There is already much evidence to suggest that a diet with plenty of antioxidant-rich vegetables protects against age-related diseases but there is less evidence to support the benefits of single antioxidants against ageing and disease.
Writing in the 5 May online edition of Science(10.1126/science.1106653), Dr Peter Rabinovitch and colleagues at the University of Washington School of Medicine said they helped show free radicals can damage cells and DNA.
The researchers genetically engineered mice to produce extra amounts of catalase. The enzyme acts as an antioxidant by breaking down hydrogen peroxide, which is a waste product of metabolism and thought to be a source of free radicals.
The mice were designed to produce extra catalase in certain areas of the body, including the mitochondria, a cell's powerhouse. Cellualar damage in the GM mice was significantly lower than in control mice and they also had healthier heart muscle tissue, indicating the catalase helped protect from age-related heart problems seen in normal mice.
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."
"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 realizing now is that by intervening in the underlying ageing process, we may be able to produce very significant increases in 'healthspan,' or healthy lifespan," he added.