how long will we live? -- 4/5/23
Today's selection -- from Lifespan: Why We Age -- and Why We Don't Have To by David A. Sinclair, PhD. How long will we live?:
"Let's do a little math. And let's make it conservative math. Let's assume that … vastly different technologies emerging over the next fifty years independently contributes to a longer, healthier lifespan.
"DNA monitoring will soon be alerting doctors to diseases long before they become acute. We will identify and begin to fight cancer years earlier. If you have an infection, it will be diagnosed within minutes. If your heartbeat is irregular, your car seat will let you know. A breath analyzer will detect an immune disease beginning to develop. Keystrokes on the keyboard will signal early Parkinson's disease or multiple sclerosis. Doctors will have far more information about their patients -- and they will have access to it long before patients arrive at a clinic or hospital. Medical errors and misdiagnoses will be slashed. The result of any one of these innovations could be decades of prolonged healthy life.
"Let's say, though, that all of these developments together will give us a decade. Once people begin to accept that aging is not an inevitable part of life, will they take better care of themselves? I certainly have. So, too, it seems, have most of my friends and family members. Even as we have all stepped forward to be early adopters of biomedical and technological interventions that reduce the noise in our epigenomes and keep watch over the biochemical systems that keep us alive and healthy, I've noticed a definite tendency to eat fewer calories, reduce animal-based amines; engage in more exercise, and stoke the development of brown fat by embracing a life outside the thermoneutral zone.
|Jeanne Calment at age 70 in 1945. She lived to 122.|
"These are remedies available to most people regardless of socioeconomic status, and the impact on vitality has been exceptionally well studied. Ten additional healthy years is not an unreasonable expectation for people who eat well and stay active. But let's cut that by half. Let's call it five.
"That's fifteen years.
"Molecules that bolster our survival circuit, putting our longevity genes to work, have offered between 10 and 40 percent more healthy years in animal studies. But let's go with 10 percent, which gives us another eight years.
"That's twenty-three years total.
"How long will it be before we are able to reset our epigenome, either with molecules we ingest or by generically modifying our bodies, as my student now does in mice? How long until we can destroy senescent cells either by drugs or outright vaccination? How long until we can replace parts of organs, grow entire ones in genetically altered farm animals; or create them in a 3D printer? A couple of decades, perhaps. Maybe three. One or all of those innovations is coming well within the ever-increasing lifespans of most of us, though. And when that happens, how many more years will we get? The maximum potential could be centuries, but let’s say it's only ten years.
"That's thirty-three years.
"At the moment, median lifespan in the developed world is a tad over 80 years. Add 33 to that.
"That's 113 years, a conservative estimate of life expectancy in the future, as long as most people come along for the ride. And recall that this number means that over half the population will exceed that number. It's true that not all of these advances will be additive, and not everyone will eat well and exercise. But also consider that the longer we live, the greater chance we have of benefiting from radical medical advances that we cannot foresee. And the advances we've already made are not going away.
"That's why, as we move faster and faster toward a Star Trek world, for every month you manage to stay alive, you gain another week of life. Forty years from now, it could be another two weeks. Eighty years from now, another three. Things could get really interesting around the end of the century if, for every month you are alive, you live another four weeks.
"This is why I say that Jeanne Calment, who may have had the longest lifespan of any person on our planet, will eventually fall off the list of the top ten oldest humans in history. And it won't be more than a few decades after that that she will leave the top 100. After that she will leave the top million. Imagine if people who have lived beyond 110 had had access to all these technologies. Could they have made it to 120 or 130? Perhaps.
"Fellow scientists often warn me not to be so publicly optimistic. ‘It's not a good look,’ one well-meaning colleague recently told me.
"‘Why?’ I asked.
"‘Because the public isn't ready for these numbers.’ I disagree.
"Ten years ago, I was a pariah to many of my colleagues for even talking about making medicines to help patients. One scientist told me that our job as researchers is to ‘just show a molecule extends lifespan in mice, and the public will take it from there.’ Sadly, I wish that were true.
"Today, many of my colleagues are just as optimistic as I am, even if they don't admit it publicly. I'd wager that about a third of them take metformin or an NAD booster. A few of them even take low doses of rapamycin intermittently. International conferences specifically about longevity interventions are now held every few weeks, the participants not charlatans but renowned scientists from the world's most prestigious universities and research centers. In these gatherings it is no longer unusual to hear chatter about how raising the average human lifespan by a decade, if not more, will change our world. Mind you, the debate is not about whether this will happen; it is about what we should do when it happens.
"The same is increasingly true among the political, business, and religious leaders with whom I spend more and more of my time these days, talking not just about new technologies but about their implications. Slowly but surely, these individuals -- legislators, heads of state, CEOs; and thought leaders -- are coming to recognize the world-changing potential of the work being done in the field of aging, and they want to be ready.
"All these people might be wrong. I might be wrong. But I expect to be around long enough to know one way or the other.
"If I am wrong, it might be that I was too conservative in my predictions."