SCIENTISTS MAY have discovered a way to slow the ageing process and extend life span. The US research is the first to conclusively show how a process inside cells has a direct role in how fast we age.
Scientists have known for decades that if you eat less you will live longer.
It works in many species from spiders to monkeys and some people are voluntarily reducing calorie intake by 25 per cent in the hope of extending life. How reducing calories achieves this has remained a complete mystery until now.
Scientists at the University of Wisconsin-Madison and the University of Tokyo have discovered a biochemical substance in cells known as Sirt3.
They found there is a direct connection between Sirt3 and the anti-ageing effects seen with low calorie intake.
It represented “the first clear evidence that [Sirt3] have anti-ageing effects in mammals”, Dr John Denu said.
He and colleagues at University of Wisconsin-Madison, including Dr Tomas Prolla, publish their findings this morning in the journal Cell.
The research helps explain the sequence of events inside the body that contribute to ageing. More importantly, it also provides a direct target for drug treatments that might slow ageing and contribute to better health in old age.
The scientists followed the Sirt3 pathway inside the cell and discovered it works on structures that act like power plants to deliver energy to help the cell do its job.
Like all power plants these structures also release a kind of pollution known as “free radicals”, forms of oxygen that cause damage and promote the effects of ageing.
The researchers showed that Sirt3 acts on the energy structures to reduce the free radicals, and so reduce damage.
Keeping calorie levels low causes the cell to make more Sirt3 and so improve the clearance of free radicals.
“This study is the first direct proof for a mechanism underlying the anti-ageing effects we observe under caloric restriction,” Dr Prolla said. They showed how the approach could work using mice that develop age-related hearing loss, much the same as in humans. Their hearing loss was prevented by reducing food intake.
The scientists also used cell cultures to show how Sirt3 could protect against cell stress and death caused by free radicals.
The goal now will be to find a drug that can boost Sirt3 production as a way to slow ageing.
The findings raise the prospect of adding years to the average human life span.