Researchers Just Found A ‘Rewind Button’ For Muscle Ageing

Research has already shown that exercise can help us to live longer – and we’ve written before about the 14 hallmarks of ageing that regular exercise helps to slow down.

Now, a new paper published in the journal Proceedings of the National Academy of Sciences (PNAS) has identified the biological “rewind button” that helps physical activity reverse or prevent age-related muscle loss (sarcopenia).

In this study, researchers found that exercise seems to restore a key balance in muscle cells that gets disrupted as we age.

Healthy muscles rely on a growth pathway called mTORC1, which is in charge of protein production and tissue maintenance.

But when we age, this pathway becomes overactive, offering too many muscle-building new proteins without clearing away the old, damaged ones. We’ve known for a while that this buildup of damaged proteins leads to greater muscle weakness, but we weren’t sure why it happened.

This study showed that a gene called DEAF1 may be responsible.

When they artificially raised the levels of DEAF1 in mice and fruit flies, they found that the mTORC1 imbalance linked to greater muscle ageing kicked in.

Usually, DEAF1 is kept in check by regulatory proteins called FOXOs. These seem to decline over time, though exercise looks like it could rewind that process.

The study’s lead author, assistant professor Tang Hong-Wen, from the Cancer and Stem Cell Biology Programme at Duke-NUS, said: “Physical activity activates certain proteins which lower DEAF1 levels, bringing the growth pathway back into balance.

“This allows ageing muscles to clear out damaged proteins, rebuild themselves properly, and help them stay stronger and more resilient.”

There’s a caveat, however.

In some older muscles, DEAF1 levels are so high, and/or FOXO production is so impaired, that exercise alone can’t reverse the damage linked to ageing.

The study authors think that adjusting DEAF1 levels in people with ageing muscles may help to mimic the effects of exercise, even among those with limited physical activity.

The study’s first author, Priscillia Choy Sze Mun, said: “Exercise tells muscles to ‘clean up and reset.’

“Lowering DEAF1 helps older muscles regain strength and balance, almost like hitting the rewind button. With millions of older adults at risk of muscle decline, understanding DEAF1 could lead to new ways to protect muscles and improve quality of life.”

And Professor Patrick Tan, Senior Vice-Dean for Research at Duke-NUS (whose researchers were involved in the study) said: “This study helps explain, at a molecular level, why ageing muscles lose their ability to repair themselves and why exercise can restore that balance in some individuals.

“By identifying DEAF1 as a key regulator in this process, these findings may lead to new ways in which the benefits of exercise can be brought to societies with rapidly ageing populations.”