Few people know, but in the XVIII century the average life expectancy of a person was only 24 years. After 100 years, this number doubled - up to 48 years. Now a newborn can live on average 76 years. Given the latest discoveries in biology, scientists believe that this figure will be unchanged for a long time.
Introduction
Today, searches for “rejuvenating apples” and the answer to the question of why a person is aging are concentrated in the field of studying the genetic structure of cells, and less and less attention is paid to the role of stress and diets in people's lives. Those who want to achieve immortality go to anti-aging clinics, paying $ 20,000 each year for hormone therapy, DNA analysis and space surgery. However, these experimental methods do not give any guarantees of immortality - just experts promise to prolong life.
Let's find out together when and why a person is aging, what are the signs and causes of aging and how to slow down the aging process.
The concept of "aging"
The word "old age" is currently associated with anti-aging cosmetics and surgical operations. This is due to the fact that modern science is more focused on the study of outer space and the invention of the latest technologies. Immortality is simply forgotten.
But Dr. John Langmore, a professor at the University of Michigan, and his group “peered” inside the cells, into the very essence of human life. In particular, he studied a DNA molecule and discovered at its ends a chain of repeating pairs of enzymes, which were later called "telomeres". They work as protective "caps" at the end of the chromosomes, which over time do not allow the molecules to split in half, which leads to aging and death of a person.
What are telomeres?
Scientists note that when a person gets older, the length of the telomeric chains decreases. In the end, they become so short that cell replication causes fatal errors or missing fragments in the DNA sequence, impeding the ability of the cell to replace itself. This limit point, when the cell has lost the vital DNA code and cannot reproduce itself, is called the Hayflick limit. This is a measure of how many times a cell can copy itself before it dies.
Some cells in our body have a very high Hayflick limit. For example, cells that are inside our mouths and intestines are constantly erased and replaced. Indeed, they appear to be able to grow telomeres even in adulthood. Scientists then became interested in why some cells interfere with telomere growth with age, and some do not.
"Programmed" cells
Dr. Langmore, using physical, biochemical and genetic methods to study the structure and function of telomeres, developed a cell-free system for restoring a functional model of telomeres using synthetic DNA. He also revealed the mechanism by which telomeres can “stabilize”, and the conditions that lead to their instability.
Protein factors “responsible” for stabilizing the ends of chromosomes have been cloned and studied. Electron microscopy made it possible to directly visualize the structure of the telomere model. This interesting study has led to many promising discoveries.
Scientists have discovered an important enzyme that can “turn off” telomeres so that the DNA molecule can endlessly bifurcate. It is called telomerase. But, as we get older, the number of telomerases in the cells decreases. This is the answer to the question of why the human body is aging.
Five basic theories
So, scientists have proved that death occurs in connection with the loss of a large number of cells. There are several theories that explain how the Hayflick limit is expressed in the cells of our body. Let's consider them in more detail:
1. The hypothesis of an error. This theory determines the errors that can occur in chemical reactions during the production of DNA and RNA, since the metabolic mechanism is not 100% accurate. Cell death may result from these unresolved errors.
2. The theory of free radicals. Answers the question of why a person is aging, in his own way. Uncontrolled free radicals can damage the membranes that surround cells and cellular DNA and RNA molecules. This damage ultimately leads to cell death.
This theory is currently under investigation. Experiments on mice showed that a 40% reduction in calorie intake leads to a doubling of their life expectancy and a decrease in the number of free radicals. In addition, scientists have found that vitamins E and C absorb them well.
3. The theory of crosslinking states that aging of living organisms is due to the random formation (by crosslinking) of “bridges” between protein molecules, which then interfere with the production of RNA and DNA. This crosslinking can be caused by many chemicals that usually appear in the cells as a result of metabolism, as well as by pollutants (such as lead and tobacco smoke).
4. The brain hypothesis answers the question of why people quickly age, differently. This is due to a “breakdown” in the homeostasis of body functions, especially in the control of the hypothalamus over the pituitary gland, which, in turn, causes an upset in the control of the endocrine glands.
5. Autoimmune theory. It was proposed by Dr. Roy Walford in Los Angeles, who suggests that the two types of protein blood cells in the immune system (B and T) lose their energy due to the “attack” of bacteria, viruses and cancer cells. And when B and T cells become malfunctioning, they infect healthy cells in the body.
Why a person is aging: causes and symptoms
At some point in life, often closer to 30 years, the warning signs of aging begin to be apparent. They can be seen in everything: wrinkles appear on the skin, the strength and flexibility of bones and joints decrease, the cardiovascular, digestive and nervous systems undergo changes.
So far, no one can say exactly why a person is aging. But it is definitely revealed that genetics, diets, physical exercises, illnesses and other factors influence this process.
