A composition, food supplement or neutraceutical comprising angiogenin or an angiogenin agonist for treating a disorder characterised by elevated myostatin, for treating disorders where the interaction between follistatin and angiogenin can be used to improve function in tissues, for promoting muscle growth, for improving recovery of muscle from injury or use, for improving muscle strength, for improving exercise tolerance, for increasing the proportion of muscle, for decreasing fat, for decreasing an individual's fat to muscle ratio, for treating neurological diseases or disorders, for treating spinal injuries or diseases, for treating bone diseases or disorders, for treating diseases involving glucose homeostasis, for wound healing, or for providing neuroprotection, nervous system functional support, managing metabolic diseases and/or increasing the bone density of an individual.