Toronto: This may come as a real shock to you. Free radicals - also known as oxidants produced by our bodies as we process oxygen - act on a molecular mechanism that, in other circumstances, tells a cell to kill itself!
In other words, free radicals actually promote longevity, research says.
“People believe that free radicals are damaging and cause ageing but the so-called 'free radical theory of ageing' is incorrect,” claimed Siegfried Hekimi, a professor in at Canada-based McGill University's department of biology.
“Free radical production increases during ageing because free radicals actually combat - not cause - ageing. In fact, in our model organism, we can elevate free radical generation and thus induce a substantially longer life,” Hekimi explained.
Programmed cell death, or apoptosis, is a process by which damaged cells commit suicide in a variety of situations: to avoid becoming cancerous, to avoid inducing auto-immune disease, or to kill off viruses that have invaded the cell.
The main molecular mechanism by which this happens is well conserved in all animals, but was first discovered in C. elegans - a discovery that resulted in a Nobel Prize.
The McGill researchers found that this same mechanism, when stimulated in the right way by free radicals, actually reinforces the cell's defenses and increases its lifespan.
It also means that apoptosis signaling can be used to stimulate mechanisms that slow down ageing, researchers noted in a study published in the journal Cell.