We carefully examine the signs and causes of aging of the main body systems:
1. Cells, organs and tissues:
- telomeres, which are located at the ends of chromosomes inside each cell, over time interfere with the split of the DNA molecule;
- waste accumulates in the cells;
- connective tissue becomes more rigid;
- The maximum functional ability of many organs is reduced.
2. Heart and blood vessels:
- the wall of the heart becomes thicker;
- the heart muscles begin to work less efficiently, pumping the same amount of blood;
- Aorta become thicker, tougher and less flexible;
- arteries supply blood to the heart and brain more slowly, which is the reason why a person is aging, the signs are obvious.
3. Vital functions:
- the body becomes more difficult to control the temperature;
- The heart rate takes longer to return to normal after a workout.
4. Bones, muscles, joints:
- bones become thinner and less strong;
- joints - more rigid and less flexible;
- cartilage in the bones and joints begin to weaken;
- muscle tissue also loses its strength, this explains why a person is aging, the reasons for this process.
5. Digestive system:
- the stomach, liver, pancreas and small intestine produce significantly less digestive juices;
- the movement of food through the digestive system slows down.
6. Brain and nervous system:
- the number of nerve cells in the brain and spinal cord decreases;
- abnormal structures such as “plaques” and “tangles” can form in the brain, which lead to a deterioration in its performance;
- the number of connections between nerve cells decreases.
7. Eyes and ears:
- the retina becomes thinner, and the pupils become stiffer;
- lenses are less clear;
- the walls of the ear canal become thinner, and the eardrum is thicker.
8. Skin, nails and hair:
- the skin will become thinner and less elastic with age, which is the reason why people age externally;
- sweat glands produce less sweat;
- nails grow more slowly;
- the hair gets a gray color, and some even stop growing.
Symptoms of aging
There are general symptoms of aging that include the following:
- increased susceptibility to infections;
- a slight decrease in growth;
- increased risk of heat stroke or hypothermia;
- bones break easier;
- stoop;
- slow motion;
- decrease in total energy;
- constipation and urinary incontinence;
- slight slowdown of the thinking process and memory impairment;
- decreased coordination;
- deterioration in visual acuity and a decrease in peripheral vision;
- hearing loss;
- sagging and wrinkling of the skin;
- graying hair;
- weight loss.
Next, consider what is the reason why a person is aging, and what things make us older.
Sugar effect
People who love sweets will be unpleasant to know that sugar “accelerates” our old age. If you consume it in large quantities, you will soon gain weight quickly, and your body will become more susceptible to chronic diseases. They, of course, will slowly “take root” in a person’s life for a long time. However, every chronic disease adversely affects all cells in the body. Which becomes the reason why a person is aging slowly.
Smoking
Even a child knows that smoking is unhealthy. In New Zealand, for example, 5,000 people die every year due to the adverse effects of smoking (including passive). This is 13 people a day!
Each smoked cigarette will add wrinkles to your face. And in combination with a lot of sunlight, it also contributes to the appearance of dying cells on the skin.
Divorce
Yes, you were not mistaken! A break with the one you loved very much certainly has a negative effect not only on your psychological state, but also on your appearance and health.
In 2009, scientists conducted studies with identical twins, as a result of which it turned out that the separated pairs look much older than those that have always been together.
Sun exposure
The sun's rays have a positive effect on the human body, but to a certain extent. They can cause wrinkles on the skin, then it will become clear why some people age faster than others.
Excessive sun exposure can lead to elastosis (a decrease in skin elasticity) and to the appearance of numerous age spots on the face.
Phobias and Stresses
Recent studies have found that personal phobias and experiences accelerate aging and add a few years to your appearance. Chronic stress leads to the constant release of hormones of fear, which have a negative effect on internal organs and tissues. And also contribute to the formation of free radicals, which is the reason why people quickly age.
How to slow down a biological clock
There are several recommendations that will help you slow down the aging process in your body yourself and without investing huge amounts:
1. Learn to manage your fears and deal with feelings.
2. Limiting calorie intake significantly slows down your old age. Preliminary results from studies on monkeys have shown that rational diets can “slow down” age-related physiological changes.
3. Exercise regularly. After all, they contribute to the release of growth hormones.
4. Try to get enough sleep every day. Only during sleep can we fully restore all our strengths.
5. Relax. Choose your relaxation method. Perhaps it will be dancing, reading books, listening to music or just taking hot baths.
In conclusion, we can say that we will all grow old, whether we like it or not. But we now know how to slow down this process, even at the cellular level. It is necessary not only to lead a healthy lifestyle, but also to minimize all factors that negatively affect our body.