State of the artComments on the history of medical-biological studies of aging, the birth of scientific gerontology

Recent books (Immunity. How Elie Metchnikoff changed the course of modern medicine and Expectations of Life) reviewed the important contribution of Metchnikoff to the emergence of gerontology as a new branch of biomedical sciences. Here, we insist on Metchnikoff's contribution and pivotal role in the emergence of nutrition as a science and its importance for health and longevity. The discovery of phagocytosis by Metchnikoff and of its evolutionary ancestry are at the origin of the emergence of cellular immunity as an independent science besides humoral immunity. The longevity of Metchnikoff (71 years) at a time when average life expectancy of men did hardly pass 50 years certainly contributed to the acceptance of his teachings. The recent increase of the senior population in most advanced countries is a good opportunity to review the contributions of nutrition to longevity.