This year’s flu season has spread across the U.S. in devastating fashion, killing young and old, closing schools and challenging emergency rooms and urgent care centers. But while public health officials have consistently warned of the dangers to the most vulnerable among us, namely children, seniors and pregnant women, one little-known fact is rarely discussed.
Men seem to have weaker immune responses to the flu than women and may actually experience the illness worse. This phenomenon has been dubbed the “man flu.” So those who believe men are whining too much about their symptoms might have to reconsider their assessment, according to a recently published report in the British-based medical journey, BMJ. The author of the report examined many years’ worth of sex-related flu research and concluded that the assumption of men as crybabies who complain too much and exaggerate their symptoms was “potentially unjust.”
Men with influenza are more likely to need hospitalization or die and they are also less responsive to flu vaccines. What’s more, when the BMJ researcher looked at viral respiratory illnesses, it appeared that men take longer to recover from those, too.
Dr. Thomas M. Hooton, an infectious disease expert with the University of Miami Health System, agrees. “Maybe what we’re seeing is men having appropriate responses to the symptoms they’re experiencing.” Then he added, jokingly, “I think my wife complains more than I do anyway.”
Though Dr. Hooton’s experience with sex-influenced reactions to the flu is anecdotal, he says research on this topic has been pretty consistent, whether done on mice or humans. “There are pretty good data to back this observation up,” he says, “but it’s still not clearly understood.”
Wives’ attitudes aside, other studies before the BMJ report have shown that sex and stress hormones seem to affect influenza outcomes, with men getting the short end of the benefits. One, published in the journal Brain, Behavior and Immunity, reported that adult male mice exposed to bacteria similar to the flu virus displayed more symptoms of sickness than female adult mice, including more fluctuations in body temperature, fever, and signs of inflammation. They also took longer to recover. While this study, as well as others, was done on lab animals, researchers believe the conclusions may still be applicable to humans. Other studies, on human cells, have confirmed that male immune cells have more active receptors for certain pathogens than female immune cells.
This means that men’s immune systems respond to trouble by sending more illness-fighting cells to the site of an infection, making men feel symptoms more acutely. Researchers have further hypothesized that testosterone may affect immune receptors in different ways, with testosterone suppressing the immune system. The BMJ researcher writes that there may be an evolutionary reason for this because men were more likely “to die from trauma before an infection kills them.”
However, in the debate about which sex is stronger (or at least healthier), the battle lines aren’t as clearly drawn as one would expect. A 2016 article published in Nature Reviews Immunology showed that women are more susceptible to autoimmune diseases, while men show increased susceptibility to non-reproductive cancers.
Dr. Hooton suggests that, in addition to physiological reasons, there may also be some psychological explanations for the differences between the sexes. For example, studies show men tend to wash their hands less as well as visit their physician fewer times. “If you don’t go to the doctor and don’t take medications and don’t get the flu shot, that might play into it,” he adds. “Maybe what we’re seeing is a delayed reaction to this behavior of not seeking help when they really should.”
Dr. Hooton calls for further research to help figure out why the sexes appear to have different responses to the flu. In the meantime, he echoes what health officials have been advocating all along: Get the flu shot.
In Their Words
Ana Veciana-Suarez, Guest Contributor
Ana is a regular contributor to the University of Miami Health System. She is a renowned journalist and author, who has worked at The Miami Herald, The Miami News and The Palm Beach Post. Visit her website at anavecianasuarez.com or follow @AnaVeciana on Twitter.