Aging and How to Defeat It
Feedback
ShareAging is caused by the accumulation of damage in the human body. Aging damage eventually leads to age-related disease and ultimately death. Medical therapies designed to repair this damage could restore the body to a youthful and healthy state.
The Aging Process
The aging process is caused by the long-term accumulation of damage in the human body at the molecular and cellular level. This damage occurs as a side-effect of normal metabolism—the process that keeps the body alive from day to day. As aging damage accumulates in the body's molecular and cellular structures, it eventually leads to increasing frailty and disability due to age-related diseases such as cancer, diabetes, heart disease, Alzheimer's disease, and Parkinson's disease. This downward spiral caused by aging ultimately ends in death.
Two Ways To Fight Aging
There are two broad ways to fight aging: the traditional and engineering approach. The traditional approach seeks to slow the rate at which age-related diseases occur. One way to do this (called "gerontology") is to slow the rate at which metabolism lays down aging damage. Another way (called "geriatrics") is to slow the rate at which aging damage causes disease. Unfortunately, the traditional approach will always be a loosing battle, because merely slowing the rate at which aging damage causes disease will just postpone the suffering and death caused by aging by only a few years at most. The engineering approach (called "Strategies for Engineered Negligible Senescence" or "SENS") seeks to reverse aging by repairing the damage metabolism causes the body. By repairing this disease-causing damage, SENS would restore a chronologically old body to a biologically youthful state thus curing any age-related frailty and disease while also maintaining the body's youthfulness indefinitely.
The Human Body and Classic Cars
The human body is similar to complicated machines like cars. There are classic cars on the road today that came off the assembly line before our grandparents were born. Clearly, those cars would not be running if wear and tear damage was allowed to accumulate without periodic maintenance and repair. The human body is much more complicated than a car, and the human aging process is similarly more complicated. However, the process is the same in principle; the repair of aging damage should maintain the human body in a healthy state for an indefinite period of time just like maintenance and repair of cars can keep them running just as well as they did when they rolled off the assembly line.
Repairing The Damage
Dr. Aubrey de Grey was the first to compile a list of all the major types of aging damage and suggest that an engineering approach in the form of SENS could defeat aging entirely instead of merely postponing disease like the traditional approach. Currently, SENS is comprised of the following seven major types of medical therapies addressing seven major categories of aging damage:
| Aging Damage | Discovery | Age-Related Diseases | SENS Therapy |
|---|---|---|---|
| Cell loss This kind of damage consists of the loss of cells in different tissues of the body such as the brain, heart, and skeletal muscle. This cell loss eventually leads to tissue and organ dysfunction. |
1955 | Alzheimer's disease Heart disease Immune system dysfunction Muscle atrophy Parkinson's disease Skin aging |
RepleniSENS: Stem cells and tissue engineering This kind of therapy aims to replace lost cells and organs that are damaged beyond repair. This could be accomplished by injecting stem cells into tissues and replacing entire organs with ones grown outside the body using tissue engineering techniques. |
| Mutations in the cell's nucleus This kind of damage consists of mutations in the genes of the cell's nucleus. While most mutations aren't very harmful, some mutations lead to cancer. |
1959, 1982 | Cancer | OncoSENS: Development of cancer cures This kind of therapy would rely on true cures for cancer. This could be accomplished by several, potentially revolutionary approaches—from the removal of telomeres which cancer depends on to grow to the use of the body's own immune system to kill cancer. |
| Mutations in the cell's mitochondria This kind of damage consists of the accumulation of mutations in the 13 genes of mitochondria, the power plants of the cell, that—although present in a relatively small number (about 1%) of cells—generate free radical damage that spreads throughout the entire body. This free radical damage may lead to increased frailty. |
