A recent study in the American Journal of Physiology suggests that the age-old male complaint, the man-flu, may have some validity after all.
The researchers, from the Johns Hopkins Bloomberg School of Public Health and School of Medicine, found that certain oestrogen-based compounds can make it harder for flu viruses to infect cells.
Their findings add more weight to other recent studies along similar lines, including one by Harvard University in 2014. Scientists there believe that a lack of oestrogen makes men more likely to succumb to pneumonia and other respiratory diseases.
Oestrogen, of course, is a female reproductive hormone so it was no surprise that the oestrogen compounds, including drugs that are used to treat breast cancer, worked better against the flu in cells that came from women than those that came from men.
The latest study didn’t prove that women exposed to the flu were less likely to get sick than men.
The researchers only studied cells, in a lab dish, taken from the nasal passages of men and women.
But what it did suggest was that there might be something about the female hormonal physiology that might be worth looking into for new flu fighting methods.
There’s some precedent for investigating the connection between oestrogen and the immune system. Studies show that inflammation, one of the immune system’s responses against infection, changes in the presence of estrogen.
Women’s inflammatory responses also change during their life course as their levels of oestrogen fluctuate before, during and after menopause, and also during pregnancy.
So the fact that introducing oestrogen-related agents can lower the flu virus’ ability to replicate isn’t entirely implausible, says researchers.
But the report also states that more research needs to be done to move the work from the lab dish into human volunteers.
Scientists need to understand exactly how the hormone interacts with the immune system in more detail before that can happen, adds the journal.