'Longevity gene' may be dead end: study

Research over the last decade showing that proteins called sirtuins can increase lifespan is deeply flawed, according to a new study in Nature that debunks prior claims of a direct causal link.

Pioneering experiments on earthworms and fruitflies - commonly used as models to examine the biology of human ageing - suggested that an extra dose of the naturally-occurring enzymes could prolong life by up to 50 percent.

These early results unleashed a flood of new research, much of which backed up the original findings.

They also spawned a flourishing market in dubious health products claiming to boost sirtuins, and thus slow down one's biological clock.

Many contained resveratrol, a molecule - also found in red wine - thought to activate the enzyme.

But the new research, led by David Gems at the Institute of Healthy Ageing at the University College London, provides solid evidence that the supposed cause-and-effect relationship between the proteins and longer life is a mirage.

Gems and colleagues reproduced benchmark studies to test whether the links might be attributable to other factors besides the allegedly miracle gene, known as Sir2 in worms and flies, and SIRT1 in mammals.

"We have re-examined the key experiments linking sirtuin with longevity in animals and none seem to stand up to close scrutiny," Gem said in statement.

"Sirtuins, far from being a key to longevity, appear to have nothing to do with extending life."

The main problem with most of these earlier experiments was the failure to account for all the possible differences between genetically manipulated organisms and the "wild" ones against which they compared.

For nematode worms, for example, once precautions were taken to ensure that the only difference between normal and test animals was the higher sirtuin levels, the added lifespan disappeared.

It turned out that other mutations had occurred but escaped notice.

Leonard Guarante of MIT, who conducted some of these pathbreaking studies, acknowledged in a "brief communication," also published in Nature, that his earlier work had been flawed.

Gem and colleagues then reproduced similar experiments done with fruit flies, again showing that the results attributed to sirtuins were in fact due to other genetic drivers.

The researchers also created synthetic fruitfly sirtuin to see if it could be activated by resveratrol, as previously claimed. But neither of two separate laboratories, using multiple techniques, could make it work.

Finally, the study refutes the claim that enhanced lifespan due to dietary restriction - itself not in doubt - also depended on sirtuins.

"Studies on yeast lifespan were the first to cast doubt on the role of sirtuins in longevity," note Carles Canto and Johan Auwerx from the Ecole Polytechnique Federale de Lausanne.

The new study "puts a final nail in the coffin," they wrote in a commentary, also in Nature.

But even if sirtuins are not the long hoped-for life-prolonging elixir, they may still confer important health benefits, they added.

Whether directly or indirectly, the protein has been shown to protect mammals - notably mice - from the metabolic damage caused by high-fat diets and age-related diseases.

"SIRT1 activation remains a promising approach to delaying general age-related physiological decline and to treating numerous inherited and acquired diseases," they argue.

The protein may not cause an otherwise healthy animal live longer, in other words, but it could help one who over-eats to reduce related stress on its system.

mh/pvh

 

News
people
Arts and Entertainment
Armstrong, left, and Bain's writing credits include Peep Show, Fresh Meat, and The Old Guys
TVThe pair have presented their view of 21st-century foibles in shows such as Peep Show and Fresh Meat
Arts and Entertainment
Keys to success: Andrew and Julian Lloyd Webber
arts + entsMrs Bach had too many kids to write the great man's music, says Julian Lloyd Webber
Sport
footballMan City manager would have loved to have signed Argentine
PROMOTED VIDEO
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
News
people
News
i100
Arts and Entertainment
Hand out press photograph/film still from the movie Mad Max Fury Road (Downloaded from the Warner Bro's media site/Jasin Boland/© 2014 Warner Bros. Entertainment Inc.)
films'You have to try everything and it’s all a process of elimination, but ultimately you find your path'
Arts and Entertainment
Imelda Staunton as Dolores Umbridge in the Harry Potter films
books

New essay by JK Rowling went live on Pottermore site on Friday

News
people

Top Gear presenter is no stranger to foot-in-mouth controversy

News
Russia Today’s new UK channel began broadcasting yesterday. Discussions so far have included why Britons see Russia as ‘the bad guy’
news

