Boosting the body's levels of natural antioxidants could be the key to a long life, according to US scientists.
Antioxidants might be the key to a long life
Mice engineered to produce high levels of an antioxidant enzyme lived 20% longer and had less heart and other age-related diseases, they found.
If the same is true in humans, people could live beyond 100 years.
The University of Washington work in Science Express backs the idea that high reactive oxygen molecules, called free-radicals, cause ageing.
Free-radicals have been linked with heart disease, cancer and other age-related diseases.
Dr Peter Rabinovitch and colleagues bred mice that over-expressed the enzyme catalase.
Catalase acts as an antioxidant by removing damaging hydrogen peroxide, which is a waste product of metabolism and is a source of free-radicals.
Free radical damage can lead to more flaws in the cell's chemical processes and more free radicals, making a vicious cycle.
Dr Rabinovitch said: "This study is very supportive of the free-radical theory of ageing.
"It shows the significance of free radicals, and of reactive oxygen species in particular, in the ageing process."
Dr Rabinovitch said the discovery could help could pave the way for future development of drugs or other treatments that protected the body from free radicals, and possibly some age-related conditions.
"People used to only focus on specific age-related diseases, because it was believed that the ageing process itself could not be affected.
"What we're realising now is that by intervening in the underlying ageing process, we may be able to produce very significant increases in health span, or healthy lifespan," he said.
Professor Pat Monaghan from the University of Glasgow, UK, said: "This is certainly a very interesting study.
"Making the leap from what is going on in the cell to what happens to the animal is difficult and often controversial since there are so many intervening steps.
"However, this study does seem to point to a direct link between mopping up free radicals at the cellular sites where they are generated and consequences for the lifespan of the whole animal.
But she added: "We are obviously a long way from downing catalase to gain eternal youth, and we need to know much more about what the consequences of high catalase levels would be for other aspects of the animal's life history.
"You rarely get something for nothing."