Are Black Teens at Increased Risk ofBulimia Nervosa?

First, authors of a study from the University of Southern California challenged the long-held belief that bulimia nervosa primarily affects affluent white teenagers. Data from a 10-year study by the National Heart, Lung and Blood Institute (WHLBI) of more than 2,300 girls in schools in California, Ohio, and Washington, DC (Am J Psychiatry 2003;1601326) showed that African-American girls were 50% more likely than white girls to be bulimic. Then, two well-known eating disorders experts challenged the study’s findings.

Findings challenged:
“African-American girls 50% more likely than white girls to be bulimic.”

USC economist Michelle Goeree and fellow economists John Ham, from the University of Maryland, and Daniela Iorio, from University Autonoma, Barcelona, Spain, found a striking difference between public perception and their study’s results. Girls from families in the lowest income bracket were 153% more likely to be bulimic than were girls from the highest income bracket. The girls were surveyed beginning at age 9 or 10, and were asked about eating habits and affiliated psychological issues such as body image and depression.

Some of the other results were:

• Black girls were 50% more likely than white girls to exhibit bulimic behavior, including both binge eating and purging. About 2.6% of the black girls were clinically bulimic, compared to 1.7% of the white girls.
• Black girls scored an average of 17 percentage points higher than their white counterparts on the severity of their bulimia.
• Girls from families in the lowest income bracket were significantly more likely to experience bulimia than were their wealthier peers.
• Bulimia affected 1.5% of girls in households where at least one parent had a college degree. For girls whose parents had a high school education or less, the rate of bulimia was more than double—3.3%.

According to Dr. Goeree, past research has relied upon data from hospital admissions, creating a “sample bias” that overlooks those who exhibit bulimic behavior but do not receive or have the means to receive professional help. She added that girls who are African-American or from low-income families are much less likely to be diagnosed. Since only about half of those with bulimia nervosa fully recover, and many struggle with their symptoms for decades, Dr. Goeree stated that the study results suggest a much larger cross-section of young women are affected than was previously believed.

A challenge from two specialists

James L. Hudson, MD, and Linda Smolak, PhD, think that the USC study is flawed, and have challenged some of the findings. Dr. Hudson, who is director of the Psychiatric Epidemiology Program, Maclean Hospital, Belmont, MA, noted that data from an earlier national study do not support the view that BN is more common among black teens than whites. Dr. Hudson was the lead investigator for the National Comorbidity Survey Replication, a survey of more than 9000 persons across the U.S., and the first national surgery of individuals with eating disorders.

Dr. Smolak, professor of psychology at Kenyon College, Gambier, OH, and an advisor to the National Eating Disorders Association (NEDA), pointed out that economists had not previously used the NHLBI data but that psychologists had extensively analyzed the data. The BN measure used by Dr. Goeree and colleagues, the Eating Disorders Inventory-BN scale, is widely used in research but Dr. Smolak said that psychologists virtually never use it to diagnose BN. Because of this, Dr. Smolak says it is misleading to say that black girls are more likely to have BN than white girls; instead, it would more appropriate to say that black girls report more symptoms than do white girls. She also singled out a 2003 study showing that the prevalence rates of subjects meeting the criteria for BN were higher in white women than in black women (Am J Psychiatry 2003; 160:1326).

Despite her challenges to the USC study data, Dr. Smolak thinks the study is helpful for dispelling the notion that African-American girls are immune to eating disorders.