Malleability of Human Aging The Curious Case of Old-Age Mortality in Japan

• Published in: Annual review of gerontology & geriatrics 2013-01, Vol.33 (1), p.49-59
• Main Authors: Engelaer, Frouke M., Milne, Eugene M. G., van Bodegom, David, Saito, Yasuhiko, Westendorp, Rudi G. J., Kirkwood, Thomas B. L.
• Format: Article
• Language: English
• Subjects: Aging; Cardiovascular disease; Mortality; Older people
• ISSN: 0198-8794; 1944-4036
• DOI: 10.1891/0198-8794.33.49

Steady growth in human life expectancy has been a key feature of the last century, with projected further increases likely to have enormous impacts on societies worldwide. Despite the significance of these changes, our understanding of the factors shaping this trend is incomplete. During most of the historical increase, by far, the major influence was progressive decline in early and midlife death rates because of the reduction in premature deaths, caused chiefly by infection. Recent decades have seen the emergence of a new driver of increasing longevity-declining mortality among those who are old already, pointing to greater malleability in human aging than had been foreseen. There is still debate, however, as to how much of this decrease in old age mortality is caused by a better early-life environment and how much is caused by improved conditions in late life. A unique resource exists in the case of Japan, where material circumstances for the general population were consistently adverse through the early decades of the 20th century but improved rapidly after 1950. Here, we compare the Japanese birth cohorts of 1900, 1910, and 1920 and follow their period and cohort mortal- ity trends. The results show that cohorts with similar environments early in life have very different mortality trajectories in old age. This strengthens the expectation that preventive measures in later life can deliver great benefit, while not contradicting the importance of life course approaches, to improving health and well-being. [PUBLICATION ABSTRACT]