[Molecular gerontology: towards healthy aging].

For many years aging research was confined to statistics, psychology, and socioeconomic aspects of old age. However, today the study of aging is one of the most attractive and prosperous fields in biology. This change followed on from observations that single gene mutations can modulate the aging process, demonstrating the dynamic and plastic nature of the pathways involved. The field of aging is continually being fuelled by the discovery of new genes and pathways that extend lifespan when manipulated in organisms ranging from unicellular yeast to the more complex round worm C. elegans and the fruit fly Drosophila melanogaster. Such interventions have also been successful in mammals, proving the principle that discoveries in invertebrates can be evolutionarily relevant to humans. The most successful and evolutionary conserved interventions are those related to nutrient sensing pathways, the effector pathways upon which dietary restriction operates to promote health and longevity. To validate the existence of genes that modify the aging process in humans, biogerontologists have opted for a genome-wide approach to studying centenarians, those fortunate to live beyond 100 years of age. By studying these individuals, they hope to unravel the genetic signatures that promote healthy ageing and long life.