Boosting the body's levels of
natural antioxidants could be the key to a long life,
according to US scientists.
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.
Long life
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.
Free radicals
"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."
