Relating Diets & Tissue HUFA

The proportions of omega-6 and omega-3 eicosanoid precursors stored in the 20- and 22-carbon highly unsaturated fatty acids (HUFA) is predicted by an empirical relationship published in 1992 [Lands, W.E.M., Libelt, B., Morris, A., Kramer, N.C., Prewitt, T.E., Bowen, P., Schmeisser, D., Davidson, M.H., and Burns, J.H. Maintenance of lower proportions of n-6 eicosanoid precursors in phospholipids of human plasma in response to added dietary n-3 fatty acids. Biochem Biophys. Acta, 1180:147-162 (1992) ]. The equation relates metabolic competitions among four separate types of essential fatty acid in the dietary supply expressed as a percent of food energy (en%): 1. 18-carbon omega-3 PUFA (en% P3) 2. 18-carbon omega-6 PUFA (en% P6) 3. 20- and 22-carbon omega-3 HUFA (en% H3) 4. 20- and 22-carbon omega-6 HUFA (en% H6). Each of the four types of EFA contributes differently to the overall tissue balance. Recent analyses with hundreds of added people led to revision of three of the eight constants from 1992 to give the values shown above.

This empirical relationship is used in the interactive food choice software, KIM-2, to estimate the proportions of n-3 and n-6 HUFA likely to be maintained in tissues following a given set of food choices with their resulting en% intakes of various EFA.