CHAPEL HILL -- An entire large pizza, a bowl of pasta, half a dozen Twinkies, and three bowls of cereal -- all consumed in 20 minutes -- form a typical "binge" meal for a woman suffering from the eating disorder known as bulimia nervosa.
"We're not talking about occasional over-eating, like at Thanksgiving," said Dr. Susan Girdler, assistant professor of psychiatry at the University of North Carolina at Chapel Hill School of Medicine.
"For many of these women, life revolves around extreme binge eating followed by self-induced vomiting," said Girdler, principal investigator in a new bulimia study. "When the binges occur, the bulimic feels a tremendous loss of self-control."
Girdler's preliminary findings confirm that bulimia isn't just about over-eating. Bulimics exhibit a host of physiological and psychological abnormalities including abnormal blood pressure, poor response to stress, other illnesses and low self-esteem.
Associates Jeannie Koo, a graduate student in experimental psychology, and Dr. Cort Pedersen, associate professor of psychiatry, worked with Girdler on the study, funded by the Foundation of Hope for Research and Treatment of Mental Illness in Raleigh, N.C.
Comparing 15 bulimic women with 15 unaffected women, the researchers found that those with the disorder demonstrated significantly less sensitivity to painful stimuli than the control group.
Bulimics also reacted differently to stress. At rest, both groups looked exactly the same, but under stress, bulimics' blood pressure dropped while their levels of the stress hormones adrenaline and cortisol went up.
"This may contribute to bulimics' increased risk for cardiovascular problems and may increase major depression," Girdler said.
Tests showed that more than 60 percent of the bulimics were suffering from at least two psychological disorders simultaneously, chiefly depression and anxiety. Bulimics also felt more stressed by their lives than the control group, but they showed poor coping skills.
"When faced with stress, bulimics are much more likely to engage in avoidance behavior," Girdler said. "They also blame themselves for their stress and tend to engage in wishful thinking, which is not a very effective coping strategy."
Self-induced purging dramatically reduces blood pressure which in turn produces temporary inner calm. Hypothetically, she said, affected women might be substituting the binge-purge cycle for more positive ways of coping with stress.
Bulimics also reported having fewer supportive people in their lives and were not satisfied with support they did receive.
"This was the first time many of these women had talked openly about their experiences," Girdler said. "Bulimia is a secretive disorder. Unlike anorexics, who tend to look emaciated, bulimics can appear normal. But some of the women had suffered in silence for up to 15 years."
As a group, the bulimics are more hostile, more confused and less self-confident than other women. They also reported significantly lower self-esteem.
"It's important to realize that this is not just a disorder about eating," Girdler said. "It's about a whole lot of other psychological and psycho-social stressors."
She applauds the Office for Research on Women's Health at the National Institutes of Health for placing eating disorders on the top-10 list of issues meriting research.
"Bulimia and other eating disorders are on the rise," Girdler said. "We were amazed at the number of inquiries we received about our study right here on campus. Many women are unduly concerned with their body images. They are starving themselves, eating and exercising compulsively and regularly purging their systems."
These are extremely serious disorders, with potentially life-threatening consequences, said the researcher, who hopes to do a larger study within a year.
"Once you better understand the underlying psychological and physiological abnormalities, you can then design better treatment," she said.
Note: Girdler can be reached at 919-966-2546.