Abstract
BACKGROUND: Zinc plays an important role in appetite regulation. L-Carnosine, an endogenous dipeptide, may also regulate eating behavior via its histaminergic and antiglutamatergic properties. Polaprezinc (zinc-L-carnosine complex) is a medication for gastric ulcers. A small case series reported successful treatment of binge eating with add-on polaprezinc. METHODS: This was an open trial of add-on polaprezinc in patients with binge eating disorder (BED; n = 22) or bulimia nervosa (BN; n = 7) receiving antidepressants. A 4-week baseline period was followed by a 16-week polaprezinc treatment at 150 mg/d (containing 34 mg zinc and 116 mg L-carnosine) in addition to ongoing psychotropic medications. We also assessed their zinc status via a laboratory index and zinc deficiency-related symptoms. RESULTS: At the study end, both conditions showed a significant reduction in the 4-week frequency of combined objective and subjective binge eating episodes, the 4-week frequency of days when at least 1 such episode occurred (only in BED), several aspects of eating disorder psychopathology (rated by the Eating Disorder Examination-Questionnaire), and comorbid depressive symptoms (rated by the 16-item Quick Inventory of Depressive Symptomatology [Self-Report]). Serum copper/zinc ratio decreased from 1.4 to 1.1 on average in both conditions. All patients had multiple zinc deficiency-related symptoms at baseline that substantially improved after polaprezinc treatment. Overall, the effectiveness of polaprezinc was greater in BED patients than in BN patients, with minor adverse effects. CONCLUSIONS: These findings offer preliminary evidence for the effectiveness of polaprezinc in treating BED and BN and suggest the involvement of zinc deficiency in these conditions.