Objective means of diagnosing anorexia nervosa and bulimia nervosa in hair

Abstract

The measurement of stable isotope ratios in hair has the potential to provide a unique method for objectively diagnosing individuals with eating disorders. When the body is in an anabolic state, it incorporates dietary proteins into growing hair. Likewise, when the body becomes catabolic, the 15N/14N ratio of the individual’s tissues increases further due to something functionally similar to an increase in trophic level. As the individual loses weight, the individual’s body consumes its own energy and protein stores. The remaining proteins are 15N-enriched, and their amino acids are recycled. Some of these amino acids are incorporated into new hair growth, providing a signal of the change in diet. Also SEM microanalysis was used to assess hair concentration of calcium (Ca), sulphur (S) and silicon (Si) in patients with anorexia nervosa and its change with improvement of nutritional status.