The present rate of increase of life expectancy at birth is 1 year every 5 years. The rate of increase of life expectancy at 65 is 1 year every 10 years. These are highly artificial measures, a metric of what will happen if technological progress freezes at its present point.

Technological progress will not freeze. Past increases in life expectancy due to slowing of aging (versus control over infectious disease to reduce early life mortality) have been incidental, not intentional. They arguably largely arise from that control over infectious disease. But the research and development community are now transitioning into a deliberate targeting of the mechanisms of aging. The difference will be night and day. Great discontinuities in the curve of life expectancy lie in the near future, upward leaps of five years here and ten years there as therapies that repair the root causes of aging become available. Senolytics will be the first of these - already something that the adventurous can get out there and try. There will be many more.

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I will be 85 somewhere in the mid 2050s. It seems like a mirage, an impossible thing, but the future eventually arrives regardless of whatever you or I might think about it. We all have a vision of what it is to be 85 today, informed by our interactions with elder family members, if nothing else. People at that age are greatly impacted by aging. They falter, their minds are often slowed. They are physically weak, in need of aid. Perhaps that is why we find it hard to put ourselves into that position; it isn't a pleasant topic to think about. Four decades out into the future may as well be a science fiction novel, a far away land, a tale told to children, for all the influence it has on our present considerations. There is no weight to it.

When I am 85, there have been next to no senescent cells in my body for going on thirty years. I bear only a small fraction of the inflammatory burden of older people of past generations. I paid for the products of companies descended from Oisin Biotechnologies and Unity Biotechnology, every few years wiping away the accumulation of senescent cells, each new approach more effective than the last. Eventually, I took one of the permanent gene therapy options, made possible by biochemical discrimination between short-term beneficial senescence and long-term harmful senescence, and then there was little need for ongoing treatments. Artificial DNA machinery floats in every cell, a backup for the normal mechanisms of apoptosis, triggered by lingering senescence.

When I am 85, the senolytic DNA machinery are far from the only addition to my cells. I underwent a half dozen gene therapies over the years. I picked the most useful of the many more that were available, starting once the price fell into the affordable-but-painful range, after the initial frenzy of high-cost treatments subsided into business as usual. My cholesterol transport system is enhanced to attack atherosclerotic lesions, my muscle maintenance and neurogenesis operate at levels far above what was once a normal range for my age, and my mitochondria are both enhanced in operation and well-protected against damage by additional copies of mitochondrial genes backed up elsewhere in the cell. Some of these additions were rendered moot by later advances in medicine, but they get the job done.

When I am 85, my thymus is as active as that of a 10-year-old child. Gene and cell therapies were applied over the past few decades, and as a result my immune system is well gardened, in good shape. A combination of replacement hematopoietic stem cells, applied once a decade, the enhanced thymus, and periodic targeted destruction of problem immune cells keeps at bay most of the age-related decline in immune function, most of the growth in inflammation. The downside is that age-related autoimmunity has now become a whole lot more complex when it does occur, but even that can be dealt with by destroying and recreating the immune system. By the 2030s this was a day-long procedure with little accompanying risk, and the price fell thereafter.

When I am 85, atherosclerosis is curable, preventable, and reversable, and that has been the case for a few decades. There are five or six different viable approaches in the marketplace, all of which basically work. I used several of their predecessors back in the day, as well. Most people in the wealthier parts of the world have arteries nearly free from the buildup of fat and calcification. Cardiovascular disease with age now has a very different character, focused more failure of tissue maintenance and muscle strength and the remaining small portions of hypertension that are still problematic for some individuals. But that too can be effectively postponed through a variety of regenerative therapies.

When I am 85, there is an insignificant level of cross-linking in most of my tissues, as was the case since my early 60s. My skin has the old-young look of someone who went a fair way down the path before being rescued. Not that I care much about that - I'm much more interested in the state of my blood vessels, the degree to which they are stiff and dysfunctional. That is why removal of cross-links is valuable. That is the reason to keep on taking the yearly treatments of cross-link breakers, or undergo one of the permanent gene therapies to have your cells produce protective enzymes as needed.

When I am 85, I have a three decade patchwork history of treatments to partially clear this form of amyloid or that component of lipofuscin. Modified enzymes are delivered here, a gene therapy applied there. I will not suffer Alzheimer's disease. I will not suffer any of the common forms of amyloidosis that degrade heart muscle performance or disrupt function in other organs. The potential for such conditions is controlled, shut down with the removal of the protein aggregates that cause cellular dysfunction. There is such a breadth of molecular waste, however: while the important ones are addressed, plenty more remain. This is one of the continuing serious impacts to the health of older individuals, and a highly active area of research and development.

When I am 85, I am the experienced veteran of several potentially serious incidences of cancer, all of which were identified early and eradicated by a targeted therapy that produced minimal side-effects. The therapies evolve rapidly over the years: a bewildering range of hyper-efficient immunotherapies, as well as treatments that sabotage telomere lengthening or other commonalities shared by all cancer cells. They were outpatient procedures, simple and quick, with a few follow-up visits, so routine that they obscured the point that I would be dead several times over without them. The individual rejuvenation technologies I availed myself of over the years were narrowly focused, not perfect, and not available as early as I would have liked. Cancer is an inevitable side-effect of decades of a mix of greater tissue maintenance and unrepaired damage.

Do we know today what the state of health of a well-kept 85-year-old will be in the 2050s? No. It is next to impossible to say how the differences noted above will perform in the real world. They are all on the near horizon, however. The major causes of age-related death today will be largely controlled and cured in the 2050s, at least for those in wealthier regions. If you are in your 40s today, and fortunate enough to live in one of those wealthier region, then it is a given that you will not die from Alzheimer's disease. You will not suffer from other common age-related amyloidosis conditions. Atherosclerosis will be reliably controlled before it might kill you. Inflammatory conditions of aging will be a shadow of what they once were, because of senolytic therapies presently under development. Your immune system will be restored and bolstered. The stem cells in at least your bone marrow and muscles will be periodically augmented. The cross-links that cause stiffening of tissues will be removed. Scores of other issues in aging process, both large and small, will have useful solutions available in the broader medical marketplace. We will all live longer and in better health as a result, but no-one will be able to say for just how long until this all is tried.