The XX Factor

New Study Finds That Men Become Less Manly When They Lose Estrogen

Kansas City Chiefs v. Green Bay Packers: Feel the estrogen.

Photo by Jamie Squire/Getty Images

Score one for those hippy progressives who are always saying that men and women aren’t really opposites: A new study published in the New England Journal of Medicine shows that men suffering from some common midlife health woes, like weight gain and decreased libido, have not only falling testosterone levels to blame, but also falling estrogen levels. This news will no doubt surprise many, because there’s a widespread belief that estrogen is the “female” hormone and testosterone the “male” one, but in reality, all people generate a mix of both, and biological gender presentation is determined more by what kind of mix you have (alongside other complex factors). What is a little more surprising is that even though biologists have understood this for decades, the research has still been very gendered. Gina Kolata at the New York Times reports:

“We had ignored this hormone in men, but we are studying it now,” said Dr. Alvin M. Matsumoto, a testosterone and geriatrics researcher at the University of Washington School of Medicine and the V.A. Puget Sound Health Care System, who is a Testosterone Trial researcher. “We are just starting out on this road.”

Both men and women make estrogen out of testosterone, and men make so much that they end up with at least twice as much estrogen as postmenopausal women. As levels of both hormones decline with age, the body changes. But until now, researchers have focused almost exclusively on how estrogen affects women and how testosterone affects men.

The good news is this opens up exciting research possibilities that could lead to longer, healthier lives for men. The bad news is that the most immediate impulse—to replace the declining estrogen for men—is not necessarily the preferred path, because researchers believe that estrogen pills would cause men unwanted and, for most, alarming symptoms, like growing breasts.

In a fun coincidence, this study came out in the same week that popular blogger and biologist P.Z. Myers, at his blog Pharyngula, begged the science community to take more seriously some of the ideas of postmodernism, which would presumably include the claim that the categories “male” and “female” are social constructs. The estrogen study demonstrates the wisdom of his argument; you can only step outside of the box if you realize that you are in a box.

Speaking of boxes, how soon till we see estrogen treatments in boxes covered in trucks and explosions?