Aging is generally considered to be a gradual process of the entire body.
Although everyone’s aging rate is different,
it is very useful to analyze the aging mechanism of human organs from a holistic perspective.
93-year-old liver transplantation
First tell a true story.
A Turkish girl encountered the darkest moment in her life when she was 19 years old. She was suffering from liver disease in urgent need of liver transplantation. However, due to organ failure, she suffered from hepatic encephalopathy while waiting for the liver source. A large amount of toxins were in the blood. It accumulates and damages her brain. Soon after, her liver stopped working completely. The doctors urgently needed a liver transplant to save her life.
However, as time goes by, if you want to complete this transplant in a short period of time, the only option is to transplant a liver that has been rejected by other hospitals. The former owner was a 93-year-old woman who died recently. The condition is not good. In addition to the 93-year-old “old age”, it also contains a cyst tissue caused by a parasite infection. From the perspective of transplant surgery standards, this organ is already very old, especially for a girl patient who is only 19 years old.
But because there were no other organs available, and no other treatment options, doctors had to transplant the 93-year-old liver to the girl. It is gratifying that the liver transplant operation performed at the Institute of Liver Transplantation of Inonu University in Turkey in 2008 was finally successful, and the 19-year-old girl patient survived. Six years later, she gave birth to a healthy baby girl. On the day of her daughter’s first birthday, the 26-year-old woman also coincided with her 100th birthday of a liver transplant.
Few people know what it would be like to transplant a century-old liver organ in the body? However, some human organs do have the ability to live longer than humans. The aging degree of human organs and tissues can reflect the actual age of our body more accurately than calculating birthdays.
One interesting aspect of longevity research is that your actual age does not seem to be as important as you think. In fact, researchers are more interested in the difference between the actual age of an individual (that is, how many years have passed since you were born) and the biological age. Biological age is used to describe how our body actually changes with age.
These two numbers may be closely related, but intuitively speaking, they are not always a perfect match. We all know that long-term unhealthy diet and lack of sleep can make us age prematurely.
Aging is generally considered to be a gradual process of the entire body. Although everyone’s aging rate is different, it is very useful to analyze the aging mechanism of human organs from a holistic perspective. Studies have shown that the complex genes, lifestyle, and environmental factors that determine the aging speed of our bodies do not affect all our organs to the same degree.
Therefore, a study of the adult population found that although we may have a 38-year-old appearance, our kidneys may be as old and weak as those of a 61-year-old. Vice versa, we may have serious wrinkles and hair loss on our face. It looks like an 80-year-old man’s appearance, but we still have a heart that beats like a 40-year-old middle-aged person would have.
Geneticists compare the human body to a car, “Over time, the overall function of the car will decline, but some parts wear out faster than others. If the car engine is running, all parts will be constantly repaired during driving. In the same way, the human body is also the same situation. When the function of the body organs declines after the human body ages, people can repair these organs and tissues.”
The age of the body’s organs
Although it is useful to know people’s total biological age, if we want to live longer and enjoy a healthier life, we should understand that not all body organs The age is the same.
It is not a simple matter to accurately estimate the biological age of any organ. Although many websites provide “calculators” to assess the age of different organs and tissues, such as the heart or lungs, determining the biological age of an organ requires detailed examination of organ function, tissue structure, Cell composition, genetic health, etc., to accurately assess.
Transplantation data can provide some interesting clues as to which organs will get better with age. The researchers compared factors such as the age of the donor and the life span of the recipient after the operation. The results showed that, overall, older organ transplants are usually less successful. However, there are significant differences between different organs, indicating that certain organs do not age significantly with age and have “longevity function”.
Although the success rate of heart and pancreas transplantation decreases after the age of 40, researchers have found that the age difference of transplanted lungs occurs between organ donors over 65 years old. The cornea is the most resistant of all organs. However, elderly recipients have little effect on the resistance of the donor’s cornea.
Researchers believe that these organs are relatively complex, and they are more dependent on blood vessels, which will be a key factor in coping with age problems. Age-related changes in blood vessels and capillaries in different organs and tissues are important factors that cause age-related dysfunction.
The organ transplant data also raises a question: Is there an upper limit on the life span of certain organs? For example, the regenerative function of the liver is well known. The cases of patients with two-thirds of the liver surgically removed show that the liver can be completely restored to normal size within one year after surgery.
The researchers took several successful liver transplant operations in recent years as an example: the elderly in their 90s are largely an untapped potential liver donor group, and some scientists are closely monitoring a group of over 100 years old. The liver organs of the elderly are found to be decades younger than their biological age.
Some organs may be more sensitive to certain aspects of our lifestyle. Lung and environmental pollution are a good example. In urban or highly polluted environments, human lungs are more likely to function aging.
