You’d all like to be remembered with beautiful and tasteful photographs of youthful days. Though you’re living longer lives, it’s clear that you’re not happy with the effects of ageing. You don’t seem to care that wrinkles are merely indicators of past smiles. Anti-aging cosmetic products have become an industry and the products are freely available across the counter. Makers of anti-aging creams claim to give you a face several decades younger by firming up the skin that has sagged, eliminating the spots that have formed and leaving you with a rejuvenated glow.
Writing in the journal Nature, scientists from France, Germany, Hungary, the United Kingdom and the United States present evidence showing that proteins believed to significantly increase lifespan in a number of organisms do not in fact affect animal longevity.
The gene that produces this protein, called sirtuin, is often what anti-ageing creams claim to target. Many in the beauty industry believe that sirtuin, often dubbed the ‘longevity gene’ is activated by resveratrol – a plant derived drug found at trace levels in red wine. But research has shown that this belief is ill-founded.
Sirtuins had previously been linked to ageing and longevity in yeast, the nematode worm and the fruit fly, organisms commonly used as models for the biology of human aging. Researchers had shown that when the organism’s genes overproduced sirtuin, its lifespan was significantly extended. In the nematode worms this was sometimes by as much as 50%.
This study provides almost conclusive evidence that the effects on animal longevity seen in earlier experiments were not in fact connected to sirtuin.
Precautions were taken to ensure that the only difference between control and test worms was the elevation of sirtuin levels, they found that the longevity disappeared. This implied that some other genetic factors must have caused the longevity initially seen. In one of the two original strains, they identified this as a mutation in a gene involved in the development of nerve cells.
Dr Gems comments: ‘These results are very surprising. 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 aging.’
The team also examined a transgenic version of the fruit fly, Drosophila melanogaster, in which the sirtuin levels were raised. This transgenic model had been the subject of earlier research which appeared to show that over activation of sirtuins in the fruit fly increased longevity.
The team was able to prove that genetic factors other than sirtuins genes were the real cause of the longevity.