Dementia is a term used to describe the brain-wasting effects of diseases such as Alzheimer’s. Currently, any diagnosis with an end result of dementia is effectively a slow death sentence. Typically, these diseases begin with a deterioration in short term memory and end with a complete loss of mental function, so severe in many cases that simple tasks such as using the restroom become impossible. However, there is hope that a treatment for dementia could be developed. Advances using adult stem cells as the basis for regenerative treatments are beginning to show great promise. An obvious prerequisite for effectively researching and developing treatments using stem cells is getting access to a sufficiently large quantity of them in the first place. One such resource-rich reservoir of adult stem cells is dental pulp, which is found inside of all healthy teeth. Teeth-derived stem cells may someday play a role in changing a dementia diagnosis from an automatic death sentence into a treatable disease.
When George W. Bush was president, he placed severe restrictions on the use of government funding for research on embryonic stem cells. Regardless of one’s opinion on the moral issues surrounding embryonic stem cells, this policy stance and the limelight it placed on the term “stem cell” did the United States a huge disservice by mis-educating the public at large on what a stem cell actually is. Because at the time, nearly all research being done in the stem cell field was with embryonic stem cells, the media and the public at large began associating the words “stem cell” exclusively with embryos. This is akin to saying that “because football fields are made with grass, the only place you will find grass is on a football field.” Worse, it put a bad taste in many people’s mouths about stem cells in general, when they are actually one of the most promising avenues for developing treatments and cures for nearly all diseases.
A stem cell is essentially a manufacturing facility whose product is a variety of different types of cells. Hundreds of millions of stem cells in every human body are making new blood cells, new lung cells, new brain cells and every other type of cell in the body all day long. At a high level, there are two distinct types of stem cells: embryonic and adult. Embryonic stem cells are capable of turning into every type of cell in the body.
This makes sense, because embryos turn into humans. Adult stem cells, on the other hand, are more limited in the variety of cells they can manufacture. Scientists started researching embryonic stem cells first because it was intuitive to them that being able to differentiate into any cell type (rather than a specific list of cell types) should make them more useful in treatments. What they have learned in the past 10 years, however, is that the opposite is true. Because embryonic stem cells can turn into anything, they are hard to control. The inability to control stem cells is very dangerous because out-of-control cell replication is the textbook definition of cancer. Adult stem cells are much easier to control, and scientists are making advances on an almost daily basis with respect to their ability to coax adult stem cells into manufacturing a specifically-desired cell type.
There are two primary types of adult stem cells: hematopoietic stem cells and mesenchymal stem cells. Hematopoietic stem cells are blood stem cells. They are responsible for differentiating into any other type of blood cell (white, red or dendritic). Mesenchymal stem cells are responsible for replenishing any type of soft or hard tissue in the body (cartilage, bone or muscle).
A stem cell’s ability to turn into numerous types of other cells makes them an obvious place for scientists to look for treatments and cures. When a person contracts a disease such as Alzheimer’s or cancer, what has occurred at a structural level is that the cells in that location of the body are either damaged or are replicating improperly. Both issues can theoretically be solved by coaxing adult stem cells to healthily replicate into the desired cell type, and then either replace or overwhelm the damaged cells. Teeth are home to mesenchymal stem cells – the kind of cell responsible for replenishing the same type of tissue damaged by dementia – and they are currently being researched as potential weapons to combat numerous diseases that were previously guaranteed death sentences.
The U.S. government’s clinical trials website lists more than 4,000 studies involving adult stem cells. These studies represent billions of dollars of investment, and tens of thousands of researchers all over the world trying to figure out how to make use of these incredibly powerful manufacturing facilities. While the future continues to brighten, scientists are still just breaching the surface of adult stem cells’ potential. Today, the most common way in which adult stem cells are used is to treat blood and immune system diseases such as leukemia, and to help people rebuild their immune systems after chemotherapy has torn them down. There are around 50,000 treatments every year worldwide, and almost all of them are using blood stem cells.
Blood stem cells can be found in bone marrow, and because many of the qualities of bone marrow have been understood for decades, infrastructure for collecting bone marrow from donors has been developed. Much more research has been conducted into uses for blood stem cells than has been conducted using mesenchymal stem cells. However, interest in mesenchymal stem cells has been experiencing exponential growth. During the year 2000, there were no studies looking into mesenchymal stem cells. Between 2001 and 2009, there were only 28. Currently, there are over 400, including five studies focusing on dementia and eight studies specifically for Alzheimer’s.
Because of the vast promise of stem cell-related treatments, parents worldwide have started to store their children’s stem cells when they are born. When a child is born, the blood from the umbilical cord contains blood stem cells, and the cord tissue itself contains mesenchymal stem cells. By cryogenically freezing these stem cells at birth, parents ensure that their children will have access to these cells if they ever need them for treatments in the future. An added benefit of storing them when a child is born is that the cells are as healthy as they will ever be, and they will not age in cryogenic stasis. If the child grows up and develops cancer as an old man, or if he needs a heart transplant and wants to use his own stem cells to grow tissue around a 3D printed heart, he will have his own uncorrupted pre-disease state cells.
While it is doubtful that stem cells from a 20-year-old body are much less valuable than stem cells from a 10-year-old body, what is known is that stem cells collected when the body is in a pre-disease state are much more useful than stem cells collected after the body has already become sick. People need to collect their stem cells before being diagnosed with a disease such as Alzheimer’s, other forms of dementia, heart disease or cancer, but that does not mean that people who have not already done so are out of luck.
Thanks to companies such as Vault Stem Cell, which works with oral surgeons (the primary extractors of wisdom teeth – 10 million of which are removed from U.S. citizens annually), any patient who is having a healthy tooth extracted is given a second chance to collect their stem cells. For anyone who still has healthy teeth, a second chance exists to capture this valuable resource. The ability to bank stem cells from teeth has numerous potentially game-changing benefits. The sheer volume of teeth extractions coupled with a much lower price point (about half the cost of cord blood banking) combine to dramatically increase the size of the stem cell banking market. This in turn will lower the cost of setting up a public adult stem cell bank, similar to the bone marrow and blood banks that exist now. Lastly, an expanded supply will serve to lower the cost of researching treatments that use adult stem cells, thereby increasing investment. Teeth, it seems, may just end up playing a role in serving dementia its own death sentence.
Commentary by Benjamin A. Buchanan