Helping people live longer has been a central goal of medicine for decades. The quest to extend life raises an interesting question: Should we keep investing in research aimed at adding even more years to the already impressive gains in the average life expectancy that occurred during the 20th century?
We can only go so far. There’s likely an unalterable biological limit to the human life span, somewhere around 115 years (though there are, of course, occasional outliers). Virtually all humans die before reaching that age, most of them before they turn 90.
This limit should give us pause.
As we wrote in Annals of Internal Medicine, the 21-year gain in life expectancy during the first half of the 20th century emerged mainly from public health initiatives like improved sanitation, access to clean water, and safer food. The development of vaccines and improvements in medical care drove the smaller nine-year increase in the second half of the century. But these aren’t likely to be replicated.
Advances in medical treatment, including cancer treatments, are increasingly unlikely to provide further significant gains in human longevity. An analysis of 71 cancer drugs consecutively approved between 2001 and 2012, for example, suggests that their overall contribution to survival was just 2.1 months; the gains attributable to personalized cancer medicine have, so far, also been minimal.
Lacking evidence that the human life span can be radically increased by new medical technologies, we believe it’s time to shift our country’s investment priorities away from medical research that aims to extend life and instead focus on the same social, cultural, and political factors that successfully prolonged life in the last century.
That means more public investment in education, transportation, and housing. That kind of investment would directly contribute to the prevention of chronic diseases such as diabetes, heart disease, and many cancers, and would do more to improve the quality of life of the population than additional medical research aimed at treating individuals with specific diseases.
Don’t get us wrong. We aren’t suggesting that we should eliminate funding for medical research to try to prevent, or even cure, diseases. Instead, we are suggesting that public funding should emphasize research on improving and sustaining quality of life rather than focusing on increasing length of life. This means giving greater priority to diseases that affect decades of people’s lives, such as arthritis, autism, macular degeneration, and Alzheimer’s disease over end-of-life diseases like extreme dementia and many cancers.
It also means implementing new approaches to make death and dying as humane as possible. While medicine is slowly accepting palliative care, it is often seen as a byproduct of medical failure, something to make death less difficult only because we could not prevent it. Fully accepting the inevitability of death is worth studying further. It is also important to acknowledge dying with dignity as a concern for population health, not just medical care for individual patients.
One way to preserve quality of life throughout the life span is to compress aging-related illness and disease into as short a time as possible.
Others before us have suggested that the U.S. is now at the point of diminishing returns in high-tech medicine. Unfortunately, calls to redirect resources away from research into extending life and toward quality of life have been ignored in the past, and the same will likely happen now. We believe that is a mistake.
Tempering our exuberant optimism for extending the life span isn’t admitting defeat. Instead, doing that can perhaps paradoxically lead to better health throughout our largely biologically determined life span by better investing resources toward creating healthier populations.
By limiting aging-related illness and disability to the end of the life span, healthy aging could lead to “dying healthy.” That’s a worthwhile personal and public health goal.
George J. Annas, J.D., is a professor at the Boston University School of Public Health and director of the university’s Center for Health Law, Ethics & Human Rights. Sandro Galea, M.D., is professor and dean of the Boston University School of Public Health and author of “Healthier: Fifty Thoughts on the Foundations of Population Health” (Oxford University Press, 2017). A longer version of this article was published in Annals of Internal Medicine.