Can we control or even delay aging?
In aging research, scientists and doctors are more than divided on the key question: What is aging and why does it happen?
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The cause of aging lies in the heavy work that our bodies have to do over decades to maintain the complex functions of life. From supplying cells and organs with energy, to transporting nutrients and metabolites from one end of the body to the other, to regulating cell growth and finally cell death. But what exactly happens during these mechanisms, and can we use targeted approaches to control these processes and thus delay or even reverse aging?
It has been very well researched so far that damage to genetic material, cells and tissues, which accumulates with age and can no longer be repaired by the body, is the cause of the aging process. There are two theories for this: Program theory, which assumes that aging is a predetermined process controlled by genes. The theory of wear and tear assumes that the accumulation of DNA damage, the effects of free radicals or reactive oxygen species (ROS) and failure in cell signaling are responsible for aging.
On the one hand, this means that the aging process is inevitable and that the natural decline cannot be delayed indefinitely. On the other hand, recent research suggests that genes can be switched on and off to a certain extent in order to slow down, stop or even reset the aging process.
There is agreement that aging is a complex process that is determined by a combination of life-long influences such as environment, diet, exercise, heredity, wear and tear, and other factors.
It is also recognized that there are multiple mechanisms associated with aging, the most notable being the nutrient sensing pathway known as insulin/ IGF-1. Studies in mice, for example, show that mutations that interfere with IGF-1 and cause growth hormone to be dysregulated affect longevity.
The results of calorie restriction confirm that longevity is increased by regulating nutrient sensing pathways and genes when an organism or a person is exposed to a reduced-calorie regime, i.e. consumes less than the recommended daily calories. But calorie restriction only has a marginal effect on human longevity, so science needs to look at how these mechanisms work, along with a few others, and determine how (if at all) they can be affected.
The signs of aging
In general, nine characteristics associated with the aging process have been established among scientists in the field of aging, most of which are linked to each other.
1. Genomic instability
Each body cell has instructions that are necessary for carrying out its individual functions. This blueprint is our DNA, which in turn consists of DNA building blocks that form the genome. The correct functioning of every cell is a prerequisite for proper bodily functions. However, the genome is constantly exposed to internal and external attacks. DNA damage can be caused by external factors such as air pollution, solar radiation, or chemicals in the environment, or by internal stimuli such as free radicals, pathogens, or chemicals that have been ingested. It is estimated that this happens up to a million times a day. However, most cells are equipped with mechanisms that can repair damage and rebuild the cell. During this repair process, however, it can happen that part of the information is lost or copied incorrectly, resulting in mutations. These accumulate with age and can thus accumulate damage that affects the body systems and leads to diseases.
2. Telomere wear
At the ends of each chromosome of the human genome are telomeres, which help maintain genetic stability. However, during each of the 60 cell divisions, a piece of telomeres is lost, so that the ends get shorter and shorter as you get older. When they reach a certain minimum length, they are unable to divide and cell death occurs. Such dead cells can cause inflammation and trigger age-related diseases. Lifestyle factors such as diet and exercise and even pharmaceuticals can have a positive impact on this process, slowing down and in some cases even reversing the shortening.
3. Epigenetic changes
Epigenetics is a very new science of genetics that deals with gene expression, i.e. the activity of the gene. This involves conveying epigenetic information that prevents or releases DNA sequences without changing the DNA itself. Our health is therefore determined not only by the genes themselves, but also by the epigenetic code. In addition to environmental influences and eating habits, other aspects of lifestyle such as chronic stress and medications determine which gene is activated.
4. loss of proteostasis
Genes make proteins, such as enzymes or hormones, which are used throughout the body to regulate biochemical reactions or to form structural tissues such as hair, muscles, and skin. Proteins are folded into complex shapes. As they age, their shapes become distorted or collapse, which affects their ability to work properly. Diseases such as Alzheimer's, Parkinson's and cataracts are linked to damaged proteins.
5. Impaired perception of nutrients
Nutrients are essential for survival. The body is finely tuned to recognize when nutrients are scarce or abundant. Physiological mechanisms respond to supply and demand to ensure that cells get what they need. Cell damage can unbalance this system and be linked to the onset of inflammation, which can then influence the progression of age-related diseases.
6. Mitochondrial dysfunction
Mitochondria are components of a cell and its energy producer. They are therefore also referred to as the “strength of the cell.” Free radicals, also known as reactive oxygen species, are a natural by-product of energy production in cells. It has long been assumed that when their production increases too much, mitochondrial function worsens and thus damages the cell. However, it has been known for several years that free radicals act more as signals to initiate mechanisms for cell survival. Endurance training and intermittent fasting are two behaviors that could help revive diseased mitochondria.
7. Cellular senescence
Cells divide to make an organism grow or to replace old cells in a specific tissue or organ. However, this process is limited because the vast majority of cells cannot divide infinitely often. As soon as a cell has reached its dividing end, the senescent phase begins. This can be triggered when telomeres shorten, as well as a number of other causes, such as DNA damage. At best, they are removed from the body by immune cells. But if they stay, they can secrete inflammatory compounds that contribute to aging.
