Young people are constantly told to eat their greens to make them big and strong. Unfortunately for broccoli-phobes of all ages, diet really can have direct effects on how mammalian muscles age. This stripy section through a mouse calf muscle was pictured through a high-powered microscope. Inside, tiny muscle fibres (seen here running diagonally from bottom left to top right) contract, bunch-up and expand to give power to the legs. Over its life, this mouse’s diet was calorie-restricted – an extreme diet involving loss of calories without malnutrition – which preserved its muscle fibres (each 25,000 thinner than an elastic band) from the eroding effects of age. Calorie-restriction maintained the defences of the muscles fibres against toxic chemicals called reactive oxygen species, protecting their energy factories, the mitochondria (the dark, bean shaped structures in this picture) and allowing this mouse – a senior gent of advancing years – to scurry about like a young’un.
Written by John Ankers
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