In a special Christmas issue of the BMJ, a Canadian academic set out to determine whether men really experience worse flu symptoms than women.
After analysing a wide range of data, Dr Kyle Sue, a clinical assistant professor at Memorial University of Newfoundland in Canada, concluded that “men may not be exaggerating symptoms” after all.
He suggested that men have weaker immune responses to viral respiratory viruses, which can lead to greater risk of becoming ill, or even dying, compared to women.
Lead author of the study, Sabra Klein, from Johns Hopkins University, said that the female sex hormone actually helps to reduce the replication of the influenza virus in cells.
More recently, Dr Sue set out to determine whether the term ‘man flu’ is appropriate or accurate. He analysed relevant research and found some evidence that adult men have a higher risk of hospital admission and higher rates of influenza-associated deaths compared with women in the same age groups, regardless of underlying disease.
For many acute respiratory diseases, males are also more susceptible to complications and exhibit a higher risk of death. Meanwhile some evidence supports men suffering more from viral respiratory illness than women because they have a less robust immune system.
Dr Sue said further higher quality research is needed to clarify other aspects of man flu and concluded that the concept of man flu, as commonly defined, is potentially unjust.
“Men may not be exaggerating symptoms but have weaker immune responses to viral respiratory viruses, leading to greater morbidity and mortality than seen in women,” he said.
That said, there might be an evolutionary benefit to a less robust immune system, he added, as it has allowed men to invest their energy in other biological processes - such as growth, secondary sex characteristics (features that appear during puberty in humans) and reproduction.
He suggested that there are also benefits to energy conservation when ill. “Lying on the couch, not getting out of bed, or receiving assistance with activities of daily living could also be evolutionarily behaviours that protect against predators,” he explained.
“Perhaps now is the time for male friendly spaces, equipped with enormous televisions and reclining chairs, to be set up where men can recover from the debilitating effects of man flu in safety and comfort.”