Scientists say humans could live to a maximum age of 156 years. Here's how
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For the first time, scientists have set a hard upper limit to human lifespan.
A study has noted that humans could theoretically live up to 190 years if certain hallmarks of ageing are completely removed. When age is de-linked with mortality, the median age is 1,759 years. However, with somatic mutations, this number comes down to 156 years.
A study has determined that the maximum age up to which humans can ever survive is 156 years. A mathematical model suggests this theoretical figure could be achieved if every reversible hallmark of ageing were eliminated, barring one. This marks the first time that researchers have set a firm limit on human longevity based entirely on how much irreversible cell damage accumulates over a lifetime. Even as scientists work to increase human lifespan, the study states that even the most advanced anti-ageing interventions will hit a biological curb. The only way to break through that barrier is to control genomic damage.
How long could humans live?
The limit to human lifespan comes into play because of the tissues that cannot regenerate, that is, the brain and the heart, the authors wrote in the study published in npj Aging. The team used a multistage model in which ageing mechanisms were switched on one after the other. They measured how long a human could live if all of them were cured, except somatic mutations. They found that eliminating all the ageing processes still caps the median lifespan at between 146 and 194 years.
“Neurons and cardiomyocytes" acted as "the main limiting factors," co-author Evgeniy Efimov said in a statement. Therapies to reverse certain characteristics of ageing are present today, but there is none that can do the same with somatic mutations. They accumulate in tissues slowly and in tissues that cannot replace their cells. The mathematical model showed that while liver and other renewing organs can withstand thousands of years of mutation accumulation because of continuous cell turnover, brain and heart cells, which do not divide, ultimately give in.
The model started off with a hypothetical “non-ageing human” for whom the increasing age is not a factor in mortality. The median lifespan in this case stood at 1,759 years. The addition of somatic mutations led to the lifespan collapsing to 156 years. The researchers say they will soon expand their model to include other hallmarks of ageing.
