Why do women tend to outlive men? Some to do with biology, and some to do with behavior.
Men are more likely to smoke, drink excessively and be overweight. They are also less likely to seek medical help early, and, if diagnosed with a disease, they are more likely to be non-adherent to treatment. On top of all that, he says, men are more likely to take life-threatening risks and to die in car accidents, brawls or gun fights.
There’s evidence that a man’s biology—namely, his elevated levels of the male sex hormone testosterone—may lead him into the kind of trouble that could shorten his life. Research from Duke University has found that elevated testosterone levels are associated with risky behaviors.
Experts say testosterone may abbreviate a man’s lifespan in other ways. Male sex hormones decrease immune function and increase the risk for cardiovascular diseases.
While the links between testosterone and immune function aren’t clear, Min’s study points to lab research showing that testosterone may block the release of some disease-fighting immune cells. On the other hand, there’s also a good amount of research linking low levels of testosterone to heart disease and poor health outcomes in men, so the relationships between testosterone and a man’s health are complex.
It may well be that a man’s hormones aren’t to blame; instead, a woman’s hormones may offer her some added lifespan benefits. Estrogen appears to be protective—it has been shown to have an antioxidant role,” says Sachdev. A 2013 review in the International Journal of Endocrinology found evidence that estrogen can prevent the kind of DNA damage that leads to disease. That review also turned up evidence that estrogen can help maintain normal, healthy cell function.
Life expectancy for women has increased dramatically since the 1900s, thanks in part to healthier mothers and babies.
At the beginning of the 20th century, for every 1,000 live births, six to nine women in the United States died of pregnancy-related complications, and approximately 100 infants died before their first birthday. According to the Centers for Disease Control and Prevention’s Achievements in Public Health 1900-1999 report, maternal mortality rates were highest in this century from 1900 to 1930. Poor obstetric education and delivery practices were mainly responsible for the high numbers of maternal deaths, most of which were preventable.
This discrepancy has generally widened since the beginnings of World War II. During World War II, about 12% of the total U.S. population was part of the armed forces, according to Census Bureau and Department of Defense data. The data also reports that the U.S. would experience over 400,000 military personnel deaths.
There is some evidence of a narrowing of the gender gap during the 1990s, which is probably due to men beginning to quit smoking in the 1960s in significant numbers, while women were just embracing the habit.
There is a lag in outcomes for men and women because it takes about 30 years for the negative health effects of smoking to begin to take their toll – and for the positive effects of not smoking to have an impact.