Few people know, but in the XVIII century the average life expectancy of a person was only 24 years. After 100 years, this number has doubled - up to 48 years. Now a newborn can live an average of 76 years. Given the latest discoveries in biology, scientists believe that this figure will remain unchanged for a long time.
Introduction
Today, the search for "rejuvenating apples" and the answer to the question of why a person ages is concentrated in the field of studying the genetic structure of cells, while less and less attention is paid to the role of stress and diets in people's lives. Those who want to achieve immortality turn 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 guarantee of immortality - they just promise to prolong life.
Let's find out together when and why a person ages, what are the signs and causes of aging and how to slow down the aging process.
The concept of "aging"
Word"old age" is now 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. They simply forgot about immortality.
But Dr. John Langmore, a professor at the University of Michigan, and his group have "looked" into cells, into the very essence of human life. In particular, he studied the DNA molecule and found at its ends a chain of repeating pairs of enzymes, which were later called "telomeres". They work as protective "caps" at the end of chromosomes, which over time prevent the molecules from splitting in half, which leads to aging and death of a person.
What are "telomeres"
Scientists note that as a person gets older, the length of telomeric chains decreases. Eventually they become so short that cell replication causes fatal errors or missing pieces in the DNA sequence, hindering the cell's ability to replace itself. This limit point, when the cell has lost its DNA life 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, the cells that are inside our mouth and in our intestines are constantly being erased and replaced. Indeed, they appear to be able to grow telomeres even into adulthood. Then scientists became interested in why some cells prevent the growth of telomeres with age, and some do not.
"Programmed" Cells
Dr. Langmore, using physical, biochemical and genetic methods to study the structure and function of telomeres, has developed a cell-free system to reconstruct the functional model of telomeres using synthetic DNA. He also identified the mechanism by which telomeres can "stabilize" and the conditions that lead to their instability.
Protein factors "responsible" for stabilizing chromosome ends have been cloned and studied. Electron microscopy made it possible to directly visualize the structure of the telomere model. This interesting research led to many promising discoveries.
Scientists have discovered an important enzyme that can "turn off" telomeres so that the DNA molecule can bifurcate indefinitely. It's called telomerase. But as we get older, the number of telomerase in cells decreases. This is the answer to the question of why the human body is aging.
Five main theories
So, scientists have proven that death occurs due to 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. Consider them in more detail:
1. error hypothesis. This theory defines errors that can occur in chemical reactions in the production of DNA and RNA, since the metabolic mechanism is not 100% accurate. Cell death can bethe result of these unresolved errors.
2. Theory of free radicals. Answers the question of why a person ages, in his own way. Uncontrolled free radicals can damage the membranes that surround cells and cellular DNA and RNA molecules. This damage eventually leads to cell death.
This theory is currently being hotly researched. Experiments on mice have shown 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. Crosslinking theory states that the 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 cross-linking can be caused by many chemicals normally found in cells through metabolism, as well as by pollutants (such as lead and tobacco smoke).
4. The brain hypothesis answers the question of why people age quickly in a different way. 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 a breakdown in the control of the endocrine glands.
5. autoimmune theory. It was proposed by Dr. Roy Walford in Los Angeles, who suggests that two types of immune system protein blood cells (B and T) lose their energy due to the "attack" of bacteria,viruses and cancer cells. And when B and T cells fail, they infect he althy cells in the body.
Why a person is aging: causes and signs
At some point in life, often around the age of 30, the tell-tale signs of aging begin to become apparent. They can be seen everywhere: wrinkles appear on the skin, the strength and flexibility of bones and joints decrease, the cardiovascular, digestive and nervous systems undergo changes.
While no one can say exactly why a person is aging. But genetics, diet, exercise, disease and other factors have definitely been shown to influence this process.
Let's take a closer look at 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 prevent the splitting of the DNA molecule;
- waste accumulates in cells;
- connective tissue becomes more rigid;
- The maximum functional capacity of many organs is reduced.
2. Heart and blood vessels:
- the wall of the heart becomes thicker;
- heart muscles begin to work less efficiently, pumping the same amount of blood;
- aortas become thicker, stiffer and less flexible;
- arteries supply blood to the heart and brain more slowly, which is the reason why a person ages, the signs are obvious.
3. Vital Functions:
- the body becomes more difficult to control the temperature;
- frequencyheart rate takes longer to return to normal after exercise.
4. Bones, muscles, joints:
- bones become thinner and less strong;
- joints are more rigid and less flexible;
- cartilage in bones and joints begins to weaken;
- muscle tissue also loses its strength, this explains why a person ages, the reasons for this process.
5. Digestive system:
- 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 leads 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 harder;
- lenses less clear;
- the walls of the ear canal become thinner and the eardrums thicker.
8. Skin, nails and hair:
- the skin becomes thinner and less elastic with age, which is the reason why people look older;
- sweat glands produce less sweat;
- nails grow slower;
- hair turns gray and some even stop growing.
Symptoms of Aging
There arecommon symptoms of aging which include:
- increased susceptibility to infections;
- slight decline in growth;
- increased risk of heat stroke or hypothermia;
- bones break more easily;
- stoop;
- slow motion;
- decrease in total energy;
- constipation and urinary incontinence;
- a slight slowdown in the thinking process and memory impairment;
- decreased coordination;
- deterioration in visual acuity and decrease in peripheral vision;
- hearing loss;
- sagging and wrinkling of the skin;
- graying hair;
- weight loss.
Next, let's look at what causes people to age and what things make us older.
The effect of sugar
People who like sweets will be disgusted to know that sugar "accelerates" our old age. If you consume it in large quantities, you will soon quickly gain weight, and your body will become more susceptible to chronic diseases. They, of course, will slowly "introduce" into a person's life for a long time. However, every chronic disease negatively affects all cells in the body. Which is the reason why a person slowly ages.
Smoking
Even a child knows that smoking is bad for he alth. In New Zealand, for example, 5,000 people die every year due to the adverse effects of smoking (including passive smoking). This is13 people per day!
Every cigarette you smoke 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 read that right! Breaking up with someone you loved deeply certainly has a negative impact not only on your psychological state, but also on your appearance and he alth.
In 2009, scientists conducted a study with identical twins, which revealed that separated couples look much older than those who 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 becomes clear why some people age faster than others.
Excessive sun can lead to elastosis (reduced skin elasticity) and 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 years to your appearance. Chronic stress leads to the constant release of fear hormones, which have a negative effect on internal organs and tissues. They also contribute to the formation of free radicals, which is the reason why people age quickly.
How to slow down the biological clock
There are several recommendations that will help you on your own and without investmenthuge amounts to slow down the aging process in the body:
1. Learn to manage your fears and deal with your worries.
2. Restricting your calorie intake significantly slows down your old age. Preliminary results from studies in monkeys show that rational diets can "slow down" age-related physiological changes.
3. Get regular exercise. 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 strength.
5. Relax. Choose the relaxation method that suits you. Perhaps it will be dancing, reading books, listening to music, or simply taking hot baths.
In conclusion, we can all 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 he althy lifestyle, but also to minimize all factors that negatively affect our body.