8. Stem cell exhaustion
Cells replicate and therefore regenerate throughout life. This enables the natural process of repairing damaged cells and regenerating tissue. Stem cells are the ultimate source of new cells. But healthy stem cells can decline as we age, and body systems and tissues can atrophy as a result.
9. Altered intracellular communication
Since cells are interconnected and able to communicate, some changes in the body come from internal stimuli. Aging can hinder lines of communication. When cells become senescent or inflamed, signal transmission can be impaired. Hormones may not work as effectively, and immune cells may not show optimal ability to deal with pathogens. A decline in function in one part of the body can then increase the risk of collapse in other areas.
References
Publiziert
9.9.2024
Kategorie
Longevity
Experte
Scientific Terms
Genome
The entire DNA sequence of an organism or virus. The genome is essentially a huge set of instructions for making the individual parts of a cell and for controlling the entire process.
Genomics
The study of the genome, the entire DNA of a particular organism. It includes the DNA sequence of a genome, the organization and control of genes, the molecules that interact with DNA, and how these various components influence cell growth and function.
Epigenetics
From ancient Greek π epi 'to, moreover, 'and genetics
Refers to changes in a cell's gene expression that do not involve a change in the DNA code. Instead, the DNA and histones around which the DNA is wrapped are “marked” with removable chemical signals (see demethylation and deacetylation). Epigenetic tags tell other proteins where and when to read the DNA. This is comparable to a post-it on a book page that says “Skip.” A reader will ignore the page, but the book itself hasn't been changed.
Epigenetic clock
A type of DNA clock that relies on measuring natural DNA methylation levels to estimate the biological age of a tissue, cell type, or organ, such as the Horvath clock.
Mitochondrion
Mitochondria are often referred to as the cell's powerhouse and break down nutrients to generate energy in a process called cellular respiration. They contain their own circular genome.
Stem Cell
Stem cells are the body's raw material — cells that give rise to all other cells with specialized functions. Under the right conditions in the body or in the laboratory, stem cells divide and form further cells, the so-called daughter cells.
Seneszens
Latin senescere “getting old”, “aging”
The process of deterioration with age.
Cellular Senescence
The process that occurs when normal cells stop dividing and start releasing inflammatory molecules, sometimes caused by telomere shortening, DNA damage, or epigenomic noise. Despite their apparent “zombie” state, senescent cells remain alive and damage neighboring cells with their inflammatory secretions.
Proteostasis
The term proteostasis comprises various interlinked processes that control protein activity at the cellular level.
The cause of aging lies in the heavy work that our bodies have to do over decades to maintain the complex functions of life. From supplying cells and organs with energy, to transporting nutrients and metabolites from one end of the body to the other, to regulating cell growth and finally cell death. But what exactly happens during these mechanisms, and can we use targeted approaches to control these processes and thus delay or even reverse aging?
It has been very well researched so far that damage to genetic material, cells and tissues, which accumulates with age and can no longer be repaired by the body, is the cause of the aging process. There are two theories for this: Program theory, which assumes that aging is a predetermined process controlled by genes. The theory of wear and tear assumes that the accumulation of DNA damage, the effects of free radicals or reactive oxygen species (ROS) and failure in cell signaling are responsible for aging.
On the one hand, this means that the aging process is inevitable and that the natural decline cannot be delayed indefinitely. On the other hand, recent research suggests that genes can be switched on and off to a certain extent in order to slow down, stop or even reset the aging process.
There is agreement that aging is a complex process that is determined by a combination of life-long influences such as environment, diet, exercise, heredity, wear and tear, and other factors.
It is also recognized that there are multiple mechanisms associated with aging, the most notable being the nutrient sensing pathway known as insulin/ IGF-1. Studies in mice, for example, show that mutations that interfere with IGF-1 and cause growth hormone to be dysregulated affect longevity.
The results of calorie restriction confirm that longevity is increased by regulating nutrient sensing pathways and genes when an organism or a person is exposed to a reduced-calorie regime, i.e. consumes less than the recommended daily calories. But calorie restriction only has a marginal effect on human longevity, so science needs to look at how these mechanisms work, along with a few others, and determine how (if at all) they can be affected.
The signs of aging
In general, nine characteristics associated with the aging process have been established among scientists in the field of aging, most of which are linked to each other.
1. Genomic instability
Each body cell has instructions that are necessary for carrying out its individual functions. This blueprint is our DNA, which in turn consists of DNA building blocks that form the genome. The correct functioning of every cell is a prerequisite for proper bodily functions. However, the genome is constantly exposed to internal and external attacks. DNA damage can be caused by external factors such as air pollution, solar radiation, or chemicals in the environment, or by internal stimuli such as free radicals, pathogens, or chemicals that have been ingested. It is estimated that this happens up to a million times a day. However, most cells are equipped with mechanisms that can repair damage and rebuild the cell. During this repair process, however, it can happen that part of the information is lost or copied incorrectly, resulting in mutations. These accumulate with age and can thus accumulate damage that affects the body systems and leads to diseases.
