Scientists discover key to a longer life (maybe)

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

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

If similar results are applied to humans then 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 in the online journal Science Express found some of the mice lived for an average of up to five and half months longer than they would normally. The scientists also found that the longest-lived mice were those with the highest levels of the catalase enzyme in the tiny powerhouses of the cell, called the mitochondria, thought to generate many free radicals.

Peter Rabinovitch, professor of pathology at the University of Washington in Seattle and leader of the study, said the findings supported the idea that the mitochondria are one of the key factors that influence the ageing process. "This study is very supportive of the free-radical theory of ageing," he said. "It shows the significance of free radicals, and of reactive oxygen species in particular, in the ageing process."

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

"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."