The mystery and exploration of human longevity: the challenge of approaching the upper limit of life expectancy

Author: Cheng Wing Chun Duan Yuechu

In the vast universe, life is like the twinkling stars, short-lived and precious. Since ancient times, humans have been curious about the mystery of life and have tried to unlock the code of the tree of life. With the development of modern science, we have gradually uncovered a corner of the mystery of life - telomeres, a key link in the chemical reaction of life.

Telomeres are located at the ends of chromosomes and are a repetitive DNA sequence. They are like the annual rings of the tree of life. Each time a cell divides, it shortens until it can no longer divide and the cell dies. Therefore, the length of telomeres is closely related to life expectancy. Scientists have found that individuals with longer telomeres generally have longer lifespans, while individuals with shorter telomeres are more likely to age and die. If life is compared to a marathon, then telomeres are the timer of this race, recording every cycle of life until the end.

However, telomeres are not completely impossible to extend. Telomerase is an enzyme that can extend telomeres. It is active in certain cells, allowing these cells to divide continuously and extend their lifespan. Cancer cells have telomerase activity, which is one of the reasons why they can proliferate indefinitely. In recent years, scientists have been committed to studying the mechanism of action of telomerase, hoping to extend life by activating telomerase and extending telomeres. This research not only reveals the biological mechanism of aging, but also helps us find a possible way to delay aging and extend lifespan.

Although scientists have made significant progress in the field of telomere and lifespan research, the increase in human lifespan seems to have hit a bottleneck. According to a new study, humans are approaching the upper limit of life expectancy. In countries with the longest life expectancy, despite great advances in medical technology and genetic research, the phenomenon of shortened lifespan has increased and overall lifespan has not increased significantly. S. Jay Olshansky, a researcher at the University of Illinois at Chicago, pointed out that we must recognize that there are limits to the increase in lifespan, and perhaps we should re-evaluate assumptions about when people should retire and how much money they need to get through their lives.

Life expectancy, an estimate of how long a baby born in a given year can expect to live, is one of the world's most important health indicators. However, the metric has its limitations and doesn't account for deadly epidemics, miracle cures or other unforeseen developments that could kill or save millions of people. In the new study, Olshansky and his research partners tracked life expectancy estimates from 1990 to 2019, focusing on the eight places in the world with the longest lifespans. They found that women are still living longer than men, and that life expectancy is still improving, but at a slower pace.

The problem is worse in the United States because it is more vulnerable to a range of problems that kill people before they reach old age, including drug overdoses, shootings, obesity and inequality. These problems make it difficult for some people to get adequate health care, further exacerbating the decline in life expectancy. However, even if all deaths before age 50 were eliminated, researchers estimate that the gains in life expectancy would be limited.

Experts say the number of centenarians is likely to increase in the coming decades, but that will be due to population growth rather than longer life expectancy. The proportion of people who reach 100 is still limited, with perhaps less than 15% of women and 5% of men making it to that age in most countries.

In the face of this challenge, we should not only pay attention to the length of life, but also the quality of life. Prolonging life is not the ultimate goal. The real goal is to allow people to have a healthy and happy life for a longer period of time. Therefore, on the road of science, we need to continue to explore the mysteries of life and find new ways to prolong life and improve the quality of life. At the same time, we also need to re-examine and adjust our lifestyles and concepts to better adapt to this era of challenges and opportunities.