1972 | Specific diseases unknown (but causes body-wide, free radical damage that may lead to increased frailty) | MitoSENS: Mitigation of mitochondrial mutations This kind of therapy aims to mitigate mitochondrial mutations. This could be accomplished by copying the mitochondrion's 13 genes into the cell's better-protected nucleus where most mitochondrial DNA resides anyway, replacing the mitochondrion's mutated genes with new ones, or preventing cells with mutant mitochondria from spreading free radicals to the rest of the body. |
| Death-resistant cells This kind of damage consists of the accumulation of cells that don't die when they are supposed to and damage neighboring, healthy cells by secreting harmful substances. Death-resistant fat cells promote type II diabetes, other death-resistant cells promote the progression of cancer, and death-resistant immune cells impair the healthy functioning of the immune system. |
1965 | Cancer Diabetes, type II Heart disease (unconfirmed but possible) Immune system dysfunction Osteoporosis (unconfirmed but possible) |
ApoptoSENS: Elimination of death-resistant cells This kind of therapy aims to get rid of death-resistant cells. This could be accomplished by injecting substances that kill only the problem cells, using genetic engineering to cause unwanted cells to self-destruct, or stimulating the immune system to destroy the target cells. |
| Tissue stiffening This kind of damage consists of structural proteins outside of cells that stick together ("cross-link") instead of easily moving past each other to provide flexible support for such tissues as artery walls, eye lenses, and ligaments. These cross-linked proteins stiffen tissues like the artery wall leading to high blood pressure. |
1958, 1981 | Arthritis Atherosclerosis Cataracts Diabetes, type II Heart disease Kidney disease Skin aging |
RepleniSENS: Stem cells and tissue engineering This kind of therapy aims to replace lost cells and organs that are damaged beyond repair. This could be accomplished by injecting stem cells into tissues and replacing entire organs with ones grown outside the body using tissue engineering techniques. GlycoSENS: Breaking protein cross links This kind of therapy aims to break protein cross-links. This could be accomplished by developing specially-designed, cross link-breaking drugs, enzymes, or proteins. |
| Junk outside cells This kind of damage consists of the protein junk, amyloid, that accumulates outside cells and serves no useful biological purpose. The most well-known protein junk of this kind, beta-amyloid, is thought to be responsible for the development of Alzheimer's disease. |
1907 | Alzheimer's disease Diabetes, type II Heart failure (affects people over 110 years old) Multiple organ failure (possibly affects people over 110 years old) Stroke |
AmyloSENS: Clearing junk outside cells This kind of therapy aims to clear the protein junk, amyloid, that accumulates outside cells. This could be accomplished by using a vaccine to stimulate the immune system to digest this junk. |
| Junk inside cells This kind of damage consists of various kinds of junk that accumulate inside certain types of cells and can not be broken down by the lysosome, the cell's most powerful garbage disposal machinery. This junk eventually fills up the cell making it dysfunctional or even killing it. |
1959 | Alzheimer's disease Atherosclerosis Macular degeneration Parkinson's disease Skin aging |
LysoSENS: Clearing junk inside cells This kind of therapy aims to clear junk that accumulates inside cells. This could be accomplished by equipping the lysosome with new enzymes taken from soil bacteria that are capable of degrading this junk. |
We can be confident that this list of aging damage is complete, because scientists have not discovered any new kinds of damage in nearly a generation despite the fact that research into aging has been accelerating and that scientists have had ever-increasingly powerful tools with which to investigate the aging body. This implies that if there are other kinds of damage that we don't know about, they probably don't contribute as much to aging damage to make a difference.
Timeframes
SENS therapies first have to be fully developed and tested in mice before they can be adapted for human use. According to Dr. de Grey, with sufficient funding ($100 million per year for a decade) these therapies could be tested in mice within 10 years. After being successfully applied to mice, the therapies will be funded by the government and could take approximately 15 years to be adapted and tested for human use. Regardless of the accuracy of this forecast, it is clear that the sooner these therapies start to be developed the sooner aging will be defeated.
Further Resources
 |
|
| Dr. Aubrey de Grey's Ted Talk | Ending Aging by Dr. Aubrey de Grey and Michael Rae |