Are people genetically programmed to live a certain number of years?  Can lifestyle overcome genetics when it comes to longevity?  Is it possible to not only live longer but live better?

As the number of senior citizens in the United Stated rapidly increases, so too does our level of angst over what the future holds. The first of the baby boomers are turning 60 this year and, in true baby boomer fashion, they expect to live longer and be less disabled than previous generations.  Some of those expectations are being shaken, though, as their sense of immortality is assaulted by changes they observe in their friends and in themselves.  Could baby boomers, once credited with creating a "youth revolution," create a "longevity revolution?"

Past increases in life expectancy have come from preventing early death.  Prior to 1950, the strongest statistical effect was caused by reduction in infant mortality with lesser contributions from progress in nutrition and medicine.  Since 1950, improvements to life expectancy have largely been due to saving lives after age sixty-five with interventions aimed at heart and infectious diseases.   

The view that humans have a finite life expectancy is hotly debated.  But, at least for now, most scientists believe that if everybody adopted a healthy lifestyle and medical advances in prevention, early detection and treatment of disease continue at their present pace, we could achieve an average life expectancy of 85 or 90.  They stress that we need to fully understand why we age and why we die before we can determine if there's a limit to the maximum number of years that a human can live and, if so, what that limit might be.  The real question, of course, is if we can extend a healthy, active and independent span of life.  When asked, most people have no desire for extra years that include disability and suffering. 

There's reason to be optimistic.  Scientists are beginning to understand:

• The mechanisms behind cancer, how to prevent it, and how to cure it
• The causes of dementia and Alzheimer's disease 
• How to regenerate blood vessels in heart tissue
• The underlying processes of aging itself 

Researchers have discovered a number of ways to slow aging in creatures as different as yeast and mice.  Most believe it's possible that there could be major breakthroughs that enable people to live a lot longer – and a lot better – within just a few decades.