Summary

In the known history of humanity, life expectancy scarcely exceeded 30 years, with half of newborns dying before age five, up to the 18th century. However, from the 18th century onward, major epidemics were combatted more efficiently, famines became less frequent, and life expectancy thus began to increase, first in Northwest Europe, then spreading to North America, Australia, Japan, and to the rest of Europe. The health transition reached Latin America, the rest of Asia, and Africa only in the 20th century.

In 2015–2020, worldwide life expectancy at birth reached 72.5 years. However, differences remained large between regions and countries. The Japanese experienced the highest level at 84.4 years, thanks to their increasingly effective noncommunicable disease (NCD) control and an especially dramatic decrease in cardiovascular mortality. On average, life expectancy was 80.9 years in high income countries, 71.4 in middle income countries and 63.4 in low income countries. It was only 60 years in sub-Saharan Africa, with some countries barely exceeding 50. High mortality countries suffer a heavy burden from both infectious and NCDs.

Due to increasing life expectancy, deaths shifting to older ages, and changing cause-of-death patterns, questions arise concerning the health of populations. The health expectancies made available mainly in high income countries are indicators that combine mortality and health data. Although it seems that severe disability has not increased in the early 21st century, the results for less severe disabilities diverge from one country to the other. Along their longer life expectancy, females live more unhealthy years than males; in some countries they even live fewer healthy years than males.

The future may see life expectancy surpassing 90 years in the most advanced countries, likely before the end of the 21st century. However, achieving this requires that humanity face major challenges, especially in overcoming infectious diseases, impeding NCDs, reducing poverty and socioeconomic inequalities, and combating the deterioration of our environment.