2. Telomere wear
At the ends of each chromosome of the human genome are telomeres, which help maintain genetic stability. However, during each of the 60 cell divisions, a piece of telomeres is lost, so that the ends get shorter and shorter as you get older. When they reach a certain minimum length, they are unable to divide and cell death occurs. Such dead cells can cause inflammation and trigger age-related diseases. Lifestyle factors such as diet and exercise and even pharmaceuticals can have a positive impact on this process, slowing down and in some cases even reversing the shortening.
3. Epigenetic changes
Epigenetics is a very new science of genetics that deals with gene expression, i.e. the activity of the gene. This involves conveying epigenetic information that prevents or releases DNA sequences without changing the DNA itself. Our health is therefore determined not only by the genes themselves, but also by the epigenetic code. In addition to environmental influences and eating habits, other aspects of lifestyle such as chronic stress and medications determine which gene is activated.
4. loss of proteostasis
Genes make proteins, such as enzymes or hormones, which are used throughout the body to regulate biochemical reactions or to form structural tissues such as hair, muscles, and skin. Proteins are folded into complex shapes. As they age, their shapes become distorted or collapse, which affects their ability to work properly. Diseases such as Alzheimer's, Parkinson's and cataracts are linked to damaged proteins.
5. Impaired perception of nutrients
Nutrients are essential for survival. The body is finely tuned to recognize when nutrients are scarce or abundant. Physiological mechanisms respond to supply and demand to ensure that cells get what they need. Cell damage can unbalance this system and be linked to the onset of inflammation, which can then influence the progression of age-related diseases.
6. Mitochondrial dysfunction
Mitochondria are components of a cell and its energy producer. They are therefore also referred to as the “strength of the cell.” Free radicals, also known as reactive oxygen species, are a natural by-product of energy production in cells. It has long been assumed that when their production increases too much, mitochondrial function worsens and thus damages the cell. However, it has been known for several years that free radicals act more as signals to initiate mechanisms for cell survival. Endurance training and intermittent fasting are two behaviors that could help revive diseased mitochondria.
7. Cellular senescence
Cells divide to make an organism grow or to replace old cells in a specific tissue or organ. However, this process is limited because the vast majority of cells cannot divide infinitely often. As soon as a cell has reached its dividing end, the senescent phase begins. This can be triggered when telomeres shorten, as well as a number of other causes, such as DNA damage. At best, they are removed from the body by immune cells. But if they stay, they can secrete inflammatory compounds that contribute to aging.
8. Stem cell exhaustion
Cells replicate and therefore regenerate throughout life. This enables the natural process of repairing damaged cells and regenerating tissue. Stem cells are the ultimate source of new cells. But healthy stem cells can decline as we age, and body systems and tissues can atrophy as a result.
9. Altered intracellular communication
Since cells are interconnected and able to communicate, some changes in the body come from internal stimuli. Aging can hinder lines of communication. When cells become senescent or inflamed, signal transmission can be impaired. Hormones may not work as effectively, and immune cells may not show optimal ability to deal with pathogens. A decline in function in one part of the body can then increase the risk of collapse in other areas.
Experte
Referenzen
Publiziert
9.9.2024
Kategorie
Longevity
Wissenschaftliche Begriffe
Genome
The entire DNA sequence of an organism or virus. The genome is essentially a huge set of instructions for making the individual parts of a cell and for controlling the entire process.
Genomics
The study of the genome, the entire DNA of a particular organism. It includes the DNA sequence of a genome, the organization and control of genes, the molecules that interact with DNA, and how these various components influence cell growth and function.
Epigenetics
From ancient Greek π epi 'to, moreover, 'and genetics
Refers to changes in a cell's gene expression that do not involve a change in the DNA code. Instead, the DNA and histones around which the DNA is wrapped are “marked” with removable chemical signals (see demethylation and deacetylation). Epigenetic tags tell other proteins where and when to read the DNA. This is comparable to a post-it on a book page that says “Skip.” A reader will ignore the page, but the book itself hasn't been changed.
Epigenetic clock
A type of DNA clock that relies on measuring natural DNA methylation levels to estimate the biological age of a tissue, cell type, or organ, such as the Horvath clock.
Mitochondrion
Mitochondria are often referred to as the cell's powerhouse and break down nutrients to generate energy in a process called cellular respiration. They contain their own circular genome.
Stem Cell
Stem cells are the body's raw material — cells that give rise to all other cells with specialized functions. Under the right conditions in the body or in the laboratory, stem cells divide and form further cells, the so-called daughter cells.
Seneszens
Latin senescere “getting old”, “aging”
The process of deterioration with age.
Cellular Senescence
The process that occurs when normal cells stop dividing and start releasing inflammatory molecules, sometimes caused by telomere shortening, DNA damage, or epigenomic noise. Despite their apparent “zombie” state, senescent cells remain alive and damage neighboring cells with their inflammatory secretions.
Proteostasis
The term proteostasis comprises various interlinked processes that control protein activity at the cellular level.
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