Ageing is a process which affects all living organisms (Weale 1993). It starts from birth and, despite our best efforts, continues relentlessly until the biological clock finally expires. Cicero noted that ‘the onset of old age is shrouded in a mist, though there is no equivocation about its end’. 

Issues associated with ageing have percolated towards the top of the political agenda over the past few decades on account of the changing demographics in many developed countries. In the UK, the average life expectancy in 1900 was 45.7 years for males and 49.6 years for females. By the turn of the new millennium, improvements in nutrition, living conditions and social/medical care had increased life expectancy to 75 and 79.9 years respectively (UK Statistics Authority).