It’s a well known fact that human lifespans have increased markedly over the last century. Even taking this into account, it’s still quite an accomplishment to live past the ripe old age of 100. But imagine not only living well past your 100th birthday, but also maintaining good health at such an advanced age. Hendrikje van Andel-Schipper managed to achieve both these milestones, reaching the age of 115 without suffering from chronic disease or cognitive decline. Over the last several years, researchers have attempted to unlock the secrets behind van Andel-Schipper’s long and healthy life.
Do Cells Hold the Answer?
At the time of her death in 2005, van Andel-Schipper was believed to be the world’s oldest living person. In addition, she also claimed the honor as the longest-living person in the history of the Netherlands. Towards the end of her life, van Andel-Schipper agreed to allow medical science to study her body following her passing. In April 2014, nearly nine years since her death, researchers published a report on van Andel-Schipper’s nearly unrivaled longevity.
Appearing in the journal Genome Research, the study based its conclusions on a collection of blood and tissue samples. Using this approach, the researchers unearthed some notable facts regarding the cellular activity inside the centenarian’s body. In the years immediately prior to her 2005 death, just two stem cells produced the bulk of van Andel-Schipper’s white blood cells.
Because of this finding, researchers concluded that most of the 115-year old’s stem cells had ceased to function or exist. To put this in proper perspective, the average body has roughly 20,000 blood stem cells at birth. Furthermore, the body uses about 1,300 such cells at any given time to maintain its supply of blood.
Aging had also altered appearance of van Andel-Schipper’s white blood cells. In younger individuals, these cells have relatively long telomeres, or segments of DNA attached to the end of chromosomes. Previous studies have found that the length of these structures diminishes greatly over time. In van Andel-Schipper’s body, the white blood cells’ telomeres had eroded considerably, to the point that they were 17 times shorter than the telomeres in her brain cells.
Importance of the Study
The steep decline in the number of stem cells, along with the white blood cells’ deteriorating condition, lends credence to the “stem cell exhaustion” theory of aging. This theory contends that the body starts to age when cells lose their ability to reproduce through division. The reason for this development involves the length of the cells’ telomeres, which get shorter each time a cell divides.
In the human body, cells go through a total of roughly fifty divisions. After this point, the telomeres become too short to allow for further reproduction. Once cells have reached the end of the line and can no longer divide, they begin to die off from “division exhaustion.” As a result, the number of cells in the body steadily decreases with age, rendering it less able to repair damaged tissues and fend off disease.
If the cell exhaustion theory of aging is correct, one very interesting possibility comes to mind: could injections of youthful stem cells prolong the human lifespan? Though such a notion might seem far-fetched, some researchers consider it an idea well worth exploring. In the meantime, the research team plans to further study van Andel-Schipper’s genetic data. It is hoped that these efforts will yield clues as to body’s defenses against Alzheimer’s.