Why can't it be 'reversing', or at least reversing effects of ageing? A major part of ageing is the progressive degradation of the body's ability to repair itse

Why can't it be 'reversing', or at least reversing effects of ageing? A major part of ageing is the progressive degradation of the body's ability to repair itself, resulting in illness. If a therapy improves the ability of the body to repair itself, and age related illnesses are thus overcome, then arguably ageing has been reversed.