Advances in life expectancy have slowed, with major gains ‘implausible in this century’

Key takeaways:

• The rate of life expectancy growth slowed to below 0.2 years annually in several countries, including the U.S.
• The findings suggest the era of rapid growth in life expectancy has ended, the researchers noted.

The rise in human life expectancy has slowed significantly in the past couple of decades, with only a small percentage of recent births expected to reach the age of 100 years, an analysis in Nature Aging showed.

The findings suggest any dramatic increase in life expectancy among individuals living in the nations with the longest life expectancies is highly unlikely absent new discoveries that slow biological aging, according to researchers.

Healio previously reported that the COVID-19 pandemic destroyed a decade’s worth of improvement in global life expectancy, with individual longevity dropping by 1.8 years to 71.4 between 2019 and 2021.

According to S. Jay Olshansky, PhD, a professor at the School of Public Health at the University of Illinois Chicago, and colleagues, life expectancy at birth rose in high-income nations by approximately 30 years throughout the 20th century, with increases driven by advances in public health and medicine.

“Accurately predicting future life expectancy trends holds important implications for societal, health and economic policies,” they wrote.

The researchers compared the mortality data of Hong Kong and the eight countries with the current longest average lifespans — Australia, France, Italy, Japan, South Korea, Spain, Sweden and Switzerland — with those of the United States between 1990 and 2019 to determine changes in radical life extension, the probability of recent newborns living to the age of 100 years and the rate of change in future mortality rates needed to raise life expectancy at birth by 1 year.

The average life expectancy in the eight countries and Hong Kong rose by a total of 6.5 years over the study’s time period.

Olshansky and colleagues found slower change in life expectancy during the most recent decade in every population used in the analysis compared with the last decade of the twentieth century.

The annual rise in life expectancy decelerated to below 0.2 years annually in every country except Hong Kong and China.

The researchers added that the U.S. emerged as one of a small number of countries to experience a lower life expectancy at birth at the end of any decade vs. the beginning of the same decade.

Olshansky and colleagues also found that the probability of recent births surviving to age 100 years across all the populations may reach 5.3% among females and 1.8% of males.

Researchers reported that females (12.8%) and males (4.4%) born in Hong Kong in 2019 had the highest probability of surviving to the age of 100 years.

“It would be optimistic if 15% of females and 5% of males in any human birth cohort could live to age 100 in most countries in this century — a limit that could theoretically be breached but only if gerotherapeutics are developed that slow biological aging,” the researchers wrote. “Even then, survival to age 100 for most people is not a certainty.”

Study investigators also reported that steep mortality reductions would be needed to increase life expectancy. For example, in populations where females lived to the age of 88 years, a 20.3% reduction in all-cause mortality at every age would be needed for life expectancy to reach the age of 89 years.

“For males, a rise from [ages] 82 years to 83 years would require a reduction in total mortality at every age of 9.5%,” Olshansky and colleagues wrote.

They ultimately concluded that the findings suggest that the time of rapid rises in human longevity has ended, but a second era of increases in life expectancy may be coming due to factors like advances in geroscience.

“However, until it becomes possible to modulate the biological rate of aging and fundamentally alter the primary factors that drive human health and longevity, radical life extension in already long-lived national populations remains implausible in this century,” they wrote.