Here's why women live longer than men

A new study has shed light on the biggest question of the 20th century

The study by University of Southern California researchers explained that people needed to understand that differences in life expectancies between the sexes had emerged in 20th century only and this was because previously people used to adopt infectious disease prevention, improved diets and other positive health behaviors.

The researchers also reviewed the lifespan of people born between 1800 and 1935 in 13 developed nations and found that heart diseases were the main culprit behind the uneven decrease in mortality.

Professor Eileen Crimmins said that they were surprised at how the divergence in mortality between men and women, which originated as early as 1870, was concentrated in the 50 to 70 age range and faded out sharply after age 80.

Focusing on mortality in adults over the age of 40, the team found that in individuals born after 1880, female death rates decreased 70 percent faster than those of males, although after controlling smoking-related illnesses, cardiovascular disease appeared to still be the cause of the vast majority of excess deaths in adult men over 40 for the same time period.

The study is published in the Proceedings of the National Academy of Sciences.