When I was a kid, adults told me that medicine would be so advanced by the time I grew up, I’d live to be 150.
It seems possible. Alas, not for me, personally, but as a concept. After all, modern medicine has surely been extending the human lifespan for hundreds of years … hasn’t it?
The 17th-century English philosopher Thomas Hobbes famously called life before the modern era “nasty, brutish and short.” People still echo that idea today, albeit without the same pithy elegance.
“Hunter-gatherers all died when they were, like, 30,” a friend told me recently. “When the average old age death was people in their 40’s, did they look as old as people in their 90’s or 100’s look now?” asked someone on Quora.
Many imagine that humans in the past all died young and that, thanks to medical science, people are now living longer and longer. Soon, perhaps, we’ll all hit that 150th birthday — or achieve immortality.
It’s a nice idea; it’s just entirely fictional.
I may outlive my ancestors, but doctors and pills will likely have little to do with it.
In the grand scheme of human longevity, “the contribution of modern medicine is minor,” said Jan Vijg, a genetics professor at the Albert Einstein College of Medicine in New York. In fact, it’s barely moved the needle.
‘Back To Where We Used To Be’
Thousands of years ago, all humans were hunter-gatherers, and life expectancy for those ancestors was indeed low, in the 30s or so. But back then ― and for most of human history ― a lot of babies and children died, driving down the average age of death.
People who survived childhood most commonly lived 68 to 78 years, said Michael Gurven, an anthropologist at UC Santa Barbara who studies the hunter-gatherer lifespan.
More than 10,000 years later, the numbers look eerily similar.
The average person can expect to live 71.4 years, says the World Health Organization based on 2016 data. In the U.S., the Centers for Disease Control and Prevention put life expectancy at 78.6 years in 2017, down from 78.7 in 2016. The WHO estimate of American life expectancy is a bit lower — 78.5 years — and both government data and a global health study from the University of Washington show that number is on the decline.
When humans started shedding their nomadic ways and cultivating crops, populations boomed — and life expectancy took a nosedive.
“As soon as farming got involved, [life expectancy] shot down,” said Daniel E. Lieberman, an evolutionary biology professor at Harvard University. “Very few people lived to be very old once farming starts.”
Farmers, he explained, grew more food, creating larger populations that lived in close quarters, often with domestic animals. This spread infectious diseases (and still does — remember swine and bird flu?). While hunter-gatherers found varied diets for themselves, those early farmers were actually more likely to suffer from malnutrition. Their skeletons showed more evidence of things like anemia and stress lines. They died on average around age 20, estimates one 2007 study. That’s 10 years younger than hunter-gatherers.
Eventually, humans adjusted to farming and began surviving somewhat longer, but life expectancy remained in something of a slump for millennia.
“The worst thing you could possibly be was a French peasant in the 16th century,” Lieberman said. Ironically, the lives of many of Hobbes’ contemporaries were probably a good deal shorter than those of his Paleolithic ancestors.
“We didn’t need cardiologists in the Paleolithic.”
Life expectancy only increased significantly a hundred years ago or so. And contrary to popular belief, this change had little to do with modern medicine.
“The most important thing is not medication; it’s sanitation,” Lieberman said. During the late 19th and early 20th centuries, people learned how germs worked and started doing things like building more sewers, boiling water for childbirth and making sure drinking water was clean. Countries also got better at distributing food, which decreased starvation, Vijg said.
“We can thank public health far more than we can thank medicines,” Lieberman said, noting that by the time antibiotic use became widespread after World War II, mortality rates had already plummeted. In 1870, the average person in Europe or America lived to their mid-30s. Life expectancy rose steadily from there, reaching 58 to 65 years in 1950.
Not that medicine has been useless. After sanitation, antibiotics and vaccines have been the biggest boons to life expectancy, partly because they fight diseases that became common when people started farming.
“They’ve basically got us back to where we used to be,” Lieberman said, adding, “The average person who walks in to see a doctor is seeing them for a disease that we didn’t used to get.”
According to Lieberman, hunter-gatherers rarely developed heart disease. Now it is the No. 1 cause of death in the U.S. “We didn’t need cardiologists in the Paleolithic,” he said.
He also stressed that “almost all heart disease is preventable” and that smoking, poor diet and lack of exercise account for the vast majority of deaths in the U.S.
What Medicine Can — And Can’t — Do
“So, why do I hear so many people talking about medicine like it’s some ticket to immortality?” I asked Lieberman. He laughed.
“Do you know what the leading causes of death in the U.S. are?” he replied. After heart disease comes cancer. The third is medical error.
At least, that last bit is what a 2016 British Journal of Medicine study found. But you can’t write “medical error” on a death certificate, so no one’s quite clear on how many die that way.
Which isn’t to say that doctors are bad and we should board up all the hospitals. But our perspective on the true value of modern medicine may be a tad warped.
Americans spend $3.5 trillion on health care every year. That’s 17.9 percent of the economy or $10,739 per person. The number of people working in health care more than doubled in the last 18 years — and there’s still a health care worker shortage.
We’re deeply invested in the myth that medicine has drastically increased the human lifespan and will continue to do so. As Lieberman pointed out, the health care industry heavily markets its own importance and pushes treating illness over preventing it with lifestyle modification. And humans are lazy; it’s easier to take pills than exercise.
“Doctors can’t cure many chronic diseases. But they can keep people dying longer.”
“Medicine does do some wonderful things,” Lieberman said. “We all know people who wouldn’t be alive if not for medicine.”
But doctors typically only help once a person is sick, and doctors can’t cure many chronic diseases. But they can keep people dying longer.
“We can keep you going for quite a long time,” Lieberman said. But “at that point, the damage is done. We’re not curing them; we’re just keeping them alive longer.”
Alive but not well, that is. While life expectancy in the U.S. now teeters around the 80-year mark (under for men, just over for women), “healthy life expectancy,” a measure that discounts the years a person spends severely ill, finds the average American only has 68.5 healthy years (63.1 globally).
As far as living to 150 (let alone achieving immortality), we’re no closer today than we were 10,000 years ago.
For the hopefuls out there, a better aim would be 115, which scientists consider the age at which humans have evolved to die. After that, Vijg said, “You fall apart. Everything breaks down.”
That may sound dark, but it can be empowering when viewed through a certain lens. If we want to live long, healthy lives, most of us don’t have to hire the best doctors or wait for scientists to invent a magic pill. More bike lanes and salads will do the trick.