The ageing process

Abstract

Average life expectancy at birth has risen from 42 to 78 in the last 150 years. 6 This is partly due to decreasing neonatal and infant mortality, but life expectancy in middle age is also rising -in contrast with maximum lifespan, which has probably only doubled since man evolved. 7,8 So while it has been argued mathematically that there is no evidence for a finite human lifespan, it seems likely that the potential for modifying the rate of ageing is greater than that for avoiding it altogether. 9 The existence of wide variability in ageing between individuals supports this idea. 10 The development of effective anti-ageing interventions, however, requires understanding of the underlying processes and how they may be influenced.In this review we discuss some of the complexities involved in understanding ageing, including the wide range of theories. The genetic contribution is considered together with the role of random events. There is growing support for the importance of repair processes and evidence for this is presented. The final section addresses the potential for modification of the ageing process and describes recent developments. SummaryAgeing may be simply defined but is yet to be well understood. Research in this area is considered a priority, with the population growing older and increasing disability, morbidity and mortality predicted. There are many theories and ageing has been described from changes at the molecular level to characteristics of ageing populations. However, distinguishing cause from effect has proved problematic largely because the underlying reasons for ageing have not been understood. Progress has now been made and the central role for repair processes is increasingly accepted. A number of approaches to modifying ageing have been explored but the only reliable method to alter the rate remains diet restriction. Instituted after weaning, diet restriction slows ageing in a number of species and has an opposite effect when started in earlier life. There is now preliminary evidence that poor early growth is associated with increased human ageing and this is an important area for future research. Downloaded from prerequisites are incorporated: a careful consideration of an appropriate comparator, discounting and a sensitivity analysis.

Inhibition of iNOS protects endothelial-dependent vasodilation in aged rats

“…How to delay aging and promote the quality of older life has been a "hot" point in this field. Aging is a complex process caused by multiple factors [4] , in which the attenuation of endothelial vasodilatation has proven to be a striking feature [5] . It is well known that vascular endothelial dysfunction is a common trigger for many cardio-cerebral vascular diseases [6] , so protecting endothelial function is very important for prevention of agerelated cardiovascular diseases.…”