New UK station Russia Today gives a very bizarre view of Britain

Arts and Entertainment
Keira Knightley and Benedict Cumberbatch at the premiere of The Imitation Game at the BFI London Film Festival
filmsKeira Knightley tried to miss The Imitation Game premiere to watch Bake Off
News
i100
Sport
Enner Valencia
footballStriker has enjoyed a rapid rise to fame via winning the title with ‘The Blue Ballet’ in Ecuador
Arts and Entertainment
A top literary agent has compared online giant Amazon to Isis
arts + entsAndrew Wylie has pulled no punches in criticism of Amazon
Arts and Entertainment
Charlie Sheen said he would
tv

Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Mobile Developer (.NET / C# / Jason / Jquery / SOA)

    £40000 - £65000 per annum + bonus + benefits + OT: Ampersand Consulting LLP: M...

    Humanities Teacher - Greater Manchester

    £22800 - £33600 per annum: Randstad Education Manchester Secondary: The JobAt ...

    Design Technology Teacher

    £22800 - £33600 per annum: Randstad Education Manchester Secondary: Calling al...

    Foundation Teacher

    £100 - £125 per day: Randstad Education Chelmsford: EYFS Teachers - East Essex...

    Day In a Page

    Bryan Adams' heartstopping images of wounded British soldiers to go on show at Somerset House

    Bryan Adams' images of wounded soldiers

    Taken over the course of four years, Adams' portraits are an astonishing document of the aftermath of war
    The drugs revolution starts now as MPs agree its high time for change

    The drugs revolution starts now as MPs agree its high time for change

    Commons debate highlights growing cross-party consensus on softening UK drugs legislation, unchanged for 43 years
    The camera is turned on tabloid editors in Richard Peppiatt's 'One Rogue Reporter'

    Gotcha! The camera is turned on tabloid editors

    Hugh Grant says Richard Peppiatt's 'One Rogue Reporter' documentary will highlight issues raised by Leveson
    Fall of the Berlin Wall: It was thanks to Mikhail Gorbachev that this symbol of division fell

    Fall of the Berlin Wall

    It was thanks to Gorbachev that this symbol of division fell
    Halloween 2014: What makes Ouija boards, demon dolls, and evil clowns so frightening?

    What makes ouija boards and demon dolls scary?

    Ouija boards, demon dolls, evil children and clowns are all classic tropes of horror, and this year’s Halloween releases feature them all. What makes them so frightening, decade after decade?
    A safari in modern Britain: Rose Rouse reveals how her four-year tour of Harlesden taught her as much about the UK as it did about NW10

    Rose Rouse's safari in modern Britain

    Rouse decided to walk and talk with as many different people as possible in her neighbourhood of Harlesden and her experiences have been published in a new book
    Welcome to my world of no smell and odd tastes: How a bike accident left one woman living with unwanted food mash-ups

    'My world of no smell and odd tastes'

    A head injury from a bicycle accident had the surprising effect of robbing Nell Frizzell of two of her senses

    Matt Parker is proud of his square roots

    The "stand-up mathematician" is using comedy nights to preach maths to big audiences
    Paul Scholes column: Beating Manchester City is vital part of life at Manchester United. This is first major test for Luke Shaw, Angel Di Maria and Radamel Falcao – it’s not a game to lose

    Paul Scholes column

    Beating City is vital part of life at United. This is first major test for Shaw, Di Maria and Falcao – it’s not a game to lose
    Frank Warren: Call me an old git, but I just can't see that there's a place for women’s boxing

    Frank Warren column

    Call me an old git, but I just can't see that there's a place for women’s boxing
    Adrian Heath interview: Former Everton striker prepares his Orlando City side for the MLS - and having Kaka in the dressing room

    Adrian Heath's American dream...

    Former Everton striker prepares his Orlando City side for the MLS - and having Kaka in the dressing room
    Simon Hart: Manchester City will rise again but they need to change their attitude

    Manchester City will rise again but they need to change their attitude

    Manuel Pellegrini’s side are too good to fail and derby allows them to start again, says Simon Hart
    Isis in Syria: A general reveals the lack of communication with the US - and his country's awkward relationship with their allies-by-default

    A Syrian general speaks

    A senior officer of Bashar al-Assad’s regime talks to Robert Fisk about his army’s brutal struggle with Isis, in a dirty war whose challenges include widespread atrocities