The Scientific Explanation Behind ‘Man-Flu’

Before you brush off your husband’s case of man-flu, you may want to read this article. Scientific evidence may exist to back up the concept of “man-flu,” or the idea that men experience illness worse than women. According to a new study, evolution may have engineered viruses to go easier on women so they would pass on the infection to children via pregnancy.


The study, which is published online in Nature Communications, proposes that there may be an evolutionary advantage for viruses to be gentler on women than men, New Scientist reported. Before viruses can spread, they must create copies of themselves, which in turn causes an immune response from the body that we experience as symptoms of an illness. Viruses would have a better chance of surviving and being passed on to babies if a female host lives long enough to spread the germs.

We already know that certain viruses have worse outcomes for males than females. For example, New Scientist reported that human T-cell lymphotropic virus type 1 (HTLV-1) inexplicably progresses to leukaemia much more commonly in Japanese men than Japanese women. The phenomenon can even be seen in the animal kingdom; when flocks of chickens are infected with a particular virus, more of the males develop tumors than females.

Though viruses in some cases are infecting males and females differently, and evolution may be behind the discrepancy, scientists still aren’t sure how viruses distinguish between the two sexes. The team is working to find out.

“We could try to make the virus think it’s in a female body rather than a male body and therefore take a different course of action,” study co-author Vincent Jansen at Royal Holloway University of London,