The theory that shortening cell structures called telomeres play a key role in aging has received support from a finding that birds with longer telomeres also have a longer lifespan.
Telomeres cap chromosomes and in normal cells get shorter with each cell division. When they shorten enough, cells die.
Many researchers believe that this is one mechanism that accounts for aging and age-related diseases. Accordingly, companies such as Reno, Nevada-based Sierra Sciences are working on life extension interventions aimed at preventing telomere shortening.
Other companies, such as Menlo Park, California-based Geron, are working on telomere-inhibiting interventions aimed at fighting cancer cells, which produce an enzyme called telomerase that keeps telomeres long and cancer cells replicating indefinitely.