The physiology and pathophysiology of ageing

Ageing is a physiological process which impairs vitality and ultimately leads to death. It is found in all differentiated multicellular organisms. Recent theories attribute ageing to an accumulation of errors as the capacity of mechanisms for their repair and compensation becomes limited. Erroneous processes leading to ageing and death stem mainly from the protein-synthesizing machinery of the cell. At present, three types of hypotheses to explain ageing are under consideration. These are (1) the limited stability of genetic information, (2) a restriction in the availability of genetic information and (3) the liability to error of the information flow in protein synthesis. Recently, increasing interest has also been shown in certain post-synthetic changes in biological molecules which may impair cell functions. However, ageing cannot be explained entirely at the molecular and cellular level. Since it has been shown that faults may also emerge at the higher organizational levels of multicellular organisms, it is necessary to study ageing processes at various levels, taking into account the specific type of order innate in living organisms. The relationship between ageing and disease is characterized by increased morbidity and accompanied by an increasing chance of dying from certain diseases. The following events may be of major importance: (1) the progressive loss of specific order ('bionomic order') which leads to a reduced capacity of adaptation, compensation and repair; (2) continuous changes of the organism throughout life ('biomorphosis') which lose their usefulness after the attainment of maturity and promote pathological changes; (3) the long term accumulation of low-level noxious influences which increase the chance of becoming ill as age advances.