Scientists are one step closer to unlocking the secrets to anti-aging.
They announced the development of a holy grail drug that switches off a protein linked to accelerating old age, finding the treatment extended the lifespan of rats by 25 percent.
In just 25 weeks following the therapy, the animals had a lower risk of cancer, no gray hair, improved vision and better muscle functionality.
The 75-week-old animals, equivalent to a 55-year-old human, lived for an average of 155 weeks, compared to the 120 weeks for those not treated.
Humans inherited the protein, called interleukin-11, from fish some 450 million years ago.
The gene has been linked to chronic inflammation, organ tissue scarring, metabolism disorders, muscle wasting and cardiac fibrosis.
'These findings are very exciting,' said Professor Stuart Cook, who was co-corresponding author, from the UK's Medical Research Council Laboratory of Medical Science (MRC LMS).
'The treated mice had fewer cancers, and were free from the usual signs of ageing and frailty, but we also saw reduced muscle wasting and improvement in muscle strength.
'In other words, the old mice receiving anti-IL11 were healthier.
'While these findings are only in mice, it raises the tantalizing possibility that the drugs could have a similar effect in elderly humans.
'Anti-IL-11 treatments are currently in human clinical trials for other conditions, potentially providing exciting opportunities to study its effects in ageing humans in the future.'
Professor Cook told BBC that while the trial is not yet completed, the data has suggested that the drug is safe for humans.
The team conducted two experiments for their research, the first genetically modified rats to eliminate IL-11.
The deletion extended animals' lifespans by more than 20 percent on average.
However, the 'dramatic' results were seen when they injected an anti-IL-11 drug, which stopped the protein from causing age-related effects in the body.
Both male and female rats had an increased lifespan of up to 25 percent.
Not only did the treatment offer protection against chronic illnesses, and age-related loss of muscle mass and strength, the therapy also reduced the rate of telomere shortening.
Telomeres are the caps that sit at the end of each chromosome, holding them together.
As we get older, the telomere wears down and gets shorter, leading to illnesses like cancer, Alzheimer's and Parkinson's.
'Our aim is that one day, anti-IL-11 therapy will be used as widely as possible, so that people the world over can lead healthier lives for longer,' Professor Cook said.
'However, this is not easy, as approval pathways for drugs to treat aging are not well-defined, and raising funds to do clinical trials in this area is very challenging.'
The researchers have been investigating IL-11 for many years and in 2018, they were the first to show that IL-11 is a pro-fibrotic and pro-inflammatory protein, overturning years of incorrect characterization as anti-fibrotic and anti-inflammatory.
'This project started back in 2017 when a collaborator of ours sent us some tissue samples for another project,' said Assistant Professor Anissa Widjaja, who was co-corresponding author, from Duke-NUS Medical School, Singapore.
'Out of curiosity, I ran some experiments to check for IL-11 levels.
'From the readings, we could clearly see that the levels of IL-11 increased with age and that's when we got really excited!
'We found these rising levels contribute to negative effects in the body, such as inflammation and preventing organs from healing and regenerating after injury.
'Although our work was done in mice, we hope that these findings will be highly relevant to human health, given that we have seen similar effects in studies of human cells and tissues.
'This research is an important step toward better understanding ageing and we have demonstrated, in mice, a therapy that could potentially extend healthy ageing, by reducing frailty and the physiological manifestations of ageing.'
