Cells can actually stop replicating when telomeres become too short. This is known as "cell senescence", which is said to be the cellular equivalent to aging. This inability to stop replicating has the potential to cause numerous health problems; cancer being one of them. God designed the body in such a way to keep it in health by cells replicating and dying. If cells stop dying but keep replicating there is now an imbalance in the system because there are too many of one kind of cell. These groups of cells form tumors.
What Elizabeth Blackburn and her colleagues discovered is an enzyme, telomerase, that adds back DNA to the end caps as they wear down. They stated that the better your telomeres are protected, the less chance you have of getting any of the big diseases.
How to Stop the Erosion
Relax! Stress has been found to cause damage to the telomeres, and the more stress, the more the telomeres wear down. One of the best ways to eliminate stress is exercise! However, they found it is best to do a variety of exercises opposed to the same thing every day. The greater the variety of exercises, the better results.
"And Moses was an hundred and twenty years old when he died: his eye was not dim, nor his natural force abated." Deut. 34:7