Inonu University Liver Transplant Institute in Malatya, Turkey, in 2008, a 19-year-old girl was lying hopelessly in a hospital bed. She suffered from a dangerous disease called hepatic brain. It occurs when the liver is so weak that it can no longer remove toxins from the blood.
As a result, the toxin accumulates causing brain damage. With a particularly serious condition, the girl was placed on the waiting list for the priority transplant. But the response was just a desperate wait.
No liver is suitable for a 19-year-old girl.
Until one day, the doctors realized that the girl’s survival index had reached an extreme low. Her liver was completely dead, and they needed to save her life immediately. In the extreme, the organ transplant center told the doctors that they had an extra liver, a liver that all other hospitals in the system refused.
Indeed, it is a very bad liver. It contained a cyst due to a parasitic infection and once belonged to a recently lost 93-year-old woman. By transplant standards, this liver is not suitable, especially for the body of a 19-year-old girl.
But it was really the last chance that the girl had, the doctors were determined to perform the transplant and it was great when they succeeded. The young girl not only survived, but also recovered surprisingly. Six years after the surgery, the girl gave birth to a healthy baby.
In 2015, on the very first birthday of her child, the girl celebrated another special birthday. It was also the day when her liver was 100 years old.
Each of our organs has a different age
The story is an indisputable evidence that shows that in our bodies, there are organs that can live longer than its owner. The 93-year-old lady’s liver could have lived if she were alive.
In contrast, there are organs that die before the body, they age faster, age more and are weaker like the liver of a 19-year-old girl.
In many cases, the age of an organ can be a more important measurement than your own age. It is like a number that scientists call “biological age “.
Biological age is defined as the age estimated by biological indicators in the body instead of the number of years you live in the world. These two numbers are not always the same. And so is the age of each organ based on its biological indicators.
A healthy young man in his 20s and 30s has a completely youthful appearance. But his unhealthy eating habits may have made his pancreas look like the pancreas of a 50-year-old middle-aged man. A real study found a 38 year old person with kidneys of people over 60.
On the contrary, there are also people who are over 80 years old but possess a heart that seems to be beating for only 4 decades. They have a strong heart, know how to practice and preserve it carefully.
Geneticist Michael Snyder at Stanford University likens the human body to a car. Over time, the entire function of a car will be depreciated. “But among components and parts, there are parts that will wear out faster than others. “he said.
The data collected from organ transplants reveal fascinating clues about the aging of various organs in the body. Accordingly, there are some common organs that may be younger or older than the person who wears it.
The heart and pancreas usually age faster than a person’s true age after four weeks, that is, beyond 40 years old. However, our lungs tend to be younger if we take care of them carefully, not smoking. The cornea is the most durable organ that is less affected by age.
At the cellular level, the notion of an organ’s age is even fainter, scientists don’t know much about them. They only know that every cell that makes up an organ or organ can be worn out over time.
A self-destruct trigger in the gene will cause them to die after a while, to be replaced with newly born cells. The process occurs steadily, meaning the cells and tissues that make up every organ are regenerated.
Only the rate of regeneration is very different, in each cell type and each organ. A red blood cell circulates in your arteries and veins for an average of up to four months. Meanwhile, the red blood cells in the small intestine must be replaced after only a few days.
At the other extreme, most brain or nerve cells live by our own age. They are not replaced by new cells so their deaths will cause great problems for the body.
How to know the age of each organ?
Researchers at the University of Liverpool, UK, argue that the complexity of the structure of organs, along with their dependence on blood vessels to function, is probably the main determinant of age. them.
Interestingly, the age of some internal organs is more sensitive to our lifestyles. A good example is the lungs, said Richard Siow, director of aging research at King’s College London.
Smokers’ lungs have a shorter life span than non-smokers. And research shows that the lungs of people living in cities get older sooner than those living in the countryside, because the air in the city is more polluted.
According to Siow, any lifestyle factor can affect the complex aging pattern of our bodies. What we eat and how we eat it, the way we sleep and our sleep time – all of these can affect our internal organs in different ways.
Obviously, not all have the same durability over time. And if we want to live longer and healthier, we should also know which parts of our body are aging first.
But estimating the exact biological age of any organ in the body is not a simple task. Although many websites provide estimates of the biological age of the heart or lungs, most of those results lack a scientific basis.
To calculate the age of a specific organ, you must type its details, examine its structure, cell structure, and even DNA to get an accurate assessment.
A 2020 study by Stanford University has identified at least 87 molecules and bacteria in the body that can be used as biomarkers to estimate human organ age. By following a group of volunteers tested every quarter for two years, the team found that these biomarkers exhibit aging through various biological mechanisms.
Moreover, they found it possible to classify individuals into different age categories, by grouping the biomarkers based on the organ or system most representative of their aging. For example, one of the four aging pathways that can predominate in a person’s body – the kidneys, liver, metabolism and immune system.
Like a person with high cholesterol levels who need to exercise and check their cardiovascular health, a person with a high liver aging index may need to consider cutting back on drinking alcohol or sugary drinks.
These biomarkers in the future can contribute to determining the age of each organ, to give each person the right advice and direction for life from an early age.
Now, recent advances in machine learning can allow us to estimate cell and organ ages more accurately. One of these methods involves the methylation of DNA. It is the accumulation of a group of methyl chemicals attached to different parts of DNA.
Using methylation measurements, scientists can create an epigenetic map to compare the biological age of different tissues and organs. For example, one study calculated the biological age of breast tissue in women who were often older than their age. This may be an explanation for why many women have breast cancer.
And there’s an opportunity, that if we can somehow reverse the methylation process, we can help our tissue get younger, thereby repelling cancer before it even appears.
Can we reverse the aging process of organs?
It can be seen that, although we consider the aging of the body from any angle, the ultimate goal is to slow down or reverse it. At the cellular level, that would have been a viable target. In March 2020, researchers from Stanford Medical University said they had found a way to rejuvenate cells taken from older volunteers.
They did this by creating Yamanaka elements, proteins that were previously inserted into cells to turn them back into embryonic states. Using the Yamanaka element after a few days, the cells extracted from the older volunteers became significantly younger.
But it is below the cellular level, rejuvenating an entire human organ or organ is certainly much harder. Some scientists are willing to surrender to specific aging processes towards a simpler goal, slowing down the overall aging process.
This goal focuses on extending the healthy life span – Healthspan – of the elderly instead of extending life – Lifespan for them. A recent University College London study found that certain drugs like rapamycin, metformin and lithium may delay the onset of age-related illness.
That means using these drugs will help an older person to reach fuller old age, not be bothered by disease. But they will still age, and can’t reverse their overall aging process, just avoid certain diseases.
Richard Siow said that, in general, the research strategy to find out the age of each internal organ is very meaningful. Because we can use the age of our organs to plan health care strategies.
But he said the organ’s longevity cannot be separated from the overall aging of a system. This is because the aging of one organ will certainly affect the aging of other organs.
“If you have inflammation in the joints, that inflammation will also affect your brain and heart,” Richard Siow said. “Each different organ has a different aging trajectory, but they are all related to each other. ”