Only relatively recently have scientists begun to seriously investigate gender differences in physical responses to illness and medications. As a result we now know that women respond differently to some pain medications, often needing different doses from men; they’re more likely to develop lung cancer if they smoke and they’re more likely to suffer with inflammatory diseases such as lupus or rheumatoid arthritis (RA). This latest study from the University of California, Berkeley sheds some light on why women are more likely to be diagnosed with inflammatory diseases: it seems that higher oestrogen levels leads to less effective control of inflammation and so to a longer injury recovery period too.
Using injured male and female mice, researchers gave additional oestrogen to the male mice to assess how it affected wound healing. Although male animals, including humans, have oestrogen in their bodies, they have far less than females of the same species. The researchers then assessed how quickly and efficiently the injury healed by checking the status of specific lipid pathways. Lipids are molecules that are used by the body for signalling, as well as storing energy. The lipid pathways help to balance inflammatory response in the body, ensuring that wounds heal but keeping inflammation within a safe range. Inflammation is an essential element of wound healing as it helps fight infection and induces the process of cell regeneration. But when there’s too great an inflammatory response, it can lead to tissue damage.
The researchers found that oestrogen had a negative impact on one specific lipid pathway that has been found to be important in protecting against disease – it helps regulate the inflammatory response. So with naturally higher oestrogen levels, a female’s lipid pathways may not function as effectively as a male’s. This could help explain why women might be more likely to be diagnosed with inflammatory diseases such as RA or lupus. If studies on humans show similar results, reducing or balancing oestrogen levels could form part of a treatment for these illnesses in women, helping to improve their body’s inflammatory response.