The gap in life expectancy between U.S. women and men widened to nearly six years in 2021, reaching a near two-decade high due to COVID mortality and “twin crises of deaths from despair and firearm violence.”

That’s according to a research letter published on November 13 in the journal JAMA Internal Medicine, authored by medical professionals at Harvard University, Boston University, the University of California, and the U.S. Center for Disease Control and Prevention.

Researchers examined mortality data from the National Center for Health Statistics and found that in pre-pandemic years, from 2010 to 2019, the life expectancy gap between women—who have lived longer than men for more than a century—and men increased by roughly two and a half months largely due to the following factors:

• accidental injuries

• diabetes

• suicide

• homicide

• heart disease

From 2019 through 2021, however—during the pandemic—that gap more than tripled to seven and a half months, with women continuing to outlive men. The main reasons:

• COVID

• accidental injuries

• homicide

• heart disease

• suicide

Men experienced more COVID deaths, the authors wrote, likely due to a number of factors, including:

• higher burden of disease

• differences in health behaviors

• socioeconomic factors like jobs, incarceration, and homelessness

The gap in life expectancy between women and men during the pandemic would have widened even further had there not been a rise in maternal deaths, the authors noted.

A shrinking U.S. life expectancy

The news comes as life expectancy in the U.S. for both genders is shortening. In 2021, life expectancy—76.1 years—decreased for a second consecutive year, fueled by the COVID pandemic and “deaths of despair.” It sat at 78.8 years in 2019 and 77 years in 2020.

The term “deaths of despair” refers to deaths from causes like suicide, drug use, and alcoholic liver disease—factors often connected to economic hardship, depression, and stress, according to Harvard’s T.H. Chan School of Public Health.

“While rates of death from drug overdose and homicide have climbed for both men and women, it is clear that men constitute an increasingly disproportionate share of these deaths,” the first author of the letter, Brandon Yan—a University of California at San Francisco internal medicine resident physician and research collaborator at Harvard Chan School—said in a news release about the study.

In both 2020 and 2021, around 80% of suicides and 70% of accidental drug overdoses were among men, according to a 2023 article in the International Journal for Health Equity and data from the National Center for Health Statistics.

Men also bore the brunt of COVID deaths, suffering 55% of them.

The uneven numbers point to the potential need for specialized care for men in areas like mental health to close the life expectancy gap, according to Yan.

“We have brought insights to a worrisome trend,” he said, adding that researchers will need to closely examine numbers from 2022 and beyond to see if the trends hold.

Why do women live longer than men?

Women outlive men in almost every country in the world, according to the Population Reference Bureau. Globally, the average life expectancy is 79 years for women and 72 years for men. In developed countries like the U.S., the gap widened consistently and dramatically from the 1920s through the 1970s.

Why does such a gap exist? Men are more likely to smoke and take risks, the agency points out. Other differences are likely biological. Estrogen in women may help combat heart disease, and women may have a stronger immune system than men.