How long can humans really live?

A new study suggests that even if all other causes of aging were eliminated, human lifespan might still be limited by the accumulation of genetic mutations within cells. Researchers estimate that under ideal conditions, humans could live between 146 and 194 years, with some individuals potentially reaching over 550 years. The findings, published in the scientific journal NPJ Aging, focus on understanding one possible mechanism behind aging rather than predicting future life expectancy. The research team explored a hypothetical scenario: what would happen if all reversible causes of aging were removed, except for the natural genetic changes that occur in cells throughout a person's lifetime. These changes, known as somatic mutations, arise during cell division and can accumulate over time. While many of these mutations are harmless, their cumulative effect could eventually impact cellular function and increase cancer risk. According to the study, these genetic alterations would gradually affect key organs, leading to their eventual failure. Over decades, the damage caused by these mutations would build up in vital systems such as the heart and brain. Once the damage becomes too severe, essential organs would no longer be able to perform their functions, ultimately resulting in the failure of critical bodily systems. This process could set a biological limit on human longevity, even in a world where other factors contributing to aging have been addressed. The researchers emphasized that their findings should not be interpreted as a prediction of future human lifespans. Instead, they aim to provide insight into one potential mechanism of aging. The mathematical model used in the study primarily considers the accumulation of somatic mutations and does not account for all processes influencing aging. It also does not fully capture how different organs interact and influence each other’s aging processes. The study highlights the complexity of aging and the need for further research to develop a more comprehensive theory. Scientists believe that integrating findings from multiple research groups will help better understand the intricate processes occurring within the body over decades. This approach could lead to a more complete understanding of aging mechanisms and potentially inform strategies for extending human lifespan. One intriguing possibility raised by the study is that aging may not solely result from the gradual accumulation of physical damage in the body. Alternative theories suggest that aging could also be linked to other biological processes, which remain poorly understood. Further investigation into these alternative explanations is necessary to gain a fuller picture of the aging process. The research underscores the importance of continued exploration into the fundamental limits of human biology. While the study provides valuable insights, it also highlights the challenges in accurately modeling complex biological phenomena. As scientists work toward unraveling the mysteries of aging, the findings contribute to a broader conversation about the potential boundaries of human life.