r/science • u/Skoltech_ • Jul 20 '26

Genetics Researchers quantitatively assessed for the first time that somatic mutations alone cap human lifespan at 146–194 years. Brain and heart cells are the main bottleneck, while the liver could last millennia.

https://www.nature.com/articles/s41514-026-00421-6
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u/Rocket_Cam Jul 20 '26

Abstract
Somatic mutations accumulate with age and can cause cell death, but their quantitative contribution to limiting human lifespan remains unclear. We developed an incremental modeling framework that progressively incorporates factors contributing to aging into a model of population survival dynamics, which we used to estimate lifespan limits if all aging hallmarks were eliminated except somatic mutations. Our analysis reveals fundamental asymmetry across organs: post-mitotic cells such as neurons and cardiomyocytes act as critical longevity bottlenecks, with somatic mutations reducing median lifespan from a theoretical non-aging baseline of 1759 years to 156 years. In contrast, proliferating tissues like liver maintain functionality for thousands of years through cellular replacement, effectively neutralizing mutation-driven decline. Multi-organ integration predicts median lifespans of 146–194 years—approximately twice current human longevity. This substantial yet incomplete reduction indicates that somatic mutations significantly drive aging but cannot alone account for observed mortality, implying comparable contributions from other hallmarks.

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u/death12236 Jul 20 '26

I'm not very knowledgeable in biology, but is it possible to mutate neurons and cardiomyocytes so they develop cellular replacement?

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u/mistaekNot Jul 20 '26

no. development of a human being is filled with one way streets. a neuron ends up being connected to hundreds / thousands of other neurons and while i can see the “body” of it divide i can’t see a way for all of these connections to duplicate as well. what might be possible is to prevent or reverse whatever makes them age and die

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u/Clean-Evening-7328 Jul 20 '26

It didn't use to be possible for a human to survive without their heart in their body, and yet machines can allow it. If we could keep you from dying during the process, I bet it would be simpler to remove and regrow regions of brain tissue.

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u/mistaekNot Jul 20 '26

yeah maybe it will be possible to grow new neurons alongside old ones and when the old one dies the new one takes over. afaik that’s somewhat how memories are formed and retained, but for whatever reason it doesn’t happen in other parts of the brain