It is very hard to coax a damaged machine into continued operation without repairing the damage. It is expensive and time-consuming, the machine works poorly, and fails catastrophically only a little later than it would have done without all of that effort. Keeping damaged machines running is exactly the goal of near all work on treating age-related disease, however. Very few projects are focused on addressing the cell and tissue damage that causes aging. Anything other than repairing or otherwise reversing that damage will produce only marginal gains, at great expense.
This has been well demonstrated. With the best will in the world, an enormous amount of effort has been put towards helping older people by treating age-related diseases, but near all of that effort has gone towards therapies that cannot even in principle help all that much - because they do not address aging, the cause of age-related disease. So we have marginally longer lives, but increased disability, at great cost. This must change, and the focus must shift towards therapies that address the underlying mechanisms of aging, to repair the damage and make the machine work well once again. That is the only cost-effective way to extend healthy life spans.
Notably, the societal triumph of longevity is plagued with debilitating morbidity, accentuated towards the end of life. The average life expectancy - a benchmark of population health - has risen from 47 to 73 years of age in these seven decades, a 26-year expansion. This remarkable trajectory in human longevity has generated a redistribution in demographic structure underpinned by a disproportionate surge in those over 70 years of age. Notably, the societal triumph of longevity is plagued with debilitating morbidity, accentuated towards the end of life.
Lifelong (also referred as "chronic" or "non-communicable") diseases are the leading cause of mortality and disability worldwide. Collectively, chronic diseases are responsible for 40 million or 71% out of 56 million annual deaths globally, and 79% of all years lived with disability. Four common conditions, namely cardiovascular diseases, cancer, diabetes, and chronic respiratory diseases, account for 80% of chronic disease related deaths. The imposed socioeconomic burden is estimated to represent a $47 trillion loss over the last two decades. Fifty-eight percent of chronic disease-related mortality occurs in persons over 70 years of age. This growing age segment thus warrants special attention.
Age-associated outcomes are profoundly aggravated by frailty. Indeed, there is a recognized gap between lifespan, i.e., the total life lived, and healthspan, i.e., the period free from disease. Using health-adjusted life expectancy, that considers life expectancy, years lived with disability, and premature death from disease, the healthspan-lifespan gap is estimated at around 9 years. This gap appears refractory to current practice paradigms. In fact, one-fifth of an individual's life will be lived with morbidity. Extending lifespan alone without delaying disease onset and/or reducing disease severity would actually aggravate the healthspan-lifespan gap.
The insidious accumulation of chronic disease and frailty must engender disruptive innovation. Targeting the root cause at latent stages offers the prospect of implementing proactive, prophylactic actions. Growing regenerative options offer opportunities to boost innate healing, and address aging-associated decline. Diverse aging populations are thus at the cusp of a promising horizon.