Beyond Longevity: Healthy Aging as a Universal Goal
What is the difference between life span and health span? The first reflects longevity measured by the number of years lived, while the second represents the ability to enjoy a reasonably healthy condition throughout most of those years. How big is the gap between the two? This question is a bit harder to answer but still simple: the gap is apparently much larger than what we would like it to be. Why? Now that is a much harder question, which gets even trickier when we realize that the gap may actually be wider (i.e., worse) in the world’s more developed, higher-income countries.
I began to construct the pieces of the answer to this last question as I was attending the 45th Annual Conference of the American Aging Association, held 1–5 June 2016 in Seattle, Washington. The conference provided valuable insights into the research on healthy aging, its current state of affairs, its main challenges, and what must be done to ensure the kind of progress critically needed not just by older people around the world but also by the communities and countries in which they live. I have much to share but will focus on three main issues and then discuss an aspect not covered in detail at the conference talks but that is relevant to the readership of IEEE Pulse: the role of engineering and technology in achieving the cardinal goal of healthy aging.
Life Span Versus Health Span
Millennials are the first generation in human history expected to spend about one-third of their lives as “old” people. Looking at the demographics of developed and higher-income countries, it becomes instantly clear that the populations of these countries are aging populations. The oldest country in the world is Germany, where the median age is 45 (half of the population is younger than 45, and the other half is older). For the United States, the median age is 36. With regard to one statistical term, life expectancy has increased greatly over a century ago.
However, many of those who live longer today do not have a smooth ride during their “longevity years.” The increase in life expectancy in developed countries correlates closely with advances in all aspects of life, including education and other services available to citizens. But the story is not as bright for health span for many reasons. Policies, services, and infrastructures in these countries have not adequately anticipated the consequences of increased longevity. Health systems were not designed with older people in mind, long-term care is still lacking, and “aging in place“ as a concept is neither mature nor consistently enabled.
In many African countries, the median age is lower than 20. Although life expectancy there is also much better than a century ago, the overall populations in these countries are fairly young, and the gap between life span and health span does not appear to be as serious as that in more developed countries. Younger countries are still catching up to the problem. Those countries have the chance to plan for it, but do they have the resources and the will? In short, different countries and societies face different challenges in terms of promoting the healthy aging of their populations, but all countries need to work hard to achieve this universal goal.
Healthy Aging Research
The challenges facing research aimed at understanding and promoting healthy aging are numerous. At the top of the list is the diversity issue: different people age differently for different reasons. It is believed that 25% of this diversity is genetic in nature, while 75% is related to individual behavior and the surrounding environment. Because most medical research is disease based, the effort exerted to understand aging processes in light of this diversity issue is meager at best. The diseaseoriented nature of medical research also causes a severe lack of funding for aging research. Another major challenge is that most existing health services do not, in general, represent a good fit with the needs of older individuals. This, in turn, deprives the research community of valuable case study sources.
Still, opportunities related to the study of healthy aging are not in short supply, including epigenetic clock markers, agecombating drugs, gender differences in aging, aging-induced mitochondrial dysfunctions, and factors that can affect the slow-down of aging. Of particular interest here is research related to epigenetic markers and the delay of aging.
An epigenetic clock is a deoxyribonucleic acid (DNA)-based marker that can be used to estimate the biological age of a cell type, a tissue, or an organ. As we age, our DNA undergoes many changes. Some of these changes modify the DNA without altering the genetic sequence itself ( therefore, the name epigenetic). These changes affect how cells in different parts of the body use the genetic code in the DNA to perform further functions. One such epigenetic clock is the Horvath’s epigenetic clock (named for Prof. Steve Horvath of the University of California, Los Angeles). It uses such markers to measure the biological age of tissue and compare this to the tissue’s corresponding chronological age. These clocks can prove valuable in a number of ways, including testing various biological aging theories, diagnosing age-related diseases, and developing and testing possible aging-delay methods.
Another interesting (and very controversial) topic is the potential role of some drugs in promoting both healthy aging and longevity. One example is metformin, a drug that has demonstrated high rates of efficacy and safety in managing type II diabetes. The results are still inconclusive, but I found it interesting that one conference attendee, a physician, has put himself on metformin (a 1-g daily dose) for ten years now. He seems to be in good health at age 55. It is still too early to tell, however, even for this one statistical data point.
Plenty of Room for Pseudoscience and Predatory Medicine
The lack of research and conclusive results related to healthy aging makes the amount of actual science produced by the medical community in this area largely inadequate In the presence of a huge demand by populations that are growing older, the lack of rigorous science has opened the door wide to products and procedures based on pseudoscience. One conference presenter has even called this phenomenon predatory medicine. In their hope of finding any type of progress that might provide better opportunities for healthy aging, older individuals may fall prey to unproven products or even risky clinical procedures.
Even worse, older individuals may be taken in by wildly speculative media hype that raises expectations to unrealistic levels. “The Fountain of Youth,” read one headline in a respected newspaper. “The Alzheimer’s Pill,” claimed another in a renowned magazine. The title of a recent book even proposed as a legitimate question, “The End of Alzheimer’s?” Such unfounded claims and undisciplined statements (even if in the form of a question) are dangerous as they may provide false hope and, worse, make older individuals more vulnerable to scams.
The Role of Engineering and Technology in Enabling Healthy Aging
For engineering researchers and technology experts interested in this area, the stakes are too high to ignore. Opportunities abound for new devices, methods, and information systems. Telemonitoring and e-health systems are essential for providing more access to care, long-term monitoring, and development and evaluation of benchmarks. Artificial intelligence, cognitive computing, and machine- learning techniques can provide opportunities for analysis and interaction that were not previously possible for both assessment and assistive purposes. Big data and analytics concepts can help guide and expand medical research in areas such as epigenetic clocks as well as others that require extensive data analysis. Engineering research can also play a major role in the critical success trinity— need, fit, and preferences of the older individual—in any candidate technology.
How much of enabling healthy aging will be pharmacology based versus technology driven? I don’t know the answer to this question, but I believe it should be determined by engineering researchers just as much as it can be determined by medical researchers. Central to this belief is the necessity of understanding that longevity should no longer be the main goal of the global community. Rather, the goal should be healthy longevity.