Many other avenues are being explored, including a diabetes drug that could have broad health benefits; drugs based on a potential anti-aging compound discovered in the soil of Rapa Nui (Easter Island); attempts to rejuvenate the immune system; gene therapies designed to boost muscle or extend the number of times our cells can divide; and many, many more. Other researchers are pursuing ways to clear out the aged, worn-out cells in our bodies. These senescent cells appear to pump out chemicals that harm the surrounding tissues. Around eight years ago, scientists found that mice cleared of senescent cells lived 25% longer than untreated ones. They also had healthier hearts and took much longer to develop age-related diseases like cancer and cataracts. They even looked younger.
Unfortunately, human trials of senolytics—drugs that target senescent cells—haven’t been quite as successful. Unity Biotechnology, a company cofounded by leading researchers in the field, tested such a drug in people with osteoarthritis. In 2020, the company officially abandoned that drug after it was found to be no better than a placebo in treating the condition.
That doesn’t mean we won’t one day figure out how to treat age-related diseases, or even aging itself, by targeting senescent cells. But it does illustrate how complicated the biology of aging is. Researchers can’t even agree on what the exact mechanisms of aging are and which they should be targeting. Debates continue to rage over how long it’s possible for humans to live—and whether there is a limit at all.
Still, we are getting better at testing potential therapies in more humanlike models. We’re finding new and improved ways to measure the aging process itself. The X Prize is offering $101 million to researchers who find a way to restore at least 10 years of “muscle, cognitive, and immune function” in 65- to 80-year-olds with a treatment that takes one year or less to administer. Given that the competition runs for seven years, it’s a tall order; Jamie Justice, executive director of the X Prize’s health-span domain, told me she initially fought back on the challenging goal and told the organization’s founder, Peter Diamandis, there was “no way” researchers could achieve it. But we’ve seen stranger things in science.
Some people are banking on this kind of progress. Not just the billionaires who have already spent millions of dollars and a significant chunk of their time on strategies that might help them defy aging, but also the people who have opted for cryopreservation. There are hundreds of bodies in storage—bodies of people who believed they might one day be reanimated. For them, the hopes are slim. I asked Justice whether she thought they stood a chance at a second life. “Honest answer?” she said. “No.”
It looks likely that something will be developed in the coming decades that will help us live longer, in better health. Not an elixir for eternal life, but perhaps something—or a few somethings—that can help us stave off some of the age-related diseases that tend to kill a lot of us. Such therapies may well push life expectancy up. I don’t feel we need a massive increase, but perhaps I’ll feel differently when I’m approaching 88.
The ONS website gives me a one in four chance of making it to 96, and a one in 10 chance of seeing my 100th birthday. To me, that sounds like an impressive number—as long as I get there in semi-decent health.
I’d still be a long way from the current record of 122 years. But it might just be that there are some limitations we must simply come to terms with—as individuals and in society at large. In a 2017 paper making the case for a limit to the human life span, scientists Jan Vijg and Eric Le Bourg wrote something that has stuck with me—and is worth bearing in mind when considering the future of human longevity: “A species does not need to live for eternity to thrive.”