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An ingredient of red wine extends lifespan by up to 70% - in yeast1. The compound seems to mimic the age-enhancing effects of calorie restriction on the single-celled organism. Capitalizing on the chemical, called resveratrol, is a long way off in humans, says David Sinclair of Harvard Medical School in Boston, Massachusetts, who led the research. To match the yeast doses, he says, humans would need to drink a glass of their favourite vintage morning, noon and night. But the research may help explain why red-quaffing Mediterraneans live to a ripe old age. Resveratrol boosts levels of an enzyme called Sir2, which is thought to extend lifespan by stabilizing DNA. "It's highly plausible that boosting enzyme activity will slow functional decline in old age," agrees Peter Piper, who studies ageing at University College London.

Resveratrol is one of a group of chemicals called polyphenols. Previous research has suggested that these can protect against heart disease and osteoporosis in humans. "It may not be just a longer life - it may also be a healthier one," says Sinclair.

The compound is one of 17 plant molecules so far found to extend life in baker's yeast (Saccharomyces cerevisiae). Resveratrol also gives fruitflies, which typically live for around a month, an extra ten days of life, says Sinclair. Studies on mice are in the pipeline.

Sinclair gave his yeast fresh grape extract. Normally, the organism divides around 25 times and then dies. Resveratrol-treated yeast underwent an extra 15 replications.

Many polyphenols are also found in tea, fruit and vegetables, says Piper. "It stresses the importance of eating a healthy, balanced diet," he says. Pharmacologists are also developing a stable, slow-release resveratrol pill.

References
Howitz, K. T. Small molecule activators of sirtuins extend Saccharamyces cerevisiae lifespan. Nature, published online, doi:10.1038/nature01960 (2003).

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