- The Washington Times - Sunday, April 2, 2000

Women who have a sister or mother who suffers from an eating disorder may be at a much higher risk of developing anorexia or bulimia themselves, two new studies report.

By identifying a genetic component to those behavioral disorders, doctors can get one step closer to eventually developing a medication to try to control the sometimes devastating progression of eating disorders, says Marsha Marcus, a psychologist and chief of the Eating Disorders Department at the University of Pittsburgh School of Medicine.

"It is still early, but these findings are very exciting," she says. "There is an increasing likelihood that there is a biological component to eating disorders that puts certain women at greater vulnerability. Conditions like anorexia and bulimia are probably triggered and maintained by psychological and cultural factors, but if we can identify a biological component, there might be medicines we can develop to control it."

Anorexia, a distorted body image and refusal to maintain a healthy weight, affects between .5 percent and 1 percent of women in the United States, according to the National Institute of Mental Health (NIMH). Bulimia, which is binge eating followed by purging, affects between 1 percent and 3 percent.

Exact numbers are hard to determine because many victims keep eating disorders a secret and may have some symptoms, but not a full-blown eating disorder. NIMH researchers estimate that 90 percent of cases are in women and girls, and a majority of the cases occur from age 13 to 20.

Researchers at the University of Pittsburgh compared rates of eating disorders among 1,831 family members of 504 women ages 18 to 28 with anorexia or bulimia.

Dr. Michael Strober, lead author of the study, says nearly 12 percent of women with severe anorexia had female relatives who had had some symptoms of the disease. Four percent of the women with bulimia also had relatives with bulimia.

"The rate of bulimia and anorexia nervosa among female relatives of persons with eating disorders was between four and 11 times higher compared with incidents of illness in women without relatives with an eating disorder," Dr. Strober says.

Male relatives did not appear to be affected by a family member's eating disorder, he reports.

Milder cases of anorexia and bulimia in which women have not lost dangerous amounts of weight but are preoccupied with dieting also seemed to run in families, Dr. Strober says.

In another study, researchers at Virginia Commonwealth University in Richmond examined rates of anorexia and depression among 2,163 female twins, both fraternal and identical. Overall, 77 women (3.6 percent) had been diagnosed as suffering from anorexia, and six of the women had a twin who shared the diagnosis.

Though researchers admit that is not a huge percentage, it is enough for them to say that genes influence a susceptibility to the disorder. They also found 140 sets of twins suffered from major depression, leading the researchers to believe there is a genetic component to both disorders. Past research has indicated that 50 percent of women with anorexia have major lifetime depression.

The VCU study authors report that living in a shared environment may be somewhat responsible for twins' propensity toward an eating disorder.

Dr. Strober says it is not clear which factors genetic or family environment play a more important role when it comes to the clustering of eating disorders in particular families.

Ms. Marcus says it likely is a combination of the two.

"There is likely a vulnerability that some women have, and our culture is particularly toxic" toward women and body image, she says.

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