A Revolution in Ageing: The New Biology of Ageing and its Implications

Until recently the biology of ageing, like that of consciousness, seemed an unassailable topic. Ageing was to biologists an intractable labyrinth of diverse deteriorative processes within which primary causes were impossible to locate. But around 15 years ago, discoveries in the genetics of ageing initiated a startling forward march in biogerontology (the study of the biology of ageing). In particular, studies of long-lived mutants in simple organisms, including a tiny nematode worm with a long name (Caenorhabditis elegans), have lead to the discovery of genes and biochemical pathways that control the pace of the ageing process. Recent discoveries imply that some of these ageing-control mechanisms are operative in higher animals, perhaps including human beings. Given the present rapid rate of progress in studies of ageing, the prospects are that we may quite soon attain, at long last, a real understanding of the biology of this determinant of the human condition. How easily such a knowledge will translate into treatments for human ageing is unclear. However, in animal models, scientists have not only achieved striking increases in lifespan but also a postponement of the infirmity and illness associated with ageing. This last finding is of critical importance, since it demonstrates that biological ageing is an effective point of intervention for prophylaxis against ageing-related diseases. In humans, these include the major mortal illnesses of the developed world: cardiovascular disease, type II diabetes, neurodegenerative diseases such as Alzheimer's and Parkinson's disease, and cancer. While these advances are exciting, it is sometimes said that one should be cautious of achieving one's innermost desires. Since the dawn of culture, we have sought cures for ageing; but would their discovery be a good thing? Given the benefits of treating ageing in terms of protection against disease and of alleviating human suffering, this, surely, is something that we must pursue. However, current studies suggest that treating ageing may reduce incidence of age-related diseases at any given age, but not overall, lifetime incidence. Such findings direct us to a question of growing importance: What should the goals of biogerontology be?