The Moral Imperative for Extending Human Lifespan
The most basic instinct of every living thing is to stay alive. Humans are no different. Throughout our recorded history so far on this planet there has been a constant struggle to avoid aging and death. And it was a lost cause. There was no amount of exercise we could do, no type of food we could eat, no ritual we could practice to avoid ultimately getting old. But that has changed.
The last few decades have brought many scientific discoveries that have opened the doors to the internal mechanisms of living things, and human biology. One important milestone was the discovery of the structure of DNA molecules by James Watson and Francis Crick. Not just because of the central role of this specific molecule in biology, but because of the paradigm shift in biology and medicine, the development of molecular biology and the understanding of the molecular basis of disease.
Today we know much about the structure of tissues, the shapes and functions of cells in those tissues, and the molecules that compose those cells. And how these molecules interact with each other following the rules of chemistry and quantum physics. And even though our knowledge is still very incomplete, and our ability to manipulate these systems is lacking, there is a general understanding that “this is all there is”. There’s no magic behind it. Life has been reduced to quantum chemistry. For sure, this is an incredibly complex system with billions of cells, each with billions of molecules. But we now understand the rules of this system.
Which means we are starting to understand the molecular mechanisms of aging. One of the most interesting ideas put forward is that a big part of (perhaps all of) aging is caused by damage to cells of a few different types (these are called the hallmarks of aging). For example, mutations in DNA molecules. Or the shortening of the telomeres at the end of chromosomes. In a way aging is moving from a syndrome to a disease, where we start to understand the deterministic process behind it.
And here is the exciting part, we have been able to manipulate some of these mechanisms in order to reduce the damage to cells, and the overall aging of organisms. For example, there have been numerous experiments in mice, in which we were able to extend the lifespan of mice by 10%, 20% or more. For example, by manipulating some of the nutrient sensing pathways in cells, or removing senescent cells. We were able to take perfectly normal mice, give them certain drugs and have them live longer, healthier lives.
Obviously it will be harder to get these results in humans, and there hasn’t been enough research yet. But many experts in the field are starting to believe that extending human lifespan is within our reach.
Even adding an extra year or two of lifespan to an adult would be a great success. But one of the keys of lifespan extension is that it’s not necessary to solve the problem all at once. Here’s why: therapies for lifespan extension may be combined, and will give us more time to develop other therapies. A treatment to reduce extracellular matrix stiffening may add a couple of years on average, and another treatment to lengthen telomeres may add another couple of years on average, and the combination of both may add 4 or more years.
And science of course doesn’t pause during this time. There may be yet another treatment discovered or developed during those 4 years. Up until recently we have seen 100 years of continued progress, scientific discoveries and medical therapies which enabled us to add 1 to 2 years of lifespan every decade. In some countries, like Japan, the average lifespan is already 84 years. If we just maintain the same rate of discovery we may push that to 100 years on average by the end of this century. If we find just one new longevity therapy every decade capable of adding another 2 years, that would push the average lifespan to 116. That would mean many of us born in the 1980s would see the twenty second century.
The real kicker is that not only are we continuously making scientific discoveries, but that our rate of discovery is also increasing. Finding a therapy within this decade which can consistently increase human healthy lifespan by 2 years would be a massive development. But by the 2100s our understanding of biology and medical technology may be so advanced that we may be able to develop several of these. There may be a point in which we develop technology faster than we age. And at that point we would have achieved the equivalent of aging escape velocity. Most of us tend to overestimate what can be accomplished in a few years and underestimate what can be done in decades. Aging research is a multi decade project.
Even today, there are already several potential candidate therapies, such as removing senescent cells (with dasatinib and quercetin), intermittent fasting mimetics and other nutrient sensing pathway therapies via mTOR or sirtuins, removal of extracellular detritus such as arterial plaque, mitochondrial transplantation, partial induced pluripotency, stem cell treatments, CAR cell therapies to cure different types of cancer and many others.
To give an example familiar to many of us, think of saving for retirement. If you have a pool of savings, and get a return on your savings of 5% per year (after accounting for all inflation and taxes), and you spend 7% of your savings per year, the money will eventually run out. If you get a return of 7% per year and you spend only 5% per year, then those savings will last you for all your life (no matter how long). What makes this magic work is the compound net rate of return on your savings. And if that rate is positive you achieve escape velocity.
