Anti-oxidants not anti-ageing

Anti-oxidants don't slow down the effects of ageing, according to a new study published in the journal Genes and Development.

Researchers at the Institute of Healthy Ageing, University College London questioned the theory that excess 'superoxide' free radicals increase the effect and speed of the ageing process. Free radicals are unbalanced oxygen molecules produced naturally in the body and are believed to damage tissue.^1,2

The researchers modified key genes involved in removing excess superoxide free radicals in the worm Caenorhabditis elegans. They found that the gene changes didn't affect the worms' lifespan.

Caenorhabditis elegans is often used in genetic research into ageing because it has a similar genetic structure to more complex organisms, and is easy to control and change.

"The results of this study challenge the popular belief that superoxides are a key factor in ageing and mopping them up is beneficial," said Dr Christine Bennett, Bupa Australia's Chief Medical Officer.

Researchers in the 1950's suggested that damage done by too many free radicals in the body was responsible for ageing. Since then a number of papers have been published in support of this theory and it has remained unchallenged for over 50 years. However, this new study has questioned the theory.

A recent Cochrane review, published in April 2008, looked at the results from 67 studies into anti-oxidant supplements and mortality. This independent review found no evidence to suggest that anti-oxidant supplements such as vitamin A, C and E, selenium and beta-carotene can decrease mortality.³

These new findings, combined with the Cochrane review, support a new argument that anti-oxidants in food may not be the quick fix many people are looking for.

Key facts:

There is not a compelling body of evidence to suggest antioxidants decrease mortality or slow ageing.
People who take supplements should consider why they do.
Anti-oxidants can be found naturally in tea, citrus fruits, leafy greens, broccoli, mangoes, pumpkin, berries, among other foods.
Eating a balanced, healthy diet can reduce the risk of developing heart disease, cancer and type 2 diabetes.
A healthy, balanced diet should provide all the vitamins and minerals your body needs. Speak to your doctor or a registered dietitian for advice if you think you are not getting enough vitamins and minerals to support your health.⁴

Sources:

Doonan, R. et al. Against the oxidative damage theory of aging: superoxide dismutases protect against oxidative stress but have little or no effect on life span in Caenorhabditis elegans. Genes & Development 2008.
Online medical dictionary: free radicals
Bjelakovic G et al. Anti-oxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database of Systematic Reviews 2008, Issue 2. Art. No.: CD007176. DOI: 10.1002/14651858.CD007176.
Anti-oxidants and cancer prevention: Better Health Channel, Victorian Government

Review date: 04-01-2010