Every person, regardless of health, loses stem cells over the course of their life. At birth, 1 in 10,000 of our body’s cells are stem cells. By age 16-18, only 1 in 100,000 cells are stem cells. By age 50, 1 in 400,000. Between age 70-80, only 1 in 2,000,000 cells are stem cells. These numbers could be even worse when you factor in circumstances such as the current health of the individual. What This Means: This means that your ability to use your own stem cells effectively in treating yourself decreases with age. The stem cells you will get from a younger donor will be much more concentrated than those you can get from yourself in virtually all cases. The fact that they come from an outside donor does not impact their effectiveness so long as they are the right kind of stem cells, containing MSCs described earlier, as they have the ability to differentiate into different cell types. For this reason, your body does not ‘reject’ stem cells as we think of a body rejecting an organ transplant if it doesn’t match perfectly.