Why Live Another 20 Years?

Here is a short editorial recently posted to the Gerontology Research Group mailing list by coordinator Stephen Coles:

According to Homo sapiens DNA sequences, the "overall design" of the human body hasn't changed much over the last 200,000 years, when we first started out as active hunter/gatherers. Prior to the invention of agriculture, however, some 10,000 years ago, our bodies were well adapted by Darwinian evolution to our peripatetic ecological niche, even though our species almost experienced extinction several times.

As little as 100 years ago, that barely mattered. But today it does matter! US life expectancy jumped by more than 25 years - from ~50 to 75+ - over the course of the last century, largely due to public health measures, antibiotics, obstetrical techniques for C-Sections during difficult child births, and so forth. Therefore, on average, we're living much further past our "evolutionary design expectations." Nevertheless, we're not only living longer in modern societies, we're also staying healthier, as measured by a number of biomarkers. Fortunately for us, that means we have the time to enjoy the leisure and freedom we've earned. But it also means that we're almost certain to face very different health problems during our lifetimes, especially at the very end of life - problems that our ancestors never had the opportunity to experience, and for which evolution never prepared us. Therefore, we need to take the evolutionary legacy of our DNA into our own hands: we must read and understand this curious 3.1 GigaBasePair sequence, and then edit it or add the new code that will be needed to rejuvenate our frail bodies.

The good news is that if we can manage to live for another 20 years or so, when new developments in stem-cell therapies and synthetic chromosomes now on the horizon lead to commonplace therapeutic interventions, there should be no reason to compromise our independence or restrict our activities in later years of life. At least not if you are prepared to exploit new DNA/stem-cell technologies by staying abreast of the latest therapies, therapies that will be described in the future pages of this GRG Discussion Group.

Cole's bias is towards some types of therapies that I might not see as favorable roads ahead (such as editing our DNA to change the operation of our metabolism), but the general point being made here is true and important. Progress in science today is very rapid, and this is something new and unusual in the history of humanity. We stand on the cusp of great and sudden advances in biotechnology and medical science; two decades of additional life will make a very large difference in the medical technology you have access to in later life.

The Gerontology Research Group, you might recall, is something of a watering hole for the gerontology community - which is still a comparatively small gathering in comparison to the wider field of human life science research. You'll find that representatives and leaders from most of the present factions and research groups show up on the GRG mailing list from time to time. The core list community is associated with research into supercentenarians, however: as the Supercentenarian Research Foundation, volunteers establish and validate records, and more recently have made inroads into understanding thereasons why supercentarians ultimately die.

"The superseniors deviate from the norm not just in how long they live but in how they die," says Coles, who arranges autopsies of the oldest old as part of his work with the recently established Supercentenarian Research Foundation. ... Coles argues, based on these autopsies, that supers aren't perishing from the typical scourges of old age, such as cancer, heart disease, stroke, and Alzheimer's Disease. What kills most of them, he says, is a condition, extremely rare among younger people, called senile cardiac TTR Amyloidosis. TTR is a protein that cradles the thyroid hormone thyroxine and whisks it around the body. In TTR Amyloidosis, the protein amasses in and clogs blood vessels, forcing the heart to work harder and eventually fail. "The same thing that happens in the pipes of an old house happens in your blood vessels," says Coles.