After nearly doubling during the 20th century, the growth rate of life expectancy has significantly decreased over the past thirty years, as revealed in a new study.
Throughout the 19th and 20th centuries, we witnessed remarkable increases in life expectancy due to improved nutrition, advances in medicine, and various enhancements to quality of life.
However, following its near doubling in the 20th century, the growth rate of life expectancy has markedly declined in the last thirty years, as per a recent study from the University of Illinois Chicago.
Even with ongoing advancements in medicine and public health, the average life expectancy at birth in the regions with the longest lifespans around the world has risen by just around six and a half years since 1990. This improvement is much slower than some experts had anticipated, who expected a faster rise in life expectancy this century, leading many to believe that individuals born today would likely live beyond 100 years.
The paper published in Nature Aging, titled “Implausibility of Radical Life Extension in Humans in the 21st Century,” provides new insights suggesting that humans may be nearing a biological limit on lifespan. According to the lead author, S. Jay Olshansky from the UIC School of Public Health, the most significant increases in life expectancy have already been achieved through successful disease-fighting strategies, leaving the negative impacts of aging as a primary barrier to further longevity.
“Most people who are older today are enjoying life extensions made possible by medical advancements,” explained Olshansky, who specializes in epidemiology and biostatistics. “However, these medical interventions are contributing fewer additional years of life, suggesting that the era of rapid increases in life expectancy has now ended.”
This also implies that attempting to further increase life expectancy by aiming to reduce disease could be counterproductive if the added years are not accompanied by good health, Olshansky asserted. “Our focus should shift towards slowing down aging and enhancing healthspan,” he stated. Healthspan, a relatively new concept, refers to the number of years an individual remains healthy, rather than simply alive.
This analysis, conducted alongside researchers from the University of Hawaii, Harvard, and UCLA, adds a new chapter to a thirty-year discussion regarding the potential limits of human lifespan.
Back in 1990, Olshansky released a paper in Science arguing that humanity is approaching a lifespan ceiling of around 85 years, indicating that the most substantial advancements have already occurred. Others believed that medical and public health innovations would drive the upward trends of the 20th century into the 21st century.
Now, thirty-four years later, the findings reported in the 2024 Nature Aging study support the assertion that improvements in life expectancy are likely to continue decelerating as more individuals face the negative and unavoidable impacts of aging. The study analyzed data from the eight countries with the longest life expectancies and Hong Kong, along with the United States – one of the few nations experiencing a decline in life expectancy during the studied period.
“Our findings contradict the common belief that there are greater life expectancy prospects ahead of us,” Olshansky noted. “In reality, it seems we may have already surpassed that threshold, likely between 30 and 60 years. We’ve shown that modern medicine yields progressively smaller increases in longevity, even though advancements continue at a rapid pace.”
While it’s possible that more individuals may reach 100 years or older in this century, such cases will remain exceptions and won’t significantly elevate the overall life expectancy, Olshansky emphasized.
This conclusion challenges the assumptions held by industries, such as insurance and wealth management, that increasingly base their projections on the idea that the majority of people will live to be 100.
“This assumption is misleading because only a small fraction of the population is likely to live that long within this century,” Olshansky cautioned.
Nevertheless, the research does not rule out further improvements from medicine and science, he added. Instead, he argues that there is a greater potential for enhancing quality of life in older age rather than simply extending life. Increased focus and funding in geroscience – the study of aging – could unlock the next phase of health and lifespan extension.
“We’re facing a glass ceiling, not a brick wall,” Olshansky remarked. “There are numerous opportunities for enhancement: tackling risk factors, addressing disparities, and motivating people to lead healthier lives can all contribute to longer and healthier living. We can break through this glass ceiling in health and longevity with the support of geroscience and initiatives aimed at mitigating the effects of aging.”