Many lifestyle factors may affect our complex aging patterns, what we eat, how we eat, how we sleep, and when we sleep. All these things will affect human organs in different ways, but we don’t fully understand.
At the micro level, the concept of organ age will become more vague. The individual cells that make up most of the human organs will be lost and need to be replaced regularly. This means that over time, many human tissues will be completely regenerated, but they are regenerated. The speed will also vary greatly.
Under normal circumstances, it takes an average of 4 months for red blood cells to circulate in the veins and arteries of the human body, and the cells in the chaotic intestinal system are replaced in only a few days. At the same time, most brain cells or neurons will not follow The human body is replaced by aging, which means that they are usually the same as the body’s biological age.
But a research team made a surprising discovery in 2019: Neurons are not the only long-lived cells in mammals. They found “old cells” in the liver and pancreas of mice that are equivalent to the physiological age of mice, and these cells can interact with The coexistence of younger cells is called “age mosaicism”. Since longer-lived cells are more susceptible to age-related depletion than those younger cells, the fact that they exist outside the brain will provide researchers with important clues to learn more about the mechanisms of aging in other organs.
No matter how resilient and adaptable human organs are in the face of aging, all organs Tissues will gradually age and their functionality will decline over time, but the latest research shows that in the future, people may be able to predict which organ will fail first.
In 2020, a research team found that there are at least 87 kinds of molecules and microorganisms in the human body that can be used as “biomarkers” of aging. A group of volunteers will undergo a two-year quarterly physical examination to observe how these “biomarkers” change. . Eventually they concluded that people seem to age gradually through different biological mechanisms. More importantly, they found that by grouping the biomarkers of the most closely related organs or systems of individuals, individuals can be divided into different “age types.”
Based on the main manifestations of human aging-kidney, liver, metabolism and immunity, the research team found four different types of aging related evidence. But they believe that this phenomenon also exists in other types of elderly groups, such as the elderly who like aerobic exercise. It is worth noting that they can determine the age type of people, which may be related to the combination of human genes and environmental factors. If this research theory is correct, one day in the future young people will be told that as they age, they need to pay attention Which organs and tissues have health problems.
If you are a cardiologist, you will definitely pay attention to your cholesterol index, check your heart, maintain physical fitness, and for metabolic regulators, you must control your diet and drink less.
Strengthening physical exercise and a healthy diet are good for the human body, but if your heart or kidneys are depleted, you may need a more direct strategy-we don’t know whether the “aging type” identified by the Stanford University research team will be in a short-term study Physiological changes will have a long-term negative impact on health. But we are entering an era of more personalized anti-aging interventions. One size fits all cannot solve the problem. Overall, exercise and good eating habits are good for the human body, but if your heart and kidneys fail, you may need to take more Targeted strategy.
Reversing the aging clock
Research progress in the field of machine learning enables scientists to obtain more accurate biological aging assessment data, One of the methods is to study the permanent changes in DNA, that is, methylation characteristics. Different genes are turned on or off during the process, which involves the attachment of methyl chemical groups to our DNA. It is believed that this process is a series of “epigenetic” changes in human DNA. These changes determine how our genes are affected by our lifestyle and living environment. The amount of DNA methylation changes with our age and changes in epigenetic patterns, which allows biologists to develop an “epigenetic clock”, which they believe is a powerful predictor of biological age.
This kind of clock can also compare and analyze the biological age of different tissues. For example, some evidences show that female breast tissue ages faster than other parts. This raises the question of whether the epigenetic clock can be used to predict breast cancer. Some scientists point out that even if they prove to be accurate, we don’t yet know whether slowing these clock treatments will slow the aging process.
No matter how we view human aging objectively, the ultimate goal of many longevity research institutions is not only to slow down the aging clock, but to reverse the aging clock. At the cellular level, this seems to be possible. In March 2000, Stanford University researchers stated that they can successfully obtain young cells by making the elderly people produce Yamanaka factor. Previous studies have confirmed that Yamanaka factor is a protein that can restore cells to an embryonic state. After a few days The results show that the cells in the elderly population are a few years younger.
A similar “longevity experiment” for whole organs and tissues is even more challenging, but this research may be the first step in a new therapy to reverse the biological clock of cells and tissues without removing them from the body.
However, many scientists are currently focusing on extending the healthy life of the elderly. Recently, researchers have emphasized that drugs such as rapamycin, metformin, and lithium can be used to delay the onset of disease, but these interventions can almost reverse aging. Many symptoms. Others agree that anti-aging treatments may have “tissue-specific” effects, highlighting the need for scientists to understand how the aging process affects different organs and tissues in different ways.
Although the aging methods of each organ and tissue are not the same, it is meaningful to take care of them carefully. Every organ of the human body is connected to form a whole system, and the aging disease of one organ will inevitably affect other organs and tissues.