This Is the Real Reason Women Live Longer Than Men

It’s common knowledge that women outlive men, but a new study from the journal Scientific Reports has shed some light on why that is.

After analyzing the records of 140,600 reproducing individuals from the Utah Population Database, researchers from Uppsala University in Sweden uncovered a direct link between lower birth rates and longer lifespans.

According to the data, men who were born in the early 1800s lived two years longer than women who were also born during that timeframe. But as the fertility rate lowered with each passing year, a woman’s lifespan increased. In the early 1900s, the birth rate was an average of 4.2 children per woman, down from 8.5 the previous decade. During that period, women outlived men by four years.

The data also acts as further proof that having kids definitely takes its toll on a woman’s overall lifespan. Women who gave birth to 15 children or more lived six years less than women who only gave birth to one child, whereas a man’s lifespan was in no way affected by the number of children he fathered.

“This illustrates the importance of considering biological factors when elucidating the causes of shifting mortality patterns in human populations,” said Elisabeth Bolund, a postdoctoral research fellow at Uppsala University. “Our results have implications for demographic forecasts, because fertility patterns and expected lifespans are continuously changing throughout the world.”

As of 2014, the average life expectancy for women in the United States was at a record high of 81.4 years old, with heart disease, cancer, and strokes listed as the leading causes of death.

With the advances of modern medicine and technology, childbirth doesn’t affect a woman’s lifespan like it used to. Unfortunately, we can’t say the same thing about getting a good night’s sleep.

Planning on starting a family? Pick up a copy of Allison Person’s book I Don’t Know How She Does Itand let us know if news that giving birth shortens lifespan will affect your decision to have kids in the comments below.