I found some interesting research on the role of sex hormones in the development of anorexia. One was an older paper, from this past December, titled "Intrauterine hormonal environment and risk of developing anorexia nervosa." It looked at twins and how it affected the development of AN. The researchers compared same sex twins and opposite sex twins, and calculated the likelihood that one of the twins would develop anorexia.

Not surprisingly, women were more likely to develop anorexia than men. Though the number of male eating disorder sufferers is growing (either from improved diagnosis or an actual increase in numbers), it is still less than the number of women. When comparing the rates of anorexia in men, they found something interesting. The men with a female twin was more likely to develop anorexia than a male twin.

The researchers think it has to do with exposure to estrogen, etc, in the womb, not that men with anorexia are some how "girly." One of the reasons is that the onset of puberty tends to be the most likely time someone will develop anorexia. And the hormones that are released turn on different genes- some of which can change the brain chemistry.

This doesn't explain all cases of anorexia in men, but it does start to tease out what might be some of the earliest possible environmental influences on a person.

The research gets even more interesting when I found out about a new paper that showed that a female twin was less likely to develop anorexia if she had a male twin. Why? It could be that testosterone is somewhat protective. The testosterone in the womb might slightly alter some of the genes that ultimately affect neurochemistry.

This paper was called "Prenatal hormone exposure and risk for eating disorders: a comparison of opposite-sex and same-sex twins."

It's a good reminder, in all of our talk of environmental triggers like size zero models and fears of obesity, that there are plenty of other important triggers. NOT causes. Triggers. And that they might not be as obvious as we think.

If you want a pdf of these papers, drop me an email (it's in my profile!) and I'll pass it along. Mention "ED Bites" or something in the subject line so I can find it should it land in the spam folder.

*This was actually a quote from a friend of mine in college. We were both freshmen in organic chemistry, and we had this huge project due before spring break. So D has a breakdown in our professor's office the night before it was due, panicking and sobbing, and he asks her what is wrong. And she looked at him, teary-eyed and dripping snot and wails, "I'm sorry- I'm just hormonal!" The poor man had no idea what to do.