Do you know how many years the longest-lived people in the world live? A South African woman was certified by Guinness as the longest-lived person in 2008 and she lived a full 134 years.
Moloko Temo, the world's longest-lived South African woman
What does human longevity have to do with it? Is it possible for human beings to achieve immortality?
Is the method of longevity of animals applicable to humans? What are the existing ways to increase longevity?
Let's take a look at the longevity secret that scientists have found in male sheep, although this method may be applicable to humans, but it is extremely confusing.
How is human longevity affected?
No matter what kind of creatures on earth, they will eventually die, but their life spans are different, but there is one creature that can theoretically achieve immortality, that is, the lighthouse jellyfish.
Lighthouse jellyfish
Humans have lived on Earth for millions of years, and scientists have studied human beings at every stage and found that there are many factors on Earth that affect human lifespan.
For example, in times of war, human life expectancy is short, while in times of peace, human beings live longer.
Under the development of modern science and technology, scientists have found that the most fundamental reason that affects human life expectancy is genes.
Scientists have found that genes in the human body are multi-faceted, that is, some of them are harmful to the human body, some are beneficial, this phenomenon is called antagonism gene pleiotropy, these harmful genes can lead to aging.
Genes are fragments of DNA with genetic information
This phenomenon was demonstrated in experiments on the "Caenorhabditis elegans" worm.
- Man cannot attain eternal life
In addition, studies have shown that most of the cells in the human body are in a state of iterative renewal.
Scientist Leonard Hayfrick proposed the Hefrik limit in 1961, the limit of human lifespan.
Hayflik believes that mammalian cells renew in division, but they divide a limited number of times.
Schematic diagram of cell division
Cells divide once for about 2 years, and they age after 40-60 divisions and then gradually die.
From this, it is estimated that the maximum human life expectancy is 150 years, and it is believed that this limit cannot be broken.
So even with the best medical technology, human beings cannot achieve immortality.
cell division
The secret of male sheep longevity
However, in the records, humans have not yet reached this age, and as we mentioned earlier, the longest-lived elderly people are only 134 years old.
In the study, the scientists also found that women's life expectancy seems to be much longer than men's at each stage.
Scientists at the University of Otago in New Zealand conducted a study of a castrated male sheep.
- Castrated male sheep
In New Zealand, local farmers have found that if male sheep are castrated, their life expectancy can be extended, and thus a few more years of wool can be harvested.
Cute and cute New Zealand sheep
Shrek, the male sheep of a new Zealand farm, was castrated when he escaped from the farm in 1998.
6 years later, people saw a sheep with strong hair in the mountains, and they didn't expect it to be Shrek.
At this time, it was ten years old, and the wool was 27 kilograms.
In general, sheep live between 10-15 years, but usually live for ten years.
But after Shrek was found, it barely aged like a normal sheep, and it wasn't until 2011 that it was euthanized on the farm.
Shrek with unusually strong hair
By this time it was 16 years old, almost 60 percent longer than other uncastrated male sheep.
- The epigenetic clock of male sheep will be slower
Before scientists formally studied sheep's DNA, scientists and local farmers alike were no surprised by the phenomenon.
In the study, in order to observe the aging of dna in different sheep, scientists created an epigenetic clock that measures the aging of organisms based on methyl groups.
Sluggish sheep in the farm
The clock can be used to detect the biological age of a variety of mammals, and in more than 200 species, it is clear that female clocks will jump more slowly than males.
Male sheep that are castrated have a similar pattern of DNA methylation to that of female sheep, meaning that their epigenetic clocks will jump more slowly than normal male sheep.
Female and male sheep
- The method may work, but men are struggling
Researchers at the University of Otago believe that this approach is equally applicable to human males, and that removing the testicles can give men a longer lifespan.
Many men say that although this can prolong their lifespan, the knife can ruin their sexual life and the ability to reproduce, and even become incomplete.
So they are very entangled in this method.
In fact, as far as the current average life expectancy in New Zealand is concerned, women are 83.5 years old, while men are 80 years old, which seems to be a big gap, so it is normal to be entangled.
Women in New Zealand live longer on average than men
But some people say, can such a method really be applied to humans? After all, the internal mechanisms of the human body will still be different from other animals.
Is it applicable to humans?
There is one group that may be able to tell us the answer to this question, the eunuchs.
Before DNA demonstrating that castrated male sheep had a longer lifespan, scientists analyzed the records of Korea's centuries-old "eunuch family."
Their findings were published in the journal Contemporary Biology.
They found that these castrated men lived 19 years longer than contemporaries and men of the same social class, and some even longer than royals.
The image of a eunuch in a film and television drama
Eunuchs have a longer lifespan
The scientists also studied the life expectancy of 81 eunuchs born and lived between 1556 and 1861, and the average life expectancy of these eunuchs was 70 years, including 3 centenarians, the oldest of whom lived to the age of 109.
During this period, men born in the nobility lived at most in their 50s, and the average age was only 45 years old, which was simply staggering.
Scientists believe that male hormones produced in men's testicles, such as testosterone, can weaken men's immune systems to some extent and even damage the heart.
Women and these castrated eunuchs will have less male hormones in their bodies, so their average life expectancy will be longer than other men's.
Eunuch stills
- How men live longer
Based on both studies, we can see the effect of castration on male longevity.
But in reality, this approach doesn't seem to be very suitable for adult men.
Because both male sheep and human males are castrated earlier, the male hormones in the body are not enough to cause harm to the body, so their life expectancy will be longer.
But when scientists studied the longevity of castrated and uncastrated singers in the Middle Ages, they found that there was not a big gap in their longevity.
Castrated singer
This method will be less effective for adult men, but it is not without effect.
Based on the fact that humans need to reproduce, we certainly can't castrate underage males in order to prolong life, so scientists have proposed therapy to reduce testosterone.
This can also extend men's lifespan to some extent, but there are also side effects, such as reducing men's libido.
So even though it is known that this method of castration can make men live longer, many men also say that they are very entangled.
The way humans live long
Under the development of medical technology now, the average life expectancy of human beings has increased by more than 60 years compared with 2,000 years ago.
Life is in motion
This is mainly due to the fact that the environment in which human beings live has gradually improved, the bacteria exposed to them have also decreased a lot, and many of the original incurable diseases have also found a cure.
But in addition to external influencing factors, our own attitude towards life has also become a major factor.
For ourselves, we should be as little as possible to contact things that are harmful to the body, such as the most important thing to do is not to smoke, in addition to maintaining exercise habits, choosing a healthy diet, etc.
A healthy diet is a protection for the body
In order for ourselves to enjoy more of the beauty of modern society, we should also better protect our bodies.