Earlier this week, I wrote about the rise of the “American Immortal”: a cultural archetype coined by bioethicist Zeke Emanuel, to describe Americans’ quest to cheat death. The desire for perpetual life is nothing new: You can go as far back as you want in humanity’s history and still find plenty of examples of this kind of striving. But in recent times, biotechnology research has taken this bull by the horns. And the result is the creation of bioethical assumptions that remain, for the most part, unexplored.
In the 1990s and 2000s, the response to our yen for immortality was thought to be a gene, or genes, that could radically extend our lives. After all, we could extend the lives of laboratory animals by significant amounts, so why not humans? The hunt for the human anti-aging gene was on.
There was a problem with this approach, though. Simply prolonging human life wouldn’t address the issue of chronic illness in old age. We might live longer, but the quality of life in those later years wouldn’t necessarily be better.
In response, this older form of anti-aging research is now being abandoned in favor of something much more ambitious. The goal is to compress the infirmities of old age into a shorter period, so the length of our healthy life increases. The central features of this longevity research include an embrace of big data, a pivot away from studies that hope to find aging genes, and the recognition that multiple genes influence aging and that aging is best thought of a collection of diseases, not just one disease.
We know that some of the answers likely lie in three major biochemical pathways that are implicated in aging (if you want to read more about these processes, check out my recent review in Nature Biotechnology). But understanding the complexity of interactions among the pathways is the challenge that drives this new generation of research and companies. The questions of if and when these pathways might impact our health span and lifespan are better addressed to the bench scientists. However, of the technologies I’ve reviewed, parabiosis research—where blood transfused from young individuals seems to reverse the diseases of aging—seems to be the most promising. It is straightforward, has lower regulatory hurdles than a new drug might, since blood transfusions are already common procedures, and is already in a clinical trial, where plasma from young blood donors is being transfused into early-stage Alzheimer’s patients. Uncovering exactly which proteins in the plasma might have a rejuvenating effect will take some time, but we could end up seeing a clinical benefit.
I’m fascinated by how quickly this has taken off, especially since classic aging research yielded so little, and became saddled with hype and pseudomedicine. (See the debate over reseveratrol, an organic compound found in wine and dark chocolate that some claimed was a silver bullet for a wide array of diseases, including heart disease. The truth turned out to be much more complicated.)
Longevity research has that same feel to it. From an ethics and policy perspective, one question is whether the promise of healthy lifespans will outrun the reality of the science. (You can listen and read more about my thoughts on it here and here.) On the way, there are highly consequential decisions (funding research, creating new companies, establishing new scientific disciplines), technological inventions, and social changes that are being pursued based on the tacit assumption that such decisions, inventions, and changes do, in fact, lead to a healthier, longer life and the promise of a better future. These assumptions have yet to be probed.
It will be interesting to see whether longevity research will somehow duck the ethical and social issues that plagued aging research, or whether a supercharged repeat is in store. Human immortality has never been achieved. We are the only species that is aware it will eventually die, and that awareness leads to our attempts to enrich the very mortal lives we lead. What form of life do we want to be? Will radical changes in our mortality change the way we approach life?
The realities of war, migration, climate change, family dynamics, scarce resources, and distributive justice also raise a larger, thorny set of questions about long lives. My project will explore how a wide array of stakeholders approaches these often-conflicting questions about living long and living well. Let’s say we can extend our health-span to age 100 or beyond. How will we deal with a vital, active, population of elders? How will increased health-span impact the sustainability of human life? Who will benefit? Who will be left behind? And, most importantly: who decides?
Read a Q&A with Christopher Scott about his research here.
Photo courtesy of Juhan Sonin (Creative Commons license).