Women now tend to live longer than their male counterparts in every country in the world, but anatomy alone cannot fully explain why. Looking to solve this riddle, researchers at the University of Wisconsin-Madison recently studied how the primary causes of death have changed over the past few centuries. They found that men and women had comparable life expectancies during the 19th century and that the aforementioned “mortality gap” actually emerged during the 20th century. Cigarettes and high-fat diets exploded in popularity during the early 1900s, implicating smoking and heart disease as the driving forces behind this morbid discrepancy.
Smoking has generally been more popular among men than among women, but it only accounts for 30% of excess male mortality. Cardiovascular disease appears to be responsible for the remaining 70%. Substantial evidence suggests that men not only tend to eat more animal products than women do, but also that they are inherently more susceptible to heart ailments. Due to differing compositions of sex hormones, men are more likely to accumulate visceral fat (“belly fat”) around their abdomens when they gain weight, while women typically store subcutaneous fat around their hips, thighs, and buttocks. Importantly, visceral fat has been linked to the development of heart disease while subcutaneous fat has not (and may even be protective). Comparing the life expectancies of men and women who eat healthy diets, therefore, could quantify the mortality gap reduction that results from swapping out cheeseburgers with Caesar salads.
Acknowledgments: Many thanks to Mary Gearing, a graduate student in the Biological and Biomedical Sciences Ph.D. program at Harvard University, for providing her expertise and commentary on the topic.
Managing Correspondent: Christopher Gerry
Original article: Twentieth century surge of excess adult male mortality – Proceedings of the National Academy of Sciences
Media coverage: Why do women outlive men? Science zeroes in on answer – Los Angeles Times