Existing lines of inquiry into prolonging lifespan are based either on removing the Hayflick limit, which would have all sorts of untoward consequences, or suppressing production of the oxidative chemicals that are believed to cause much of the cellular damage which is bracketed together and labelled as senescence.

ECONOMIST: A way to counteract part of the process of growing old

Damage that occurs at the cellular or molecular level can disrupt the body's natural control processes and allow an uncontrolled growth of cells, or cancer.

WSJ: Radiation's Effect Depends on Amount

Much of the damage looks like the result of oxidation by free radicals (oxygen-rich compounds released during cellular energy production).

ECONOMIST: Disposing of dementia | The