An international team of scientists have identified for the first time a key factor responsible for declining muscle repair during ageing, and discovered how to halt the process in mice with a common drug. Although an early study, the findings provide clues as to how muscles lose mass with age, which can result in weakness that affects mobility and may cause falls.

The study, to be published in the journal Nature, involved researchers from King’s College London, Harvard University and Massachusetts General Hospital.

The study looked at stem cells found inside muscle – which are responsible for repairing injury – to find out why the ability of muscles to regenerate declines with age. A dormant reservoir of stem cells is present inside every muscle, ready to be activated by exercise and injury to repair any damage. When needed, these cells divide into hundreds of new muscle fibres that repair the muscle. At the end of the repairing process some of these cells also replenish the pool of dormant stem cells so that the muscle retains the ability to repair itself again and again.