Why do people age? It's related to telomeres

Today we will talk about why people age.

From a microscopic perspective, humans and most living things age and die because cells in the body gradually die, eventually leading to problems throughout the body.

But why do healthy cells age and die? This question has puzzled scientists for many years.

In the 1970s, Elizabeth Blackburn, a molecular biologist at the University of California, San Francisco, and two other colleagues discovered that there is a special section of DNA at the end of chromosomes in human and other organisms that can protect genetic material from degradation and destruction during cell mitosis. They named this section of DNA "telomere".

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As cells divide and age, telomeres continue to shorten. When they become too short, DNA may break or mutate when cells divide, which can lead to cancer or cell death. When telomeres are too short, cells can no longer divide. Therefore, telomere length is considered by scientists to be a key marker of aging. In recognition of the Blackburn trio's discovery of the protective effects of telomeres and telomerase on chromosomes, the Royal Swedish Academy of Sciences awarded the trio the Nobel Prize in Physiology or Medicine in 2009.

In 2005, Hendrickje van Andel-Schipper, then the world's oldest person, died at the age of 115. Researchers analyzed her white blood cells and found that the telomeres of her white blood cells were very short, much shorter than those of other body cells, indicating that her hematopoietic stem cells had almost no ability to divide again. It may be for this reason that she died peacefully in her sleep.

According to this theory, does it mean that as long as we find a way to slow down the shortening of telomeres, we can prolong our life?

One of the most commonly used telomere lengths in clinical research is “leukocyte telomere length (LTL).”

In 2022, a paper on the relationship between LTL and healthy lifestyle was published in The Lancet - Health in Aging. The researchers analyzed more than 400,000 participants and 117 factors that may change LTL, such as smoking, drinking, exercise frequency, eating habits, etc. The results showed that although 71 of these factors were significantly associated with LTL, the actual impact of these factors on LTL was not significant, even less than the impact of being one year older.

Therefore, humans have not yet fully understood what affects the speed of telomere changes, and do not know how to use the relationship between aging and telomere length to prolong life. Gene therapy is still in its infancy, and scientists have not yet uncovered all the secrets contained in these genetic materials. For ordinary people like us, thinking about the meaning of immortality may be more valuable.

This article is a work supported by Science Popularization China Starry Sky Project

Author: The Nutcracker

Review: Tao Ning

Produced by: China Association for Science and Technology Department of Science Popularization

Producer: China Science and Technology Press Co., Ltd., Beijing Zhongke Xinghe Culture Media Co., Ltd.