A gene that scientists say could deliver the fountain of youth may be just a bucket of water, according to research published Wednesday.

Researchers previously identified life-extending genes that produce sirtuins, found in everything from yeast to humans. The more sirtuin that yeast, worms and mice produce, the longer the critters lived researchers found over the past decade. Further studies found that an animal's age span could be increased through calorie restriction - a process mediated through sirtuin. Researchers also found that an ingredient in red wine, resveratrol, could activate sirtuin proteins, promising for anti-ageing creams.

However, research published Wednesday in Nature found that the original 2001 studies on life extension could not be replicated with different strains of worms or fruit flies, commonly used as model organisms

These results are very surprising, said David Gems, biologist at the Institute of Healthy Ageing at the University College London and lead researcher of the study. We have re-examined the key experiments linking sirtuin with longevity in animals and none seem to stand up to close scrutiny. Sirtuins, far from being a key to longevity appear to have nothing to do with extending life. But I think this is good news in a way: after all, revising old ideas can be as important as presenting new ones to assure scientific progress. This work should help to redirect scientific efforts toward those processes that really do control ageing.

However, some scientists in the field said that the new study was faulty given that in the past 10 years, over 3,000 papers published on the protein found a life-expansive connection.

They're wrong, in a word, said Leonard Guarente, biology professor at MIT whose lab first linked sirtuins with longevity in animals.

As far as sirtuins as targets for drug development, they're great and I don't think this new paper does anything to dampen that, said Guarente who published a counter study in Wednesday's issue of Nature defending the original research.

In a seminal 2001 paper, Guarente's lab showed that ramping up production of sirtuins in worms increased their life span. The problem was that the worm strains had a mutation that affected life expansion.

Mea culpa, we did have a problem with one of our strains in our 2001 paper, Guarente told International Business Times. We addressed that in our new paper.

The issue isn't just technical - millions of dollars are potentially at stake. For example, GlaxoSmithKline pharmaceutical giant bought the sirtuin-based biotech start up Sirtris Pharmaceuticals for $720 million in 2008.

The anti-ageing market is expected to grow to $292 billion by 2015, according to data from Global Industry Analysts, a marketing research firm based out of San Jose, Calif.

Glaxosmithkline London Medicine Aging