A compelling new study from researchers in Finland has compared the physical and cognitive performance of a group of older people in 2017 with a similarly aged group three decades earlier. Improvements were seen in almost every test, suggesting progress has been made extending healthspan, the number of healthy years a person lives.
Over the last century humans have, on average, been living longer and longer. Life expectancy has been consistently increasing, however, over the past few decades some researchers have begun to suggest medical research should focus more on quality of life, instead of quantity.
In 2001 the World Health Organization incorporated a new metric into its global analyses. HALE, healthy life expectancy, is a novel calculation of how many years a person can expect to live in optimal health. This renewed focus on healthspan, not just lifespan, suggests as human beings consistently begin to live well past the age of 70, attention must be paid to the quality of these senior years.
In a relatively unique pair of new studies, researchers from the University of Jyväskylä in Finland have compared physical and cognitive performance in two cohorts of similarly aged subjects born around 30 years apart.
The first cohort of around 500 subjects, aged between 75 and 80 (born between 1910 and 1914), participated in a variety of physical and cognitive tests in 1989. The second cohort, again aged between 75 and 80 (born between 1938 and 1943), completed the same barrage of tests in 2017.
Taina Rantanen, principle investigator on the project, says this research allowed for a novel way to measure the progress made in extending healthspan from one generation to the next.
“This research is unique because there are only a few studies in the world that have compared performance-based maximum measures between people of the same age in different historical times,” says Rantanen. “Performance-based measurements describe how older people manage in their daily life, and at the same time, the measurements reflect one’s functional age.”
Improvements were noted across almost all tested metrics in the later-born cohort. Looking at physical performance, walking speed was faster, grip strength improved between five and 25 percent, knee extension strength improved between 20 and 47 percent, and lung function measurements were better. Similar improvements were also seen in the later-born cohort across most cognitive performance tests.
Matti Manukka, a postdoctoral researcher working on the project, suggests a broad variety of factors can explain why the later-born cohort displayed such consistent healthspan improvements.
“The cohort of 75- and 80-year-olds born later has grown up and lived in a different world than did their counterparts born three decades ago,” says Manukka. “There have been many favorable changes. These include better nutrition and hygiene, improvements in health care and the school system, better accessibility to education and improved working life.”
The researchers do note the findings may, to a degree, be unique to Finland, a country that was still largely agrarian and undeveloped when the earlier cohort were born around 1910. A number of social reforms, including longer obligatory education and better nutritional recommendations, occurring in the 1940s and 50s are cited as key to many of the physical and cognitive improvements seen in the later-born cohort.
Ultimately, Rantanen suggests, as life expectancy continues to grow, scientists must pay close attention to the balance between more healthy years lived, and the care systems necessary to manage very old populations at the end of their lives. Expanding the period of non-disabled mid-life years and limiting one’s disabled end-of-life years should be a priority for aging researchers, says Rantanen.
“Increased life expectancy provides us with more non-disabled years, but at the same time, the last years of life comes at higher and higher ages, increasing the need for care,” says Rantanen. “Among the aging population, two simultaneous changes are happening: continuation of healthy years to higher ages and an increased number of very old people who need external care.”
The cognitive performance comparative study was published in the journal Aging Clinical and Experimental Research, while the physical performance comparative study was published in The Journals of Gerontology: Series A.
Source: University of Jyväskylä