According to a predictive report on the increase in the elderly population in various countries, Japan and Korea are poised to become the world’s top two nations, with constantly high elderly populations approaching 35–40 % in the latter half of this century. The rapidly aging populations in Japan and Korea promote movement toward a “senescent” society. Amazingly, however, if we examine the numbers of people living to over 100 years old, more than 60,000 centenarians currently reside in Japan. In Korea, the centenarian population is approximately 3,300, but it is estimated to grow to almost 40,000 by the year 2050. Japan and Korea are thus growing old so rapidly that we are indeed moving “into the unknown,” as described in a special report in The Economist several years ago (November 18, 2010). In such nations, research on aging is important not only sociologically but also biologically to understand the background of aging in our population.
During the last several decades, our knowledge concerning aging research has been growing rapidly. However, we are still far from achieving a complete understanding of the whole mechanism of aging: how we, as animals, age and how our lifespan is determined. Many researchers are working in this field in both Japan and Korea, and our scientific societies in relation to biomedical aging in the two countries have been interacting with each other. When one of the editors (N.M.) moved from the National Institute for Longevity Science (Research Institute, National Center for Geriatrics and Gerontology, Nagoya) to Nagasaki in 2006, we met on the small island of Ioujima in Nagasaki to discuss and exchange ideas on the basic science of aging. We called this discussion forum the “Asian Aging Core for Longevity” (AACL), and we have continued this series of AACL meetings for the last 10 years, alternating between Japan and Korea. In the last 5 years, it was supported by the Asian CORE program of the Japan Society for the Promotion of Science (JSPS). The studies described in this book were supported, at least in part, by the fund of the JSPS-Asian CORE program, through an intimate discussion at the AACL meetings.
This book was initially planned to summarize the aging research among all of the members of the AACL. However, owing to space and time limitations, we could not include the work of all the AACL members. The book is composed of a series of topics in aging research which were explored through the daily dedicated laboratory work of our AACL members and their colleagues. Based on the topics of each manuscript, we, the editors, ordered each chapter such that the stories would facilitate the understanding of the scientific outcomes of our latest research on aging from the basic biology of longevity, metabolism, and brain aging with the goal of developing potential therapeutics for age-related diseases, such as Alzheimer’s.