There are several reasonable but uncertain assumptions here: first, that scientific discoveries are accelerating, second, that we would be able to apply these therapies in an independent manner, and that their results can be combined, and third, that as we gain extra years of lifespan by solving the easier problems we will develop new technologies to solve harder life extension problems. But if these assumptions are right, and many in the biogerontology field believe they are, then we may see dramatic progress within the next few decades, which will benefit many of us alive today.
I hope I have given you enough justification for how we can do this, so now let me tell you why we must.
The most obvious argument is that longer, healthier lives are better for everyone. Imagine that 150 years ago we were having a discussion about whether it’s a good thing to create antibiotics that prevent infections by germs. Some people would argue that the natural order of things is to live up to 35 to 40 years old on average, and only those gifted with exceptional health may survive to 80, which is an “unnatural advanced age”. What difference is there in that argument if we add 40 years to these numbers? Maybe we are now accustomed to living 80 years or longer, but the thought of living 120 or more seems unnatural.
Second, longer lives would lead to higher standards of living for most. In modern societies most of us have to work in order to generate wealth to sustain ourselves, and then we retire and consume that wealth. There is a clear definite period of wealth generation characterized by healthy and productive adults. Simple economics tells us that the longer the work period, the more wealth is generated, all other things being equal. Moreover, an increase in health in the later years of life would probably lead to less anxiety regarding retirement, better structured social safety net programs, and more balanced lifestyles in which adults work to a level that makes them comfortable without worrying about saving until a retirement that may come many decades later.
Social safety nets in particular are in tremendous peril because of the way they are structured. They were intially set up to help those who couldn’t work any more after an age of around 65, back when most folks would live around 65 or 70. But now we live regularly until 80 or 85, and the much longer retirement benefit period imposes a heavier financial load on the trust funds. A longer healthspan will enable restructuring these programs to make them viable in the long term. Increasing retirement ages to account for longer work periods without difficulty, as healthier adults can continue working without health problems.
Even more, it’s also well accepted that the longer the work experience, the more productive a person becomes. It’s unfortunate that many folks have to retire due to health or other problems related to age, precisely at the point in which they are the most productive, experienced, well connected and able to generate wealth. How that wealth is distributed is a big question by itself, but all other things being equal, dividing a bigger pie is better than dividing a smaller one. And a world with more healthy productive people is wealthier than one with less.
Some argue that longer lives would lead to overpopulation, and exploitation of the environment. That would not necessarily be the case. Aging is the largest, but certainly not the only cause of death. Other illnesses and accidents will persist for many years. And the birth rate has been steadily declining in most developed countries, and even developing countries as they raise their standard of living. A decrease in birth rate would compensate for the increase in the maximum healthspan, and Earth’s population will eventually stabilize. Even with dramatic life extension we would be far from reaching out the limits for population size that the Earth can sustain.
A unique argument for lifespan extension is the development of stronger personal responsibility over the future of the planet. Most of us, and most of our organizations, suffer from short term thinking. The next paycheck, the next earnings quarter, the next election cycle, the next few decades of our lives. This way of thinking cascades in decisions which may be good for the next short time period but don’t take into account many decades or centuries, or the future of humanity as a whole. For example, many of us don’t really care about the climate change crisis, presumably because it doesn’t affect us directly today. We may say that we do, but very few of us have stopped everyday activities that impact climate change, such as driving cars, eating meat, running the air conditioning, or traveling internationally. That may change if we all knew that we would live on this planet for the next several hundred years. As a thought experiment, consider what would happen if, instead of relegating these problems to the next generation or the following, we had to think about our own future just a few decades from now. Today some of the biggest challenges that humanity faces are merely “someone else’s problem”. Many people alive today would not have to suffer from climate change, water scarcity or antibiotic resistance. That would change drastically with significant lifespan extension.
One last argument is that most of us alive today will simply need more time in order to experience scientific and technological achievements which seem within our grasp, but are not quite there yet. Achievements such as artificial general intelligence, traveling to Mars and across the entire solar system, virtual reality simulations which are indistinguishable from the real world, high throughput brain computer interfaces, realistic humanoid robots, or discovering the mystery of consciousness. All these will take at least several decades if not centuries. The only way any of us alive today will see them become reality is if we discover how to extend our own lifespan.
The vast majority of us, when thinking objectively, would agree that longer healthier lives are better than shorter ones. And we demonstrate that belief every day we keep ourselves alive. That is the ultimate justification for the moral obligation to do as much as we can to make human lifespan extension possible. For ourselves, our loved ones and as many other people as possible. A moral imperative to extend human healthspan.