Men prone to exaggerating their suffering when struck down with a cold often jokingly refer to “man flu” – the implication being that the illness is much more severe than anything their unsympathetic wives and girlfriends might catch. Perhaps men are owed an apology however, as a Canadian study has shown that male immune systems may not be as strong as women’s.
Scientists at McGill University discovered that the female sex hormone oestrogen can stop an enzyme from interfering with the body’s defences against bacteria and viruses. The enzyme Caspase-12 stops the natural inflammatory process which works to fight off infections, so the researchers used mice to find out how it works.
By implanting the human gene for Caspase-12 in to mice they discovered that the males became more prone to infection. The females however retained the natural resistance of mice without the Caspase-12 gene. Lead researcher Dr Maya Saleh and her colleagues concluded that oestrogen in the female mice were responsible for the difference.
“These results demonstrate that women have a more powerful inflammatory response than men,” she said. The team are confident that their research will also apply to humans, because they used a human gene.
They suggest that women could have evolved a better immune system because their health is key to being able to reproduce, a view shared by Dr Lesley Knapp, of the University of Cambridge:
“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.”
The research could lead to new immune system aids through genetic manipulation. But then how would men complain when they got the sniffles?