Disordered eating, menstrual disturbances, and low bone mineral density in dancers: a systematic review.

OBJECTIVE: To assemble and synthesize the best evidence on the epidemiology, diagnosis, prognosis, treatment, and prevention of disordered eating, menstrual disturbances, and low bone mineral density in dancers. DATA SOURCES: Medline, CINAHL, PsycINFO, Embase, and other electronic databases were searched from 1966 to 2010 using key words such as "dance," "dancer," "dancing," "eating disorders," "menstruation disturbances," and "bone density." In addition, the reference lists of relevant studies were examined, specialized journals were hand-searched, and the websites of major dance associations were scanned for relevant information. STUDY SELECTION: Citations were screened for relevance using a priori criteria, and relevant studies were critically reviewed for scientific merit by the best evidence synthesis method. After 2748 abstracts were screened, 124 articles were reviewed, and 23 (18.5%) of these were accepted as scientifically admissible (representing 19 unique studies). DATA EXTRACTION: Data from accepted studies were abstracted into evidence tables relating to prevalence and associated factors; incidence and risk factors; diagnosis; and prevention of disordered eating, menstrual disturbances, and/or low bone mineral density in dancers. DATA SYNTHESIS: The scientifically admissible studies consisted of 13 (68%) cross-sectional studies and 6 (32%) cohort studies. Disordered eating and menstrual disturbances are common in dancers. The lifetime prevalence of any eating disorder was 50% in professional dancers, while the point prevalence ranged between 13.6% and 26.5% in young student dancers. In their first year of intensive dance training, 32% of university-level dancers developed a menstrual disturbance. The incidence of disordered eating and low bone mineral density in dancers is unknown. Several potential risk factors are suggested by the literature, but there is little compelling evidence for any of these. There is preliminary evidence that multifaceted sociocultural prevention strategies may help decrease the incidence of disordered eating.
CONCLUSIONS: The dance medicine literature is heterogeneous. The best available evidence suggests that disordered eating, menstrual disturbances, and low bone mineral density are important health issues for dancers at all skill levels. Future research would benefit from clear and relevant research questions being addressed with appropriate study designs and better reporting of studies in line with current scientific standards.