'Free radicals' hold the key to a longer life

Scientists have prolonged the lives of laboratory mice by 20 per cent using a technique that boosts natural antioxidants.

If similar results are applied to humans, it would mean average lifespans could be extended from the present 75 years or so to more than 100 years.

The findings demonstrate for the first time the important role damaging oxidising substances called "free radicals" play in the ageing process, the researchers said.

Free radicals are electrically charged, highly reactive substances produced as by-products of biological metabolism. They have been linked with heart disease, cancer and other age-related disorders.

The mice were genetically engineered to produce high levels of a human enzyme called catalase which destroys the chemical hydrogen peroxide, a rich source of free radicals in the cells of the body.

A study found some mice lived for an average of up to 5 1/2 months longer than normal. The longest-lived mice were those with the highest levels of the catalase enzyme, called the mitochondria, thought to generate many free radicals.

Peter Rabinovitch, professor of pathology at the University of Washington in Seattle, said the findings supported the idea that the mitochondria are one of the key factors that influence the ageing process.

Although it would not be possible to perform the same process on humans, the study has helped identify the chemical reactions in the body that protect against the damaging actions of free radicals. He said this could lead to new anti-ageing drugs.

- THE INDEPENDENT