Official: why man flu is worse than girl flu!

We all know that blokes are supposed to make more fuss than women about colds and flu — but new research suggests that there might be a good reason for it.

A Canadian study on mice suggests that the female sex hormone oestrogen gives women's immune systems the edge when it comes to fighting off infection. This may be because women need a stronger immune system because of their role in producing and nurturing young.

Lead researcher Dr Maya Saleh said: 'Our results demonstrate that women have a more powerful inflammatory response than men.'

So should men be given oaestoen to boost their immunse systems? Saleh wasn't so sure. 'A question remains: will men be amenable to the idea of being treated with an exclusively female hormone?' she said.

Dr Leslie Knapp, of the University of Cambridge, told the BBC: 'Women are well known to be able to respond more robustly to infections, and to recover more quickly than men.

'In evolutionary terms it only takes one male to reproduce with lots of females, but females are much more important in terms of producing offspring.'

Oestrogen the key

The researchers focused on an enzyme called Caspase-12, which is known to put a brake on the inflammatory process, the body's first line of defence against harmful invaders such as bacteria and viruses.

The human Caspase-12 gene was implanted into a group of male and female mice, but only the males became more prone to infection. The researchers concluded that oestrogen produced by the female mice blocked the expression of the human Caspase-12 gene. They were also able to locate the precise place where oestrogen binds to the gene in order to block its activity.

Since the experiments were conducted using a human gene, the researchers are confident their work is applicable to humans.

What do you think?