Expert: Walter Hintz - 2/10/2006

Question
What causes people to age ? What is the "biological clock"?

Answer
Hi Pam
The aging process seems inevitible and is still mysterious.  We believe that individual cells are basically immortal in that they eventually reproduce rather than die when by thenmselves but when in tissues and organs they age and are replaced by new cells. They simply "wear out". The destruction of old cells is called apoptosis.
 The body is composed of organs and these organs eventually were out when cellular divisions slow down.
 Recent studies point to chemical changes with the increase in free radicals in body cells which act as oxidents that play a role in aging cells.
As to the biological clocks.  The body is attuned to something called a circadian rhythm that controls body activity and hormonal secretions. Metabolism is based upon a 24 hour cycle.