Changes in life expectancy 1900-1990.

Life expectancy at birth has risen in all industrialized countries during the last 100 years, but mortality improvements by gender and region often have proceeded at very different rates. Although some countries have experienced increases in overall mortality during recent decades, the levels of life expectancy gains in countries such as Japan have confounded demographic predictions and have led to renewed research and debate over future mortality decline and the limits to human life. This paper reviews levels of and changes in life expectancy at birth and at older ages in industrialized countries during the 20th century. Trends in mortality and morbidity at older ages are summarized in the context of the historic epidemiological disease transition from infectious to chronic. Cause-specific and active/inactive decompositions of life expectancy are examined, as are initial attempts to correlate life expectancy with physical attributes that may reflect differential nutritional status.