Although Bryan Johnson and other biohackers are focused on trying to “live forever” by slowing or even reversing aging, researchers say there may be a far more realistic upper limit to how long humans can survive.
Johnson is among the most prominent people pursuing longevity through intensive self-experimentation, including unusually strict habits and routines designed to turn back his biological age.
But a new study published in July 2026 suggests that even if scientists could one day neutralize many other hallmarks of aging, one basic process may still impose a hard ceiling on human life: the accumulation of somatic mutations.
Researchers from the Skolkovo Institute of Science and Technology in Russia, along with co-authors from AIRI, examined how these mutations may place a theoretical cap on human lifespan. Their work uses mathematical modeling rather than a real-world longevity experiment, so the numbers should be read as estimates of what might be biologically possible under highly idealized conditions.
Somatic mutations are random DNA changes that build up in cells over a person’s lifetime. They can occur across all tissues and, unlike inherited mutations, are not passed from parents to children. According to the Wellcome Sanger Institute, these mutations can damage cells, weaken how they function, and raise the risk of age-related conditions including cancer.
In simple terms, researchers believe these mutations play an enormous role in determining how long people can live.
Evgeny Efimov, one of the key authors of the study, explained in a Medical Xpress news release:
“The key finding of the study is the discovery of substantial differences between tissue types.
“Neurons and cardiomyocytes, which lack the ability to divide, turned out to be the main limiting factors: when all other causes of aging are eliminated, somatic mutations alone reduce the theoretical median lifespan from 1,759 years (for a hypothetical non-aging human organism) to 156 years.”
Efimov added:
“At the same time, tissues with high regenerative capacity—such as the liver—can maintain their function for thousands of years through continuous cell renewal, effectively neutralizing the negative impact of mutations.”
That distinction is important. Some parts of the body, such as the liver and skin, are able to keep replacing cells over time. Others, especially the brain and heart, do not regenerate in the same way, making them more vulnerable to long-term damage.
Using a model that accounted for all critical organs, the researchers concluded that even if every other reversible feature of aging could somehow be removed, somatic mutations would still restrict the median human lifespan to roughly 146 to 194 years.
That would be far beyond today’s average life expectancy, but it is still a long way from the idea of indefinite life extension.
The study’s broader conclusion is more modest than the headline number might suggest: somatic mutations appear to be a major contributor to aging, but they are unlikely to be the only one. In other words, even a future in which mutation damage could be minimized would probably still have to contend with other aging processes.
Still, the scientists say somatic mutations are only one piece of the puzzle. Dmitrii Kriukov, a research scientist at the Skoltech Biomed Technologies Center and a senior research scientist at AIRI, said:
“Our study shows that somatic mutations contribute significantly to aging, but they cannot by themselves explain the observed mortality,” he explained.
“This means that other aging mechanisms—such as loss of proteostasis, mitochondrial dysfunction or epigenetic changes—contribute comparably to limiting lifespan.”
That means the true upper limit of human life, if one exists at all, would likely depend on a combination of biological bottlenecks rather than a single cause. For now, the study offers a provocative estimate of what mutation-free aging might look like, not a prediction that anyone is about to live to 194.