Mediterranean diet 'extends life'

Drinking red wine and cooking with olive oil may help us to live longer, say scientists.

They have found that key ingredients in both substances can significantly increase the lifespan of yeast.

Since yeast and humans share many genes, scientists have speculated they may have the same effect in people.

The findings provide more evidence to suggest that the Mediterranean diet may be the secret to living a long and healthy life.

Key molecule

The scientists, from Harvard Medical School and Biomol research laboratory in Philadelphia, have identified resveratrol as the key ingredient in red wine.

This molecule is abundant in red wine. It gives red wine its anti-cancer and anti-heart disease properties.

They have found that this molecule can influence genes that have been linked to lifespan in yeast.

The found that quercetin, which is abundant in olive oil, has a similar effect.

In particular, they affect those genes that have been shown to extend life as a result of a calorie-restricted diet by enabling cells to live longer.

In the case of resveratrol it was found to extend the life of some yeast cells by as much as 70%.

Previous studies have suggested that severe calorie restriction can increase the lifespan of organisms like yeast, fruit flies, worms and rats.

Scientists are trying to develop drugs that could have a similar impact on humans. The discovery that resveratrol and quercetin can increase the lifespan in yeast could boost those efforts.

"It is early days but we consider this to be a really striking breakthrough," Dr Konrad Howitz, one of the authors of the study, told BBC News Online.

"It certainly brings us closer to being able to intervene pharmacologically in humans to extend longevity."

The scientists found that resveratrol could increase the lifespan of yeast cells in a variety of doses.

However, similar tests on human cells showed that dosage is important.

"A very broad range of doses were very effective in yeast. However, it was different with human cells.

"There appeared to be a very narrow range at the low end. If doses were too high they appeared to have the opposite effect," said Dr Howitz.

The scientists are planning similar tests on other species, including mice, to see if the molecules can extend their life.

"I think it highlights the potential health benefits of the Mediterranean diet," he said.

The study is published in the journal Nature.

Figures from the European Union show that people living in Mediterranean countries like Spain and Italy can expect to live longer on average than people in other countries.

Average life expectancy in Spain is 75 for men and 83 for women. This compares to the UK, where men can expect to live until they are 75 but women can expect to live to 80.

In the US, average life expectancy is 74 for men and 80 for women.