Scientists at Duke-NUS have pinpointed a gene called DEAF1 as a key driver of age-related muscle decline. As DEAF1 levels rise with age, muscles lose their ability to clear out damaged proteins and repair themselves. Exercise lowers DEAF1, restoring that balance — though in some older adults, the decline may be too advanced for exercise alone to fully reverse.
Researchers at Duke-NUS Medical School have cracked open a major mystery in muscle aging: why does exercise keep older muscles strong, and why doesn't it work equally well for everyone? The answer, it turns out, hinges on a gene called DEAF1.
As we age, DEAF1 levels rise in muscle cells, ramping up a growth pathway called mTORC1. This throws muscles out of balance — they keep producing new proteins but lose the ability to clear out damaged ones. The result? Accumulated cellular debris, chronic stress, and gradual muscle weakening. Exercise counters this by activating proteins that suppress DEAF1, essentially hitting a biological "reset button" and restoring the muscle's self-repair capacity.
But there's a catch: in some older adults, DEAF1 levels climb so high — or the counterbalancing FOXO proteins drop so low — that exercise alone can't fully restore muscle function. This may explain why exercise benefits vary so widely among older people.
Key Takeaways:
Why it matters: With aging populations straining healthcare systems globally, muscle loss is a growing public health concern. Understanding DEAF1 opens the door to drug or gene-based therapies that could preserve muscle strength and independence in older adults — even those who can't exercise.
