The "ageing is optional" era gained cachet in 2003 by Harvard scientists who (prematurely) claimed they had found the holy grail of ageing, the Sirtuin1 gene, and that a molecular mimic of calorie-restricted diets, resveratrol, might target that gene and produce profound longevity.

More intriguing was the fact resveratrol is concentrated in red wine. It could explain the French paradox — the fact the French eat high-fat, high-calorie diets yet remain slender and have 30 per cent fewer heart attacks than Americans.

Resveratrol was off to a scientific flying start, extending the life of yeast cells, fruit flies, roundworms, fresh-water fish and even fat-engorged mice.

But more recent research has been disappointing — one study showed over-activation of the Sirtuin1 gene induced heart failure among rodents.

The whole idea of targeting a single gene is now coming into question. The magic of red wine might be in its combination of polyphenolic molecules — resveratrol, quercetin, catechin, ferulic acid, galic acid, kaempferol. In a 2008 experiment, mice were placed on a limited-calorie diet or a standard-calorie diet with added resveratrol, or a matrix of natural molecules like those found in red wine.

The limited-calorie diet exerted significant influence over 198 genes: the resveratrol-fed diet differentiated 225 genes; the matrix diet 1,711 genes. It was the first experiment of its kind to show synergistic biological action — nine-fold greater than plain resveratrol at a dose of resveratrol that was 17 to 320 times lower than that used in prior studies.

Roger Corder, professor of experimental therapeutics at the William Harvey Research Institute of London and author of The Red Wine Diet, says it is the combination of polyphenolic molecules in red wine, about 60mg per glass, about three to five glasses per day (180-300mg of polyphenols), that produces wine's beneficial health effects. Larger doses may not be beneficial and may even induce enaemia and other side effects. Look for research with combination polyphenols to boom in 2009.