CityReads│Rage, Rage Against Aging
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Rage, Rage Against Aging
Why we shouldn’t fear aging?
The aging of the world is happening fast. Japan leads—more than a quarter of its population is 65 or older—but Germany, Italy, Finland, and much of the rest of the European Union aren’t far behind. Americans 65 and older are now 16% of the population and will make up 21% by 2035. At that point, they will outnumber those under 18. A quarter of the people in Europe and North America will be 65 or older by 2050. By the end of 2018, 65 and older accounted for 11.9% of the total population in China, amounting to167 million.
This trend is being driven by lower fertility rates and longer lives. While life expectancy has slowed its increase in some advanced countries in recent years, it continues its upward trend worldwide. A female baby born today in Japan is expected on average to live to 87.
Not only is the overall population aging; you will probably spend much more of your life being old. In 1960, if you were 65, you could expect to live to around 79. These days, you’re expected to live to nearly 85. If you’re already 75, you should expect to live until 87.
It’s a huge shift that is changing our economy, our social and cultural values, and even the way we perceive and plan our lives.
The conventional wisdom is that an aging population is toxic for economic growth. Who will do all the work? How will we pay for all those old people’s medical and welfare programs? Economists like to call it the dependency ratio: the size of the working-age population relative to those too old (or too young) to have a job. And they like to show scary projections of how this demographic crisis is coming to get us, such as the gray tsunami, the demographic cliff, and the demographic time bomb.
Aging societies aren’t worse off
The truth is that we don’t know much about how an aging population will affect us.
“There has been a productivity hit,” says Nicole Maestas, an economist at Harvard. “It’s big, and it’s economically meaningful.” She and her colleagues have calculated, on the basis of data from 1980 to 2010, that a 10% increase in the population age 60 and older has decreased growth in GDP per capita by 5.5%. It means that the aging US population could slow economic growth by 1.2 percentage points this decade and 0.6 percentage points in the next. Some of this will be because fewer people are working, but two-thirds of it will be because the workforce is less productive on average.
But Maestas cautions that the projections are based on historical trends and may not be accurate predictions. Her guess is that productivity has fallen as the population ages because the most skilled and experienced people have left in larger numbers, since they’re more successful and wealthier and can afford to retire. If she’s right, then it’s not that workers become less productive as they age, but that the most productive ones stop working. This means that a big drop in productivity isn’t inevitable. New technologies and business policies might keep talented people working longer.
Looking at GDP data from 1990 to 2015, Daron Acemoglu at MIT and Boston University’s Pascual Restrepo found no correlation between aging demographics and slowed economic growth. In fact, countries like South Korea, Japan, and Germany, all with rapidly aging populations, are actually doing well.
One possible reason? Automation. Countries with aging workforces have been quicker to adopt industrial robots to compensate. The resulting boost to productivity is “softening the doom and gloom around aging,” says Acemoglu, who says he went into the research expecting that the impact of aging “wasn’t as dark” as many suspected but was surprised by “the total lack of any evidence of negative effects from aging.” Still, Acemoglu also stresses how much remains to be learned. “We’re not sufficiently prepared to know what happens when the society ages, and we don’t know how to navigate it,” he says.
Living better, but not longer
The increase in life expectancy over the last hundred years has been one of our great technological achievements. At the start of the 20th century, average life expectancy was around 50; by 1960 it was 70, and by 2010 it was up to nearly 80. Most of the early progress was due to keeping children healthier—in 1900 nearly one in four died before age 10. Later progress came in the treatment of things like cardiovascular disease, allowing most people to liveinto their 70s.
But don’t expect this remarkable run to continue. Average life expectancy is leveling off and appears to be hitting a ceiling at just a little over 80. S. Jay Olshansky, at the University of Illinois at Chicago's school of public health, has been predicting this slow down for years. He says we’re near our upper limit for average life spans. “Possibly we can get it up from 80 to 85,”he says, noting that already “Japan is closing in on it.”
What if aging was a curable disease?
The oldest among our species can reach 115 and, in exceptionally rare cases, only a few more years past that. But is a human lifespan stuck at that limit?
One thing we haven’t been able to do is intervene to slow the aging process itself. But a first wave of promising anti-aging drugs—the result of several decades of breakthroughs in understanding the biology of aging—are being tested in humans.
For now, the hope for these molecules—which include rapamycin-like compounds that affect immune function, ones that activate proteins called sirtuins, and“senolytic” drugs that clean up damaged and aging cells—is that they can help with age-related ailments. Most ambitious, scientists are planning human tests for metformin, a longtime diabetes drug, to see if it can slow multipleage-related conditions.
