Branched chain amino acids—What are they good for?

Abstract

From the above consideration it is apparent that the BCAA fulfill unique physiological functions in normal man. Thus, the BCAA constitute a principal source of nitrogen repletion in muscle tissue after the ingestion of a protein meal. In addition, the BCAA and leucine in particular have been implicated in the regulation of synthesis as well as breakdown of muscle protein. However, much remains to be learned regarding the physiological significance of the BCAA in normal and pathological states. Theoretical considerations and several preliminary studies have suggested a therapeutic role of the BCAA in certain clinical disorders although, in the case of liver coma, the present evidence does not support such a role, The possible clinical usefulness of BCAA after trauma and infection still remain to be clarified and the papers by Freund et al , Hartig et al , and Schmitz et al in this issue of Clinical Nutrition are welcome contributions to this important and rapidly developing area of research.