The mystery of human lifespan limits

Scientists debate whether there is a specific limit to how long humans can live. Some say humans can live to be 1,000 years old.

The average human lifespan has increased over the past century, thanks to advances in medicine and improved quality of life. Studies suggest that a person can live to be 70-80 years old with access to modern medicine and a healthy lifestyle, according to Fortune .

Johanna Quaas, born in 1925, was recognized by Guinness World Records in 2012 as the oldest gymnast. She was 86 years old when she competed at the time. (Photo: The Times).

To date, the world's oldest person on record is Jeanne Calment from France. She was born in 1875 and lived to be 122 years old. At the time of her birth, the average life expectancy was only 40 years.

The human age limit is still a subject of debate. Some geneticists believe that during human evolution, the age limit was 'programmed' into the genes to be 115 years, according to Scientific America.

There are scientists who make more ambitious claims. One of them is João Pedro de Magalhaês, professor of molecular biology at the University of Birmingham, UK. He believes that humans could live to be 1,000 years old.

Want to cheat death

Mr Magalhaês's claim is based on research into long-lived animals. They have characteristics that help prolong their lifespan, such as the bowhead whale's excellent DNA repair ability, or the high levels of the p53 gene that suppresses cancer in elephants.

He concluded that if the cells that cause aging were eliminated, humans could live for 1,000 years, or even 20,000 years. He said that if aging is a problem that is 'hardwired' into humans, scientists could theoretically edit the genes that play a central role in aging.

Mr Magalhaès admitted that current technology cannot do this, but that humans may create the technology in the future. He cited that in the 1920s, pneumonia was a major cause of death, but today it can be easily treated with penicillin.

Therefore, this molecular professor also bluntly declared : 'I want to outsmart death' by focusing his mind on researching anti-aging therapies.

'I don't think there will be a drug that 'cures' aging anytime soon the way penicillin does. But right now, rapamycin is a potential candidate. Rapamycin is used in transplantation. It slows down the metabolism of cells, which is why it affects aging ,' he said.

Jeanne Calment (right) was recognized as the world's longest-lived person, at the age of 122. Photo: Quartz.

Richard Fargher, a professor of biology at the University of Brighton in the UK, wrote in The Conversation in 2016 that evolutionary biology offers little support for the idea that aging genes cause people to grow old and die. Aging simply increases the likelihood of death and disease.

Controversial topic

Average life expectancy in a country is easy to calculate, but maximum life expectancy is another story. Some scientists believe that the maximum natural life expectancy could be as high as 140-150 years.

In a study published in the scientific journal PLOS One in March 2023, the research team used mathematical methods to predict mortality trends based on data from hundreds of millions of people in 19 countries, born between 1700 and 1969.

This study suggests that the later in life people are born, the more likely they are to enter the aging stage, as well as live longer than previous generations.

For example, research estimates that Japanese women born in 1919 have a 50% chance of living to 122. If born in 1940, they have a 50% chance of living to more than 130.

With this result, the research team predicts that someone will break Jeanne Calment's record for longest life in the next 40 years.

However, this study also received many criticisms because it had many major loopholes, such as not taking into account biological factors when people are susceptible to age-related diseases such as cancer. The scientific team also did not take into account the potential development of medicine that can increase life expectancy.

'Life expectancy is essentially a biological phenomenon, not a mathematical problem ,' says Stuart Jay Olshanky, professor of epidemiology and biostatistics at the University of Illinois Chicago.