Demography of longevity: past, present, and future trends.

摘要: Life expectancy at birth has roughly tripled over the course of human history. Early gains were due to a general improvement in living standards and organized efforts control spread infectious disease. Reductions infant child mortality late 19th early 20th century led rapid increase life birth. Since 1970, main factor driving continued industrialized countries is reduction death rates among elderly. In particular, cardiovascular disease cancer have declined recent decades thanks variety factors, including successful medical intervention. Based on available demographic evidence, span shows no sign approaching fixed limit imposed by biology or other factors. Rather, both average maximum increased steadily time for more than century. The complexity historical stability these changes suggest that most reliable method predicting future merely extrapolate past trends. Such methods will be about 85-87years middle 21st