Evaluating the Brain's Response to Natural Versus Artificial Sweetener in Women Who Have Had an Eating Disorder

Eating disorders often result in serious illness and can lead to prolonged health complications, including heart and kidney problems, digestive disorders, nerve damage, and low blood pressure. Anorexia nervosa and bulimia nervosa are examples eating disorders. People with anorexia nervosa do not eat enough in fear of becoming overweight, resulting in extreme weight loss. People with bulimia nervosa first binge by consuming hundreds or even thousands of calories within a very short time period and then purge by either vomiting or using laxatives. Women are at a greater risk of developing the disorders, particularly when they are between the ages of 12 and 24. Treatments for eating disorders typically include nutrition counseling, psychotherapy, and medication. To better understand eating disorders, this study will compare the brain's ability to distinguish between natural and artificial sweeteners in women with and without a history of eating disorders.

All participants in this observational study will be administered a taste test to determine if they can consciously differentiate between a sugar solution and an artificially sweetened solution. Participants may also perform several brief computerized tests, ranging from 3 to 10 minutes each, to evaluate thinking, memory, and information processing skills. Participants who cannot tell the difference between the solutions will undergo a functional magnetic resonance imaging (fMRI) scan, which will take pictures of the brain and blood flowing through the brain. Prior to the scan, blood and urine collection may occur, and participants may complete two additional computerized tests. The scan will require 60 to 90 minutes to complete. During the scan, participants will hold two thin tubes in their mouth. At various intervals, these tubes will deliver 1 ml of liquid containing either sugar water or an artificial sweetener into each participant's mouth. A screen projection of abstract pictures will also be shown to each participant throughout the scan, either before the liquid is delivered or alone. This study will require a 6- to 9-hour time commitment. The results from this study may provide valuable information regarding anorexia nervosa and bulimia nervosa and may eventually lead to the development of new and better treatment options for these complex and serious disorders.

Inclusion criteria

• Right-handed
• Recovered from anorexia or bulimia nervosa at least 12 months prior to study entry
• Met DSM criteria for anorexia or bulimia nervosa at one time within 3 years prior to study entry

Exclusion criteria

• Pregnant or breastfeeding
• Currently taking any medication (except birth control)
• Any current mental illness
• Any metal in body