According to a study conducted by the American Physiological Society (APS) and published in the American Journal of Physiology — Lung Cellular and Molecular Physiology, the female sex hormone Estrogen can protect women against the flu virus.
In the lab, researchers took the nasal cells – as those are the ones most often infected by the flu virus—from both male and female donors and exposed them to the virus, estrogen, the environmental estrogen bisphenol A and selective estrogen receptor modulators (SERM), which are compounds that act like estrogen that are used for hormone therapy.
According to the study, how much a virus replicates determines how severe the virus is. The results of the study were a significantly lower replication rate from the female donors as opposed to the men due to the greater amount of estrogen in the female donor cells.
“Because estrogen levels cycle in premenopausal women, it may be difficult to see this protective effect in the general population,” one researcher noted. “But, premenopausal women on certain kinds of birth control or post-menopausal women on hormone replacement may be better protected during seasonal influenza epidemics,” she said. “We see clinical potential in the finding that therapeutic estrogens that are used for treating infertility and menopause may also protect against the flu.”
For more information, read the full study.