changed not only with medicine, but also with new views on history. And new research into rare aging disorders is revealing clues about how aging works, and whether it can be dramatically slowed down to extend lives.
For decades, some bad science perpetuated the misconception that people’s lives were much shorter in the ancient times than they generally are today. For example, in 1950, Scientific American published a paper that reported that the average length of life in ancient Greece was 35 years, and in ancient Rome 32. The problem with those numbers is that they estimated an average lifespan for every member of the population, including those who died in infancy, those who died at war or from other violent causes.
In fact, when the numbers are properly adjusted to include only those adults who died naturally of old age, it appears that our ancestors lived nearly as long as we do today. Prominent philosophers, poets, and politicians of ancient Greece generally lived up to 68 years of age: Plato died at 80, Aristotle at 62. Great Italian painters of the Renaissance lived to around 63: Leonardo da Vinci died at 67, Michelangelo at 88.
Because ancient historians were more attentive to the lives of men than women, we lack sufficient data to compare gender differences in life expectancy before the 15th century. Still, over the 500 years from the late 15th to the early 20th century, life expectancy for women rose by 30 years. While men, by and large, enjoyed life well into their 70s even before the medical advances of the 20th century, women’s life expectancy was dramatically affected by dangers associated with childbirth.
The other important cause of lower life expectancy, for most of history, was early childhood mortality—a figure that significantly declined as medicine improved in the 19th century. Once that factor was stripped out, an average British five-year-old boy in Victorian times was projected to live until 75 years old and an average girl until 73—comparable with today’s rates of 75.9 and 81.3 years, respectively.
That said, age-associated diseases remain as common today as they were centuries ago. Twenty-four percent of elderly Americans die from heart disease, and 23 percent from cancer. So do we need to rethink the concept of aging altogether?
Investigating How Aging Works
Some researchers, like the geriatrician Richard Miller of the University of Michigan, argue that, unless scientists target the illnesses of aging holistically, we will see only very modest increases in disability-free life expectancy. Basic research into the mechanics of aging, they argue, could add healthy decades to people’s lives.
Consider Jane Doe, a perfectly average, 50-year-old American woman. Based on current health risks, she would be expected to live for another 32 years. If we could eliminate cancer mortality risks at all ages above 50, it would only increase Jane’s life expectancy by 2.7 years. If we could eliminate risks of death due to cancer, heart disease, stroke, and diabetes altogether, it would increase her life by 14 years.
At the same time, if we can slow down the aging process to an extent that is routinely achieved in laboratory animals, she might be able to enjoy a whopping 30 more years of life—on top of the average 82. And we aren’t talking about an old age bound to bed and medicine cabinets. Ninety-year-old adults could have as active and healthy lives as today’s 50 year olds.
But what about extreme cases, in which the aging process is sped up? Patients with Hutchinson-Gilford progeria syndrome, a premature aging disorder, might bear key answers to why we age, and to how we can work with nature to slow the aging down.