During the last 40 years, the study of the biological basis of aging has progressed tremendously, and it has now become an independent and respectable field of study and research. The essential cause of aging is molecular damage that slowly overwhelms cellular and organismic defense, repair and maintenance systems. In recent years, a wealth of highly sophisticated research has transformed this idea from a credible hypothesis not only to a major theory, but essentially to accepted knowledge. Aging at the Molecular Level examines the key elements in this transformation. Bringing together contributions from an international team of authors, this volume will be of interest to graduates and postgraduates in the fields of medicine and nursing, researchers of different aspects of biogerontology and those in the pharmaceutical, cosmeceutical, nutraceutical and health-care industry.

The molecular genetics of aging or life-span determination is an expanding field. One reason is because many people would consider it desirable if hu man life span could be extended. Indeed, it is difficult not to be fascinated by tales of the life and death of people who have succeeded in living a very long life. Because of this, we have placed at the head of this book the chapter by Perls et al. on Centenerians and the Genetics of Longevity. Perls and his coauthors convincingly argue that, while the average life expectancy might be mostly determined by environmental factors because the average person has an average genotype, extremely long life spans are genetically determined. Of course, studying humans to uncover the genetics of aging is not ideal, not so much because one cannot easily perform experiments as because they live such a long time. This is why most of this book describes the current state of research with model organisms such as yeast, worms, flies, and mice. J aswinski focuses on yeast and how metabolic activity and stress resistance affect the longevity of Saccharomyces cerevisiae. In the process, he discusses the concept of aging as applied to a unicellular organism such as yeast and the importance of metabolism and stress resistance for aging in all organisms.

Recent studies have indicated that epigenetic processes may play a major role in both cellular and organismal aging. These epigenetic processes include not only DNA methylation and histone modifications, but also extend to many other epigenetic mediators such as the polycomb group proteins, chromosomal position effects, and noncoding RNA. The topics of this book range from fundamental changes in DNA methylation in aging to the most recent research on intervention into epigenetic modifications to modulate the aging process. The major topics of epigenetics and aging covered in this book are: 1) DNA methylation and histone modifications in aging; 2) Other epigenetic processes and aging; 3) Impact of epigenetics on aging; 4) Epigenetics of age-related diseases; 5) Epigenetic interventions and aging: and 6) Future directions in epigenetic aging research. The most studied of epigenetic processes, DNA methylation, has been associated with cellular aging and aging of organisms for many years. It is now apparent that both global and gene-specific alterations occur not only in DNA methylation during aging, but also in several histone alterations. Many epigenetic alterations can have an impact on aging processes such as stem cell aging, control of telomerase, modifications of telomeres, and epigenetic drift can impact the aging process as evident in the recent studies of aging monozygotic twins. Numerous age-related diseases are affected by epigenetic mechanisms. For example, recent studies have shown that DNA methylation is altered in Alzheimer’s disease and autoimmunity. Other prevalent diseases that have been associated with age-related epigenetic changes include cancer and diabetes. Paternal age and epigenetic changes appear to have an effect on schizophrenia and epigenetic silencing has been associated with several of the progeroid syndromes of premature aging. Moreover, the impact of dietary or drug intervention into epigenetic processes as they affect normal aging or age-related diseases is becoming increasingly feasible.