Living to be one hundred years old. What are the chances for a child born today to reach the century mark? Fewer and decreasing, according to an analysis published today by a group of American researchers. "If most people plan to live up to 100 years, they may want to rethink their planning, as this is likely to happen only in a small segment of the population," says S. Jay Olshansky, Professor of Epidemiology and Biostatistics at the University of Illinois at Chicago, commenting to EL MUNDO on the paradigm shift many are facing.
To achieve this, Olshansky explains that "accelerated improvements in life expectancy would be required, and in reality, the exact opposite phenomenon is happening." And this is the case worldwide. "The wealthiest countries have the opportunity to experience better rates of increase," he points out. At the same time, he clarifies that this is not new, as "it has been the case for the last three decades, and the observed data demonstrate that even in these countries, the rate has slowed down. There is no way to manipulate past mortality trends to favor significant increases in life expectancy in the future. The evidence is very clear."
The data analysis work carried out by Olshansky's team published in Nature Aging concludes that the increase in human life expectancy may have hit the brakes. They have studied the mortality data from the nine regions with the highest current life expectancies (including Hong Kong, Japan, South Korea, Australia, France, Italy, Switzerland, Sweden, and Spain) to compare them with those of the United States between 1990 and 2019. The authors suggest that the results have significant implications for social, health, and economic policies.
During the 20th century, improvements in public health and medicine led to increases in human life expectancy of around three years per decade in long-lived populations. However, predicting how life expectancy will evolve during this century has been a topic of debate. Some predictions from the 1990s suggested that long-lived populations were approaching an upper limit of life expectancy, but others predicted that most children born in the 21st century would live to be 100 years old or older.
How has life expectancy slowed down in recent decades?
The rates of accelerated increase in life expectancy observed in the 20th century have slowed down, especially after 2010. Children born in recent years have a relatively low probability of reaching 100 years old (5.3% probability for women and 1.8% probability for men).
The highest specific probability by country that children born in 2019 will survive to 100 years old occurred in Hong Kong, where it is expected that 12.8% of women and 4.4% of men will reach 100 years old in their lifetime. The average figure in our country ranges, between men and women, at 3.2%. In the United States, the percentage of birth cohorts in 2019 expected to live to 100 years old is 3.1% for women and 1.3% for men.
Regarding the factors leading to this deceleration, Olshansky explains that "the biological process of aging has become the dominant risk factor for survivors at older ages, and biological aging is currently immutable." Therefore, he explains that "as life expectancy at birth increases beyond 80 years, larger segments of each birth group are exposed to aging of the body and mind."
Asked about the counterbalance of unhealthy lifestyle habits (smoking, obesity, sedentary behavior... behind non-communicable diseases) versus medical advances, the study's author says that "it is also true that harmful behavioral risk factors influence the rate of improvement. But it is believed that the reason for the deceleration is our biology, not our behavior."
With this, the University of Illinois professor highlights a series of necessary changes. "Insurance companies and pension funds often incorporate 'mortality improvement factors' into their forecasting models; now it will be necessary to reexamine them in light of these observed trends. Many companies and organizations believed that a lifespan of 100 years would be common in the modern era, but it is unlikely."
Olshansky and his colleagues suggest that there is no evidence to suggest that a radical extension of life has occurred or will occur in the 21st century and point out that, if it were to happen, significant institutional changes will be necessary, even in retirement planning and life insurance prices.
Diego Ramiro, director of the Institute of Economy, Geography, and Demography of the CSIC, states that "the conclusions are supported by data from the Human Mortality Database, which are solid and used as a reference in many studies on mortality." However, as reported by Science Media Centre, Ramiro misses the authors delving deeper into the reasons behind these brakes on accelerated growth in life expectancy. "More specifically, in the inequalities within the same society in differences in life expectancy by educational level or socioeconomic level that may mark that life expectancy grows at a different pace in each population group," he points out.