David Sinclair is an Australian geneticist and a professor at Harvard Medical School. He has a soft-spoken, almost tranquil tone, which has the effect of mellowing the audacity of his proclamations. Like this one: “I don’t see any reason why a child born today couldn’t make it to 150.” Or this: “I actually think it will be possible one day to be immortal.”
Sinclair’s forecasts are bold, but his basic research question is prosaic: Why must we grow old? From the outside, the aging process is far from mysterious: Our wrinkles deepen, our spines curve, our energy flags. But beneath the skin, it is a mystery: Every process that has kept us alive for decades slowly begins to go haywire, for no apparent reason whatsoever. “What we’re working on in my lab is trying to understand why those things happen over time,” Sinclair told me. “And I think we've solved it.”
In the latest episode of Crazy/Genius, produced by Kasia Mychajlowycz and Patricia Yacob, I spoke with Sinclair and several other scientists and technologists about the science of life extension and the allure of immortality.
In history and literature, the search for eternal life is an eternal disappointment. The Spanish conquistador Ponce de León sought the fountain of youth in the jungles of an unfamiliar continent; all he found was Florida. In Oscar Wilde’s The Picture of Dorian Gray, the protagonist initially succeeds in outsourcing the aging process to an oil painting, only to die tortured, decrepit, and suicidal. Perhaps the most hauntingly apt literary lesson for modern science is the Greek myth of Tithonus. As the story goes, Eos, goddess of the dawn, begs Zeus to grant eternal life to her mortal beau, Tithonus. But she forgets to ask for a rather essential complement: eternal youth. Zeus takes her literally, grants the gift of immortality, and Tithonus is left begging for death as he shrivels into a cicada. The gift is a curse.
Modern science has a moderate Tithonus problem: Quality-of-life extension has failed to keep up with life extension. “We’ve been really successful at keeping the heart pumping with pacemakers and cardiovascular drugs,” Sinclair says, “but we have been really pathetic in protecting the brain from aging.” In states with older populations, like Arizona, rates of Alzheimer’s disease are projected to increase by more than 40 percent in the next decade. In the past 20 years, Sinclair’s research shows that the share of life people consider “in good health” is actually declining, as our life spans increase.
If science aims to treat aging, it must treat the body and the mind. Justin Sanchez, the director of the biological technologies office at DARPA, is looking to solve this question with direct neural interface technology. His lab has used microscopic sensors embedded in the brain to allow a person to control robotic limbs with their thoughts. Sanchez has found that similar technology can stimulate memory recall in patients with short-term memory loss. In other words, as biologists tinker on a god pill for eternal life, Sanchez is at work on a kind of external search engine for our memories.
The implications of successfully extending human life spans would be myriad. The texture of families would change, with the introduction of living great-great grandparents. So, too, would the concept of marriage, amplifying the promise of “’til death do us part” while creating the possibility of rich, century-long relationships. Unevenly distributed, life-span extension would threaten to create biological castes, separating the rich, who could afford supercentenarian drugs, from the poor; it might even allow dictators and corporate leaders to hang on to power for decades longer, suppressing the influx of new and better ideas. Equally distributed, longer lives would still be a challenge, forcing governments to reevaluate their retirement policies. We may be at the precipice of a revolution in biotech that rivals this generation’s revolution in infotech.