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Feature Christmas 2017: All Creatures Great and Small

The science behind “man flu”

BMJ 2017; 359 doi: https://doi.org/10.1136/bmj.j5560 (Published 11 December 2017) Cite this as: BMJ 2017;359:j5560

Rapid Response:

The Evolutionary Benefit of "Man Flu"

I very much enjoyed Kyle Sue's investigations into whether there may be any physiological basis for the 'man flu' phenomenon, particularly as there seemed to be some fairly good evidence of sex differences in response to rhinoviruses. I was very interested in the studies suggesting that pre-menopausal women may enjoy the most benefit of these differences, compared with post-menopausal women and men of any age.

However, Dr Sue went on to spend a quarter of the article pondering what evolutionary purpose there may be for men having higher symptoms from the same viral infections; and struggled to come up with any credible theories.

When I was at university and struggling with a tricky assignment, my tutor told me to try rephrasing the question and thinking about it another way.

And so I humbly submit my own rephrasing of the question that seems to have stumped researchers so far:

"What evolutionary purpose could there be for women of child-bearing age having fewer symptoms and better survival rates from the same viral infections?"

Gosh, I do wonder. What a mystery!

Competing interests: No competing interests

20 December 2017
Catherine M Morgan
Senior Respiratory Physiologist
Hereford, UK