TNF and sarcopenia: Enhanced production of reactive oxygen species is thought to promote sarcopenia by destabilizing mitochondria in skeletal muscle fibres and thus increasing their susceptibility to apoptotic stimuli while also down‐regulating pathways associated with mitochondrial biogenesis.157, 163, 171 Oxidative stress may also promote other sarcopenia‐associated processes, such as proteolysis, up‐regulation of TNF‐α levels and inhibition of muscle cell differentiation.163, 171, 172, 173