What is the secret to ageing more slowly and living longer? Over the years, we have learnt that coffee is good for us (or possibly bad), that sugar is evil and fat is good, that dark chocolate is good and pretty bad, that portly people are at risk (and more recently, that obesity isn’t as dangerous as we once thought).
And antioxidants? Bad, irredeemably bad, right? Er… perhaps not. As the folk at McGill University in the US tell it, many people believe that free radicals, the sometimes-toxic molecules produced by our bodies as we process oxygen, are the culprits behind the nasty phenomenon we call ageing. Yet a number of studies in recent years have produced evidence that the opposite may be true.
Now, researchers at McGill have taken this finding a step further by showing how free radicals promote longevity in an experimental model organism, the teensy roundworm called C. elegans. Surprisingly, the team discovered that free radicals – also known as oxidants – act on a molecular mechanism that, in other circumstances, tells a cell to kill itself.
Say the McGill scientists: “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.”
They found that this same mechanism, when stimulated in the right way by free radicals, actually reinforces the cell’s defences and increases its lifespan. Their findings are reported in a study published online in the journal Cell. “People believe that free radicals are damaging and cause ageing, but the so-called ‘free radical theory of ageing’ is incorrect,” says Siegfried Hekimi, a professor in McGill’s Department of Biology and senior author of the study.
“We have turned this theory on its head by proving that 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.” It seems futurist Ray Kurzweil, who foresees a time when humans merge with machines and apparently has every intention of living for a long, long time, may be on the right track…
Source: McGill University