SENS5 Keynote: The future of human lifespans, a demographic perspective - Caleb Finch
Authors: C.E. Finch - University of Southern California
Since the 18th C, human life spans have increased globally from a life expectancy at birth (LE0) of 25-40y, to over 80y in healthy countries; the LE70 has also more than doubled (1-3). In essence the J-shaped mortality curve has shifted to progressively lower levels with minor changes in the accelerating (Gompertz) phase of mortality during aging (1,3). The basic contours of the J-shaped mortality curve have remained during these remarkable downward shifts in mortality. These remarkable changes are attributable to reduced loads of infections from public health and improved nutrition, starting long before immunization and antibiotics. Reduced inflammatory and infections loads are hypothesized to retard a broad suite of age-related degenerative conditions (1,2,3). Even brief exposure to infections in a well nourished population can have long-term consequences, as illustrated by the 1918 Influenza which increased later-life heart disease by 25% in the cohort that was prenatally exposed (4). Since 1975, the minimum mortality at ages 10-30 (adolescence and early adulthood) is approaching a virtual limit at 0.02% annual mortality (5). Further increases in life expectancy can only come through delay of the accelerating phase of mortality (reduced Gompertz slope), or reducing its slope. Both possibilities are documented in animal models. However, the global reality is for increases of inflammatory loads through the epidemic of obesity, rapidly spreading infections, and environmental deterioration from increased fossil fuel use and climate change (6). The life history phase of minimum mortality associated with adolescence and early adulthood warrants scrutiny for biological mechanisms accessible to anti-aging interventions.
1. Finch CE, Crimmins EM (2004) Inflammatory exposure and historical changes in human life spans. Science 305: 1736-9.
2. Crimmins EM & Finch CE (2006) Infection, inflammation, height, and longevity Proc Natl Acad Sci (USA) : 103: 498-503. 3. Finch CE (2007). The Biology of Human Longevity (Academic Press).
4. Mazumder B, Almond D, Park K, Crimmins EM, Finch CE (2010) Lingering prenatal effects of the 1918 Influenza Pandemic on cardiovascular disease. J Devel Origins Health Dis 1:26-34.
5. Crimmins EM, Drevenstedt G, Finch CE. (2007) Evolution of the human mortality curve: changes in the age of minimum mortality. Population Assoc America (Abstract), http://paa2007.princeton.edu.
6. Finch CE (2010) Evolution of the human lifespan and diseases of aging: roles of infection, nutrition, and nutrition. longevity Proc Natl Acad Sci (USA)107 (suppl. 1) 1718-24.