Why do women live longer than men?

In the United States, the average life expectancy of women is 81 years. For men, it’s 76 years. In the world, women live longer on average. Why do women outlive men more often?

Biological causes

The two main causes are biological. The first cause refers to differences in sex hormones, at least in cis-gendered people, ie persons whose gender identity corresponds to the biological sex assigned to them at birth. Cisgender women produce more estrogen and less testosterone than cis-gendered men. Estrogen provides protection against a number of diseases, such as cardiovascular diseases, which are a very common cause of death in men.

High testosterone levels, on the other hand, are associated with an increased risk of some diseases, such as endometrial and breast cancer in women and prostate cancer in men. Testosterone is also associated with risky behaviors and higher levels of aggression, which can increase the risk of dying at a younger age.

Genetic component

There is also a genetic component at play. Humans have two sex chromosomes, X and Y. Cisgendered women have two X chromosomes, and cis men have X and Y. 

"If you think about it, the Y chromosome is an X chromosome with a missing leg. It lacks genetic material," said Virginia Zarulli, an associate professor of demography at the University of Southern Denmark. "Women have this double X chromosome, the additional genetic material that allows them that, for example, they have a backup plan if there is a bad mutation on one of the two X chromosomes. The second X prolongs their lifespan. ”This is the case with diseases such as hemophilia, a type of bleeding disorder, and Duchenne muscular dystrophy, which causes progressive muscle weakness.

But, on average, women live four or five years longer than men, Zarulli added. What are the additional reasons?

Social factors 

Social factors also play a big role, she said. Men are more likely to smoke cigarettes and drink alcohol more often than women; men drink almost twice as often and are more likely to drink alcohol in the last 30 days, and 35% of men worldwide smoke compared to 6% of women. 

Women are more inclined to a healthy diet, and men prefer fatty meals and eat fast food.

Also, women are 33% more likely to visit a doctor, excluding prenatal care, than men.

The difference in life expectancy has not always been as large as it is now. Detailed mortality data show that women did not consistently live longer than men until the early 20th century. Before that, infectious diseases plagued and affected both sexes quite equally. In addition, women often died during childbirth.

Since then, women’s life expectancy has not always grown to the extent it could. Beginning in the mid-1970s, the gap between potential and observed life expectancy began to widen for women due to cigarette smoking. Until 2005, women lived on average 2.3 years less than expected precisely for this reason.

Given the constant social changes, as well as changes in the lifestyles of women and men, this practice may or may not continue in this form.