Age affects the ability to produce stem cells
The body produces more stem cells when you are young. Research shows us that the number of Mesenchymal Stem Cells in the bone marrow reduces rapidly with age (J Pathol 2009; 217:318-324). In a baby, the number of Mesenchymal Stem Cells in the bone marrow is 1 in 10,000. This falls to 1 in 1,000,000 by the time we reach the age of 70. The same applies to Menstrual Blood Stem Cells as well.
Age affects the fitness of stem cells
Fitness in stem cells refers to the capability of the cell to transform into various types of tissues/cells in the body - the basic function which makes stem cells so invaluable. The younger the cell, the higher their fitness and the greater their effectiveness in treatment.
Age affects the potency of stem cells
Potency in stem cells refers to the capability of the cell to replicate and multipy rapidly. This is vital for therapeutic uses. Younger cells have greater potency, hence are more useful, especially in multiple dosages.