Aging is damage, and the body fails in the same way that any complex, damaged machine fails. If one slows the pace of damage accumulation, as technological progress over the past century has achieved to a modest degree, albeit by accident rather than intent, both overall life span and the time spent in a period of damage and dysfunction at the end of life should extend. This is what we see happening, as is noted by the authors of today's open access paper. In order to extend healthy life and put off that period of damage and dysfunction, periodic repair of the underlying damage of aging is required. You make a machine last longer in a useful way by maintaining it.
This approach of repair, targeting the cell and tissue damage that causes aging, was not attempted by the scientific and medical communities until quite recently. The first repair based rejuvenation therapies worthy of the name are the various senolytic treatments that selectively remove senescent cells from aged tissues. Lingering senescent cells actively disrupt tissue maintenance and function, and eliminating them has been shown to reverse aspects of aging in mice. Senolytics emerged in the past decade, and are only now entering human clinical trials as a means of turning back selected conditions in which they are known to be a major component of pathology. There is still a lot more of aging to address if we want to change the past trend of increasing life span coupled to a longer period of damage and decline.
Populations are ageing worldwide. Globally, the proportion of those aged 65 and over has increased by 9% in the last two decades, and is expected to grow by a further 16% by 2050. This demographic shift will require societies to adapt. If longer lives are spent in poor health, governments face the challenge of providing accessible, high quality and sustainable long-term care. The growth in life expectancy is a positive, but with this comes a responsibility to ensure people have the support they need as they age, and to facilitate ageing in place.