When it comes to our genes, it may be that less does in fact mean more.

Researchers have discovered 238 genes - 119 of which are found in mammalian cells - that when removed from living cells can extend their lifespan.

They say the findings could help identify new ways of improving human health.

Surprisingly, deleting segments of DNA (illustrated) that code for key genes can actually increase the lifespan of cells, researchers have discovered. They hope the findings will lead to new ways of improving human health

The study has also helped scientists to identify 189 genes that were previously not known to play a role in aging.

In some cases deleting a single gene could have a 'significant' effect on the longevity of a cell.

If this could be translated into new drugs, for example, it could allow humans to live for far longer, healthier lives.

IS 3.5 MILLION YEAR OLD BACTERIA THE KEY TO ETERNAL LIFE? A controversial Russian scientist has injected himself with a 3.5 million year old 'eternal life' bacteria fund in the Siberian permafrost - and says he is now stronger and never gets ill. Anatoli Brouchkov, head of the Geocryology Department at Moscow State University, says he has not had flu for two years following his injection. The bacteria,named Bacillus F, has remained alive in permafrost for millions of years. Scientists have tested it on mice and human blood cells, but Brouchkov says he decided to become a guinea pig for the experiment. 'I started to work longer, I've never had a flu for the last two years,' he told The Siberian Times 'After successful experiments on mice and fruit flies, I thought it would be interesting to try the inactivated bacterial culture,' . The bacteria is actually in trace amounts in the water of the region, he claims. Advertisement

Dr Brian Kennedy, a biochemist at the Buck Institute for Research on Aging in Novato, California, said: 'This study looks at aging in the context of the whole genome and gives us a more complete picture of what aging is.

'It also sets up a framework to define the entire network that influences aging in this organism.'

The research team, which also included scientists from the University of Washington, tested the impact of deleting 4,698 individual genes in a strain of yeast called Saccharomyces cerevisiae.

They found 238 of these seemed to improve the lifespan of the yeast cells.

Around half of the genes, however, are also found in mammals.

Yeast typically has around 6,275 genes in its genome while the human genome contains around 21,000 genes.

In one example, deleting a gene called LOS1 was found to be particularly effective at extending the lifespan of the cells.

This gene is known to help transport genetic information called tRNA, which are involved in helping to build proteins in the cells.

It is also influenced by a master switch called mTOR, which has long been associated with longer lifespans in animals with restricted calorie diets.

LOS1 in turn influences another gene called Gcn4, which helps to govern the repair of DNA damage.

The researchers deleted 4,698 individual genes from yeast cells and looked at the effect each had on lifespan. They found removing 238 actually extended the life of the cells. A gel showing a sequence of DNA is pictured

Dr Kennedy said: 'Calorie restriction has been known to extend lifespan for a long time.

'The DNA damage response is linked to aging as well. LOS1 may be connecting these different processes.'

However the research is only part of a larger body of work to map the relationships between all the genes that govern aging in cells.

If scientists are able to identify the genetic pathways involved in aging, they may also be able to find drugs or therapies that can help extend healthy lifespans.

Dr Kennedy said: 'Almost half of the genes we found that affect aging are conserved in mammals.

'In theory, any of these factors could be therapeutic targets to extend healthspan. What we have to do now is figure out which ones are amenable to targeting.'