Man flu IS real: Men have 'weaker immune systems and are more affected by symptoms of a cold'

They are the subject of ridicule among women - the whining, moaning men forever complaining about being ill.

But one expert says man flu is not a myth, and that men may have weaker immune systems or be more affected by the symptoms of a cold than women. 

Dr Sergio Diez Alvarez, director of medicine at The Maitland and Kurri Kurri Hospital, University of Newcastle, says the female hormone oestrogen may strengthen women's immune systems.

The male equivalent - testosterone - impair the body's capacity to fight off viruses, studies show.

And the part of their brain which triggers fever during inflammatory illnesses is bigger in men - suggesting they may have a stronger response to a cold than women. 

Here, he reviews all the evidence on man flu - deciding it may well be real...

One study showed men cope less well than women when confronted by more than one physical illness - such as the cluster of symptoms in a cold, according to Dr Sergio Diez Alvarez of the University of Newcastle

IS MAN FLU A MYTH 

'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?

MEN COPE LESS WELL WITH ILLNESS

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.

Men have larger pre-optic areas in the brain, which is the area involved in the production of fever during inflammatory illnesses. This suggests they may have a stronger response to illness 

WHAT THE BASIC SCIENCE SAYS 

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.

Oestrogen, the female hormone, is linked with a stronger immune system as it can impair viruses ability to reproduce

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?

The main male hormone testosterone enhances the action of a set of genes that impair the body's capacity to fight off viruses, studies show (file photo)

HOW COMMON IS MAN FLU? 

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.