Interesting fact: Does exercise have an impact on human life expectancy?

Some time ago, I was watching videos and saw that people were running marathons in many places. Suddenly, a question came to my mind. While exercising speeds up metabolism, will it also speed up cell division (telomere theory: the number of cell divisions is limited and the telomeres shorten with each division), thereby shortening human lifespan?

In fact, this question is also one of the important problems in life sciences, and there is basically no definitive answer. Because it involves two major areas, today I will talk to you from the perspective of these two areas and telomeres!

01. Whole and Part

Our human body is made up of cells, but cells cannot replace individuals. In other words, exercise is implemented on individuals, but there is still a distance between individuals and cells, and the distance between cells and individuals is also very long.

02. Balance Theory

Equilibrium theory is a common theory at present. Whether it is from the early, macroscopic steady state, such as the temperature balance of the human body, or the current ROS balance theory, it shows that this thing has a degree.

Long-lived creatures mainly have low metabolism (even thousand-year-old turtles may live for ten-thousand years, of course there are some with high metabolism); however, moderate exercise can promote longevity.

(But it has seen through everything)

But where is the degree? ? ? So confusing.

Generally speaking, moderate exercise can improve immunity, which is good. However, there is a lot of evidence that excessive exercise can accelerate aging.

03. Telomere???

Many people think that telomeres are the key to longevity, but they actually confuse the relationship between cells and individuals. We are not afraid of telomeres at all!

Telomeres are the parts at both ends of DNA. When the telomeres shorten to a certain extent, the cells initiate programmed cell death.

In the last century, there was an empirical law that normal cells can divide for 50-60 generations, which is called the Hayflick limit. The characteristic of cancer cells is that they can repair telomeres infinitely, so they are immortal. However, the human body lives so long, if it really plays 50-60 generations, it is estimated that many people would have died long ago. In fact, we can culture normal fibroblasts in vitro, and it only takes half a year to raise dozens of generations.

What's more, for aging cells, death is the best thing. Instead of repairing old cells, it is more convenient to grow new cells. Therefore, cells will play with autophagy or programmed death.

The human body has this programmed death, which won the Nobel Prize in 2002.

So this brings us back to the next question.

04. What we fear is stem cell aging

Why can the human body ignore the Hayflick limit? That's because we have stem cells.

What should we do if human cells keep dying? Stem cells can make up for it. Stem cells have two major characteristics:

1. Can divide into new tissue cells.

Just like an embryonic liver cell can develop into a complete human being

2. It can multiply indefinitely.

For adults, this is the most powerful point of stem cells, they can replenish what is lacking. Our body is constantly replenishing cells, and it is stem cells that play a role.

In theory, stem cells can proliferate indefinitely, but for some reason, the activity and regenerative capacity of human stem cells change with age. Therefore, the main reason for our death is the decline of repair ability, which leads to cell damage, tissue damage, and individual death. If we can stimulate human stem cells and maintain their ability, longevity is just around the corner.

So is there a way to do this? It seems that there is.

Primary method: telomere extension; Current situation: Few people do it, because organisms are not that smart and always over-extend their telomeres, which causes cancer.

Advanced method: stem cells. Artificial induction of stem cells is our main idea at present, which is the content of Shinya Yamanaka's Nobel Prize in 2012. Simply put, it is to reprogram our normal cells and finally turn them into stem cells. Through this method, we can replenish stem cells. However, the problem still exists, that is, carcinogenicity!

It's really terrible. No matter what you do, it will basically cause cancer. Cancer is really a curse for mankind.

I have previously written about the evolution of cancer and mentioned that cancer cells are an extremely ancient defense mechanism , which may be a trace of a single-celled organism . Cancer cells have stronger vitality than normal cells and can resist special environments. However, cancer cells are too focused on their own survival and therefore ignore the collective interests, which leads to individual death.

How can we achieve longevity without getting cancer? Maybe time is the ultimate answer, hahahahaha.