ABSTRACT
This chapter describes the results from a series of human studies which used deuterium-labeled monounsaturated fatty acid isomers to compare the absorption, turnover, and distribution in plasma lipids of these monounsaturated fatty acid isomers relative to oleic acid. The negative plasma-triglycerides selectivity values are evidence for selective removal of isomeric fatty acids by muscle tissue. The well-known absolute requirement for this essential fatty acid is not satisfied by positional or geometric isomers of linoleic acid, and, in fact, the daily requirement is actually increased by the presence of isomeric fatty acids. Both radio- and stable isotope-labeled fats provide a means of investigating absorption and incorporation of dietary fats into blood lipids, although use of radioactive iodine-labeled fats cannot be recommended. Intravenous infusion of fats at constant rates is useful for assessment of fatty acid turnover and is preferred to single-pulse infusion.
