The Quest for Immortality

How long can humans actually live? This question has intrigued humanity since time immemorial. One of the earliest scientific inquiries into this topic was conducted by Benjamin Gompertz, who analyzed demographic data and concluded that once individuals reach the age of thirty, their likelihood of dying increases significantly with each passing year. His findings indicated that mortality risk continues to rise until it theoretically reaches 100%. Although not entirely accurate, Gompertz’s mortality model remains a reliable estimate of the chances of dying for individuals between the ages of thirty and eighty.

In a more recent study published in Nature, a team of geneticists from the Albert Einstein College of Medicine investigated the oldest recorded deaths in developed nations, including France, Japan, and the United States. Their analysis suggested that living beyond 125 years is exceedingly unlikely, thus implying a natural limit to human lifespan. This conclusion aligns with the record-holder for longevity, Jeanne Calment, who lived to be 122 years and five months old.

However, just two years later, researchers from Sapienza University in Rome presented opposing evidence by examining a cohort of Italians over the age of 105. Their statistical analysis indicated that Gompertz's exponential mortality model does not apply indefinitely, as it appears to plateau at advanced ages. Could this mean that humans do not have a definitive lifespan limit?

In the past ten years, scientists have identified nine critical hallmarks of aging:

• Genomic instability (the accumulation of mutations over time)
• Telomere attrition (the shortening of chromosome ends with cell replication)
• Epigenetic alterations (modifications to DNA that do not change the sequence)
• Loss of proteostasis (inability to manage toxic proteins)
• Deregulated nutrient-sensing (decreased efficiency in nutrient management)
• Mitochondrial dysfunction (reduced energy production for cells)
• Cellular senescence (when cells cease to divide)
• Stem cell exhaustion (the decline in the ability to regenerate essential cells)
• Altered intercellular communication (disruption in cell signaling)

While these factors increase with age, the question remains: do they actually cause aging, or are they merely consequences of our biological systems gradually shutting down?

Interestingly, humans are less adept at survival compared to certain organisms. For instance, the Hydra, a freshwater creature, exhibits near-immortality due to its remarkable regenerative abilities. The Turritopsis dohrnii, often referred to as the "immortal jellyfish," can revert to its juvenile form after reaching maturity, potentially enabling it to repeat this cycle indefinitely.

If we could possess the regenerative capabilities of Hydra or Turritopsis dohrnii, would it enhance the value of life? Or does the transient nature of existence contribute to its significance? If something were eternal, would it still hold the same worth?

Current scientific endeavors aim to reverse the hallmarks of aging, driven by the belief that many people would desire such an option. Who wouldn't want the opportunity to explore diverse careers, travel extensively, or enjoy time with future generations?

But is this truly what we seek? As advancements are made in extending human life, we risk improving longevity without enhancing the quality of life. Would you wish to live to 150 if the last fifty years were spent in a state of immobility? At what point does life cease to be meaningful? What defines a life worth living?

While we await further developments in lifespan extension, the poignant words of Paul Kalanithi in When Breath Becomes Air resonate: “Death comes for all of us. It is our fate as living, breathing, metabolizing organisms…There is a moment, a cusp, when the sum of gathered experience is worn down by the details of living. We are never so wise as when we live in this moment.”

In the video titled "How Long Did People Use To Live?," viewers can explore the historical perspectives on human lifespan and the scientific inquiries that have shaped our understanding of longevity.

Another insightful video, "Gravitas | Study: Humans can live up to 150 years," delves into recent research suggesting that humans may extend their lives significantly, raising questions about the implications of such longevity.