The wear and tear theory of aging states that the effects ofagingThey are caused by progressive damage to cells and systems in the body over time.Essentially, human bodies "wear out" with use. Once they wear out, they can no longer function properly.
It is sometimes called the simple decomposition theory or the fundamental limitation theory. It's one of many theories about aging that keep popping up. Some consider aging to be a more intentional process.
This article examines the wear and tear theory of aging, its basic scientific assumptions, and the evidence for and against it. He also discusses various theories of aging that are compared to him.
An overview of aging theories
It is important to realize that there are severalaging theories🇧🇷 The wear and tear theory is only one.
Every theory has evidence for and against. There are two main categories of aging: programmed theories and error theories.
Programmed theories of agingThey believe that aging is a normal process, just as puberty is a normal developmental process. These include:
- Phenoptosis, a view that cells are programmed to die, leading to aging and death.
- Endocrine (hormonal) theory, meaning that hormonal activity over time causes aging
- immune theory(and "inflammatory"), who view aging as a response of the immune system
Error theories of aging assume that aging is not something programmed, but is the result of a series of "accidents". These include:
- Live-Theorie-Rate, which states that your body can only take a few steps or heartbeats before it collapses
- Free radical theory, which links aging to DNA damage caused by “free radicals” hitting cells
- Theory of protein cross-linking, based on chemical changes that interact with each other in the body
- Somatic theory of DNA damage, which states that your genetic makeup controls aging until death
The attrition theory of aging falls into the latter category of failure theories.
Programmed theories view aging as a natural process that follows a "healthy" cycle in the body. Error theories see aging as an accident and a "problem" to be solved. The differences go far beyond biology and become a philosophical discussion.
Basic principles of wear theory.
The theory of wear essentially states that bodies wear out over time. This theory can easily make sense when it comes to inanimate objects, from cars to clothing, that wear out and lose function over time.
Causes of wear damage
A variety of internal and external factors can damage the body's systems. Exposure to radiation, toxins, and ultraviolet light can damage genes. The effects of the body's functions can also cause damage. When the body metabolizes oxygen, free radicals are created, which can damage cells and tissues.
There are some cellular systems that do not replace themselves throughout life, such as nerve cells in the brain. If these cells are lost, function will eventually be lost.
The wear and tear theory views cells as socks that only last so long before they fray or puncture. They can repair themselves like socks, but only a few times before they stop working.
In cells that continue to divide, DNA can become damaged and errors can accumulate.The simple act of sharing shortens time and time againChromosomen-Telomere, ultimately resulting in a senescent cell that can no longer divide.
Oxidative damage to cells results in cross-linking of proteins, preventing them from performing their function in cells. Free radicals in the mitochondria, the powerhouses of your body cells, damage the cell membranes, making them unable to function as well.
Evidence for and against
It may seem that the attrition theory "makes sense" based on observations, but it's important to compare these opinions to what is scientifically known about the body and aging.
Under the microscope, there are some processes that support wear as a factor in aging, but some other findings question this process. There is evidence for and against this theory.
Corresponds to the common perception of aging.
It corresponds to the entropy law.
Many bodily processes slow down with age.
Cells are well equipped to repair damage.
Humans and other organisms are strengthened from youth to maturity.
Organisms vary widely throughout their lives, rather than all following the same pattern.
The wear and tear theory of aging is more in line with the perceived sense of aging. In fact, the term "aging" is used regardless of chronological age to describe the progressive deterioration of a person or object.
On a broad scale, the theory of wear fits perfectly with one of the fundamental laws of chemistry and physics, that of entropy. This law states that all systems tend towards a state of increasing entropy or progressive disorganization.
Visually, there are structural changes with age in human skin and bones. At the cellular level, there are a number of functions that decline with age. Even with a good diet, as we age, cells have a reduced ability to absorb nutrients.
The strongest evidence against the wear and tear theory is that bodies have a tremendous ability to repair damage. DNA is linked to DNA repair genes (such asTumorsuppressorgene) working to repair genetic damage.
Additionally, some studies have found that the aging process can be partially or fully reversed simply by changing the microenvironment of cells or certain hormonal factors.Of course, not all damage can be completely repaired and repair failures can accumulate over time.
Another argument against the attrition theory is that organisms become stronger as they grow. Rather than starting off at peak performance, like a car fresh off the assembly line or a new computer ready to start, living organisms often begin life fragile.
As they age, they develop strength and endurance. They can repair and replace most broken parts. Finally, there are some circumstances where wear and tear increases life expectancy.
Another argument arises from the biochemical nature of the body. Why does life expectancy vary so much between different animal species? Why do some whales live almost twice as long as humans?
Against Progressive Decay and Attrition: Why, after a long and vigorous swim upstream, do salmon spawn and then die, seemingly in optimal physical condition?
Conclusion on the causes of aging.
The question of why aging occurs goes back much further than Weisman's 19th-century theory. Shakespeare addressed aging in his "Seven Ages," and religious texts have done so for millennia.
Although the attrition theory initially seems more natural and makes more sense based on observation, it becomes clear that there is much more going on in the body that cannot be explained with this theory.
A more likely explanation, according to some researchers, is that the decline in function called "wear and tear" in the "wear and tear" theory is actually the result and not the cause of aging.Perhaps with a better understanding of genetics, there is better information on what exactly causes bodies to age.
What does that mean for you?
Regardless of which theory of aging is correct, or whether aging is instead the sum total of several of those theories, the real conclusion is that aging is universal. Certain lifestyle factors can delay someone's death to some degree and at the very least provide a much better quality of life.
A word from Verywell
Find ways to make healthy living fun. Gardening, eating, exercise, relationships - they all support the quality of life and can also increase it quantitatively.
frequently asked questions
Who invented the attrition theory?
The wear and tear theory was first proposed in 1882 by the German biologist Dr. August Weismann scientifically proposed.The burnout theory is deeply embedded in human thinking, and it's the theory you'll often voice in conversation and in culture.
Learn more:How fast do we age?
What is an example of the wear and tear theory of aging?
Some examples of your body's theory of wear and tear are wrinkles and other skin changes that accumulate over time, or arthritic joints that become stiffer and more painful with age. However, research into aging continues to seek answers as to why people age and die.
Learn more:Types of aging, causes and prevention.
What is the main difference between the wear and tear theory and the cell aging theory?
The theory of cellular aging is based on the idea of senescence, which is when cells lose the ability to reproduce and grow. It is a field of study that focuses on the era of molecular medicine that is generating new knowledge.Wear theory is more consistent with the view that bodies simply "break down" over time.
Learn more:Healthy aging: expert tips for a good life