Oilseeds and fats, crops and lipids (Jan 2016)
Choosing foods to balance competing n-3 and n-6 HUFA and their actions
Abstract
Many enzymes metabolizing essential fatty acids (EFA) do not discriminate much between the n-3 and n-6 structures. Thus, relative abundances of competing n-3 and n-6 acids influence relative rates of reaction during hydrolysis, activation, elongation, desaturation and acyl transfer that control the balance of n-3 and n-6 highly unsaturated fatty acids (HUFA) accumulated in tissues. An empirical competitive, hyperbolic equation describes how dietary EFA maintain tissue HUFA balance. The %n-6 in HUFA is a useful biomarker for average dietary intakes of n-3 and n-6 EFA. An Omega 3-6 Balance Score combines data on eleven competing EFA in a food and expresses them as a single number. Average daily food scores range from –7 to +2, relating to HUFA balances from 81% to 30% n-6 in HUFA. The HUFA released by phospholipase provide substrates that form important hormone-like bioactive lipids. Formation and action is more intense with n-6 than n-3 mediators, allowing n-6 eicosanoids to shift healthy physiology toward pathophysiology for people who have a high proportion of n-6 arachidonate in tissue HUFA. The HUFA balance, expressed as the %n-6 in HUFA, is a useful biomarker for health risk assessment. The biomarker makes evident that, in the absence of dietary n-3 nutrients, dietary n-6 linoleate has a very narrow therapeutic window, and it can be widened by dietary n-3 nutrients. A useful concept for preventive nutrition is to NIX the 6 while you EAT the 3.
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