How old can a human get? Is there an upper limit to our age? Yes, according to researchers behind a new study showing that human life span has a natural limit very difficult to exceed.

The oldest human ever known was the French woman Jeanne Calment who died in 1997, 122 years old.

A new US study shows that human life span has a natural and fixed maximum upper limit which is genetically determined.

Through analyzing demographic data, the scientists noticed that the age of the world’s oldest man has not increased since the 1990s.

The researchers then examined the age of the known oldest human at death and could see a dramatic decline in survival after 110 years – the decline in survival after 100 years is steep, and after 120 years, very steep.

Lifespan programmed in our genes

What suggests that we have a limited duration on the planet is that most species are genetically programmed for different stages of life, and each species has a specific genetic set to guide the organism through these stages.

The genetic systems are found in our genome and affect the survivability of cells. Among other things, how efficient they can remove by-products of cellular function, by-products that are harmful and cause cells to malfunction.

Therefore, different species are set to different natural aging processes – they have in essence a “genetically programmed lifespan” – according to the researchers.

If compared to the animal world, we humans have really been proficient extending our life span. Technology, drug development, our ability to adapt our lifestyle and the environment around us to better suit our needs and good health have made remarkable improvements to human lifespan.

The scientists note however that the data they have collected suggest that if we are to become even older, the genetic code effectively constrains us from any such endeavor.

To further extend human lifespan beyond the limits determined by our genetically coded systems would require other interventions than just improvements to our general health, according to the researchers. As the possibility of a longer life is mainly limited by the myriad of genetic variants that determine longevity.

But there is much ongoing research into aging and who knows, perhaps we will discover the genetic triggers that determine aging in the future.

Reference:
Evidence for a limit to human lifespan