- Stem cells give rise to the cells that build up our tissues. For example, mesenchymal stem cells generate bone cells, fat cells and fibrous tissue cells. Liver stem cells build liver cells. Hematopoietic stem cells produce white blood cells and red blood cells.
- During aging, stem cells become dysfunctional or die off.
- This leads to our tissues being less replenished and maintained.
- Stem cells decline because of epigenetic changes, DNA damage, telomere shortening, protein accumulation, mitochondrial dysfunction and other aging mechanisms. These mechanisms damage and age the stem cells.
- Specific natural substances can improve stem cell health.
THE ROLE OF STEM CELLS IN AGING
Stem cells are rare cells, scattered around in the body, that produce new, differentiated cells.
Hematopoietic stem cells in the bone marrow create white and red blood cells, mesenchymal stem cells produce fat cells, bone cells, cartilage cells and connective tissue cells, liver stem cells generate liver cells, satellite stem cells maintain and create new muscle cells, and so on.
Stem cells are very important, and very powerful. In fact, your whole body was created out of one super stem cell, namely the fertilized egg cell that nestled itself in the womb of your mother.
Our body is continuously rebuilt and replenished with new cells that derive from stem cells.
The Aging Process
When we get older, our stem cells become dysfunctional or they die off. This leads to our tissues being far less replenished with new, healthy cells.
Additionally, during aging, some dysfunctional stem cells take over the existing stem cell pool. These stem cells are dysfunctional because they do not maintain the tissues properly, but they reproduce faster than the normal stem cells, outcompeting them (this process is called “clonal expansion”).
When stem cell function declines, this leads to far less healthy cells to replenish and build up our organs. Also, when our cells are less replaced with newer, healthy cells, this leads to further accumulation of damaged cells.
Processes that lead to this decline in stem cells are fundamental aging processes, like epigenetic alterations, mitochondrial dysfunction, decline in proteostasis, DNA damage, and other forms of damage in the stem cells.
Also, changes in the environment in which the stem cells reside, such as an increase in circulating inflammatory substances, also contributes to a decline in stem cell function.