CABI Blog

Man flu is considered by large segments of society to be the psychological condition of men with colds. It is often said that when men have a cold they think it is a flu and as a consequence they moan more than women and stay longer in bed until they feel better.

Man flu is not to be confused with the current H1N1 pandemic flu which is affecting humans in some 40 countries. There has also been one swine case on a farm in Canada.

A recent study published in the Proceedings of the National Academy of Sciences suggests that man flu may not be a myth after all. In this study Dr Maya Saleh, of the Research Institute of the McGill University Health Centre and McGill University, Canada shows that women have a more robust immune system than men. This is due to the production of estrogen by females, which could have a beneficial effect on the innate immune response against pathogens.

The research focused on an enzyme called Caspase-12, which increases susceptibility to infection by blocking the inflammatory response that the body uses to fight pathogens. This study was carried out using mice that lack the Caspase-12 gene, meaning that the mice were extremely resistant to infection. The human Caspase-12 gene was implanted in a group of male and female mice, yet only the males became more prone to infection. It was determined that estrogen produced by the female mice blocked the expression of the human Caspase-12 gene.

Although the study was carried out on mice, the researchers consider these results to be applicable to humans, because a human gene was used.

The positive effect of natural estrogen on our resistance to infection is raising the possibility of new therapeutic applications that stimulate the immune system. However, Dr Saleh has cautioned that men may not be amenable to the idea of being treated with an exclusively female hormone.

Men may or may not be very happy with the prospect of receiving a female hormone treatment, but judging by comments on the internet, this study is already highly valued by those who have suffered years of misunderstandings, and it may well become a reference material for men to quote the next time man flu is not taken seriously.