Question

Does anyone know why ME seems to affect more women than men?

I know quite a few people with ME and about 80% are women. This is the same sort of ratio that appears in comments on MEA Facebook – although I
accept that women may be better at communicating their feelings than men!

Has anyone done any research into this?

Answer

Firstly, all the epidemiological research evidence that’s been carried out so far suggests that the female to male ratio is somewhere in the region of 70% female to 30% male. But the simple answer to your question is that we don’t really know why women are more likely to develop ME/CFS than men.

The fact that ME/CFS seems to occur more often in some families suggests that there is a genetic component and the DecodeME research study should help to provide some useful information here.

What may be more important is the link to autoimmune diseases – which can sometimes be triggered by infections. These are conditions where the body starts to produce potentially harmful antibodies to its own tissues such as muscle and thyroid gland. There is a high female:male ratio in most of the well known autoimmune diseases such as rheumatoid arthritis, Sjögren’s syndrome and SLE (systemic lupus erythematosis) and we know that some people with ME/CFS have low levels of these autoantibodies. So while ME/CFS isn’t classified as an autoimmune disease it does appear to have an autoimmune component in some cases.

One other factor is the interaction between immune-system responses and female hormones – which also have a role in autoimmune diseases.
And it’s interesting to note that women with ME/CFS often report a significant improvement in symptoms during pregnancy. Finally, we know that there is defective energy production in ME/ CFS. And there is good research evidence to indicate that this is caused by a problem with the battery-like components of all cells – the mitochondria – where energy is produced. Linking in to the genetic component, mitochondrial DNA (the genetic material) is predominantly inherited from the mother.

So we have some important clues but more research needs to be done!