If any of them succeed, it will validate an idea that could change medicine: thatit’s possible to attack certain illnesses by intervening in natural aging processes—in other words, by treating aging itself in order to slow the contributing causes of disease.
Some of these promising compounds have already dramatically extended the life span of yeast, worms, and rodents, but we’re still a long way from performing such longevity tricks in humans.
A growing number of scientists are questioning our basic conception of aging. What if you could challenge your death—or even prevent it altogether? What if the panoply of diseases that strike us in old age are symptoms, not causes? What would change if we classified aging itself as the disease?
David Sinclair, a geneticist at Harvard Medical School, is one of those on the frontline of this movement. Medicine, he argues, should view aging not as a natural consequence of growing older, but as a condition in and of itself. Old age, inhis view, is simply a pathology—and, like all pathologies, can be successfully treated.
David Sinclair just published a book in September 2019, Lifespan: Why We Age–andWhy We Don't Have To, which is a comprehensive explanation for why we age based on information theory and a conclusion that aging is a disease, and that disease is treatable. Sinclair believes that there is a single cause of aging upstream of all the hallmarks of aging– loss of information. So the loss of information isn't in the genetic code. Rather, the loss is in the epigenome, or the expression of genetic code that instructs newly divided cells what they should be.
The book is laid out in three sections: past, present, and future. In the first part, The past, it summarizes what we know: evolution and former theories of aging. Problems with our current healthcare system and how it treats aging. Hallmarks of aging and their single upstream cause, loss of analog information. In the second part, The present, it talks about what we are learning: habits that affect aging through hormesis. Molecules that can change the epigenetic landscape. Novel treatments and ongoing mouse and human studies. In the third part, The future, it discusses where we're going: Implications for the planet of longer-living humans. A message of hope and a humanitarian push to reclassify aging as a disease.
Sinclair argues that epigenetic, rather than genetic, changes are what truly paint the landscapes of our lives. How our cells turn genes on and off as we get older –“epigenetic noise,” so to speak – is far more important than the underlying genes themselves. Lifespan is only 20-per-cent genetically determined; the restis epigenetic.
These numbers have made it fashionable to say that our genes are not our destiny, butthere’s an even more important implication. Our newly emerging understanding of aging allows us to say something that many people will have an even harder time fathoming: Aging, as we know it, is not inevitable.
Fear of our older selves
It’s been 12 years since Facebook CEO Mark Zuckerberg famously asserted that “young people are just smarter,” and almost a decade since billionaire venture capitalist Vinod Khosla told an audience, “People under 35 are the people who make change happen,” adding, “People over 45 basically die in terms of new ideas.”
There are few signs that Silicon Valley is changing its tune. Multiple tech firms have faced lawsuits over age bias. In a court filing for a 60-year-old programmer not hired by Google, the complaint noted that the company’s workforce had grown from 9,500 to 28,000 people from 2007 to 2013 with a median age of29, at a time when the US average was around 42. And Khosla himself recently doubled down on his argument, tweeting, “Experience is a bias.”
Academic research indicates that Zuckerberg and Khosla are wrong. In a rigorous study that looked at 2.7 million company founders, economists at MIT, the US Census Bureau, and Northwestern University concluded the best entrepreneurs are middle-aged. The fastest-growing startups were created by founders with an average age of 45. In a 2018 paper they found that a 50-year-old entrepreneur was nearly twice as likely to build a highly successful company as a30-year-old. And contrary to Khosla’s tweet, it turns out that industry experience was a significant positive in predicting success.
Blatantage bias might also explain why Silicon Valley has done such a terrible job of creating startups in biomedicine, clean energy, or other areas requiring scientific expertise and knowledge. In earlier research, one of the authors of last year’s paper, Benjamin Jones, an economist at Northwestern, presented evidence that most great scientific achievements in the physical sciences and medicine come in middle age, not from the precocious young.
Even if they don’t change their ideas about aging, though, it’s critical that our larger society does. “If we can’t extend health spans and lower health-care costs, if we can’t increase productivity and integrate older workers more effectively, and if we can’t tackle the disparities that challenge so many aging communities, the costs to society will be mind-blowing,” says PaulIrving, chairman of the Milken Institute Center for the Future of Aging.
Ageism is a pain caused by our own narrow thinking and limited imaginations. Ageism is a particularly pernicious bias because it is a fear of our own selves. But while aging might be inevitable, becoming unproductive is not. We might be facing a demographic tsunami, but we don’t have to be overwhelmed by it. We can take the high ground.
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