Why do women live longer than men? Study offers clues to close the gap

When it comes to longevity, women are much more likely to outlive men. In the U.S. the gap widened to 5.8 years in 2021. On average, men can expect to live just shy of 76 years, compared to 81 for women.

A new study from researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany shows this gap is true across different species. And the findings — published in the journal Science Advances — suggest there may be ways human males can narrow the gap.

The study found among 528 species of mammals — including humans’ closest relative the chimpanzee — females often have the advantage. Females live about 13% longer in 72% of species.

A mix of factors explain the gap, including genetics, mating habits — which tend to bring on risky behaviors among males, and caretaking responsibilities.

“What we found is that this female advantage in longevity is part of the evolution of mammals. It goes back millions of years,” says study author Fernando Colchero. Females have two X chromosomes, compared to an X and Y for males, which may provide a protective “backup” against potentially harmful genetic mutations. But the differences extend well beyond this.

Colchero points to the behaviors and physical changes that males in many species take on in order to mate and reproduce. For example, male deer (bucks) are bigger and they grow antlers during the breeding season to signal dominance and fight off mating rivals in an effort to attract females. “This is an evolutionary pressure, certainly, to be able to pass to the next generation as many genes as they can,” Colchero says. “But that comes at a cost in their survival.”

Risky behaviors shorten life

Though these behaviors may seem far afield from the reality for humans, there are some parallels. Men tend to engage in riskier behaviors at higher rates, including smoking and drinking. Though the gaps have narrowed, they are still significant.

“Men are also more likely than women to die of alcoholism, drug use, suicide and homicide,” says Alan Geller, a Senior Lecturer of Social and Behavioral Sciences at the Harvard T.H. Chan School of Public Health.

Geller studies the disparity in heart disease and cancer deaths among men and women. Because men have been more likely to smoke tobacco, they die at higher rates from lung cancer. Smoking also increases the risk of heart disease. It’s a clear example of how risky behavior can shorten lifespan. There are some factors men can’t control. For instance, estrogen has a protective effect on the heart.

Men also die at significantly higher rates from melanoma. “It’s fascinating because the incidence rate of melanoma is a little bit higher in men versus women, but the mortality rate for melanoma is much higher for men, Geller says. There are several reasons for this, including biology. Men’s skin is different, according to the American Academy of Dermatology Association. It tends to be thicker and contains more collagen and elastin, fibers that give the skin firmness. Research shows these differences may make the skin more vulnerable to damage from the sun’s ultraviolet rays.

But, it’s much more than biology that puts men at higher risk of death. Men are less likely to protect themselves from the sun. A survey published in 2022 in the CDC’s Mortality and Morbidity Weekly Report, found only 12.3% of men always wear sunscreen when they spend more than an hour outside on a sunny day.

In addition, men are less likely to screen for cancers. “They are less likely to go to the doctor to ask for a skin cancer examination or examine their own skin,” Geller says. “And so you have a double whammy,” increasing their risks.

Caregivers live longer

The Max Planck study found a correlation between caregiving and longevity. The sex that spends more time taking care of offspring, tends to live longer. An evolutionary explanation is that the caretaker parent needs to survive until their offspring are independent.

Colchero says the evolutionary pressures that produced this gender gap can not be overlooked. But, in humans, he’s hopeful the gap can be narrowed. “There are ways in which we can reduce it to some extent,” he says by changing behaviors and norms. Gender roles have evolved, and many men do take care of their children and focus on their own health. For instance, men who earn more money are more likely to wear sunscreen.

“Mimicking some of the behaviors that women have,” may be helpful, he says. “Let’s make sure that we go to the doctor,” for example. And Geller says much more could be done to promote the importance of preventive care including recommended screenings.

And remember: the top risk factors for the chronic diseases most Americans die from, including cancer and heart disease can be reduced by changing our habits, for both men and women. Here’s the American Heart Association’s Life’s Essential 8 to prevent disease: eat better, be more active, quit tobacco, get healthy sleep, manage weight, control cholesterol, and manage blood sugar and blood pressure.