Ageing muscles are not simply failing — Copenhagen scientists found they are trading strength to protect themselves

Why do ageing muscles shift toward slower, endurance-type fibres even as their energy factories falter? A University of Copenhagen team thinks the muscle is making a trade. They found that cardiolipin — a fat molecule that keeps mitochondria, the cell's power plants, properly folded — declines with age in both mice and humans. When they lowered it in young mice, muscles switched fibre type exactly as ageing muscles do; when they restored it to about two-thirds of normal, muscle wasting reversed and early deaths were prevented entirely. The switch, it turns out, helps muscle cells build their own antioxidants against damage. 'The fiber switch is not the muscle failing, but the muscle trading power for protection,' said first author Fabian Finger. The reversal work is in mice, not people — but it names two concrete targets, cardiolipin and a coordinating protein called ERRγ, for future therapies against age-related weakness.

SDG 3 · Good health and well-being — Mechanism: tech innovation