New research confirms that we are not yet approaching any maximum human lifespan, with longevity continuing to improve over time. The study analyzed the mortality of older individuals across 19 countries and found that using cohort data to separate changes in mortality rates over time and/or age from changes across cohorts is most suitable to clarify the biological mechanisms underlying mortality. The researchers used Gompertz law to estimate the Gompertzian Maximum Age (GMA) at which individuals first reach an assumed mortality plateau and found that the GMA has remained unchanged in some countries for centuries. However, they also discovered that mortality postponement has occurred in past and current episodes, with the GMA rising for cohorts born between 1910 and 1940.
The study concludes that longevity records may increase as cohorts born after 1910 reach advanced ages in the coming decades, although the projections of how much they will rise to depend on the modeling assumptions made. The results confirm that there is no maximum limit to human lifespan, and that if there is, we are not approaching it.
No Maximum Human Lifespan Yet, According to Study
The topic of whether or not there is a limit to human lifespan has been a point of discussion for centuries. Recent historical estimates of the maximum human lifespan suggest that it has been increasing significantly over time.
A study published in the journal PLOS ONE has analyzed the mortality rates of older individuals in richer countries, across 19 nations. The study aims to examine whether mortality is being compressed or postponed at older ages.
The researchers used the Human Mortality Database to analyze the mortality rates by birth cohort, rather than by period. Cohort data follows a fixed set of individuals over time and is most appropriate to clarify the biological mechanisms underlying mortality. The cohort data allows for the separation of changes in mortality rates over time and/or age from changes across cohorts.
Using Gompertz law, the scientists estimated the age at which individuals first reach an assumed mortality plateau, referred to as Gompertzian Maximum Age (GMA), and tested whether this age has changed across birth cohorts.
The scientists concluded that, “over much of our data, the GMA appears to have remained unchanged in some countries for centuries. But we find past and current episodes where mortality postponement has occurred and the GMA has risen.” They also noted that “for cohorts born between 1910 and 1940, we project that the GMA will increase rapidly, confirming the finding that in recent data, longevity does not appear to be approaching an upper limit.”
Contrary to previous work, the researchers found that old-age mortality patterns can be explained by cohort effects rather than period effects. These cohort patterns explain why longevity records have not changed in recent decades, despite the documented improvements in mortality at older ages across much of the industrialized world.
Overall, the study concludes that we are not yet approaching any maximum human lifespan, and that longevity continues to improve over time.
Longevity Records May Rise as Cohorts Age
New research indicates that longevity records may increase as cohorts born after 1910 reach advanced ages in the coming decades. The study shows that confidence intervals for the length of life of the longest-lived person in each cohort in each country, derived using the researchers’ approach, fit historical data on extreme longevity well. However, the projections of how much longevity records will rise to depend on the modeling assumptions made.
The study’s results confirm that if there is a maximum limit to the human lifespan, we are not approaching it.
Don’t miss interesting posts on Famousbio
