Across the world, women can expect to live longer than men.

Now a new study has revealed that heart disease is the main culprit between the differences in life expectancies.

According to the research, a gap in life expectancies between the sexes first emerged as recently as the turn of the 20th century.

In the wake of this massive but uneven decrease in mortality, a review of global data by the University of Southern California has found heart disease to be behind most of the excess deaths documented in adult men

As infectious disease prevention, improved diets and other positive health behaviours were adopted by people born during the 1800s and early 1900s, death rates plummeted.

But women began reaping the longevity benefits at a much faster rate.

In the wake of this massive but uneven decrease in mortality, a review of global data by the University of Southern California has found heart disease to be behind most of the excess deaths documented in adult men.

'We 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,' said USC professor, Eileen Crimmins.

The study examined the life spans of people born between 1800 and 1935 in 13 developed nations.

Across the world, women can expect to live longer than men. Now a new study has revealed that heart disease is the main culprit between the differences in life expectancies. Shown here are the difference in life expectancies between men and women in the UK

Focusing on mortality in adults over the age of 40, the team found that in individuals born after 1880, female death rates decreased 70 per cent faster than those of males.

Even when the researchers controlled for 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.

Surprisingly, smoking accounted for only 30 per cent of the difference in mortality between the sexes after 1890, Crimmins said.

The uneven impact of cardiovascular illness-related deaths on men, especially during middle and early older age, raises the question of whether men and women face different heart disease risks due to inherent biological risks or protective factors at different points in their lives.

'Further study could include analysis of diet and exercise activity differences between countries,' said Caleb Finch, Professor in the Neurobiology of Aging at USC.

'Deeper examination of genetics and biological vulnerability between sexes at the cell level, and the relationship of these findings to brain health at later ages.'