The absolute longest a person can live is about 150 years, according to a new study.
Somewhere between the ages of 120 and 150 the human body undergoes a "complete loss of resilience", scientists say, making that the "absolute limit" of the human lifespan" which no medicines or therapies can overcome.
They figured it out using a new measure called the 'dynamic organism state indicator', based on blood tests taken from more than 1000 subjects over a few years.
"Since determining biological age is complex and does not necessarily correlate with chronological age, studies have used blood markers, DNA methylation, or other measures to develop ageing biomarkers and predictors, that could also potentially be used clinically to determine the effectiveness of anti-ageing interventions," journal Nature Communications said in a statement.
In this latest study scientists used human blood count data from the UK Biobank to calculate a single variable called the 'dynamic organism state indicator' (DOSI), which was "associated with expected variables such as age, illness, and lifestyles".
The more a person's DOSI figure fluctuated over time, the less resilient they were - so less able to recover from health setbacks.
The progressive loss of resilience as people age pointed to 150 as being the absolute upper limit for the human lifespan - and there's nothing we know of yet which can push that back further.
"No dramatic improvement of the maximum lifespan and hence strong life extension is possible by preventing or curing diseases without interception of the aging process, the root cause of the underlying loss of resilience," the study reads.
"The loss of resilience cannot be avoided even in the most successfully aging individuals and, therefore, could explain the very high mortality seen in cohorts of super-centennials characterized by the so-called compression of morbidity."
The 'compression of morbidity' refers to a phenomenon seen amongst centenerains, who live lives generally free of serious illness but die not long after getting sick - their excessive age making them less resilient, so the illness takes them out quicker than it might someone who's still in double-digits.
"The proximity of the critical point revealed in this work indicates that the apparent human lifespan limit is not likely to be improved by therapies aimed against specific chronic diseases or frailty syndrome... We conclude that the criticality resulting in the end of life is an intrinsic biological property of an organism that is independent of stress factors and signifies a fundamental or absolute limit of human lifespan."
The findings are similar to another recent study which looked at demographic data from humans and other species, to conclude the maximum age anyone could live was 138.
But another study in 2018 said while the chance of death each year increases, once you hit about 105 it levels off at 50 percent, suggesting "there is no limit to human longevity".
The oldest person on record, French woman Jeanne Calment, died in 1997 at the age of 122. The oldest living person right now is Kane Tanaka of Japan, who is 118, and credits her longevity to "eating good food and practicing math".