Is man flu real? A look at the evidence

"Man flu" is a colloquial term based on the idea that men respond to symptoms of the common cold so exuberantly it is interpreted as the more severe and life-threatening influenza. Possibly they do it to get attention from loved ones.

Descriptions of classic symptoms of this common affliction range from inability to move off the bed or couch (whichever is nearest the television) to the more serious “losing the ability to do anything except groan in agony and claw at the uninfected”.

But is there any scientific evidence to support its widespread use in popular parlance?

In 2015, the Personality and Health Satisfaction Project data suggested men cope less well than women when confronted by more than one physical illness.

Thus it is possible men and women have a different threshold for perceiving symptoms, especially when clustered as in the common cold. This was supported by research from the University of Glasgow. This suggested men may report symptom severity differently from women – with men being more likely to overrate their symptoms.

Psychologically speaking, men may be less “in touch” with their biofeedback signals (the body letting itself know how it’s feeling). That leaves them unable to interpret the severity of symptoms when they’re sick.

In 2010, a group from Cambridge University published seminal work on the evolutionary basis for gender differences in the immune system. They propose, since males were more likely to be required to devote disproportionate levels of physiological resources to survival while foraging for food for the family, they would have to accept a weaker immune system and thus be more susceptible to infections.

There are physiological explanations for the male-female divide in variations of the immune system.

Researchers have found oestrogen, the main female hormone, has a role in modulation of immunity. This is evidenced by the higher numbers of women with auto-immune conditions such as multiple sclerosis, where the immune system has been inappropriately activated and is causing self-harm. Recently, oestrogen has been associated with an increased ability to affect viruses by impairing their ability to reproduce.

Men also have an impaired response to viruses. In 2014, influenza vaccine research showed the main male hormone testosterone enhances the action of a set of genes that impair the body’s capacity to fight off viruses.

Research suggests males have larger pre-optic areas in the brain, which is the area involved in the production of fever during inflammatory illnesses. Perhaps this could mean men have stronger inflammatory responses when ill? There is no epidemiological data, however, to show difference in temperature trends during influenza among men and women.

Studies in experimental animal studies of severe bacterial infections show the innate immune response (the body’s first defence against infectious attack) is more robust in females. They have higher production of cytokines, the molecules the immune system uses to create inflammation. It is not clear if this extends to viral illnesses.

This highlights a key gap in the literature: if man flu exists, is it because men have a more prominent response to viruses in terms of symptoms? Or a weaker immune system?

Data gathered from a wide group of community-based general practitioners in Australia is used to collate the annual report of the Influenza Surveillance Scheme. In 2008, the last year a collated annual report is available, men presented to general practice with equal frequency as women for laboratory-proven influenza throughout the year.

Hospital data in a younger cohort showed boys between the ages of 15 and 25 years were less likely than girls (with the reverse in younger children) to be admitted to hospital with respiratory tract infection.

The Australian Bureau of Statistics showed that, in 2008, the standardised death rate from influenza and pneumonia was higher among the fairer sex.

While it has yet to become a formally diagnosable condition, there is increasing research to support the view that man flu is likely to be a real entity – reassuring indeed.

Sergio Diez Alvarez, Director Of Medicine, The Maitland and Kurri Kurri Hospital, University of Newcastle

This article was originally published on The Conversation. Read the original article.