Antibiotic drugs, better sanitation, better nutrition and improved safety have all helped reduce the number of people who die young, thereby increasing average life expectancy. The effort represents a fundamental shift in how some scientists approach anti-aging research. Klatz cites Viagra, the impotence drug, as an example of an anti-aging treatment and says many more will come out of biotechnology laboratories in the years ahead. One of the most promising lines of research is into a part of the human cell called a telomere. A telomere is a kind of cap that forms around the chromosomes in cells, protecting those chromosomes from damage, especially when the cell reproduces.
Research shows that every time the cell divides, the telomeres get a little shorter.
Eventually, when the telomeres reach a certain critical length, the cell no longer can divide properly. Somehow, the cell recognizes this and begins to self-destruct. This limit on the number of times human cells can divide has been known for nearly four decades. But it is only in the past year that scientists for Geron Corp. and at the University of Texas Southwestern Medical Center have discovered a way to short-circuit that process. We don't know whether that's what really limits our life span.