Every woman sees those skinny, photo-shopped models in magazines, and it probably makes us all little crazy. But some women internalize that pressure more than others - and your genes could be the reason.
A growing number of studies are linking eating disorders to genetics, but a new study from Michigan State University is the first to find that an early indicator of eating disorders - namely, how much of the "thin-ideal" a woman buys into - could also have a genetic component.
MSU psychologist Jessica Suisman is the lead author of the study. She noticed the media gets all this blame for its focus on super-skinny bodies, and people assume that must be the reason girls get warped body images. "We hear it all the time, how it must cause women to feel horrible about their bodies. But not all women feel horrible about their bodies. Only some do. So we wondered whether there might be an inherent differences in how women respond to that media. Whether some women are more sensitive to it, while other women are more resilient to it."
So MSU psychologists studied 300 female twins, some of them identical, some fraternal.
Now all the twins grew up in the same house, saw all the same messages about being thin, but identical twins were still twice as likely to feel the same levels of pressure about being thin.
That points to a genetic component, says MSU's Jessica Suisman. She says when it comes to societal messages about being thin, "how much they internalize these ideals, how much it affects them, we found out about half of that was due to genetic influences."
"The take-home message," Suisman said, "is that the broad cultural risk factors that we thought were most influential in the development of thin-ideal internalization are not as important genetic risk."
But Suisman's quick to point out it's not just genes in play: environmental factors contribute, too. Still, researchers are rapidly learning more about how genes can be behind eating disorders, says Suisman. Yet it's not a simple science: Suisman says there's no isolated "eating disorder gene" that tells doctors a person is at high risk. Rather, studies indicate that multiple genes across the human genome contribute.
What people should do, according to Suisman, is take warning if they have a long family history of eating disorders, just as they would with heart disease or cancer.
The MSU study appears in the International Journal of Eating Disorders.